US20020128161A1 - Materials and methods for suppression of filamentous coke formation - Google Patents
Materials and methods for suppression of filamentous coke formation Download PDFInfo
- Publication number
- US20020128161A1 US20020128161A1 US10/097,324 US9732402A US2002128161A1 US 20020128161 A1 US20020128161 A1 US 20020128161A1 US 9732402 A US9732402 A US 9732402A US 2002128161 A1 US2002128161 A1 US 2002128161A1
- Authority
- US
- United States
- Prior art keywords
- composition
- hydrocarbon
- coke
- formation
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000000571 coke Substances 0.000 title claims abstract description 110
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 92
- 238000000034 method Methods 0.000 title abstract description 37
- 239000000463 material Substances 0.000 title abstract description 3
- 230000001629 suppression Effects 0.000 title description 8
- 229910052751 metal Inorganic materials 0.000 claims abstract description 83
- 239000002184 metal Substances 0.000 claims abstract description 83
- 229930195733 hydrocarbon Natural products 0.000 claims abstract description 67
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract description 67
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract description 52
- 150000003957 organoselenium compounds Chemical class 0.000 claims abstract description 41
- 239000000446 fuel Substances 0.000 claims description 61
- 239000011669 selenium Substances 0.000 claims description 51
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 claims description 42
- 229910052711 selenium Inorganic materials 0.000 claims description 42
- 239000000203 mixture Substances 0.000 claims description 33
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 30
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 29
- 238000000197 pyrolysis Methods 0.000 claims description 17
- ORQWTLCYLDRDHK-UHFFFAOYSA-N phenylselanylbenzene Chemical compound C=1C=CC=CC=1[Se]C1=CC=CC=C1 ORQWTLCYLDRDHK-UHFFFAOYSA-N 0.000 claims description 16
- 229910052742 iron Inorganic materials 0.000 claims description 15
- 229910052759 nickel Inorganic materials 0.000 claims description 15
- 229910045601 alloy Inorganic materials 0.000 claims description 14
- 239000000956 alloy Substances 0.000 claims description 14
- 238000005336 cracking Methods 0.000 claims description 12
- 230000002829 reductive effect Effects 0.000 claims description 8
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 7
- 239000005977 Ethylene Substances 0.000 claims description 7
- 230000002265 prevention Effects 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 230000001747 exhibiting effect Effects 0.000 claims 4
- WBRZELCGPCKRBO-UHFFFAOYSA-N $l^{1}-selanylmethylbenzene Chemical compound [Se]CC1=CC=CC=C1 WBRZELCGPCKRBO-UHFFFAOYSA-N 0.000 claims 1
- DWZCRWXJKIEWDY-UHFFFAOYSA-N benzylselanylmethylbenzene Chemical compound C=1C=CC=CC=1C[Se]CC1=CC=CC=C1 DWZCRWXJKIEWDY-UHFFFAOYSA-N 0.000 claims 1
- YWWZCHLUQSHMCL-UHFFFAOYSA-N diphenyl diselenide Chemical compound C=1C=CC=CC=1[Se][Se]C1=CC=CC=C1 YWWZCHLUQSHMCL-UHFFFAOYSA-N 0.000 claims 1
- 239000000654 additive Substances 0.000 abstract description 79
- 238000012545 processing Methods 0.000 abstract description 13
- -1 diarylselenides Chemical class 0.000 abstract description 8
- 230000002401 inhibitory effect Effects 0.000 abstract description 3
- 239000002816 fuel additive Substances 0.000 abstract 1
- 238000012360 testing method Methods 0.000 description 48
- 230000000996 additive effect Effects 0.000 description 41
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 25
- 229910052799 carbon Inorganic materials 0.000 description 25
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 18
- 230000008021 deposition Effects 0.000 description 13
- 230000009467 reduction Effects 0.000 description 13
- 230000001681 protective effect Effects 0.000 description 11
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- 238000002441 X-ray diffraction Methods 0.000 description 9
- 125000001931 aliphatic group Chemical group 0.000 description 9
- 125000003118 aryl group Chemical group 0.000 description 9
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 9
- 150000001247 metal acetylides Chemical class 0.000 description 9
- 229910052760 oxygen Inorganic materials 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 229910001220 stainless steel Inorganic materials 0.000 description 9
- 239000010935 stainless steel Substances 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 229910001567 cementite Inorganic materials 0.000 description 8
- 238000002474 experimental method Methods 0.000 description 8
- 230000005764 inhibitory process Effects 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 7
- 239000010959 steel Substances 0.000 description 7
- 229910052787 antimony Inorganic materials 0.000 description 6
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 6
- 238000004364 calculation method Methods 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 150000003346 selenoethers Chemical class 0.000 description 5
- 229910052710 silicon Inorganic materials 0.000 description 5
- 239000010703 silicon Substances 0.000 description 5
- HVLLSGMXQDNUAL-UHFFFAOYSA-N triphenyl phosphite Chemical compound C=1C=CC=CC=1OP(OC=1C=CC=CC=1)OC1=CC=CC=C1 HVLLSGMXQDNUAL-UHFFFAOYSA-N 0.000 description 5
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 125000004429 atom Chemical group 0.000 description 4
- 125000004432 carbon atom Chemical group C* 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 239000003112 inhibitor Substances 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910052718 tin Inorganic materials 0.000 description 4
- 150000001336 alkenes Chemical class 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 238000005235 decoking Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004817 gas chromatography Methods 0.000 description 3
- 125000005842 heteroatom Chemical group 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 239000000543 intermediate Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000004626 scanning electron microscopy Methods 0.000 description 3
- 229910000619 316 stainless steel Inorganic materials 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000004115 Sodium Silicate Substances 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 229910052797 bismuth Inorganic materials 0.000 description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 238000004939 coking Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 150000004678 hydrides Chemical class 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910001026 inconel Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 229910001092 metal group alloy Inorganic materials 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 229910052752 metalloid Inorganic materials 0.000 description 2
- 150000002738 metalloids Chemical class 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000036961 partial effect Effects 0.000 description 2
- 238000002161 passivation Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 2
- 229910052911 sodium silicate Inorganic materials 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 238000004227 thermal cracking Methods 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- VBHJUUAUIGGAPS-UHFFFAOYSA-N 2-[4-(4-bromophenyl)-1,3-thiazol-2-yl]acetonitrile Chemical compound C1=CC(Br)=CC=C1C1=CSC(CC#N)=N1 VBHJUUAUIGGAPS-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 229910005093 Ni3C Inorganic materials 0.000 description 1
- GRHZLQBPAJAHDM-SPRQWYLLSA-N [(3as,4r,6ar)-2,3,3a,4,5,6a-hexahydrofuro[2,3-b]furan-4-yl] n-[(2s,4s,5s)-5-[[2-(2,6-dimethylphenoxy)acetyl]amino]-4-hydroxy-1,6-diphenylhexan-2-yl]carbamate Chemical group CC1=CC=CC(C)=C1OCC(=O)N[C@H]([C@@H](O)C[C@H](CC=1C=CC=CC=1)NC(=O)O[C@@H]1[C@@H]2CCO[C@@H]2OC1)CC1=CC=CC=C1 GRHZLQBPAJAHDM-SPRQWYLLSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 125000003342 alkenyl group Chemical group 0.000 description 1
- 125000000304 alkynyl group Chemical group 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 239000002519 antifouling agent Substances 0.000 description 1
- 229940058905 antimony compound for treatment of leishmaniasis and trypanosomiasis Drugs 0.000 description 1
- 150000001463 antimony compounds Chemical class 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- OBXSGRKNCOCTTM-UHFFFAOYSA-N benzyl diethyl phosphate Chemical compound CCOP(=O)(OCC)OCC1=CC=CC=C1 OBXSGRKNCOCTTM-UHFFFAOYSA-N 0.000 description 1
- 150000001639 boron compounds Chemical class 0.000 description 1
- 229910052810 boron oxide Inorganic materials 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000002447 crystallographic data Methods 0.000 description 1
- 125000006165 cyclic alkyl group Chemical group 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 125000002485 formyl group Chemical group [H]C(*)=O 0.000 description 1
- 125000005843 halogen group Chemical group 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 150000002483 hydrogen compounds Chemical class 0.000 description 1
- 229910001293 incoloy Inorganic materials 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- WALCGGIJOOWJIN-UHFFFAOYSA-N iron(ii) selenide Chemical class [Se]=[Fe] WALCGGIJOOWJIN-UHFFFAOYSA-N 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 150000002898 organic sulfur compounds Chemical class 0.000 description 1
- 150000002902 organometallic compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- MOWNZPNSYMGTMD-UHFFFAOYSA-N oxidoboron Chemical class O=[B] MOWNZPNSYMGTMD-UHFFFAOYSA-N 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- HGVAUOKQFBXKDV-UHFFFAOYSA-N prop-2-enylselanylbenzene Chemical compound C=CC[Se]C1=CC=CC=C1 HGVAUOKQFBXKDV-UHFFFAOYSA-N 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 125000006413 ring segment Chemical group 0.000 description 1
- QHASIAZYSXZCGO-UHFFFAOYSA-N selanylidenenickel Chemical class [Se]=[Ni] QHASIAZYSXZCGO-UHFFFAOYSA-N 0.000 description 1
- 229940065287 selenium compound Drugs 0.000 description 1
- 150000003343 selenium compounds Chemical class 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 125000004469 siloxy group Chemical group [SiH3]O* 0.000 description 1
- 125000005353 silylalkyl group Chemical group 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 description 1
- 125000000383 tetramethylene group Chemical group [H]C([H])([*:1])C([H])([H])C([H])([H])C([H])([H])[*:2] 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 150000003606 tin compounds Chemical class 0.000 description 1
- WYXIGTJNYDDFFH-UHFFFAOYSA-Q triazanium;borate Chemical compound [NH4+].[NH4+].[NH4+].[O-]B([O-])[O-] WYXIGTJNYDDFFH-UHFFFAOYSA-Q 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- CYTQBVOFDCPGCX-UHFFFAOYSA-N trimethyl phosphite Chemical group COP(OC)OC CYTQBVOFDCPGCX-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G75/00—Inhibiting corrosion or fouling in apparatus for treatment or conversion of hydrocarbon oils, in general
- C10G75/04—Inhibiting corrosion or fouling in apparatus for treatment or conversion of hydrocarbon oils, in general by addition of antifouling agents
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
- C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
- C10G9/16—Preventing or removing incrustation
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/10—Liquid carbonaceous fuels containing additives
- C10L1/14—Organic compounds
- C10L1/24—Organic compounds containing sulfur, selenium and/or tellurium
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/10—Liquid carbonaceous fuels containing additives
- C10L1/14—Organic compounds
- C10L1/24—Organic compounds containing sulfur, selenium and/or tellurium
- C10L1/2406—Organic compounds containing sulfur, selenium and/or tellurium mercaptans; hydrocarbon sulfides
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/10—Liquid carbonaceous fuels containing additives
- C10L1/14—Organic compounds
- C10L1/24—Organic compounds containing sulfur, selenium and/or tellurium
- C10L1/2406—Organic compounds containing sulfur, selenium and/or tellurium mercaptans; hydrocarbon sulfides
- C10L1/2412—Organic compounds containing sulfur, selenium and/or tellurium mercaptans; hydrocarbon sulfides sulfur bond to an aromatic radical
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/10—Liquid carbonaceous fuels containing additives
- C10L1/14—Organic compounds
- C10L1/28—Organic compounds containing silicon
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L10/00—Use of additives to fuels or fires for particular purposes
- C10L10/06—Use of additives to fuels or fires for particular purposes for facilitating soot removal
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S585/00—Chemistry of hydrocarbon compounds
- Y10S585/949—Miscellaneous considerations
- Y10S585/95—Prevention or removal of corrosion or solid deposits
Definitions
- This invention relates generally to the inhibition or prevention of coke formation on metal surfaces in contact with hydrocarbons at high temperatures. Such conditions can occur in hydrocarbon cracking processes and in certain types of engine systems in which hydrocarbon fuels reach very high temperatures.
- the invention more specifically relates to suppression of filamentous coke formation.
- Carbon deposits can result from an interaction of the hydrocarbon processing stream and the metals contained in the walls and heat exchangers of reactors at temperatures above about 300° C. Deposits that form in the shape of long filaments approximately 1 ⁇ m in diameter are referred to as filamentous coke. Non-filamentous coke can also form under pyrolysis conditions by several different mechanism. Filamentous coke is typically more abundant at higher temperatures (greater than about 450° C.), is hard and can be difficult to remove.
- Coke formation is generally detrimental to the productivity and efficiency of the operation of a given system, causing fouling of lines and erosion of surfaces which increase operation down-time for cleaning and maintenance.
- Coke formation is also a significant problem in engine systems in which the hydrocarbon fuel temperatures can reach levels greater than about 300° C .
- hypersonic aircraft employ fuel to cool ramjet/scramjet propulsion system.
- sensible heating and endothermic reactions can be used to provide the required heat sink, but in the process, the fuel temperature can reach 650° C. (1200° F.) or more.
- carbonaceous deposits coke
- filamentous coke form on the walls of the heat exchangers. These deposits can inhibit fuel flow and reduce heat transfer across the heat exchanger surface.
- Filamentous coke formation is sensitive to the type of metal used in reactor walls.
- Nickel and iron present on the metal surface as occurs in nickel and/or iron alloys and various types of steel, for example, are believed to catalyze the formation of filamentous coke through the formation of metal carbides that decompose (Vaish, S. and D. Kunzru (1989) “Triphenyl Phosphite as a Coke Inhibitor During Naptha Pyrolysis” Ind. Eng. Chem. Res. 28, 1293-1299 and Reyniers, G. C., Froment, G. F., Kopinke, F. D., and Zimmerman, G. (1994). “Coke Formation in the Thermal Cracking of Hydrocarbons. 4.
- alumina coatings are difficult and requires the use of aluminum-containing metal alloys in processing equipment or engines.
- an inert alumina surface layer can be formed on aluminum containing alloys such as Incoloy 800 by treating the alloy at temperatures above 1000° C. in a hydrogen atmosphere with a low partial pressure of water.
- Silica coatings are not very effective.
- Atria et al. (1996) observed cracking of silica layers allowing filaments to grow.
- Ghosh and Kunzru (1992) found that passivation with sodium silicate initially reduced the coke formation rate by about 50%, but that the beneficial effect was reduced each time a decoking step was employed.
- repeated oxidation or sulfiding of metal surfaces or repeated decoking applications roughens metal surface increasing the surface area and leading to formation of larger amounts (Albright and Marek 1982). Polishing of alloy and metal surfaces has been indicated to help reduce coke formation.
- Trimethyl- or triphenylphosphite and benzyldiethylphosphate are reported to decompose at 700_C. to form phosphorous compounds which passivate metal surfaces (Kunzru, D. and Chowdhury, S. N. (1993) Can. J. Chem. Eng., V. 71, 873; Kunzru, D. and Vaish, S. (1989) Ind. Eng. Chem. Res., V. 28, 1293; Vaish, S. and D. Kunzru (1989) Ind. Eng. Chem. Res. 28, 1293-1299). However, reductions in coke deposition of only 10-30% were reported.
- U.S. Pat. No. 4,116,812 reports the use of organo-sulfur compounds to inhibit fouling at elevated temperatures in pyrolysis furnaces used to produce ethylene.
- U.S. Pat. Nos. 3,531,394; 4,024,050; 4,024,05; 4,105,540; 4,542,253; 4,835,332; 5,354,450;and 5,360,531 report the use of various phosphorous-compounds for coke suppression.
- U.S. Pat. No. 3,531,394 reports the use of bismuth-containing compounds for coke suppression. Tong and Poindexter U.S. Pat. No.
- 5,954,943 report that a mixture of sulfur and phosphorous compounds having a sulfur to phosphorous atomic ratio of at least 5:1 can be used to reduce coke formation.
- the mixture of compounds is used to pretreat the surfaces of a pyrolysis furnace for up to 20 hrs prior to introduction of hydrocarbon feed to generate a passivation layer.
- U.S. Pat. No. 4,551,227 reports the use of tin compounds, antimony compounds or both in combination with phosphorous compounds for suppression of coke formation.
- U.S. Pat. Nos. 4,555,326; 4,729,064; and 4,680,421 report the use variously of boron, boron oxides, metal borides or ammonium borate to suppress coke formation in pyrolysis furnaces.
- U.S. Pat. Nos. 5,093,032, 5,128,023 and 5,330,970 report the use of a combination of boron compounds and a dihydroxybenzene compound for inhibiting coke formation. Coke reduction levels of up to 86% (measured in mg coked formed compared to controls) were reported when combination of ammonium biborate and hydroquinone (250 ppm/150 ppm) was added in coker feedstock in a cracking furnace.
- U.S. Pat. Nos. 2,698,512; 2,959,915; and 3,173,247 relate to thermal degradation of hydrocarbon fuels at high temperatures to form gum and coke deposits. These patents report fuel compositions more stable to decomposition at high temperature that give lower levels of deposits.
- U.S. Pat. No. 5,923,944 reports surface treatment, including removing surface irregularities and deposition of a coating consisting essentially of a metal oxide (e.g., Ta 2 O 5 or SiO 2 ) and the vapors of an organometallic compound, to avoid deposition of thermal decomposition products from hydrocarbon fuels.
- a metal oxide e.g., Ta 2 O 5 or SiO 2
- This invention relates to the reduction or prevention of coke formation and deposition on metal surfaces during hydrocarbon processing at high temperature. More specifically, the invention provides selenium additives and methods of using such additives for the reduction of filamentous carbon formation in furnaces or reactors for processing hydrocarbons or in engines that employ hydrocarbon fuels. The invention is particularly useful for reducing filamentous coke formation on iron and/or nickle-containing metal and/or alloy surfaces. The invention also relates to a method of pretreating metal surfaces to inhibit or prevent filamentous coke formation by contacting an appropriately heated metal surface with an additive of this invention. The invention is based on the identification of selenium additives, including organoselenium compounds, that inhibit or prevent coke formation and particularly inhibit filamentous coke formation.
- the organoselenium additives are believed to inhibit or prevent metal carbide formation, such carbides are intermediates in the formation of coke, particularly filamentous coke.
- the invention specifically relates to organoselenium additives that prevent or inhibit the formation of nickel and iron carbides that can be formed on furnaces, reactors and/or engine surfaces having steel parts (including, for example, carbon steel and stainless steel). Additives of this invention are believed to react with metal components in furnace, reactor or engine walls or parts thereof to generate metal compounds that are sufficiently stable that they do not undergo further reaction with fuel to form metal carbides.
- Preferred selenium compounds of this invention are organoselenium compounds including without limitation, organoselenides (R—Se—R′), organodiselenides (R—Se—Se—R′), and organoselenols (R—Se—H), where R and R′, maybe the same or different, and are selected from aliphatic or aryl groups which may contain one or more heteroatoms.
- the invention also provides improved hydrocarbon feedstock and hydrocarbons fuels which contain from about 0.01 ppm selenium to about 1000 ppm selenium as an organoselenium additive that is an inhibitor of filamentous coke formation.
- Compositions of this invention can comprise less than or equal to about 100 ppm selenium. More preferred feedstock or fuel compositions comprise levels of organoselenium inhibitors ranging from about 1 ppm to about 50 ppm.
- the improved feedstock and fuel compositions exhibit improvements in reduction or prevention of coke formation and particularly in reduction of filamentous coke formation.
- Feedstock and fuel compositions may include additional additives that are known to affect coke formation, and particularly any additional additives that reduce and/or inhibit non-filamentous coke formation.
- the method and additives of this invention can be applied in any hydrocarbon processing system or engine where coke formation, particularly filamentous coke formation, occurs.
- Filamentous coke formation can be a significant problem for hydrocarbon processing under pyrolysis conditions (e.g. at high temperatures of 300° C. or more in the substantial absence of oxygen, i.e. at most about 0.1 atm. partial pressure of oxygen).
- the method and additives are useful in systems that are operated at ambient pressures or at pressures above ambient.
- the methods and additives are particularly well suited for use in pyrolysis furnaces (steam crackers or ethylene furnaces) used for hydrocarbon cracking, e.g., for the production of ethylene, and in engines or propulsion systems in which fuel can reach temperatures of 300° C. or more, e.g., in hypersonic aircraft engines.
- the method and additives of this invention are useful when the metal surface is about 650° C. as well as when the temperature of the hydrocarbon is about 800° C. or more.
- the additives described herein represent a significant improvement over the prior art.
- the additive is more effective for inhibition of filamentous coke formation at lower concentrations than other additives described previously.
- discontinuing additive injection does not lead to increases in carbon deposition.
- FIGS. 1 A-C are graphs showing the results of thermodynamics calculations.
- FIGS. 1A and B show the favored phases of iron and nickel, respectively, in large excess of a model hydrocarbon fuel at temperatures up to 900° C.
- FIG. 1C shows the favored phases of iron and nickel under the same conditions in the presence of 10 ppm selenium.
- FIG. 2 is a bar graph showing the results of coke deposition experiments with and without diphenylselenide additive.
- FIG. 3 illustrates a comparison of X-ray Diffraction (XRD) scans of stainless steel coupons.
- Scan A is a control coupon as received.
- Scan B is a test coupon after exposure to model hydrocarbon fuel (n-heptane) for 12 hrs in a test reactor at 655° C.
- Scan C is a test coupon after exposure to model hydrocarbon fuel for 12 hrs in a test reactor at 655° C. with diphenylselenide present in the fuel at a level of 300 ppm of selenium.
- This invention is based at least in part on the identification of organoselenium compounds that inhibit or prevent filamentous coke formation on metal walls in contact with hydrocarbons at high temperatures. Exposure of metal surfaces to low levels of organoselenium compounds provides selenium at the metal surface and results in inhibition or prevention of filamentous coke deposition on the surfaces. Surface selenium levels ranging upwards from about 10 atomic %, where atomic % is the ratio of atoms of selenium to total atoms in the outer one to two microns of metal substrate, as measured by Energy Dispersive Spectroscopy (EDS) techniques, provide a protective effect against filamentous coke formation.
- EDS Energy Dispersive Spectroscopy
- a protective effect (a measurable decrease in filamentous coke formation) can be achieved by exposure of a metal surface to organoselenium compounds at levels ranging from about 0.01 ppm selenium to about 1000 ppm selenium for times ranging from minutes to hours. Protective effect is retained a significant time after exposure to the organoselenium compounds is ended (10's of hours to days).
- the level and duration of protective effect provided depends generally on the concentration of organoselenium compound, the duration of exposure, and the temperature. For example, one hour of exposure to diphenylselenide at 300 ppm provided significant reductions of 90% or more in filamentous coke formation for at least 12 hours in test reactors. Substantial reductions of 50% or more in filamentous coke formation for periods of 12 hrs or more of exposure to hydrocarbon feedstock or fuel provide practical levels of surface protection.
- organoselenium additives provide selenium to the metal surface to form metal selenides, e.g., iron and nickel selenides on steel, preventing the formation of the corresponding metal carbides, e.g., Fe 3 C and Ni 3 C.
- Metal carbides have been implicated as intermediates in the formation of filamentous coke. Decomposition of metal carbides is believed to release unreactive carbon atoms which form carbon filaments at metal surfaces. The process is believed to be catalytic in that metal released from the metal carbide reacts with hydrocarbon to reform the carbide, decompose and release additional carbon atoms and metal to again form the carbide.
- FIGS. 1A and B are graphs illustrating the results of a thermodynamics calculation of the thermodynamically favored phases that are present when iron (FIG. 1A) and nickel (FIG. 1B) are exposed to a large excess of n-heptane at a pressure of 35 atm and at temperatures up to 900° C. (1650° F).
- the calculations illustrated were performed using a program that determines the forms of each element present in a system by applying routines that minimize the Gibbs Free Energy in a given system based on known thermodynamic data for given relative amounts of the elements present. HSC Chemistry thermodynamics modeling software (Outkumpu Research Oy, Pori, Finland) was specifically used.
- a low level of dissolved oxygen (70 ppm) was included in the calculation to better model experimental and real world fuel systems. Iron and nickel carbides are the favored forms under the high temperature reducing conditions modeled. The graphs also indicate that the corresponding metal phases will also be present.
- FIG. 1C is a graph illustrating the results of a similar thermodynamics calculation of favored phases, when a low level of selenium (10 ppm) is added to the model fuel containing 70 ppm of dissolved oxygen. Even at this low level of selenium and in the presence of a large excess of hydrocarbon, nickel and iron selenides are highly favored. Further, the metal selenides are favored over a wide temperature range. Only low levels of iron carbide are predicted at the highest temperatures. The high stability of the metal selenides effectively blocks the formation of metal carbides which are the favored phases in the absence of selenium.
- FIGS. 1 A- 1 C The calculations illustrated in FIGS. 1 A- 1 C are consistent with a mechanism of inhibition of coke formation by organoselenium based on the inhibition or prevention of metal carbide formation.
- the methods of this invention involve contacting a metal surface susceptible to coke formation with an organoselenium compound.
- the metal surface is contacted with the organoselenium compound at selected concentration for a selected time to provide a protective effect for the formation of coke.
- the method is particularly beneficial for prohibiting or inhibiting the formation of filamentous coke.
- the metal surface is contacted with the organoselenium compound at a concentration level and for a duration that provides at least about a 50% decrease in filamentous coke deposition (compared to control processes in the absence of treatment with the organoselenium compound).
- the organoselenium compound is provided to the metal surface at a concentration and for a time sufficient to result in at least about a 90% decrease in filamentous coke formation.
- coke deposition is determined in test apparatus by weighing the amount of coke deposited on a metal surface or metal coupon exposed to hydrocarbon feedstock or fuel at high temperatures of 300° C. or more. The presence or absence of filamentous coke on a given metal surface can be assessed qualitatively by SEM analysis where the presence of carbon filament can be observed.
- Metal surfaces that are susceptible to filamentous coke formation include those which contain metals that will form carbides on interaction with hydrocarbons at high temperatures that will decompose to release carbon atoms.
- Surfaces of iron- or nickel-containing metals or alloys are benefitted by the methods of this invention.
- Iron-containing alloys include without limitation, various steels (stainless steel, carbon steel, etc.).
- Nickel-containing alloys include without limitation, high temperature alloys, such as Inconel and related alloys. Any metal or alloy which contains more than about 1% by weight nickel, iron or a combination of both that is used in equipment that comes into contact with hydrocarbon fuels or hydrocarbon feedstock at high temperatures is benefited by the methods of this invention.
- the organoselenium additives of this invention inhibit metal carbide formation.
- the organoselenium additive is provided to the metal surface at a concentration and for a time sufficient to inhibit or prevent metal carbide formation.
- metal carbide inhibition can be assessed by XRD methods to detect the presence of metal carbides in the outer 1-2 microns of the steel surface. A decrease in metal carbide on the metal surface directly correlates with a decrease in filamentous coke formation. XRD methods are applicable, for example, to the detection of the presence of iron carbide on metal surfaces that have been exposed hydrocarbons under pyrolysis conditions. The absence of iron carbide in XRD scans after exposure to organoselenium is indicative of a protective effect against filamentous coke formation.
- Selenium can be detected on metal surfaces that have been exposed to organoselenium selenium additives of this invention, for example by EDS methods.
- Surface selenium levels of about 10 atomic % weight provide protective effect against filamentous coke formation.
- Surface levels of selenium of about 20 atomic % ⁇ 10% are associated with significant reductions of 90% or more in filamentous coke deposition on stainless steel.
- Atomic % is the ratio of atoms of selenium to total atoms in the outer one to two microns of the metal substrate and is determined as noted in the examples and as known in the art by EDS methods.
- the metal surfaces to be protected against coke formation can be contacted with organoselenium additives of this invention by introducing the additive into the hydrocarbon feedstock or fuel that is to be processed or used.
- the additive is introduced at levels ranging from about 0.01 ppm (of Se) up to about 1000 ppm (of Se) to provide protective effect. It is preferred to use the lowest level of additive that provides the desired level of protective effect at a given hydrocarbon processing temperature.
- the additive may be provided continuously, e.g., by simply adding a desired low level to the hydrocarbon before processing or use, or provided periodically, e.g., for a selected time after which addition is discontinued.
- Metal surfaces can be reexposed to additive periodically on a schedule that provides the desired protective effect.
- the additive can be selectively added to the hydrocarbon feedstock stream prior to or during processing at high temperatures at a desired effective concentration for a desired effective duration.
- organoselenium additives of this invention are of particular benefit when employed in hydrocarbon processing under pyrolysis conditions (i.e., temperatures of 300° C. or more in the substantial absence of oxygen).
- the additives also provide particular benefit in engine systems employing hydrocarbon fuels which may contain low levels of dissolved oxygen, e.g., levels up to about 70 ppm dissolved oxygen.
- metal surfaces that are to be protected can be pretreated with organoselenium compounds of this invention prior to exposure to hydrocarbons at high temperatures.
- Pretreatment can be performed using organoselenium compounds in an appropriate diluent or solvent.
- the metal should be sufficiently hot to form the metal selenide on contact with the organoselenium compound.
- the metal surface is heated to a temperature of about 300° C. or more during pretreatment to form a metal selenide.
- Metal surfaces are preferably heated to a temperature of 500° C. or more during pretreatment.
- coke deposits are removed from the metal surfaces that are to be protected prior to pretreatment with organoselenium compounds of this invention.
- Organoselenium compounds useful as additives include without limitation: organoselenides (R—Se—R′), organodiselenides (R—Se—Se—R′), and organoselenols (R—Se—H), where R and R′, may be the same or different, and are selected from aliphatic or aryl groups which may contain one or more heteroatoms.
- Aliphatic groups include for example, straight-chain, branched or cyclic alkyl groups, alkenyl groups or alkynyl groups, which may be substituted with halogens, aryl groups, OR 1 or NR 1 R 2 groups, where R 1 and R 2 , independently can be H, aliphatic and/or aryl groups, or combinations thereof.
- Aliphatic groups include ethers, aldehydes, ketones and esters in which one or more CH 2 groups are replaced with O, CHO, CO, or COO moieties, respectively. Aliphatic groups can also contain siloxy and silylalkyl groups.
- Aryl groups include groups containing one or more 5- or 6-member aromatic rings, which may be fused, wherein the ring may contain one or two heteroatoms (non-carbon atoms, e.g., O, or N), and wherein the ring atoms may be substituted with aliphatic groups (as defined above), halogens, OR 1 or NR 1 R 2 groups, where R 1 and R 2 , independently can be H, aliphatic and/or aryl groups or combinations thereof. R and R′ can be covalently linked together to form an aliphatic or aryl group.
- organoselenium additives of this invention include, among others, diarylselenides, alkylarylselenides, dialkyselenides, diaryldiselenides, alkylaryldiselenides and dialkyldiselenides.
- Preferred additives are those that reduce, inhibit or prevent filamentous coke formation and which also do not generate substantially amounts of non-filamentous coke.
- Preferred organoselenium compounds of this invention are diarylselenides and diaryldiselenides.
- organoselenium compounds are known in the art and are readily available from commercial sources or by synthesis using art known methods.
- Strem Chemicals and Aldrich Chemicals are commercial sources for a number or organoselenium compounds which are suitable for use as additives in the methods of this invention.
- Exemplary commercially available organoselenium additives are listed in Table 1.
- Preferred organoselenium compounds for use as additives are those that are soluble in the hydrocarbon feedstock or hydrocarbon fuel.
- Preferred organoselenium compounds for use as additives are those that are liquid at ambient temperatures and pressure to facilitate handling. Further, preferred organoselenium compounds are those that do not, themselves, generate large amounts of non-filamentous coke. In this regard, organoselenium compounds having at least one aryl group are preferred.
- Hydrocarbon feedstocks include any mixture of hydrocarbons that is to undergo some type of processing, e.g., cracking, at elevated temperatures, which are typically greater than about 300° C.
- Feedstocks are often mixtures of high molecular weight hydrocarbons that include species such as paraffins, olefins, aromatics, cycloparaffins, among many others.
- the molecular weight range of hydrocarbons in hydrocarbon feedstocks generally range from about C 8 -C 20 .
- Hydrocarbon fuels include any hydrocarbon mixtures useful as fuel and particularly those useful in systems in which the fuel can have a temperature greater than about 300° C. Fuels are also a complex mixture of hydrocarbons, typically ranging in molecular weight from C 10 to C 18 , which may include paraffins, olefins, aromatics, cycloparaffins, among many other species.
- Hydrocarbon fuels may contain additional additive (other than organoselenium compounds) to improve fuel performance.
- Additives may include lubricity agents and additives to improve thermal stability of the fuel components.
- TABLE 1 Exemplary List of Commercially Available Organoselenium Compounds Useful as Additives for Filamentous Coke Suppression (Phenylselenomethyl) trimethylsilane benzeneselenol 1,1 dimethyl-2-selenourea benzyl selenide 2,5 diphenyl-selenophene di-tert-butyl selenide 2-methylbenzenoselenazole dibenzyl diselenide 3-methyl-9H-selenoxanthen-9-one dimethyl diselenide 2-benzamidoethyl selenide methyl phenyl selenide benzeneseleninic acid phenyl selenocyanate benzeneseleninic acid anhydride selenophene benzeneseleninic anhydride allyl
- a model hydrocarbon fuel (n-heptane) was used to test the effect of addition of organoselenium compounds on coke formation.
- An automated test rig that has been described previously (Wickham et a. 1997, Wickham et al. 1999) was used to carry out the experiments.
- This apparatus is capable of flowing fuel at well-controlled rates at pressures up to 60 atm through test sections maintained at temperatures up to 700° C.
- the model fuel was heated to temperatures where cracking occurs and coke deposition was assessed with and without organoselenium additive.
- Diphenylselenide (available from Strem Chemicals) was the organoselenium compound tested.
- Diphenylselenide is a liquid under ambient conditions and is soluble in n-heptane.
- Test hydrocarbon fuel solutions were prepared by dissolving the appropriate volume of additive into the n-heptane reservoir prior to testing.
- the amount of coke that accumulated in a stainless steel tube during pyrolysis with and without additive present was measured.
- a previously unused test section made from a 45 cm length of 0.64-cm OD ⁇ 0.46 cm ID 316 stainless steel tube was weighed and then installed into the automated test apparatus.
- Test fuel compositions were flowed through the reactor maintaining a pressure of 37 atm and a flow rate of 2.9 ml/min (liquid hourly space velocity of 35 h ⁇ 1 ).
- a tube furnace with a heated zone of 30 cm enclosed the test section and heated the fuel from 400° C. at the inlet to the desired test temperature.
- a temperature of 655° C. was maintained as measured by a thermocouple spot-welded to the wall of the test section at the end of the heated zone.
- the product distribution exiting the test reactor was measured using a Model 8600 SRI gas chromatography (GC) equipped with a thermal conductivity detector and a 90 cm column packed with silica gel.
- GC gas chromatography
- the test conditions used in the test reactor resulted in a measured cracking level of between 65 and 70%, where percent cracking is defined as (moles carbon in products/total moles carbon)*100.
- a mixture of methane, ethane, ethylene, propane, propylene, butane and butylenes and small amounts of C 5 and C 6 paraffins and olefins were observed to be the products of the cracking reaction.
- the reactor temperature was reduced to 400° C., a nitrogen purge flow was initiated through the reactor, the flow of test fuel composition was discontinued and the reactor was cooled to ambient temperature. This sequence prevented coke formation during the shutdown, which might occur if the fuel flow was stopped while the reactor temperature was 655° C.
- the test section was cool, it was removed from the apparatus, dried at 110° C. for four hours, and weighed to determine the quantity of carbon that had accumulated during the test.
- the reactor was maintained at temperature for six hours with a flow of test fuel composition (n-heptane) with and without an additive concentration of 300 ppm (of Se) (885 ⁇ g diphenylselenide/g fuel).
- the test conditions were maintained for 12 hours and two different concentrations of additive (diphenylselenide at 300 ppm and 30 ppm (of Se)) were examined.
- FIG. 2 illustrates and compares the results of experiments performed for 6 hrs (left) and 12 hrs (right).
- This figure is a bar graph of weight (in mg) of carbon deposited inside a reactor tube section as a function of experiment duration (6 hrs or 12 hrs) with and without an additive.
- 40 mg of carbon accumulated inside the reactor tube (far left bar) during reaction to the model fuel.
- 300 ppm (Se) of diphenylselenide is added less than 1 mg of carbon accumulates inside the tube. This represents over a 98% reduction in coke deposition.
- 171 mg of carbon accumulated inside the tube (right side of FIG. 2) during reaction of the model fuel.
- a second series of tests was carried out in which the effect of the diphenylselenide on stainless steel coupons, placed inside the test section during pyrolysis was examined.
- a copper-lined reactor tube was used to eliminate carbon formation on the reactor tube wall.
- the test coupon was removed from the reactor energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) was performed to characterize the coupon surface.
- EDS provides qualitative data on the composition of a metal surface
- XRD provides information on crystalline compounds that form at depths of up to several microns.
- FIG. 3 illustrates XRD patterns obtained on three coupon samples: an as-received sample (A), a coupon used in a test with no additive (B), and a sample used in a test in which 300 ppm (Se) diphenylselenide was added to the fuel (C).
- A as-received sample
- B coupon used in a test with no additive
- C sample used in a test in which 300 ppm (Se) diphenylselenide was added to the fuel
- EDS measurements on the surfaces of the coupons and on the inside surface of a stainless steel test section following a 12-hr test with model fuel containing the organoselenium additive indicate that selenium is present on the surfaces. For example, after 12-hr exposure to the additive, the selenium concentration on the coupon surface was approximately 18 atomic % ⁇ 10%.
- Selenium is thus present at a high concentration (greater than or equal to about 10 atomic %) on the metal surface of the reactor even after 12 hours of operation without additive. This demonstrates that selenium is bound very strongly, likely with iron and nickel components of the stainless steel. These indicate that selenium at levels ranging from greater than or equal to about 18 atomic % on a metal surface, particularly a steel surface, provide for inhibition or prevention of filamentous coke formation. Further, the results indicate that protective levels of selenium on metal surfaces can be provided by exposure of the surfaces to low levels of organoselenium compounds (down to 1 ppm selenium) for relatively short times (1-6 hrs). The use of low levels of organoselenium compounds is preferred to reduce cost and any hazards associated with the use of the additive.
Abstract
Materials and methods for inhibiting the formation of filamentous coke on heated metal surfaces. Organoselenium compounds, including diarylselenides, diaryldiselenides, alkylarylselenides, and alkylaryldiselenides, are employed as hydrocarbon feedstock additives or as hydrocarbon fuel additives to inhibit filamentous coke formation on hydrocarbon processing systems, including reactors, furnaces, engines and parts thereof and in particular to inhibit filamentous coke formation on heat-exchangers in such systems.
Description
- This application is a division of U.S. patent application Ser. No. 09/629,361, filed Aug. 1, 2000, which is incorporated by reference in its entirety to the extent not inconsistent with the disclosure herein.
- [0002] This invention was made with finding from the United States government through Air Force Grant F33615-96-C-2626. The United States government has certain rights in this invention.
- This invention relates generally to the inhibition or prevention of coke formation on metal surfaces in contact with hydrocarbons at high temperatures. Such conditions can occur in hydrocarbon cracking processes and in certain types of engine systems in which hydrocarbon fuels reach very high temperatures. The invention more specifically relates to suppression of filamentous coke formation.
- Carbon deposits (coke) can result from an interaction of the hydrocarbon processing stream and the metals contained in the walls and heat exchangers of reactors at temperatures above about 300° C. Deposits that form in the shape of long filaments approximately 1 μm in diameter are referred to as filamentous coke. Non-filamentous coke can also form under pyrolysis conditions by several different mechanism. Filamentous coke is typically more abundant at higher temperatures (greater than about 450° C.), is hard and can be difficult to remove.
- Coke formation is generally detrimental to the productivity and efficiency of the operation of a given system, causing fouling of lines and erosion of surfaces which increase operation down-time for cleaning and maintenance.
- Filamentous coke formation is observed in naphtha cracking and ethylene production operations. The formation of coke in ethylene and naphtha reactors lowers product yield, heat transfer and reactor life along with the increased cost of time and money for decoking operations Froment, G. F., Reyniers, G. C., Kopinke, F., Zimmermarm, G. (1994).Ind. Eng. Chem. Res., V. 33, 2584 ). Much research on the formation of coke catalyzed by metal surfaces is based on attempts to solve these problems.
- Coke formation is also a significant problem in engine systems in which the hydrocarbon fuel temperatures can reach levels greater than about 300° C . For example, hypersonic aircraft employ fuel to cool ramjet/scramjet propulsion system. In these systems, sensible heating and endothermic reactions can be used to provide the required heat sink, but in the process, the fuel temperature can reach 650° C. (1200° F.) or more. When fuel reaches these temperatures, carbonaceous deposits (coke), including filamentous coke, form on the walls of the heat exchangers. These deposits can inhibit fuel flow and reduce heat transfer across the heat exchanger surface.
- Filamentous coke formation is sensitive to the type of metal used in reactor walls. Nickel and iron present on the metal surface, as occurs in nickel and/or iron alloys and various types of steel, for example, are believed to catalyze the formation of filamentous coke through the formation of metal carbides that decompose (Vaish, S. and D. Kunzru (1989) “Triphenyl Phosphite as a Coke Inhibitor During Naptha Pyrolysis”Ind. Eng. Chem. Res. 28, 1293-1299 and Reyniers, G. C., Froment, G. F., Kopinke, F. D., and Zimmerman, G. (1994). “Coke Formation in the Thermal Cracking of Hydrocarbons. 4. Modeling of Coke Formation in Naphtha Cracking” Ind. Eng Chem Res., 33, pp 2584-2590). Filamentous coke does not form in copper-lined reactors (Wickham, D. T., J. V. Atria, J. R. Engel, B. D. Hitch and M. E. Karpuk (1997). “Initiators for Endothermic Fuels,” October, 1997 JANNAF Combustion/JSM Meeting) and titanium metal is resistant to filamentous coke formation (Chen, F. F., Karpuk, M. E., Hitch, B. D., and Edwards, J. T. (1998), “Engineering Scale Titanium Endothermic Fuel Reactor Demonstration for a Hypersonic Scramjet Engine,” presented at the 35th JANNAF Joint Combustion, Airbreathing Propulsion, and Propulsion Systems Hazards Subcommittees Meeting, Tuscon Ariz., December 7-11).
- Significant effort has been expended to identify ways to passivate metal surfaces under high temperature pyrolysis conditions. The formation of metal oxide layers on alloys is reported to passivate the surface and reduce coking. One method is to oxidize the metal alloy with oxygen or steam to create an oxide layer such as chromia which is more resistant to carbon diffusion (Albright, L. F. and Marek, J. C. (1982) “Surface Phenomena During Pyrolysis,” inCoke Formation on Metal Surfaces, ACS Symposium Series 202, 123). The use of alumina and silica coatings are also reported to create a barrier to carbon diffusion and reduced coke filament formation on metal surfaces (Albright, L. F. and Marek, J. C. (1982); Atria, J. V, H. H. Schobert, and W. Cermignani (1996). “Nature of High Temperature Deposits from n-Alkanes in Flow Reactor Tubes,” ACS Preprints, Petroleum Chemistry, pp. 493-497; Baker, R. T. K. and Chludzinski, J. J. (1980). J. Catal., V. 64, 464; Ghosh, K. K, and D. Kunzry (1992). “Sodium Silicate as a Coke Inhibitor During Naphtha Pyrolysis,” Canadian Journal of Chemical Engineering, 70, pp. 394-397). The preparation of alumina coatings is difficult and requires the use of aluminum-containing metal alloys in processing equipment or engines. For example, an inert alumina surface layer can be formed on aluminum containing alloys such as Incoloy 800 by treating the alloy at temperatures above 1000° C. in a hydrogen atmosphere with a low partial pressure of water. Silica coatings are not very effective. Atria et al. (1996) observed cracking of silica layers allowing filaments to grow. Ghosh and Kunzru (1992) found that passivation with sodium silicate initially reduced the coke formation rate by about 50%, but that the beneficial effect was reduced each time a decoking step was employed. Further, repeated oxidation or sulfiding of metal surfaces or repeated decoking applications roughens metal surface increasing the surface area and leading to formation of larger amounts (Albright and Marek 1982). Polishing of alloy and metal surfaces has been indicated to help reduce coke formation.
- Various additives have been reported to reduce coke formation. U.S. Pat. No. 1,847,095 reports “adding or supplying” metalloids including boron, arsenic, antimony, bismuth, phosphorous, selenium and silicon or compounds thereof “to the metallic (and non-metallic, if any) materials” which come into contact with “hydrocarbons at high temperature” to diminish or prevent coke and soot formation. The patent indicates that metal surfaces can be coated or treated with the substances or that “small quantities of the hydrogen compounds” of the metalloids may be added to hydrocarbons. The hydride of selenium, among others, is reported to be of high utility in this process. The patent specifically reports addition of 0.01% -0.05% of “hydrides of silicon” to an ethylene-hydrogen-carbon dioxide mixture. GB patents 275,662 and 296,752 relate to the same or similar processes.
- Trimethyl- or triphenylphosphite and benzyldiethylphosphate are reported to decompose at 700_C. to form phosphorous compounds which passivate metal surfaces (Kunzru, D. and Chowdhury, S. N. (1993)Can. J. Chem. Eng., V. 71, 873; Kunzru, D. and Vaish, S. (1989) Ind. Eng. Chem. Res., V. 28, 1293; Vaish, S. and D. Kunzru (1989) Ind. Eng. Chem. Res. 28, 1293-1299). However, reductions in coke deposition of only 10-30% were reported. In addition, Vaish and Kunzru (1989) reported that high concentrations (up to 1000 ppm) of trimethyl- and triphenyl phosphites were required to achieve good (approximately 90%) reduction in coke formation. Further, when the additive was discontinued, the rate of coke formation increased and approached the rate measured when no additive was present.
- U.S. Pat. No. 4,116,812 reports the use of organo-sulfur compounds to inhibit fouling at elevated temperatures in pyrolysis furnaces used to produce ethylene. U.S. Pat. Nos. 3,531,394; 4,024,050; 4,024,05; 4,105,540; 4,542,253; 4,835,332; 5,354,450;and 5,360,531 report the use of various phosphorous-compounds for coke suppression. U.S. Pat. No. 3,531,394 reports the use of bismuth-containing compounds for coke suppression. Tong and Poindexter U.S. Pat. No. 5,954,943 report that a mixture of sulfur and phosphorous compounds having a sulfur to phosphorous atomic ratio of at least 5:1 can be used to reduce coke formation. The mixture of compounds is used to pretreat the surfaces of a pyrolysis furnace for up to 20 hrs prior to introduction of hydrocarbon feed to generate a passivation layer. U.S. Pat. No. 4,551,227 reports the use of tin compounds, antimony compounds or both in combination with phosphorous compounds for suppression of coke formation.
- Various patents report the use of chromium, tin and antimony (U.S. Pat. No. 4,863,892), combinations of tin and silicon, antimony and silicon, or tin, antimony and silicon (U.S. Pat. No. 4,692,234), and combinations of aluminum and antimony or aluminum, antimony and tin (U.S. Pat. No. 4,686,201) as effective antifouling agents in thermal cracking processes. In all cases, a test coupon consisting of
Inconel 800 was immersed in solutions containing the specific metals cited and then heated in air to convert the metal to its oxide form. The coupon was exposed to a coking environment and then heated in steam, converting the coke layer to CO, which was measured by gas chromatography. Although the binary combination of additives suppressed CO formation in some cases, subsequent cycles showed increased coke formation. - U.S. Pat. Nos. 4,555,326; 4,729,064; and 4,680,421 report the use variously of boron, boron oxides, metal borides or ammonium borate to suppress coke formation in pyrolysis furnaces. U.S. Pat. Nos. 5,093,032, 5,128,023 and 5,330,970 report the use of a combination of boron compounds and a dihydroxybenzene compound for inhibiting coke formation. Coke reduction levels of up to 86% (measured in mg coked formed compared to controls) were reported when combination of ammonium biborate and hydroquinone (250 ppm/150 ppm) was added in coker feedstock in a cracking furnace.
- U.S. Pat. Nos. 2,698,512; 2,959,915; and 3,173,247 relate to thermal degradation of hydrocarbon fuels at high temperatures to form gum and coke deposits. These patents report fuel compositions more stable to decomposition at high temperature that give lower levels of deposits. U.S. Pat. No. 5,923,944 reports surface treatment, including removing surface irregularities and deposition of a coating consisting essentially of a metal oxide (e.g., Ta2O5 or SiO2) and the vapors of an organometallic compound, to avoid deposition of thermal decomposition products from hydrocarbon fuels.
- While considerable efforts have been made toward identifying methods and additives for reducing coke formation from hydrocarbons under pyrolysis conditions, there is still a significant need in the art for reliable additives which provide high levels of coke suppression (about 90% or more) at low additive concentrations (less than about 100 ppm) and which are particularly effective for suppression of filamentous coke formation.
- This invention relates to the reduction or prevention of coke formation and deposition on metal surfaces during hydrocarbon processing at high temperature. More specifically, the invention provides selenium additives and methods of using such additives for the reduction of filamentous carbon formation in furnaces or reactors for processing hydrocarbons or in engines that employ hydrocarbon fuels. The invention is particularly useful for reducing filamentous coke formation on iron and/or nickle-containing metal and/or alloy surfaces. The invention also relates to a method of pretreating metal surfaces to inhibit or prevent filamentous coke formation by contacting an appropriately heated metal surface with an additive of this invention. The invention is based on the identification of selenium additives, including organoselenium compounds, that inhibit or prevent coke formation and particularly inhibit filamentous coke formation. The organoselenium additives are believed to inhibit or prevent metal carbide formation, such carbides are intermediates in the formation of coke, particularly filamentous coke. The invention specifically relates to organoselenium additives that prevent or inhibit the formation of nickel and iron carbides that can be formed on furnaces, reactors and/or engine surfaces having steel parts (including, for example, carbon steel and stainless steel). Additives of this invention are believed to react with metal components in furnace, reactor or engine walls or parts thereof to generate metal compounds that are sufficiently stable that they do not undergo further reaction with fuel to form metal carbides.
- Preferred selenium compounds of this invention are organoselenium compounds including without limitation, organoselenides (R—Se—R′), organodiselenides (R—Se—Se—R′), and organoselenols (R—Se—H), where R and R′, maybe the same or different, and are selected from aliphatic or aryl groups which may contain one or more heteroatoms.
- The invention also provides improved hydrocarbon feedstock and hydrocarbons fuels which contain from about 0.01 ppm selenium to about 1000 ppm selenium as an organoselenium additive that is an inhibitor of filamentous coke formation. Compositions of this invention can comprise less than or equal to about 100 ppm selenium. More preferred feedstock or fuel compositions comprise levels of organoselenium inhibitors ranging from about 1 ppm to about 50 ppm. The improved feedstock and fuel compositions exhibit improvements in reduction or prevention of coke formation and particularly in reduction of filamentous coke formation. Feedstock and fuel compositions may include additional additives that are known to affect coke formation, and particularly any additional additives that reduce and/or inhibit non-filamentous coke formation.
- The method and additives of this invention can be applied in any hydrocarbon processing system or engine where coke formation, particularly filamentous coke formation, occurs. Filamentous coke formation can be a significant problem for hydrocarbon processing under pyrolysis conditions (e.g. at high temperatures of 300° C. or more in the substantial absence of oxygen, i.e. at most about 0.1 atm. partial pressure of oxygen). The method and additives are useful in systems that are operated at ambient pressures or at pressures above ambient. The methods and additives are particularly well suited for use in pyrolysis furnaces (steam crackers or ethylene furnaces) used for hydrocarbon cracking, e.g., for the production of ethylene, and in engines or propulsion systems in which fuel can reach temperatures of 300° C. or more, e.g., in hypersonic aircraft engines. The method and additives of this invention are useful when the metal surface is about 650° C. as well as when the temperature of the hydrocarbon is about 800° C. or more.
- The additives described herein represent a significant improvement over the prior art. The additive is more effective for inhibition of filamentous coke formation at lower concentrations than other additives described previously. In addition, discontinuing additive injection, does not lead to increases in carbon deposition.
- FIGS.1A-C are graphs showing the results of thermodynamics calculations. FIGS. 1A and B show the favored phases of iron and nickel, respectively, in large excess of a model hydrocarbon fuel at temperatures up to 900° C. FIG. 1C shows the favored phases of iron and nickel under the same conditions in the presence of 10 ppm selenium.
- FIG. 2 is a bar graph showing the results of coke deposition experiments with and without diphenylselenide additive.
- FIG. 3 illustrates a comparison of X-ray Diffraction (XRD) scans of stainless steel coupons. Scan A is a control coupon as received. Scan B is a test coupon after exposure to model hydrocarbon fuel (n-heptane) for 12 hrs in a test reactor at 655° C. Scan C is a test coupon after exposure to model hydrocarbon fuel for 12 hrs in a test reactor at 655° C. with diphenylselenide present in the fuel at a level of 300 ppm of selenium.
- This invention is based at least in part on the identification of organoselenium compounds that inhibit or prevent filamentous coke formation on metal walls in contact with hydrocarbons at high temperatures. Exposure of metal surfaces to low levels of organoselenium compounds provides selenium at the metal surface and results in inhibition or prevention of filamentous coke deposition on the surfaces. Surface selenium levels ranging upwards from about 10 atomic %, where atomic % is the ratio of atoms of selenium to total atoms in the outer one to two microns of metal substrate, as measured by Energy Dispersive Spectroscopy (EDS) techniques, provide a protective effect against filamentous coke formation.
- A protective effect (a measurable decrease in filamentous coke formation) can be achieved by exposure of a metal surface to organoselenium compounds at levels ranging from about 0.01 ppm selenium to about 1000 ppm selenium for times ranging from minutes to hours. Protective effect is retained a significant time after exposure to the organoselenium compounds is ended (10's of hours to days). The level and duration of protective effect provided depends generally on the concentration of organoselenium compound, the duration of exposure, and the temperature. For example, one hour of exposure to diphenylselenide at 300 ppm provided significant reductions of 90% or more in filamentous coke formation for at least 12 hours in test reactors. Substantial reductions of 50% or more in filamentous coke formation for periods of 12 hrs or more of exposure to hydrocarbon feedstock or fuel provide practical levels of surface protection.
- Without wishing to be bound by any particular theory, Applicants presently believe that organoselenium additives provide selenium to the metal surface to form metal selenides, e.g., iron and nickel selenides on steel, preventing the formation of the corresponding metal carbides, e.g., Fe3C and Ni3C. Metal carbides have been implicated as intermediates in the formation of filamentous coke. Decomposition of metal carbides is believed to release unreactive carbon atoms which form carbon filaments at metal surfaces. The process is believed to be catalytic in that metal released from the metal carbide reacts with hydrocarbon to reform the carbide, decompose and release additional carbon atoms and metal to again form the carbide.
- FIGS. 1A and B are graphs illustrating the results of a thermodynamics calculation of the thermodynamically favored phases that are present when iron (FIG. 1A) and nickel (FIG. 1B) are exposed to a large excess of n-heptane at a pressure of 35 atm and at temperatures up to 900° C. (1650° F). The calculations illustrated were performed using a program that determines the forms of each element present in a system by applying routines that minimize the Gibbs Free Energy in a given system based on known thermodynamic data for given relative amounts of the elements present. HSC Chemistry thermodynamics modeling software (Outkumpu Research Oy, Pori, Finland) was specifically used. A low level of dissolved oxygen (70 ppm) was included in the calculation to better model experimental and real world fuel systems. Iron and nickel carbides are the favored forms under the high temperature reducing conditions modeled. The graphs also indicate that the corresponding metal phases will also be present.
- FIG. 1C is a graph illustrating the results of a similar thermodynamics calculation of favored phases, when a low level of selenium (10 ppm) is added to the model fuel containing 70 ppm of dissolved oxygen. Even at this low level of selenium and in the presence of a large excess of hydrocarbon, nickel and iron selenides are highly favored. Further, the metal selenides are favored over a wide temperature range. Only low levels of iron carbide are predicted at the highest temperatures. The high stability of the metal selenides effectively blocks the formation of metal carbides which are the favored phases in the absence of selenium.
- The calculations illustrated in FIGS.1A-1C are consistent with a mechanism of inhibition of coke formation by organoselenium based on the inhibition or prevention of metal carbide formation.
- The methods of this invention involve contacting a metal surface susceptible to coke formation with an organoselenium compound. The metal surface is contacted with the organoselenium compound at selected concentration for a selected time to provide a protective effect for the formation of coke. The method is particularly beneficial for prohibiting or inhibiting the formation of filamentous coke. Preferably, the metal surface is contacted with the organoselenium compound at a concentration level and for a duration that provides at least about a 50% decrease in filamentous coke deposition (compared to control processes in the absence of treatment with the organoselenium compound). More preferably, the organoselenium compound is provided to the metal surface at a concentration and for a time sufficient to result in at least about a 90% decrease in filamentous coke formation. For purposes of this invention, coke deposition is determined in test apparatus by weighing the amount of coke deposited on a metal surface or metal coupon exposed to hydrocarbon feedstock or fuel at high temperatures of 300° C. or more. The presence or absence of filamentous coke on a given metal surface can be assessed qualitatively by SEM analysis where the presence of carbon filament can be observed.
- Metal surfaces that are susceptible to filamentous coke formation, include those which contain metals that will form carbides on interaction with hydrocarbons at high temperatures that will decompose to release carbon atoms. Surfaces of iron- or nickel-containing metals or alloys are benefitted by the methods of this invention. Iron-containing alloys, include without limitation, various steels (stainless steel, carbon steel, etc.). Nickel-containing alloys, include without limitation, high temperature alloys, such as Inconel and related alloys. Any metal or alloy which contains more than about 1% by weight nickel, iron or a combination of both that is used in equipment that comes into contact with hydrocarbon fuels or hydrocarbon feedstock at high temperatures is benefited by the methods of this invention.
- It is believed that the organoselenium additives of this invention inhibit metal carbide formation. Thus, the organoselenium additive is provided to the metal surface at a concentration and for a time sufficient to inhibit or prevent metal carbide formation. For purposes of this invention, metal carbide inhibition can be assessed by XRD methods to detect the presence of metal carbides in the outer 1-2 microns of the steel surface. A decrease in metal carbide on the metal surface directly correlates with a decrease in filamentous coke formation. XRD methods are applicable, for example, to the detection of the presence of iron carbide on metal surfaces that have been exposed hydrocarbons under pyrolysis conditions. The absence of iron carbide in XRD scans after exposure to organoselenium is indicative of a protective effect against filamentous coke formation.
- Selenium can be detected on metal surfaces that have been exposed to organoselenium selenium additives of this invention, for example by EDS methods. Surface selenium levels of about 10 atomic % weight provide protective effect against filamentous coke formation. Surface levels of selenium of about 20 atomic %±10% are associated with significant reductions of 90% or more in filamentous coke deposition on stainless steel. Atomic % is the ratio of atoms of selenium to total atoms in the outer one to two microns of the metal substrate and is determined as noted in the examples and as known in the art by EDS methods.
- The metal surfaces to be protected against coke formation can be contacted with organoselenium additives of this invention by introducing the additive into the hydrocarbon feedstock or fuel that is to be processed or used. The additive is introduced at levels ranging from about 0.01 ppm (of Se) up to about 1000 ppm (of Se) to provide protective effect. It is preferred to use the lowest level of additive that provides the desired level of protective effect at a given hydrocarbon processing temperature. The additive may be provided continuously, e.g., by simply adding a desired low level to the hydrocarbon before processing or use, or provided periodically, e.g., for a selected time after which addition is discontinued. Metal surfaces can be reexposed to additive periodically on a schedule that provides the desired protective effect. In hydrocarbon processing application, e.g., pyrolytic furnaces, the additive can be selectively added to the hydrocarbon feedstock stream prior to or during processing at high temperatures at a desired effective concentration for a desired effective duration.
- The organoselenium additives of this invention are of particular benefit when employed in hydrocarbon processing under pyrolysis conditions (i.e., temperatures of 300° C. or more in the substantial absence of oxygen). The additives also provide particular benefit in engine systems employing hydrocarbon fuels which may contain low levels of dissolved oxygen, e.g., levels up to about 70 ppm dissolved oxygen.
- Alternatively, metal surfaces that are to be protected can be pretreated with organoselenium compounds of this invention prior to exposure to hydrocarbons at high temperatures. Pretreatment can be performed using organoselenium compounds in an appropriate diluent or solvent. During pretreatment, the metal should be sufficiently hot to form the metal selenide on contact with the organoselenium compound. The metal surface is heated to a temperature of about 300° C. or more during pretreatment to form a metal selenide. Metal surfaces are preferably heated to a temperature of 500° C. or more during pretreatment. Although, not required, it is preferred that coke deposits are removed from the metal surfaces that are to be protected prior to pretreatment with organoselenium compounds of this invention.
- Organoselenium compounds useful as additives include without limitation: organoselenides (R—Se—R′), organodiselenides (R—Se—Se—R′), and organoselenols (R—Se—H), where R and R′, may be the same or different, and are selected from aliphatic or aryl groups which may contain one or more heteroatoms. Aliphatic groups include for example, straight-chain, branched or cyclic alkyl groups, alkenyl groups or alkynyl groups, which may be substituted with halogens, aryl groups, OR1 or NR1R2 groups, where R1 and R2, independently can be H, aliphatic and/or aryl groups, or combinations thereof. Aliphatic groups include ethers, aldehydes, ketones and esters in which one or more CH2 groups are replaced with O, CHO, CO, or COO moieties, respectively. Aliphatic groups can also contain siloxy and silylalkyl groups. Aryl groups include groups containing one or more 5- or 6-member aromatic rings, which may be fused, wherein the ring may contain one or two heteroatoms (non-carbon atoms, e.g., O, or N), and wherein the ring atoms may be substituted with aliphatic groups (as defined above), halogens, OR1 or NR1R2 groups, where R1 and R2, independently can be H, aliphatic and/or aryl groups or combinations thereof. R and R′ can be covalently linked together to form an aliphatic or aryl group. More specifically, organoselenium additives of this invention include, among others, diarylselenides, alkylarylselenides, dialkyselenides, diaryldiselenides, alkylaryldiselenides and dialkyldiselenides. Preferred additives are those that reduce, inhibit or prevent filamentous coke formation and which also do not generate substantially amounts of non-filamentous coke. Preferred organoselenium compounds of this invention are diarylselenides and diaryldiselenides.
- A number of organoselenium compounds are known in the art and are readily available from commercial sources or by synthesis using art known methods. Strem Chemicals and Aldrich Chemicals (as illustrated in their published catalogs for 1999 and 2000 and in their current on-line catalogs) are commercial sources for a number or organoselenium compounds which are suitable for use as additives in the methods of this invention. Exemplary commercially available organoselenium additives are listed in Table 1. Preferred organoselenium compounds for use as additives are those that are soluble in the hydrocarbon feedstock or hydrocarbon fuel. Preferred organoselenium compounds for use as additives are those that are liquid at ambient temperatures and pressure to facilitate handling. Further, preferred organoselenium compounds are those that do not, themselves, generate large amounts of non-filamentous coke. In this regard, organoselenium compounds having at least one aryl group are preferred.
- Methods for preparation of organoselenium compounds are disclosed for example in U.S. Pat. Nos. 4,003,829; 4,962,207; 5,026,846; 5,166,428; and 5,442,112. These methods and other art-known methods can be used or readily adapted without expense of undue experimentation to synthesize organoselenium compounds for use as additives in the methods and compositions of this invention.
- The methods and additives of this invention are employed to inhibit or prevent filamentous coke formation on metal surfaces on interaction with hydrocarbon feedstock or hydrocarbon fuels. Hydrocarbon feedstocks include any mixture of hydrocarbons that is to undergo some type of processing, e.g., cracking, at elevated temperatures, which are typically greater than about 300° C. Feedstocks are often mixtures of high molecular weight hydrocarbons that include species such as paraffins, olefins, aromatics, cycloparaffins, among many others. The molecular weight range of hydrocarbons in hydrocarbon feedstocks generally range from about C8-C20.
- Hydrocarbon fuels include any hydrocarbon mixtures useful as fuel and particularly those useful in systems in which the fuel can have a temperature greater than about 300° C. Fuels are also a complex mixture of hydrocarbons, typically ranging in molecular weight from C10 to C18, which may include paraffins, olefins, aromatics, cycloparaffins, among many other species.
- Hydrocarbon fuels may contain additional additive (other than organoselenium compounds) to improve fuel performance. Additives may include lubricity agents and additives to improve thermal stability of the fuel components.
TABLE 1 Exemplary List of Commercially Available Organoselenium Compounds Useful as Additives for Filamentous Coke Suppression (Phenylselenomethyl) trimethylsilane benzeneselenol 1,1 dimethyl-2- selenourea benzyl selenide 2,5 diphenyl-selenophene di-tert-butyl selenide 2-methylbenzenoselenazole dibenzyl diselenide 3-methyl-9H-selenoxanthen-9-one dimethyl diselenide 2-benzamidoethyl selenide methyl phenyl selenide benzeneseleninic acid phenyl selenocyanate benzeneseleninic acid anhydride selenophene benzeneseleninic anhydride allylphenyl selenide - A model hydrocarbon fuel (n-heptane) was used to test the effect of addition of organoselenium compounds on coke formation. An automated test rig that has been described previously (Wickham et a. 1997, Wickham et al. 1999) was used to carry out the experiments. This apparatus is capable of flowing fuel at well-controlled rates at pressures up to 60 atm through test sections maintained at temperatures up to 700° C. The model fuel was heated to temperatures where cracking occurs and coke deposition was assessed with and without organoselenium additive. Diphenylselenide (available from Strem Chemicals) was the organoselenium compound tested. Diphenylselenide is a liquid under ambient conditions and is soluble in n-heptane. Test hydrocarbon fuel solutions were prepared by dissolving the appropriate volume of additive into the n-heptane reservoir prior to testing.
- In the first set of tests, the amount of coke that accumulated in a stainless steel tube during pyrolysis with and without additive present was measured. In each test, a previously unused test section made from a 45 cm length of 0.64-cm OD×0.46 cm ID 316 stainless steel tube was weighed and then installed into the automated test apparatus. Test fuel compositions were flowed through the reactor maintaining a pressure of 37 atm and a flow rate of 2.9 ml/min (liquid hourly space velocity of 35 h−1). A tube furnace with a heated zone of 30 cm enclosed the test section and heated the fuel from 400° C. at the inlet to the desired test temperature. In the first set of tests, a temperature of 655° C. was maintained as measured by a thermocouple spot-welded to the wall of the test section at the end of the heated zone.
- In addition, during each test, the product distribution exiting the test reactor was measured using a Model 8600 SRI gas chromatography (GC) equipped with a thermal conductivity detector and a 90 cm column packed with silica gel. The test conditions used in the test reactor resulted in a measured cracking level of between 65 and 70%, where percent cracking is defined as (moles carbon in products/total moles carbon)*100. A mixture of methane, ethane, ethylene, propane, propylene, butane and butylenes and small amounts of C5 and C6 paraffins and olefins were observed to be the products of the cracking reaction. At the conclusion of a test period, the reactor temperature was reduced to 400° C., a nitrogen purge flow was initiated through the reactor, the flow of test fuel composition was discontinued and the reactor was cooled to ambient temperature. This sequence prevented coke formation during the shutdown, which might occur if the fuel flow was stopped while the reactor temperature was 655° C. After the test section was cool, it was removed from the apparatus, dried at 110° C. for four hours, and weighed to determine the quantity of carbon that had accumulated during the test. In one experiment, the reactor was maintained at temperature for six hours with a flow of test fuel composition (n-heptane) with and without an additive concentration of 300 ppm (of Se) (885 μg diphenylselenide/g fuel). In a second experiment, the test conditions were maintained for 12 hours and two different concentrations of additive (diphenylselenide at 300 ppm and 30 ppm (of Se)) were examined.
- FIG. 2 illustrates and compares the results of experiments performed for 6 hrs (left) and 12 hrs (right). This figure is a bar graph of weight (in mg) of carbon deposited inside a reactor tube section as a function of experiment duration (6 hrs or 12 hrs) with and without an additive. In the 6 hour test, 40 mg of carbon accumulated inside the reactor tube (far left bar) during reaction to the model fuel. When 300 ppm (Se) of diphenylselenide is added less than 1 mg of carbon accumulates inside the tube. This represents over a 98% reduction in coke deposition. In the 12-hr test, 171 mg of carbon accumulated inside the tube (right side of FIG. 2) during reaction of the model fuel. Addition of 300 ppm (Se) diphenylselenide to the model fuel reduced carbon accumulation to 13 mg, a 93% reduction in coke formation. Scanning electron microscopic (SEM) analysis of the carbon deposited when no additive was present indicated that the coke formed was comprised of filaments approximately 0.5 to one micron in diameter (filamentous coke). SEM analysis of the carbon formed when the additive was present in the model fuel, showed that it had a different morphology and contained no carbon filaments. In view of this result, it appears that addition of the additive substantially suppressed the formation of filamentous coke. In all experiments, the SEM was operated at 10,000× with a resolution (i.e., smallest visible dimension) of about 0.1 micron.
- To investigate the possibility that the small amount of carbon deposited with the additive was from the additive itself, the additive concentration was reduced to 30 ppm (of Se), a factor of ten lower than the previous test. Only 5 mg of carbon accumulated in the tube (over a 12-hr run), representing a 97% reduction in coke formation.
- Another experiment was performed to assess whether or not continuous addition of the additive was required. In this case, the diphenylselenide additive was injected into the model fuel at a concentration of 300 ppm (of Se) for the first hour of the test only. The test was then continued for 12 hrs with fuel containing no additive. Only 13 mg of carbon accumulated under these conditions as shown in the far right bar in FIG. 2. SEM analysis showed no indication of carbon filaments in the small quantity of carbon accumulated. These results indicate that pretreatment of a reactor with an additive for a relatively short time (compared to the run time of the process) will provide high levels of inhibition of coke formation.
- A second series of tests was carried out in which the effect of the diphenylselenide on stainless steel coupons, placed inside the test section during pyrolysis was examined. For these tests, a copper-lined reactor tube was used to eliminate carbon formation on the reactor tube wall. At the conclusion of each test, the test coupon was removed from the reactor energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) was performed to characterize the coupon surface. EDS provides qualitative data on the composition of a metal surface, and XRD provides information on crystalline compounds that form at depths of up to several microns.
- FIG. 3 illustrates XRD patterns obtained on three coupon samples: an as-received sample (A), a coupon used in a test with no additive (B), and a sample used in a test in which 300 ppm (Se) diphenylselenide was added to the fuel (C). On the as received sample a small peak at a 2θ value of 43.8° and a larger peak at 44.5° are observed. Peaks at 51°, 65° and 75° are also observed. These peaks are consistent with the presence of iron, chromium, and nickel contained in the 316 stainless steel alloy. The XRD pattern for the coupon tested with no additive, which produced filamentous coke, shows some significant changes in the diffraction pattern (B). In this pattern, a small peak appears at 42.8°. The location of this peak is consistent with the formation of iron carbide, Fe3C, (International Center for Diffraction Data, 1995) and supports the idea that iron carbide is an intermediate in the filamentous coke formation process. This scan also shows changes in the intensities of the peaks associated with the steel components. The observed changes are likely due to the annealing effect caused by the exposure to high temperature. Finally, the scan C shows the XRD pattern obtained for the coupon tested with diphenylselenide (300 ppm selenium) in which no carbon filaments formed. This pattern shows no evidence of the small peak at 42.8°, indicating that no Fe3C was formed during this test. This result indicates that the selenium additive reacts with iron and nickel preventing the formation of iron and nickel carbides and as a result preventing the formation and deposition of filamentous coke.
- EDS measurements on the surfaces of the coupons and on the inside surface of a stainless steel test section following a 12-hr test with model fuel containing the organoselenium additive indicate that selenium is present on the surfaces. For example, after 12-hr exposure to the additive, the selenium concentration on the coupon surface was approximately 18 atomic %±10%. A similar EDS measurement on the inside surface of the stainless steel tube after the test in which the selenium additive was injected only for the first hour of the 12-hr test and then continued with no additive present indicated about the same level of selenium on the inside surface (approximately 20 atomic %±10%) of the tube. Selenium is thus present at a high concentration (greater than or equal to about 10 atomic %) on the metal surface of the reactor even after 12 hours of operation without additive. This demonstrates that selenium is bound very strongly, likely with iron and nickel components of the stainless steel. These indicate that selenium at levels ranging from greater than or equal to about 18 atomic % on a metal surface, particularly a steel surface, provide for inhibition or prevention of filamentous coke formation. Further, the results indicate that protective levels of selenium on metal surfaces can be provided by exposure of the surfaces to low levels of organoselenium compounds (down to 1 ppm selenium) for relatively short times (1-6 hrs). The use of low levels of organoselenium compounds is preferred to reduce cost and any hazards associated with the use of the additive.
- Those of ordinary skill in the art will appreciate that procedures, techniques, additives, reactors and hydrocarbon mixtures and fuels other than those specifically disclosed herein can be employed in the practice of this invention. For example, a number or organoselenium compounds are known and available in the art and can be used in the practice of this invention.
- All references cited in this specification are incorporated by reference herein in their entirety to the extent that they are not inconsistent with the disclosures herein.
Claims (14)
1. A hydrocarbon feedstock or hydrocarbon fuel composition exhibiting reduced levels of filamentous coke formation at a temperature above about 300° C. which comprises a hydrocarbon feedstock or a hydrocarbon fuel and an organoselenium compound present between about 0.01 ppm selenium and about 1000 ppm selenium with respect to the hydrocarbon.
2. The composition of claim 1 wherein the organoselenium compound is present at a level less than or equal to about 100 ppm selenium.
3. The composition of claim 1 wherein the organoselenium compound is present at a level ranging from about 1 ppm selenium to about 50 ppm selenium.
4. The composition of claim 1 wherein the organoselenium compound is present at a level less than or equal to about 10 ppm selenium.
5. The composition of claim 1 wherein the organoselenium compound is selected from the group consisting of a dialkylselenide, a diarylselenide, a dialkyldiselenide, a diaryldiselenide, an alkylarylselenide, an alkylaryldiselenide, a diaklylselenohalide, an alkylselenol, and an arylselenol.
6. The composition of claim 1 wherein the organoselenium compound is diphenylselenide.
7. The composition of claim 6 wherein the diphenylselenide is present at a level ranging from about 1 ppm selenium to about 30 ppm selenium.
8. The composition of claim 1 wherein the organoselenium compound is selected from the group consisting of diphenylselenide, diphenyldiselenide, dibenzylselenide, or benzylselenol.
9. The composition of claim 1 also exhibiting prevention of filamentous coke formation at a temperature above about 300° C.
10. The composition of claim 1 also exhibiting removal of coke deposits at a temperature above about 300° C.
11. The composition of claim 1 exhibiting reduced levels of filamentous coke formation on a surface comprising metal or alloy, said metal or alloy containing iron or nickel or both.
12. The composition of claim 1 wherein the hydrocarbon fuel is a fuel for an engine, a propulsion system, or a hypersonic aircraft.
13. The composition of claim 1 wherein the hydrocarbon feedstock is a feedstock for a pyrolysis furnace or a reactor.
14. The composition of claim 13 wherein the pyrolysis furnace is a cracking furnace for ethylene production.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/097,324 US20020128161A1 (en) | 2000-08-01 | 2002-03-14 | Materials and methods for suppression of filamentous coke formation |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/629,361 US6482311B1 (en) | 2000-08-01 | 2000-08-01 | Methods for suppression of filamentous coke formation |
US10/097,324 US20020128161A1 (en) | 2000-08-01 | 2002-03-14 | Materials and methods for suppression of filamentous coke formation |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/629,361 Division US6482311B1 (en) | 2000-08-01 | 2000-08-01 | Methods for suppression of filamentous coke formation |
Publications (1)
Publication Number | Publication Date |
---|---|
US20020128161A1 true US20020128161A1 (en) | 2002-09-12 |
Family
ID=24522675
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/629,361 Expired - Fee Related US6482311B1 (en) | 2000-08-01 | 2000-08-01 | Methods for suppression of filamentous coke formation |
US10/097,324 Abandoned US20020128161A1 (en) | 2000-08-01 | 2002-03-14 | Materials and methods for suppression of filamentous coke formation |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/629,361 Expired - Fee Related US6482311B1 (en) | 2000-08-01 | 2000-08-01 | Methods for suppression of filamentous coke formation |
Country Status (1)
Country | Link |
---|---|
US (2) | US6482311B1 (en) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040018295A1 (en) * | 2000-08-24 | 2004-01-29 | Yongxing Qiu | Process for surface modifying substrates and modified substrates resulting therefrom |
CN104059697A (en) * | 2014-06-23 | 2014-09-24 | 浙江大学 | Hydrocarbon fuel composition with high heat sink |
WO2015021126A1 (en) * | 2013-08-06 | 2015-02-12 | The Scripps Research Institute | Conversion of alkanes to organoseleniums and organotelluriums |
US9005700B2 (en) | 2011-10-12 | 2015-04-14 | Novartis Ag | Method for making UV-absorbing ophthalmic lenses |
US10029957B2 (en) * | 2012-08-21 | 2018-07-24 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10160697B2 (en) * | 2012-08-21 | 2018-12-25 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10166524B2 (en) * | 2012-08-21 | 2019-01-01 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10195574B2 (en) * | 2012-08-21 | 2019-02-05 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10214464B2 (en) * | 2012-08-21 | 2019-02-26 | Uop Llc | Steady state high temperature reactor |
US10338408B2 (en) | 2012-12-17 | 2019-07-02 | Novartis Ag | Method for making improved UV-absorbing ophthalmic lenses |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7763766B2 (en) * | 2005-12-22 | 2010-07-27 | Uop Llc | Methanol-to-olefins process with reduced coking |
US20090166259A1 (en) * | 2007-12-28 | 2009-07-02 | Steven Bradley | Metal-based coatings for inhibiting metal catalyzed coke formation in hydrocarbon conversion processes |
US8128887B2 (en) * | 2008-09-05 | 2012-03-06 | Uop Llc | Metal-based coatings for inhibiting metal catalyzed coke formation in hydrocarbon conversion processes |
US8124822B2 (en) * | 2009-03-04 | 2012-02-28 | Uop Llc | Process for preventing metal catalyzed coking |
US9188577B2 (en) * | 2011-03-03 | 2015-11-17 | Phillips 66 Company | Measuring coking propensity |
CN108456539B (en) * | 2017-11-24 | 2019-04-16 | 绵阳油普能源科技有限责任公司 | Hydrocarbonaceous organic matter thermal decomposition process method |
Citations (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1847095A (en) * | 1927-03-11 | 1932-03-01 | Ig Farbenindustrie Ag | Prevention of the formation of carbon in operations carried out with hydrocarbons at an elevated temperature |
US2698512A (en) * | 1949-04-04 | 1955-01-04 | Phillips Petroleum Co | Method of operating ram-jet engines |
US2959915A (en) * | 1955-12-27 | 1960-11-15 | Texaco Inc | Fuel for and method of operating a jet engine |
US3173247A (en) * | 1962-11-30 | 1965-03-16 | Monsanto Res Corp | Operation and cooling of flight vehicles with hydrocarbons |
US3531394A (en) * | 1968-04-25 | 1970-09-29 | Exxon Research Engineering Co | Antifoulant additive for steam-cracking process |
US4003829A (en) * | 1975-02-10 | 1977-01-18 | Atlantic Richfield Company | Method of removing contaminant from a hydrocarbonaceous fluid |
US4024050A (en) * | 1975-01-07 | 1977-05-17 | Nalco Chemical Company | Phosphorous ester antifoulants in crude oil refining |
US4105540A (en) * | 1977-12-15 | 1978-08-08 | Nalco Chemical Company | Phosphorus containing compounds as antifoulants in ethylene cracking furnaces |
US4166046A (en) * | 1977-08-23 | 1979-08-28 | Exxon Research & Engineering Co. | Reforming with multimetallic catalysts |
US4492767A (en) * | 1982-05-05 | 1985-01-08 | Exxon Research And Engineering Co. | Low temperature decoking process for reactivating iridium and selenium containing catalysts |
US4542253A (en) * | 1983-08-11 | 1985-09-17 | Nalco Chemical Company | Use of phosphate and thiophosphate esters neutralized with water soluble amines as ethylene furnace anti-coking antifoulants |
US4544785A (en) * | 1984-04-16 | 1985-10-01 | Atlantic Richfield Company | Methane conversion |
US4551227A (en) * | 1984-04-16 | 1985-11-05 | Phillips Petroleum Company | Antifoulants for thermal cracking processes |
US4555326A (en) * | 1984-05-17 | 1985-11-26 | Betz Laboratories, Inc. | Methods and compositions for boronizing metallic surfaces |
US4680421A (en) * | 1985-09-06 | 1987-07-14 | Betz Laboratories, Inc. | Composition and method for coke retardant during pyrolytic hydrocarbon processing |
US4686201A (en) * | 1984-07-20 | 1987-08-11 | Phillips Petroleum Company | Antifoulants comprising tin antimony and aluminum for thermal cracking processes |
US4692234A (en) * | 1986-04-09 | 1987-09-08 | Phillips Petroleum Company | Antifoulants for thermal cracking processes |
US4729064A (en) * | 1985-03-04 | 1988-03-01 | Adc Telecommunications, Inc. | Modular interconnect block with protector structure |
US4835332A (en) * | 1988-08-31 | 1989-05-30 | Nalco Chemical Company | Use of triphenylphosphine as an ethylene furnace antifoulant |
US4863892A (en) * | 1983-08-16 | 1989-09-05 | Phillips Petroleum Company | Antifoulants comprising tin, antimony and aluminum for thermal cracking processes |
US4962207A (en) * | 1985-09-30 | 1990-10-09 | Bar-Ilan University | Organic derivatives of tellurium and selenium |
US5026846A (en) * | 1988-08-18 | 1991-06-25 | Rhone-Poulenc Sante | Process for the preparation of diaryl sulphides and diaryl selenides |
US5093032A (en) * | 1991-01-03 | 1992-03-03 | Betz Laboratories, Inc. | Use of boron containing compounds and dihydroxybenzenes to reduce coking in coker furnaces |
US5128023A (en) * | 1991-03-27 | 1992-07-07 | Betz Laboratories, Inc. | Method for inhibiting coke formation and deposiiton during pyrolytic hydrocarbon processing |
US5166428A (en) * | 1990-06-08 | 1992-11-24 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Method for preparation of organo-tellurium and selenium compounds |
US5211834A (en) * | 1992-01-31 | 1993-05-18 | Betz Laboratories, Inc. | Method for controlling fouling deposit formation in a liquid hydrocarbonaceous medium using boronated derivatives of polyalkenylsuccinimides |
US5354450A (en) * | 1993-04-07 | 1994-10-11 | Nalco Chemical Company | Phosphorothioate coking inhibitors |
US5360531A (en) * | 1992-12-10 | 1994-11-01 | Nalco Chemical Company | Phosphoric triamide coking inhibitors |
US5442112A (en) * | 1991-10-03 | 1995-08-15 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Preparation of dialkyl tellurium and dialkyl selenium |
US5877379A (en) * | 1996-08-19 | 1999-03-02 | Phillips Petroleum Company | Olefin conversion process involving coke suppressor impregnated catalyst |
US5923944A (en) * | 1995-10-20 | 1999-07-13 | General Electric Company | Fluid containment article for hot hydrocarbon fluid and method of forming a coating thereon |
US5954943A (en) * | 1997-09-17 | 1999-09-21 | Nalco/Exxon Energy Chemicals, L.P. | Method of inhibiting coke deposition in pyrolysis furnaces |
US6652608B1 (en) * | 1994-03-02 | 2003-11-25 | William C. Orr | Fuel compositions exhibiting improved fuel stability |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB275662A (en) | 1926-08-07 | 1928-08-02 | Ig Farbenindustrie Ag | Improvements in the destructive hydrogenation of carbonaceous materials |
GB296752A (en) | 1927-03-03 | 1928-09-03 | Ig Farbenindustrie Ag | Improvements in the method of working with hydrocarbons at high temperatures |
-
2000
- 2000-08-01 US US09/629,361 patent/US6482311B1/en not_active Expired - Fee Related
-
2002
- 2002-03-14 US US10/097,324 patent/US20020128161A1/en not_active Abandoned
Patent Citations (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1847095A (en) * | 1927-03-11 | 1932-03-01 | Ig Farbenindustrie Ag | Prevention of the formation of carbon in operations carried out with hydrocarbons at an elevated temperature |
US2698512A (en) * | 1949-04-04 | 1955-01-04 | Phillips Petroleum Co | Method of operating ram-jet engines |
US2959915A (en) * | 1955-12-27 | 1960-11-15 | Texaco Inc | Fuel for and method of operating a jet engine |
US3173247A (en) * | 1962-11-30 | 1965-03-16 | Monsanto Res Corp | Operation and cooling of flight vehicles with hydrocarbons |
US3531394A (en) * | 1968-04-25 | 1970-09-29 | Exxon Research Engineering Co | Antifoulant additive for steam-cracking process |
US4024050A (en) * | 1975-01-07 | 1977-05-17 | Nalco Chemical Company | Phosphorous ester antifoulants in crude oil refining |
US4003829A (en) * | 1975-02-10 | 1977-01-18 | Atlantic Richfield Company | Method of removing contaminant from a hydrocarbonaceous fluid |
US4166046A (en) * | 1977-08-23 | 1979-08-28 | Exxon Research & Engineering Co. | Reforming with multimetallic catalysts |
US4105540A (en) * | 1977-12-15 | 1978-08-08 | Nalco Chemical Company | Phosphorus containing compounds as antifoulants in ethylene cracking furnaces |
US4492767A (en) * | 1982-05-05 | 1985-01-08 | Exxon Research And Engineering Co. | Low temperature decoking process for reactivating iridium and selenium containing catalysts |
US4542253A (en) * | 1983-08-11 | 1985-09-17 | Nalco Chemical Company | Use of phosphate and thiophosphate esters neutralized with water soluble amines as ethylene furnace anti-coking antifoulants |
US4863892A (en) * | 1983-08-16 | 1989-09-05 | Phillips Petroleum Company | Antifoulants comprising tin, antimony and aluminum for thermal cracking processes |
US4544785A (en) * | 1984-04-16 | 1985-10-01 | Atlantic Richfield Company | Methane conversion |
US4551227A (en) * | 1984-04-16 | 1985-11-05 | Phillips Petroleum Company | Antifoulants for thermal cracking processes |
US4555326A (en) * | 1984-05-17 | 1985-11-26 | Betz Laboratories, Inc. | Methods and compositions for boronizing metallic surfaces |
US4686201A (en) * | 1984-07-20 | 1987-08-11 | Phillips Petroleum Company | Antifoulants comprising tin antimony and aluminum for thermal cracking processes |
US4729064A (en) * | 1985-03-04 | 1988-03-01 | Adc Telecommunications, Inc. | Modular interconnect block with protector structure |
US4680421A (en) * | 1985-09-06 | 1987-07-14 | Betz Laboratories, Inc. | Composition and method for coke retardant during pyrolytic hydrocarbon processing |
US4962207A (en) * | 1985-09-30 | 1990-10-09 | Bar-Ilan University | Organic derivatives of tellurium and selenium |
US4692234A (en) * | 1986-04-09 | 1987-09-08 | Phillips Petroleum Company | Antifoulants for thermal cracking processes |
US5026846A (en) * | 1988-08-18 | 1991-06-25 | Rhone-Poulenc Sante | Process for the preparation of diaryl sulphides and diaryl selenides |
US4835332A (en) * | 1988-08-31 | 1989-05-30 | Nalco Chemical Company | Use of triphenylphosphine as an ethylene furnace antifoulant |
US5166428A (en) * | 1990-06-08 | 1992-11-24 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Method for preparation of organo-tellurium and selenium compounds |
US5093032A (en) * | 1991-01-03 | 1992-03-03 | Betz Laboratories, Inc. | Use of boron containing compounds and dihydroxybenzenes to reduce coking in coker furnaces |
US5330970A (en) * | 1991-03-27 | 1994-07-19 | Betz Laboratories, Inc. | Composition and method for inhibiting coke formation and deposition during pyrolytic hydrocarbon processing |
US5128023A (en) * | 1991-03-27 | 1992-07-07 | Betz Laboratories, Inc. | Method for inhibiting coke formation and deposiiton during pyrolytic hydrocarbon processing |
US5442112A (en) * | 1991-10-03 | 1995-08-15 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Preparation of dialkyl tellurium and dialkyl selenium |
US5211834A (en) * | 1992-01-31 | 1993-05-18 | Betz Laboratories, Inc. | Method for controlling fouling deposit formation in a liquid hydrocarbonaceous medium using boronated derivatives of polyalkenylsuccinimides |
US5360531A (en) * | 1992-12-10 | 1994-11-01 | Nalco Chemical Company | Phosphoric triamide coking inhibitors |
US5354450A (en) * | 1993-04-07 | 1994-10-11 | Nalco Chemical Company | Phosphorothioate coking inhibitors |
US6652608B1 (en) * | 1994-03-02 | 2003-11-25 | William C. Orr | Fuel compositions exhibiting improved fuel stability |
US5923944A (en) * | 1995-10-20 | 1999-07-13 | General Electric Company | Fluid containment article for hot hydrocarbon fluid and method of forming a coating thereon |
US5877379A (en) * | 1996-08-19 | 1999-03-02 | Phillips Petroleum Company | Olefin conversion process involving coke suppressor impregnated catalyst |
US5954943A (en) * | 1997-09-17 | 1999-09-21 | Nalco/Exxon Energy Chemicals, L.P. | Method of inhibiting coke deposition in pyrolysis furnaces |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7040756B2 (en) | 2000-08-24 | 2006-05-09 | Novartis Ag | Process for surface modifying substrates and modified substrates resulting therefrom |
US20040018295A1 (en) * | 2000-08-24 | 2004-01-29 | Yongxing Qiu | Process for surface modifying substrates and modified substrates resulting therefrom |
US9005700B2 (en) | 2011-10-12 | 2015-04-14 | Novartis Ag | Method for making UV-absorbing ophthalmic lenses |
US10195574B2 (en) * | 2012-08-21 | 2019-02-05 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10029957B2 (en) * | 2012-08-21 | 2018-07-24 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10160697B2 (en) * | 2012-08-21 | 2018-12-25 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10166524B2 (en) * | 2012-08-21 | 2019-01-01 | Uop Llc | Methane conversion apparatus and process using a supersonic flow reactor |
US10214464B2 (en) * | 2012-08-21 | 2019-02-26 | Uop Llc | Steady state high temperature reactor |
US10338408B2 (en) | 2012-12-17 | 2019-07-02 | Novartis Ag | Method for making improved UV-absorbing ophthalmic lenses |
WO2015021126A1 (en) * | 2013-08-06 | 2015-02-12 | The Scripps Research Institute | Conversion of alkanes to organoseleniums and organotelluriums |
US9505714B2 (en) | 2013-08-06 | 2016-11-29 | The Scripps Research Institute | Conversion of alkanes to organoseleniums and organotelluriums |
EA032269B1 (en) * | 2013-08-06 | 2019-05-31 | Дзе Скриппс Рисерч Инститьют | Conversion of alkanes to organoseleniums and organotelluriums |
CN104059697A (en) * | 2014-06-23 | 2014-09-24 | 浙江大学 | Hydrocarbon fuel composition with high heat sink |
Also Published As
Publication number | Publication date |
---|---|
US6482311B1 (en) | 2002-11-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6482311B1 (en) | Methods for suppression of filamentous coke formation | |
Towfighi et al. | Coke formation mechanisms and coke inhibiting methods in pyrolysis furnaces | |
US4410418A (en) | Method for reducing carbon formation in a thermal cracking process | |
US5298091A (en) | Inhibiting coke formation by heat treating in nitrogen atmosphere | |
JPS6137894A (en) | Method for lowering formation of coke in thermal cracking process and coke formation reducing anti-staining composition | |
JPH0762134B2 (en) | Pyrolysis method for gas streams containing hydrocarbons | |
CN101724827B (en) | Method for reducing ethylene cracking furnace tube coking and improving ethylene selectivity | |
US5128023A (en) | Method for inhibiting coke formation and deposiiton during pyrolytic hydrocarbon processing | |
JPS6279292A (en) | Prevention of corrosion, production of carbide and settlement on hydrocarbon treatment | |
AU660867B2 (en) | Phosphorothioate coking inhibitors | |
CA1246099A (en) | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon processing | |
US5922192A (en) | Apparatus and process for reducing coking of heat exchange surfaces | |
KR100277412B1 (en) | Ethylene Furnace Contaminants | |
US5733438A (en) | Coke inhibitors for pyrolysis furnaces | |
Bach et al. | Transfer-line heat exchanger fouling during pyrolysis of hydrocarbons. 1. Deposits from dry cracked gases | |
KR100300891B1 (en) | Prevention method of thermal decomposition deposit of fuel and coating product for high temperature hydrocarbon fluid | |
US5039391A (en) | Use of boron containing compounds and dihydroxybenzenes to reduce coking in coker furnaces | |
EP0839782B1 (en) | Process for the inhibition of coke formation in pyrolysis furnaces | |
EP0852256B1 (en) | A method for inhibiting coke formation with phosphonate/thiophosphonate | |
US20060182888A1 (en) | Modifying steel surfaces to mitigate fouling and corrosion | |
US5093032A (en) | Use of boron containing compounds and dihydroxybenzenes to reduce coking in coker furnaces | |
US5254183A (en) | Gas turbine elements with coke resistant surfaces | |
US5849176A (en) | Process for producing thermally cracked products from hydrocarbons | |
CN102251225A (en) | Treatment method and coating pretreatment liquid for reducing coking of furnace tube of hydrocarbon cracking furnace | |
JP3523339B2 (en) | Method for preventing the deposition of pyrolysis products of hydrocarbon fluids and products coated with metal surfaces |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: TDA RESEARCH, INC., COLORADO Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WICKHAM, DAVID T.;ENGEL, JEFFREY R.;KARPUK, MICHAEL E.;REEL/FRAME:012817/0927 Effective date: 20020318 |
|
AS | Assignment |
Owner name: AIR FORCE, UNITED STATES, OHIO Free format text: CONFIRMATORY LICENSE;ASSIGNOR:TDA RESEARCH, INC.;REEL/FRAME:013563/0247 Effective date: 20021113 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |