CA1248119A - Preparation of alkylene carbonates - Google Patents
Preparation of alkylene carbonatesInfo
- Publication number
- CA1248119A CA1248119A CA000441124A CA441124A CA1248119A CA 1248119 A CA1248119 A CA 1248119A CA 000441124 A CA000441124 A CA 000441124A CA 441124 A CA441124 A CA 441124A CA 1248119 A CA1248119 A CA 1248119A
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- CA
- Canada
- Prior art keywords
- alkylene
- water
- carbon dioxide
- carbonate
- catalyst
- 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.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D321/00—Heterocyclic compounds containing rings having two oxygen atoms as the only ring hetero atoms, not provided for by groups C07D317/00 - C07D319/00
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
- C07D319/04—1,3-Dioxanes; Hydrogenated 1,3-dioxanes
- C07D319/06—1,3-Dioxanes; Hydrogenated 1,3-dioxanes not condensed with other rings
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
TITLE
PREPARATION OF ALKYLENE CARBONATES
ABSTRACT
Alkylene carbonates, particularly ethylene carbonate, are prepared by the reaction of an alkylene oxide with carbon dioxide in the presence of a catalyst at temperatures ranging upwards from 20°C, particularly temperatures above about 90°C, preferably 90-170°C. The conversion of alkylene oxide to alkylene carbonate can be carried out in the presence of water while minimizing the undesirable hydrolysis of the carbonate to the correspond-ing alkylene glycol and formation of higher glycols. This is achieved by maintaining the water to alkylene oxide molar ratio and the carbon dioxide to alkylene oxide ratio within the stated limits and adjusting the carbon dioxide partial pressure to provide the desired selectivity to alkylene carbonate.
PREPARATION OF ALKYLENE CARBONATES
ABSTRACT
Alkylene carbonates, particularly ethylene carbonate, are prepared by the reaction of an alkylene oxide with carbon dioxide in the presence of a catalyst at temperatures ranging upwards from 20°C, particularly temperatures above about 90°C, preferably 90-170°C. The conversion of alkylene oxide to alkylene carbonate can be carried out in the presence of water while minimizing the undesirable hydrolysis of the carbonate to the correspond-ing alkylene glycol and formation of higher glycols. This is achieved by maintaining the water to alkylene oxide molar ratio and the carbon dioxide to alkylene oxide ratio within the stated limits and adjusting the carbon dioxide partial pressure to provide the desired selectivity to alkylene carbonate.
Description
i ~, L~ 19 Prior Art The invention relates to a process for the pre-paration of alk~lene carbonates by the reaction of the corresponding alkylene oxide with carbon dioxide. Such reactions are well known in the art. Alkylene carbonates are useful as solvents or as a source of the corresponding glycols~ They are considered to be intermediates in the reaction of ethylene oxide with water to form ethylene glycol in the presence of carbon dioxide, while avoiding the inefficiency associated with the conventional hydration process.
Several processes have been disclosed for a single step hydration of alkylene oxides to glycols in the presence oF a catalyst and carbon dioxide. Such processes are said to make possible the reduction in the amount of water used. The removal of excess water is a major expense in the conventional hydration process. The carbon dioxide is not consumed in the process, but it has been suggested that the hydration proceeds via the alkylene carbonate as an intermediate compound.
U.S. 3,922,314 discloses a process for the hydra-tion of ethylene oxide to ethylene glycol which uses no catalyst, but operates with an aqueous ethylene oxide solution containing at least 8 wt% ethylene oxide and at least 0.1 wt ~ carbon dioxide.
A catalytic process is described in British Patent 1,177,877 (or U.S. 3,629,343~. Alkylene oxides are hydrated to the glycols a~ temperatures of 80-220UC and pres~ures of 10-180 atmospheres in the presen~e of a halide catalyst. Preferred are alXali metal or quaternary ammonium halides, particularly bromides and iodides.
Alkali metal hydroxides, carbonates, or bicarbonates were said to be b~neficial.
A similar process is discussed in U.S. 4,160,116 where quaternary phosphonium halides, pre~erably the iodides and bromides were used to catalyze the hydration o~ alkylene oxides in the presence of carbon dioxide. The ~Z4~
temperature is 50-200-C and the pressure 3-50 kg/cm2.
Still another such process is disclosed in published Japanese Patent Application 81-45426, in which molybdenum and/or tungsten compounds are combined with known catalysts such as alkali metal halides, quaternary ammonium or phosphonium salts, organic halides, and organic amines. The reaction is stated to be carried out at 20-250C and 0-30 kg/cm2 gauge.
The formation of alkylene carbonates, as opposed to the hydration of alkylene oxides to glycols, takes place in the prior art to be discussed with no water present. Catalysts and reaction conditions similar to those described above for the hydration of alkylene oxides have been disclosed to be useful.
In U.S. 2,667,497 magnesium or calcium halides were used at 150-250-C and 500-2000 psi to produce alkylene ~arbonates from the corresponding oxides.
U.S. 2,766,258 discloses the use of qùaternary ammonium hydroxides, carbonates, and bicarbonates to catalyze the reaction of alkylene oxides with carbon dioxide. The reaction was carried out at temperatures between 100-225'C and pressures of 300-5000psig.
- The quaternary ammonium halides were used by the patentees in U.S. 2,773,070 at temperatures of 100-225~C
and pressures greater than 300 psi.
Amines were the cataIyst used for the reaction by the patentees in U.S. 2,773,881. The reaction was carried out at 100-400~C and more than 500 psi.
Three patents issued to the same assignee, i~oO
U.S. 2,994,705; ~,994,704; and 2,993,908 disclose subs~an-tially the same conditions, 93-26~C and 8-212 kg/cm2 gauge, with organic phosphonium halides, organic sulfonium halides, and urea hydrohalides given as catalysts for the preparation of alkylene carbonates from the corresponding oxirane compound.
Hydrazine or a halide salt thereof was used to .
catalyze the reaction by the patentees in U.S. 3,535,341 a~ temperatures of 100-250-C. An anion exchange resin containing quaternary ammonium groups was disclosed in U.S. 4,233,221 as useful for vapor-phase reaction.
Organic antimony halides were shown in published Japanese patent application 80-122,776 to make possible the formation of alkylene carbonates, at room temperature to 120-C, in a water-free mixture.
In commonly-assigned Cdn. patent application ; 10 Serial No. 416,748 filed December l, 1982, it was shown that the reaction of alkylene oxides to the corresponding carbonates can be carried out with known catalysts at lower temperatures than heretofore used in the art and even in the presence of substantial amounts of water. The ~ 15 hydrolysis of the carbonates to glycols can be minimized - and the principal product is the carbonate. I have now : found that higher temperatures than were previously shown to be useable may be employed, without producing large amounts of glycols, particularly higher glycols provided that the molar ratio of carbon dioxide to alkylene oxide is maintained above about 1/1 and the partial pressure of carbo~ dioxide is abova a preselected value.
Summary of the Disclosure Alkylene oxides may be reacted with carbon di-oxide to form alkylene carbonates in the presence of an effective amount of suitable catalysts at temperatures upwards from 20C, particularly above 90-C, preferably 90 -~ to 170C and in the presence of water, when the molar ratio of carbon dioxide to alkylene oxide is at least 1/1 and the partial pressure of carbon dioxide is sufficient ;~ to provide the desired selectivity to alkylene carbonate.
The pressure at which the reaction is carried out is in the range of about 10-200 kg/cm2 gauge, preferably 30 to 80 kg/cm2 gauge. Suitable catalys~s include a ` - 35 member or members of th~ group consisting of quaternary organic ammonium and phosphonium halides, o~anic - sulfonium halidest and organic antimony halides, ,.,~,. .`;'`
~-2i.~B~9 particularly methyl triphenyl phosphonium iodide, tetra-ethyl ammonium bromide, and tetraphenyl an~imony bromide.
The corresponding carboxylat~s may also be used. The quantity of catalyst used is generally up to about 0.10 mols per mol of alkylene oxide, preferably 0.001 to 0.02.
Contrary to previous expectations, water may be present in substantial amounts, even exceeding th~se used in prior art hydration processes, since the formation of large amsunts of glycol, and particularly the higher glycols, is avoided by maintaining the molar ratio of carbon dioxide to alkylene oxide above 1/1 and the partial pressure of carbon dioxide is adjusted to provide the selectivity to alkylene carbonate desired. Useful mol ratios of water to alkylene oxide are above about 0.01/1 15 and preferably from about 0.1j1 to about 4/1, most pre~erably from O.1/1 to 2/1, although higher amounts of water are not excluded. Adding water also increases the rate of carbona~e formation.
DESCRIPTION OF ~HE PREFERRED EMBODIMEN~S
Heretofore, those familiar with the reaction of alkylene oxides with carbon dioxide to form alkylene carbonates have carried out the reaction at temperatures generally in the range of 100-300C, particularly about 150~225C. Although it was not generally dis~ussed in ; 25 detail, it will be seen from prior art disclosures that the reaction was carried out in the practical absence of water. For Example, in U.S. 4,233,221 the reactants were dried by condensation of water after compression so that the moisture Ievel of the reactant gases was quite low, estimated to be about 0.2 mol percent! Since the hydroly-sis of carbonates was ~nown to take place at elevated temperatures and with catalysts also us~ful for the direct hydrolysis of alXylene oxides to glycols, it seems proba~le that prior workers in the ar~ avoided water if only the carbonate was to be produced. Otherwise, hydrolysis to the glycol could be expected.
. . .
.~ ~A
83~9 Previously, it was disclosed in Cdn. application Serial No. 416,748 that when the reaction of alkylene oxides with carbon dioxide is undertaken at temperatures substantially lower than ta~ght by the prior art, that the presence of water can be not only tolerated, but actually may be beneficial in some instances. ~lkylene carbonates can be prepared with minimal losses by hydrolysis to the glycols. Such a process has application to a stream combining carbon dioxide, ethylene oxide, and water obtained by extraction of ethylene oxide from a dilute aqueous solu~ion with near-critical or super~ritical carbon dioxide. ~owever, I have now discovered that higher temperatures, i.e. above 90UC, may be used, still without formation of large amounts of glycols, especially the higher glycols, provided that the molar ratio of carbon dioxide to al~ylene oxide is maintained above about 1/1 and the partial pressure of carbon dioxide is sufficient to provide the desired selectivity to the alkylene carbonate.
The reaction may be carried out at a wide range of temperatures, especially 90 to 170~C. Lower tempera-tures disclosed in the commonly-assigned application may be used as well, but are not preferred since the rate of alkylene carbonate formation is higher at temperatures above 90~C.
~ Total pressure is not an especially ~ritical ; variable in the reaction. Typicallv~ it will be in the range of about 10-200 kg/cm2 gauge. However, the partial pressure of carbon dioxide has been found to be very important.
~- The molar ratio of carbon dioxide to alkylene ; ~ oxide must be at least about 1/1 and may range from 1/1 to 100/1o Usually a ratio greater than 1/1 would be selec-- ted, preferably 1/1 to 10/1. Where the process of ~he invention is associated with the extraction oP al~ylene ; oxide by (near~ super-critical carbon dioxide the ratio may be as high as 40/1-60/1.
124t ~ . .
It is of particular importance that water need not hydrolyze alkylene carbonates to the glycols, particularly the higher glycols, under conditions found suitable for the pro~ess of the invention. At tempera-tures above about 90~C, the amount of glycols produced wasexpected in the earlier application to increase until eventually the~process would no longer produce carbonates, but glycols instead, as disclosed in the patents mentioned earlier. I have now found that the formation of glycols can be restrained by providing sufficient carbon dioxide.
One skilled in the art wo~ld not have predicted such a result because with water present and at the temperatures here employed, the prior art teaches that water would hydrolyze the alkylene oxide to glycol. It was thought that the reaction proceeded via formation of the alkylene carbonate as an intermediate compound. For example see U.S. Patents 4,237,324 and 4,117,250, along with U.S.
3,629,343 to Levin, et al. The alkylene carbonate was apparently not observed in any significant quantities, since quantitative yields of glycols were reported.
The amount of water which can- be tolerated, has some relation to the other process conditions and the selectivity to alkylene carbonate formed. Amounts in excess of those useful for the direct hydration of alky-lene oxides to glycols have been demonstrated at lowertemperatures, as will be seen in subsequent examples. At temperatures above about 90C, particularly 90-170C, amounts of water up to about mol ratios of 4/1 based on alXylene oxide are preferred, most preferably 0.1/1 to
Several processes have been disclosed for a single step hydration of alkylene oxides to glycols in the presence oF a catalyst and carbon dioxide. Such processes are said to make possible the reduction in the amount of water used. The removal of excess water is a major expense in the conventional hydration process. The carbon dioxide is not consumed in the process, but it has been suggested that the hydration proceeds via the alkylene carbonate as an intermediate compound.
U.S. 3,922,314 discloses a process for the hydra-tion of ethylene oxide to ethylene glycol which uses no catalyst, but operates with an aqueous ethylene oxide solution containing at least 8 wt% ethylene oxide and at least 0.1 wt ~ carbon dioxide.
A catalytic process is described in British Patent 1,177,877 (or U.S. 3,629,343~. Alkylene oxides are hydrated to the glycols a~ temperatures of 80-220UC and pres~ures of 10-180 atmospheres in the presen~e of a halide catalyst. Preferred are alXali metal or quaternary ammonium halides, particularly bromides and iodides.
Alkali metal hydroxides, carbonates, or bicarbonates were said to be b~neficial.
A similar process is discussed in U.S. 4,160,116 where quaternary phosphonium halides, pre~erably the iodides and bromides were used to catalyze the hydration o~ alkylene oxides in the presence of carbon dioxide. The ~Z4~
temperature is 50-200-C and the pressure 3-50 kg/cm2.
Still another such process is disclosed in published Japanese Patent Application 81-45426, in which molybdenum and/or tungsten compounds are combined with known catalysts such as alkali metal halides, quaternary ammonium or phosphonium salts, organic halides, and organic amines. The reaction is stated to be carried out at 20-250C and 0-30 kg/cm2 gauge.
The formation of alkylene carbonates, as opposed to the hydration of alkylene oxides to glycols, takes place in the prior art to be discussed with no water present. Catalysts and reaction conditions similar to those described above for the hydration of alkylene oxides have been disclosed to be useful.
In U.S. 2,667,497 magnesium or calcium halides were used at 150-250-C and 500-2000 psi to produce alkylene ~arbonates from the corresponding oxides.
U.S. 2,766,258 discloses the use of qùaternary ammonium hydroxides, carbonates, and bicarbonates to catalyze the reaction of alkylene oxides with carbon dioxide. The reaction was carried out at temperatures between 100-225'C and pressures of 300-5000psig.
- The quaternary ammonium halides were used by the patentees in U.S. 2,773,070 at temperatures of 100-225~C
and pressures greater than 300 psi.
Amines were the cataIyst used for the reaction by the patentees in U.S. 2,773,881. The reaction was carried out at 100-400~C and more than 500 psi.
Three patents issued to the same assignee, i~oO
U.S. 2,994,705; ~,994,704; and 2,993,908 disclose subs~an-tially the same conditions, 93-26~C and 8-212 kg/cm2 gauge, with organic phosphonium halides, organic sulfonium halides, and urea hydrohalides given as catalysts for the preparation of alkylene carbonates from the corresponding oxirane compound.
Hydrazine or a halide salt thereof was used to .
catalyze the reaction by the patentees in U.S. 3,535,341 a~ temperatures of 100-250-C. An anion exchange resin containing quaternary ammonium groups was disclosed in U.S. 4,233,221 as useful for vapor-phase reaction.
Organic antimony halides were shown in published Japanese patent application 80-122,776 to make possible the formation of alkylene carbonates, at room temperature to 120-C, in a water-free mixture.
In commonly-assigned Cdn. patent application ; 10 Serial No. 416,748 filed December l, 1982, it was shown that the reaction of alkylene oxides to the corresponding carbonates can be carried out with known catalysts at lower temperatures than heretofore used in the art and even in the presence of substantial amounts of water. The ~ 15 hydrolysis of the carbonates to glycols can be minimized - and the principal product is the carbonate. I have now : found that higher temperatures than were previously shown to be useable may be employed, without producing large amounts of glycols, particularly higher glycols provided that the molar ratio of carbon dioxide to alkylene oxide is maintained above about 1/1 and the partial pressure of carbo~ dioxide is abova a preselected value.
Summary of the Disclosure Alkylene oxides may be reacted with carbon di-oxide to form alkylene carbonates in the presence of an effective amount of suitable catalysts at temperatures upwards from 20C, particularly above 90-C, preferably 90 -~ to 170C and in the presence of water, when the molar ratio of carbon dioxide to alkylene oxide is at least 1/1 and the partial pressure of carbon dioxide is sufficient ;~ to provide the desired selectivity to alkylene carbonate.
The pressure at which the reaction is carried out is in the range of about 10-200 kg/cm2 gauge, preferably 30 to 80 kg/cm2 gauge. Suitable catalys~s include a ` - 35 member or members of th~ group consisting of quaternary organic ammonium and phosphonium halides, o~anic - sulfonium halidest and organic antimony halides, ,.,~,. .`;'`
~-2i.~B~9 particularly methyl triphenyl phosphonium iodide, tetra-ethyl ammonium bromide, and tetraphenyl an~imony bromide.
The corresponding carboxylat~s may also be used. The quantity of catalyst used is generally up to about 0.10 mols per mol of alkylene oxide, preferably 0.001 to 0.02.
Contrary to previous expectations, water may be present in substantial amounts, even exceeding th~se used in prior art hydration processes, since the formation of large amsunts of glycol, and particularly the higher glycols, is avoided by maintaining the molar ratio of carbon dioxide to alkylene oxide above 1/1 and the partial pressure of carbon dioxide is adjusted to provide the selectivity to alkylene carbonate desired. Useful mol ratios of water to alkylene oxide are above about 0.01/1 15 and preferably from about 0.1j1 to about 4/1, most pre~erably from O.1/1 to 2/1, although higher amounts of water are not excluded. Adding water also increases the rate of carbona~e formation.
DESCRIPTION OF ~HE PREFERRED EMBODIMEN~S
Heretofore, those familiar with the reaction of alkylene oxides with carbon dioxide to form alkylene carbonates have carried out the reaction at temperatures generally in the range of 100-300C, particularly about 150~225C. Although it was not generally dis~ussed in ; 25 detail, it will be seen from prior art disclosures that the reaction was carried out in the practical absence of water. For Example, in U.S. 4,233,221 the reactants were dried by condensation of water after compression so that the moisture Ievel of the reactant gases was quite low, estimated to be about 0.2 mol percent! Since the hydroly-sis of carbonates was ~nown to take place at elevated temperatures and with catalysts also us~ful for the direct hydrolysis of alXylene oxides to glycols, it seems proba~le that prior workers in the ar~ avoided water if only the carbonate was to be produced. Otherwise, hydrolysis to the glycol could be expected.
. . .
.~ ~A
83~9 Previously, it was disclosed in Cdn. application Serial No. 416,748 that when the reaction of alkylene oxides with carbon dioxide is undertaken at temperatures substantially lower than ta~ght by the prior art, that the presence of water can be not only tolerated, but actually may be beneficial in some instances. ~lkylene carbonates can be prepared with minimal losses by hydrolysis to the glycols. Such a process has application to a stream combining carbon dioxide, ethylene oxide, and water obtained by extraction of ethylene oxide from a dilute aqueous solu~ion with near-critical or super~ritical carbon dioxide. ~owever, I have now discovered that higher temperatures, i.e. above 90UC, may be used, still without formation of large amounts of glycols, especially the higher glycols, provided that the molar ratio of carbon dioxide to al~ylene oxide is maintained above about 1/1 and the partial pressure of carbon dioxide is sufficient to provide the desired selectivity to the alkylene carbonate.
The reaction may be carried out at a wide range of temperatures, especially 90 to 170~C. Lower tempera-tures disclosed in the commonly-assigned application may be used as well, but are not preferred since the rate of alkylene carbonate formation is higher at temperatures above 90~C.
~ Total pressure is not an especially ~ritical ; variable in the reaction. Typicallv~ it will be in the range of about 10-200 kg/cm2 gauge. However, the partial pressure of carbon dioxide has been found to be very important.
~- The molar ratio of carbon dioxide to alkylene ; ~ oxide must be at least about 1/1 and may range from 1/1 to 100/1o Usually a ratio greater than 1/1 would be selec-- ted, preferably 1/1 to 10/1. Where the process of ~he invention is associated with the extraction oP al~ylene ; oxide by (near~ super-critical carbon dioxide the ratio may be as high as 40/1-60/1.
124t ~ . .
It is of particular importance that water need not hydrolyze alkylene carbonates to the glycols, particularly the higher glycols, under conditions found suitable for the pro~ess of the invention. At tempera-tures above about 90~C, the amount of glycols produced wasexpected in the earlier application to increase until eventually the~process would no longer produce carbonates, but glycols instead, as disclosed in the patents mentioned earlier. I have now found that the formation of glycols can be restrained by providing sufficient carbon dioxide.
One skilled in the art wo~ld not have predicted such a result because with water present and at the temperatures here employed, the prior art teaches that water would hydrolyze the alkylene oxide to glycol. It was thought that the reaction proceeded via formation of the alkylene carbonate as an intermediate compound. For example see U.S. Patents 4,237,324 and 4,117,250, along with U.S.
3,629,343 to Levin, et al. The alkylene carbonate was apparently not observed in any significant quantities, since quantitative yields of glycols were reported.
The amount of water which can- be tolerated, has some relation to the other process conditions and the selectivity to alkylene carbonate formed. Amounts in excess of those useful for the direct hydration of alky-lene oxides to glycols have been demonstrated at lowertemperatures, as will be seen in subsequent examples. At temperatures above about 90C, particularly 90-170C, amounts of water up to about mol ratios of 4/1 based on alXylene oxide are preferred, most preferably 0.1/1 to
2/1. The presence of water has a beneficial effect on the rate of carbonate reaction, contrary to what might be expected. ~his effect may be more pronounced in associa-tion with certain catalysts, particularly those in which the bond between the halide atom and the rest~of the
3~ molecule is ionic, rather than covalent in nature, such as with the preferred quaternary phosphonium halides.
The catalysts found useful in the process of the invention include many of those known ln the art. Broad classes of compounds which may be useful include one or more members of the group consisting of organic quaternary ammonium or phosphonium halides, organic sulfonium halides, and organic antimony halides. The corresponding carboxylates also may be used. Examples of compounds which may be employed are the following ammonium com-pounds, tetraethyl ammonium bromide, and tetra ethyl ammoniurn iodide. Specific phosphonium compounds include methyl triphenyl phosphonium iodide and methyl triphenyl phosphonium bromide. Sulfonium compounds may include trimethyl sulfonium iodide and trimethyl sulfonium bromide. Antimony compounds have been found quite effective when no water is present~ but appear to be adversely affected when water is included. Typical compounds are tetraphenyl antimony bromide and triphenyl antimony dichloride. Particularly preferred catalysts when water is present are methyl triphenyl phosphonium iodide and tetraethyl ammonium bromide. Of the halides, bromides and iodides are preferred.
The amount of catalyst will be similar to that used in other processes, up to about 0.1 mols of the catalyst per mol of alkylene oxide may be used, preferably 0.001-0.02 mols per mol, although larger or smaller amounts are not intended to be excluded.
While other wor~ers in the field have indicated that relatively high temperatures of 100~C or higher would be used either to form alkylene carbonates when no water was present, or alkylene glycols when water was available to hydrolyze alkylene oxides, the present process employs temperatures ranging upward from about 20~C, preferably above 90~C, particularly 90-170JC.
The reaction to form carbonates may be carried out in the presence of substantial amounts of water. At higher temperatures typical of the prior art, glycols would be expected when water is present and, in fact, this is the basis for several processes as previously discus-sed. As will be seen, even when operating at relatively high temperatures, it is possible to minimize hydrolysis and to form carbonates instead, by control of the molar ratio o~ carbon dioxide to alkylene oxide and the partial pressure of carbon dioxide.
The firs~ five examples which follow are repeated from co-pending and commonly-assigned Canadian application Serial No. 416,748 and illustrate formation of alkylene carbonates at temperatures below 90C.
Ex~mple 1 Operating below 90C without water ~resent ~ sample of the c~talyst being tested is intro-duced to a 130 cc bomb produced by the Parr In~trument Company. Samples of ethylene oxide and carbon dioxide are charged at -78~C by immersing the bomb in a dry-ice/
acetone bath. The bomb is then closed and placed in a 35'C bath so that the internal temperature of the bomb is increased to 30~C and the reaction proceeds. Agitation is via a magnetically driven disk. After a suitable period of time, the bomb is removed from the bath and the con-tents analyzed. The results of a number of such tests are shown in Table A below.
25Table A
milli- Max.
- Feed, mols_ Pressure EC**
Test Catalyst, 3ath Time, kg/cm2 EO* Sel.
No. EO* CO2 gms*~* _ C hrs gauge Conv.
30 1 13.6 681 a 0.1456 36 19.5 28.1 51.7 2 13.6 681 b 0.4385 36 19.5 29.5 55 1Ç
3 18.2 681 c 0.3654 32 19.S 18.3 94 88.2
The catalysts found useful in the process of the invention include many of those known ln the art. Broad classes of compounds which may be useful include one or more members of the group consisting of organic quaternary ammonium or phosphonium halides, organic sulfonium halides, and organic antimony halides. The corresponding carboxylates also may be used. Examples of compounds which may be employed are the following ammonium com-pounds, tetraethyl ammonium bromide, and tetra ethyl ammoniurn iodide. Specific phosphonium compounds include methyl triphenyl phosphonium iodide and methyl triphenyl phosphonium bromide. Sulfonium compounds may include trimethyl sulfonium iodide and trimethyl sulfonium bromide. Antimony compounds have been found quite effective when no water is present~ but appear to be adversely affected when water is included. Typical compounds are tetraphenyl antimony bromide and triphenyl antimony dichloride. Particularly preferred catalysts when water is present are methyl triphenyl phosphonium iodide and tetraethyl ammonium bromide. Of the halides, bromides and iodides are preferred.
The amount of catalyst will be similar to that used in other processes, up to about 0.1 mols of the catalyst per mol of alkylene oxide may be used, preferably 0.001-0.02 mols per mol, although larger or smaller amounts are not intended to be excluded.
While other wor~ers in the field have indicated that relatively high temperatures of 100~C or higher would be used either to form alkylene carbonates when no water was present, or alkylene glycols when water was available to hydrolyze alkylene oxides, the present process employs temperatures ranging upward from about 20~C, preferably above 90~C, particularly 90-170JC.
The reaction to form carbonates may be carried out in the presence of substantial amounts of water. At higher temperatures typical of the prior art, glycols would be expected when water is present and, in fact, this is the basis for several processes as previously discus-sed. As will be seen, even when operating at relatively high temperatures, it is possible to minimize hydrolysis and to form carbonates instead, by control of the molar ratio o~ carbon dioxide to alkylene oxide and the partial pressure of carbon dioxide.
The firs~ five examples which follow are repeated from co-pending and commonly-assigned Canadian application Serial No. 416,748 and illustrate formation of alkylene carbonates at temperatures below 90C.
Ex~mple 1 Operating below 90C without water ~resent ~ sample of the c~talyst being tested is intro-duced to a 130 cc bomb produced by the Parr In~trument Company. Samples of ethylene oxide and carbon dioxide are charged at -78~C by immersing the bomb in a dry-ice/
acetone bath. The bomb is then closed and placed in a 35'C bath so that the internal temperature of the bomb is increased to 30~C and the reaction proceeds. Agitation is via a magnetically driven disk. After a suitable period of time, the bomb is removed from the bath and the con-tents analyzed. The results of a number of such tests are shown in Table A below.
25Table A
milli- Max.
- Feed, mols_ Pressure EC**
Test Catalyst, 3ath Time, kg/cm2 EO* Sel.
No. EO* CO2 gms*~* _ C hrs gauge Conv.
30 1 13.6 681 a 0.1456 36 19.5 28.1 51.7 2 13.6 681 b 0.4385 36 19.5 29.5 55 1Ç
3 18.2 681 c 0.3654 32 19.S 18.3 94 88.2
4 15.9 681 d 0.3064 37 18.5 15.5 3?.7 S 18.2 1022 e 0.3981 38 19.5 30.6 51.1 ----35 6 22.7 1022 f 0.2406 3B 19.5 78.1 77.9 50.4 :.
.-.
g It has been discovered that water may be present without formation of significant amounts of glycols, provided that the temperature is sufficiently low.
Surprisingly, it has been found that water has a beneficial effect on the selectivity to the carbonate wi~h some catalysts, while with others the selectivity appears to be suppressed.
* EO = ethylene oxide ** EC = ethylene carbonate *** a = trimethyl sulfonium iodide b = methyl triphenyl phosphonium iodide c = tetraphenyl antimony bromide d = triphenyl antimony dichloride e = methyl triphenyl phosphonium bromide f = tetraethyl ammonium bromide Example 2 Effect of Water on Catalysts The procedure of Example 1 is followed except that varying amounts of water are introduced to the Parr bomb, with the following results.
Table B
milli- Max.
Feed, mol 9 Pres. EO EC
25 Test Catalyst, Bath Time, kg/cm2 Conv. Sel.
. EO C2 H2O qms C hrs gauge %
7 19.3 1022 -- c 0.5507 33 19.5 27.8 91.1 88.5 8 18.2 1022 10 c 0.5466 34 19.5 27.4 95.6 47.1 9 20.4 1022 5 b 0.4380 37 21 44.3 86 35 30 10 20.4 1022 20 b 0.4227 37 21 42.5 92 47.4 11 20.4 1022 40 b 0.4319 37 21 43.2 93 63 12 22.7 1022 80 b 0.4365 37 21 41.1 83.8 76 The data of Table B show that the presence of water appears to have no recogni~able effect on the overall conversion of ethylene oxide, the selectivity to ethylene carbonate is reduced when catalyst "c'l is used, while when LJL~3 ~ 19 1 o -catalyst "b" is employed the selectivity to ethylene car-bonate is surprisingly improved. Catalyst "c" would be more suitable for a reaction system in which the amount of water present is not large. Note that the ratio of water to ethylene oxide is about 0~55/1 compared to the theore-tical ratio of 1/l for the hydrolysis reaction. Catalyst ~b~ appears less effective when no water is present (see test 2) but its performance is enchanced when water i5 used. Note that the ratios for this catalyst shown reach nearly 4/1 water/EO.
.
c - tetraphenyl antimony bromide b = methyl triphenyl phosphonium iodide Although the process of the invention is particu-larly useful in connection with the formation of ethylene carbonate, it is more widely appl icable to other oxirane compounds, as will be seen in the following example.
Example 3 Formation of propylene carbonate A sample of the catalyst being tested and water - (if used) is introduced to a 130 cc Parr bomb. Samples of propylene oxide and carbon dioxide are charged at -78C by immersing the bomb in a dry-ice/acetone bath. The bomb is then closed and placed in a 36C ba~h so that the internal temperature of the bomb is increased to 30C and the reaction proceeds. After a suitable period o~ time, the bomb is removed from the bath and the contents analyzed.
The results of a number of such tests are shown in Table C
below.
.
:` ' .: .
.' ~
12~1 Table C
milli- Max.
Feed, mols Pres. PO PC**
Test Catalyst, Bath Time, kg/cm2 Conv. Sel.
No. PO* CO2 H2O gms*** C hrs gauge %
_ 13 20.3 1022 -- a 0.5511 35 21 42.6 96.2 90.3 14 20.6 1022 -- b 0.4335 36 21 34.2 60.2 25.4 15 20.2 1022 -- c 0.2401 36 21 56.1 85.0 58.3 16 20.4 1022 5 b 0.4382 36 21 47.3 88.2 34.6 10 17 20.6 1022 20 b 0~4378 36 21 52.8 89.7 56.4 18 20.1 1022 40 b 0.4386 36 21 54.2 87.4 68.3 19 20.4 1022 80 b 0.4391 36 21 62.1 91.4 82.3 -* PO = propylene oxide ** PC = propylene carbonate *** a - tetraphenyl antimony bromide b = methyl triphenyl phosphonium iodide c = tetraethyl ammonium bromide Exam~e 4 Formation of 1,2 butylene carbonate The experimental procedure of Example 3 was fol-lowed with l,2-butylene oxide charged in lieu of propylene oxide. The results of a number of such tests are shown in Table D below.
Table D
milli- Max.
Feed, mols Pres. BO BC**
Test Catalyst, Bath Time, kg/cm2 Conv- Sel-
.-.
g It has been discovered that water may be present without formation of significant amounts of glycols, provided that the temperature is sufficiently low.
Surprisingly, it has been found that water has a beneficial effect on the selectivity to the carbonate wi~h some catalysts, while with others the selectivity appears to be suppressed.
* EO = ethylene oxide ** EC = ethylene carbonate *** a = trimethyl sulfonium iodide b = methyl triphenyl phosphonium iodide c = tetraphenyl antimony bromide d = triphenyl antimony dichloride e = methyl triphenyl phosphonium bromide f = tetraethyl ammonium bromide Example 2 Effect of Water on Catalysts The procedure of Example 1 is followed except that varying amounts of water are introduced to the Parr bomb, with the following results.
Table B
milli- Max.
Feed, mol 9 Pres. EO EC
25 Test Catalyst, Bath Time, kg/cm2 Conv. Sel.
. EO C2 H2O qms C hrs gauge %
7 19.3 1022 -- c 0.5507 33 19.5 27.8 91.1 88.5 8 18.2 1022 10 c 0.5466 34 19.5 27.4 95.6 47.1 9 20.4 1022 5 b 0.4380 37 21 44.3 86 35 30 10 20.4 1022 20 b 0.4227 37 21 42.5 92 47.4 11 20.4 1022 40 b 0.4319 37 21 43.2 93 63 12 22.7 1022 80 b 0.4365 37 21 41.1 83.8 76 The data of Table B show that the presence of water appears to have no recogni~able effect on the overall conversion of ethylene oxide, the selectivity to ethylene carbonate is reduced when catalyst "c'l is used, while when LJL~3 ~ 19 1 o -catalyst "b" is employed the selectivity to ethylene car-bonate is surprisingly improved. Catalyst "c" would be more suitable for a reaction system in which the amount of water present is not large. Note that the ratio of water to ethylene oxide is about 0~55/1 compared to the theore-tical ratio of 1/l for the hydrolysis reaction. Catalyst ~b~ appears less effective when no water is present (see test 2) but its performance is enchanced when water i5 used. Note that the ratios for this catalyst shown reach nearly 4/1 water/EO.
.
c - tetraphenyl antimony bromide b = methyl triphenyl phosphonium iodide Although the process of the invention is particu-larly useful in connection with the formation of ethylene carbonate, it is more widely appl icable to other oxirane compounds, as will be seen in the following example.
Example 3 Formation of propylene carbonate A sample of the catalyst being tested and water - (if used) is introduced to a 130 cc Parr bomb. Samples of propylene oxide and carbon dioxide are charged at -78C by immersing the bomb in a dry-ice/acetone bath. The bomb is then closed and placed in a 36C ba~h so that the internal temperature of the bomb is increased to 30C and the reaction proceeds. After a suitable period o~ time, the bomb is removed from the bath and the contents analyzed.
The results of a number of such tests are shown in Table C
below.
.
:` ' .: .
.' ~
12~1 Table C
milli- Max.
Feed, mols Pres. PO PC**
Test Catalyst, Bath Time, kg/cm2 Conv. Sel.
No. PO* CO2 H2O gms*** C hrs gauge %
_ 13 20.3 1022 -- a 0.5511 35 21 42.6 96.2 90.3 14 20.6 1022 -- b 0.4335 36 21 34.2 60.2 25.4 15 20.2 1022 -- c 0.2401 36 21 56.1 85.0 58.3 16 20.4 1022 5 b 0.4382 36 21 47.3 88.2 34.6 10 17 20.6 1022 20 b 0~4378 36 21 52.8 89.7 56.4 18 20.1 1022 40 b 0.4386 36 21 54.2 87.4 68.3 19 20.4 1022 80 b 0.4391 36 21 62.1 91.4 82.3 -* PO = propylene oxide ** PC = propylene carbonate *** a - tetraphenyl antimony bromide b = methyl triphenyl phosphonium iodide c = tetraethyl ammonium bromide Exam~e 4 Formation of 1,2 butylene carbonate The experimental procedure of Example 3 was fol-lowed with l,2-butylene oxide charged in lieu of propylene oxide. The results of a number of such tests are shown in Table D below.
Table D
milli- Max.
Feed, mols Pres. BO BC**
Test Catalyst, Bath Time, kg/cm2 Conv- Sel-
5 No. BO* CO2 H2O gms C hrs gauge %
20.4 1022 -- a 0.5513 36 21 44.8 92.1 87.6 21 20.7 1022 -- b 0.4378 36 21 47.2 58.3 22.6 22 20.1 1022 -- d 0.2436 36 21 42.6 82.0 53.2 23 20.1 1022 5 b 0.4386 36 21 51.8 89.2 40.5 24 20.8 1022 20 b 0.4392 36 21 43.8 91.4 59.8 20.2 1022 40 b 0.4369 36 21 56.2 93.4 72.8 26 20.6 1022 80 b 0.4381 36 21 53.6 90.8 84,3 .
* BO = 1,2-butylene oxide ** BC = 1,2-butylene carbonate *** a = tetraphenyl antimony bromide b = methyl triphenyl phosphonium iodide c = tetraethyl ammonium bromide ExampIe 5 A sample of the catalyst being tested, along with H2O and solvents (when used) is introduced to a 300 cc electrically heated stainless steel autoclave equipped with impeller agitation produced by Autoclave Engineers, Inc. Samples of ethyIene oxide and carbon dioxide are charged at -78C while the autoclave is immersed in a dry-ice/acetone bath. The autoclave is then closed and heated to the desired reaction temperature. After a suitable period of time, the autoclave is cooled and the contents analyzed. The results of a number of such tests are shown in Table E below.
`
:
: :~
:
12~
Table E
milli- Max.
Feed, mols*** Pres. EO EC****
Test Bath Time, kg/cm2 Conv. Sel.
No. EO* CO2 H2O THF C hrs ~uge % %
273~7 1590 3461262 60 452.0 95.6 97.0 28695 2794 695 -- 60 6104.8 95.8 90.5 291157 2113 583 -- 50 657.7 98.2 95.5 30349 1590 3501263 70 257.3 99.5 96.0 * EO = ethylene oxide ** THF = tetrahydrofuran *** Each test used 20 grams of methyl triphenyl phospho-nium iodide **** EC = ethylene carbonate The following examples illustrate the process of the invention, demonstrating that, contrary to the prior art it is possible to produce high yields of alkylene carbonates above about 90~C in the presence of substantial amounts of water and suppressing the formation of the higher glycols.
Example 6 Operating above 90C with water present A series of tests were carried out at tempera-tures above 90C with varying amounts of water present.
Ethylene oxide, carbon dioxide, water and methyltriphenyl phosphonium iodide dissolved in ethylene carbanate were fed continuously to a one liter, high pressure, agitated, electrically heated autoclave. Both liquid products and unconverted vapors were removed continuously from the autoclave and separated in an external vapor-liquid separator~ The composition of both liquid and vapor streams was determined by gas chromatoyraphy and the conversion and selectivities wera calculated. The results - are given in Table F.
~ 24~
Table F
Mol Mol H2O CO2 Pres. Cat. EO EC MEG DEG
Test Temp. Mol Mol kg/cm2 mol Feed EO Conv Sel Sel Sel No. ~C EO EO gauge on EO mol/hr/1 % ~ % %
3i 130 0027 2 66 0.01 6.1 95.5 99.3 0.7 nil~
32 130 0~5 1.3 66 0.012 6.5 99 96.5 3.5 nil 33 130 1.0 2.0 66 0.013 6.0 99 87.5 12.5 nil 34 130 1.0 1.3 66 0.014 6.8 99.5 ~3.3 6.7 nil 35 130 1.9 2.0 66 0.010 4.0 99 74.3 23,9 1.7 36 130 2.0 2.0 66 0.002 6.1 91 66.1 30.8 3.1 37 170 0.25 2.0 66 0.0013 6.1 97 ~4.7 5.3 nil 38 170 0.5 1.3 66 0.0022 6.4 99 ~2.1 26.1 1.8 39 170 0.9 1.3 66 0.0~2 6.8 99 4~.8 46.8 4.3 40 t70 1.9 2.0 66 0.0014 4.1 98 14.5 72.1 13.3 41 170 2.0 2.0 6~ 0.0074 4.0 98 -- 92.9 7.1 42 90 0.25 4.0 6~6 0.~13 2.~ 9~94.0 5.0 0.9 43 50 0.11 4.0 66 0.005 2.0 6594.0 4.6 1.3 ~* less than 0.25 - From the above table it can be seen that even when operating at tempera~ures as high as 170~C, that high yields of ethylene carbonate can be obtained, although the amount of wa~er present appears to have a greate~ effect ~25 at 170~C than at 130C. In fact, the results of ~ests 40 and 41 suggest that conditions can be found wher~ glycol becomes the predominent product. The molar ratio of CO2/EO was greater than 1/1 for each test.
When the CO2/EO molar ratio is below~
distinctly differant results are obtained as will be seen from the ~ollowing examples.
Effec~ of C32/EO ratio The experimental procedure~ of Example 6 were repeated to duplicate test 33, except that the~pressure was 25 kg/cm2 gauge and the molar ratio of CO2~EO was .
, 4 1`-~ ~
changed from 2.0 to 0.5. Selectivities of 63.2% to ethylene carbonate (EC) and 36% to ethylene glycol (MEG) were obtained at a CO2/EO ratio of 2, but selectivi-ties of 58~ to MEG and 41~ to EC were obtained when the CO2/EO ratio was 0.5. Also, the formation of diethyl-ene glycol (DEG) was significant at 1.4% selectivity when the CO2/EO ratio was 0.5, while only 0.8% selectivity to DEG was detected in the products when the CO2/EO
ratio was 2. It is concluded that the molar ratio of CO2/EO is an important factor if one wishes to produce alkylene carbonates instead of the corresponding glycol, when an alkylene oxide is reacted with carbon dioxide in the presence of water. In order to achieve such results, the molar ratio of CO2/EO should be at above about 1.
The most useful ratio will be selected depending upon the amount of water present and the operating temperature.
Example 8 Effect of CO2 partial pressure The importance of the partial pressure will be seen in the results of tests made in accordance with the methods of Example 6 in which the absolute pressure and the partial pressure were varied.
Table G
Mol Mol H2~ C2 Press* Cat. Feed EO EC MEG DEG
q~st Temp. Mol Mol Total mol mol/hr/l Conv Sel Sel Sel No. ~C EO EO PCO2 on EO EO ~ % % %
44 130 1.0 2.0 66/65 0.013 6.0 9987.5 12.5 nil 130 1.0 2.0 35/34 0.010 6.2 g571.9 27.7 0.4 46 130 1.0 2.0 25/24.4 0.011 6.2 92 63.2 36.0 0.8 47 t30 1.0 2.0 11/10.5 0.007 6.1 82 26.8 71.5 1.6 48 130 1.0 1.1 3.5/1.0 0.008 6.2 66 9.8 88.4 1.8 * Total press kg/cm2 gauge PCO2=partial press CO2 kg/cm2 abs It can be seen that if the partial pressure of carbon dioxide is not kept sufficiently high the reaction will produce significant amounts of glycol, which is not desirable if one wants to produce ethylene carbonate.
~z'~
instead. Consequently, the temperature, the H2O/EO
ratio, and the CO2 partial pressure will be adjusted to produce the selectivity to carbonate desired. For example, if the molar ratio of water to ethylene oxide in the feed were 1/1 and the reaction temperature were 130C, ~
then the partial pressure of carbon dioxide would be kept ~ -at 65 kg/cm2 or even higher to maximize the amount of ethylene carbonate produced.
xample 9 Effect of H2O/EO ratio In another series of tests corresponding to the procedures of Example 6, the amount of water was varied, with the following results:
Table Mol Mol H2~ C2 Pres. Cat. Feed EO EC MEG DEG
Test Temp. Mol Mol kg/cm2 mol mol/hr/l Conv Sel Sel Sel No. ~C EO EO gauge on EO . EO % % % %
49 130 0.06 2/l 6~ 0.010 3.6 92.~ ~g.8 0.2 ---5~ 130 0.25 2/l 66 0.011 4.2 97.5 8g.0 11.0 0.2 Calculation of reaction rate constants indicate that increasing the conversion of ethylene oxide from 92~
to 97.5% is equivalent to an increase in reaction rate of about four times. Thus, unexpectedly the addition of water to a dry feed increases the reaction rate markedly while the product of the reaction is sti}l predo~inantly ethylene carbonate.
.
.
~ ,~
20.4 1022 -- a 0.5513 36 21 44.8 92.1 87.6 21 20.7 1022 -- b 0.4378 36 21 47.2 58.3 22.6 22 20.1 1022 -- d 0.2436 36 21 42.6 82.0 53.2 23 20.1 1022 5 b 0.4386 36 21 51.8 89.2 40.5 24 20.8 1022 20 b 0.4392 36 21 43.8 91.4 59.8 20.2 1022 40 b 0.4369 36 21 56.2 93.4 72.8 26 20.6 1022 80 b 0.4381 36 21 53.6 90.8 84,3 .
* BO = 1,2-butylene oxide ** BC = 1,2-butylene carbonate *** a = tetraphenyl antimony bromide b = methyl triphenyl phosphonium iodide c = tetraethyl ammonium bromide ExampIe 5 A sample of the catalyst being tested, along with H2O and solvents (when used) is introduced to a 300 cc electrically heated stainless steel autoclave equipped with impeller agitation produced by Autoclave Engineers, Inc. Samples of ethyIene oxide and carbon dioxide are charged at -78C while the autoclave is immersed in a dry-ice/acetone bath. The autoclave is then closed and heated to the desired reaction temperature. After a suitable period of time, the autoclave is cooled and the contents analyzed. The results of a number of such tests are shown in Table E below.
`
:
: :~
:
12~
Table E
milli- Max.
Feed, mols*** Pres. EO EC****
Test Bath Time, kg/cm2 Conv. Sel.
No. EO* CO2 H2O THF C hrs ~uge % %
273~7 1590 3461262 60 452.0 95.6 97.0 28695 2794 695 -- 60 6104.8 95.8 90.5 291157 2113 583 -- 50 657.7 98.2 95.5 30349 1590 3501263 70 257.3 99.5 96.0 * EO = ethylene oxide ** THF = tetrahydrofuran *** Each test used 20 grams of methyl triphenyl phospho-nium iodide **** EC = ethylene carbonate The following examples illustrate the process of the invention, demonstrating that, contrary to the prior art it is possible to produce high yields of alkylene carbonates above about 90~C in the presence of substantial amounts of water and suppressing the formation of the higher glycols.
Example 6 Operating above 90C with water present A series of tests were carried out at tempera-tures above 90C with varying amounts of water present.
Ethylene oxide, carbon dioxide, water and methyltriphenyl phosphonium iodide dissolved in ethylene carbanate were fed continuously to a one liter, high pressure, agitated, electrically heated autoclave. Both liquid products and unconverted vapors were removed continuously from the autoclave and separated in an external vapor-liquid separator~ The composition of both liquid and vapor streams was determined by gas chromatoyraphy and the conversion and selectivities wera calculated. The results - are given in Table F.
~ 24~
Table F
Mol Mol H2O CO2 Pres. Cat. EO EC MEG DEG
Test Temp. Mol Mol kg/cm2 mol Feed EO Conv Sel Sel Sel No. ~C EO EO gauge on EO mol/hr/1 % ~ % %
3i 130 0027 2 66 0.01 6.1 95.5 99.3 0.7 nil~
32 130 0~5 1.3 66 0.012 6.5 99 96.5 3.5 nil 33 130 1.0 2.0 66 0.013 6.0 99 87.5 12.5 nil 34 130 1.0 1.3 66 0.014 6.8 99.5 ~3.3 6.7 nil 35 130 1.9 2.0 66 0.010 4.0 99 74.3 23,9 1.7 36 130 2.0 2.0 66 0.002 6.1 91 66.1 30.8 3.1 37 170 0.25 2.0 66 0.0013 6.1 97 ~4.7 5.3 nil 38 170 0.5 1.3 66 0.0022 6.4 99 ~2.1 26.1 1.8 39 170 0.9 1.3 66 0.0~2 6.8 99 4~.8 46.8 4.3 40 t70 1.9 2.0 66 0.0014 4.1 98 14.5 72.1 13.3 41 170 2.0 2.0 6~ 0.0074 4.0 98 -- 92.9 7.1 42 90 0.25 4.0 6~6 0.~13 2.~ 9~94.0 5.0 0.9 43 50 0.11 4.0 66 0.005 2.0 6594.0 4.6 1.3 ~* less than 0.25 - From the above table it can be seen that even when operating at tempera~ures as high as 170~C, that high yields of ethylene carbonate can be obtained, although the amount of wa~er present appears to have a greate~ effect ~25 at 170~C than at 130C. In fact, the results of ~ests 40 and 41 suggest that conditions can be found wher~ glycol becomes the predominent product. The molar ratio of CO2/EO was greater than 1/1 for each test.
When the CO2/EO molar ratio is below~
distinctly differant results are obtained as will be seen from the ~ollowing examples.
Effec~ of C32/EO ratio The experimental procedure~ of Example 6 were repeated to duplicate test 33, except that the~pressure was 25 kg/cm2 gauge and the molar ratio of CO2~EO was .
, 4 1`-~ ~
changed from 2.0 to 0.5. Selectivities of 63.2% to ethylene carbonate (EC) and 36% to ethylene glycol (MEG) were obtained at a CO2/EO ratio of 2, but selectivi-ties of 58~ to MEG and 41~ to EC were obtained when the CO2/EO ratio was 0.5. Also, the formation of diethyl-ene glycol (DEG) was significant at 1.4% selectivity when the CO2/EO ratio was 0.5, while only 0.8% selectivity to DEG was detected in the products when the CO2/EO
ratio was 2. It is concluded that the molar ratio of CO2/EO is an important factor if one wishes to produce alkylene carbonates instead of the corresponding glycol, when an alkylene oxide is reacted with carbon dioxide in the presence of water. In order to achieve such results, the molar ratio of CO2/EO should be at above about 1.
The most useful ratio will be selected depending upon the amount of water present and the operating temperature.
Example 8 Effect of CO2 partial pressure The importance of the partial pressure will be seen in the results of tests made in accordance with the methods of Example 6 in which the absolute pressure and the partial pressure were varied.
Table G
Mol Mol H2~ C2 Press* Cat. Feed EO EC MEG DEG
q~st Temp. Mol Mol Total mol mol/hr/l Conv Sel Sel Sel No. ~C EO EO PCO2 on EO EO ~ % % %
44 130 1.0 2.0 66/65 0.013 6.0 9987.5 12.5 nil 130 1.0 2.0 35/34 0.010 6.2 g571.9 27.7 0.4 46 130 1.0 2.0 25/24.4 0.011 6.2 92 63.2 36.0 0.8 47 t30 1.0 2.0 11/10.5 0.007 6.1 82 26.8 71.5 1.6 48 130 1.0 1.1 3.5/1.0 0.008 6.2 66 9.8 88.4 1.8 * Total press kg/cm2 gauge PCO2=partial press CO2 kg/cm2 abs It can be seen that if the partial pressure of carbon dioxide is not kept sufficiently high the reaction will produce significant amounts of glycol, which is not desirable if one wants to produce ethylene carbonate.
~z'~
instead. Consequently, the temperature, the H2O/EO
ratio, and the CO2 partial pressure will be adjusted to produce the selectivity to carbonate desired. For example, if the molar ratio of water to ethylene oxide in the feed were 1/1 and the reaction temperature were 130C, ~
then the partial pressure of carbon dioxide would be kept ~ -at 65 kg/cm2 or even higher to maximize the amount of ethylene carbonate produced.
xample 9 Effect of H2O/EO ratio In another series of tests corresponding to the procedures of Example 6, the amount of water was varied, with the following results:
Table Mol Mol H2~ C2 Pres. Cat. Feed EO EC MEG DEG
Test Temp. Mol Mol kg/cm2 mol mol/hr/l Conv Sel Sel Sel No. ~C EO EO gauge on EO . EO % % % %
49 130 0.06 2/l 6~ 0.010 3.6 92.~ ~g.8 0.2 ---5~ 130 0.25 2/l 66 0.011 4.2 97.5 8g.0 11.0 0.2 Calculation of reaction rate constants indicate that increasing the conversion of ethylene oxide from 92~
to 97.5% is equivalent to an increase in reaction rate of about four times. Thus, unexpectedly the addition of water to a dry feed increases the reaction rate markedly while the product of the reaction is sti}l predo~inantly ethylene carbonate.
.
.
~ ,~
Claims (9)
1. In a process for preparing alkylene carbonate by the reaction of the corresponding alkylene oxide with carbon dioxide in the presence of an effective amount of catalyst and water, the improvement comprising controlling the selectivity to alkylene carbonate and suppressing formation of higher molecular weight glycols by carrying out said reaction at temperatures above about 90°C with a molar ratio of carbon dioxide to alkylene oxide of at least about 1/1, a water to alkylene oxide molar ratio greater than about 0.01/1, and a carbon dioxide partial pressure sufficient to provide the selectivity to alkylene carbonate desired.
2. The process of claim 1 wherein said reaction temperature is between about 90°C and about 170°C.
3. The process of claim 1 wherein said molar ratio of water to alkylene oxide is between about 0.01/1 and about 4/1.
4. The process of claim 3 wherein said molar ratio of water to alkylene oxide is between about 0.1/1 and about 2/1.
5. The process of claim 1 wherein said catalyst is at least one member of the group consisting of organic quaternary ammonium halides, organic quaternary phosphonium halides, organic sulfonium halides, and organic antimony halides.
6. The process of claim 5 wherein said catalyst is an organic quaternary phosphonium halide.
7. The process of claim 6 wherein said catalyst is methyl triphenyl phosphonium iodide.
8. The process of claim 1 wherein said catalyst is up to about 0.10 mols per mol of alkylene oxide.
9. The process of claim 1 wherein said alkylene carbonate is ethylene carbonate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US441,191 | 1982-11-15 | ||
| US06/441,191 US4786741A (en) | 1982-11-15 | 1982-11-15 | Preparation of alkylene carbonates |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1248119A true CA1248119A (en) | 1989-01-03 |
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ID=23751898
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000441124A Expired CA1248119A (en) | 1982-11-15 | 1983-11-14 | Preparation of alkylene carbonates |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4786741A (en) |
| CA (1) | CA1248119A (en) |
| DD (1) | DD207204A5 (en) |
| PL (1) | PL137366B1 (en) |
| TR (1) | TR21898A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5138073A (en) * | 1981-12-02 | 1992-08-11 | Scientific Design Company, Inc. | Preparation of alkylene carbonates |
| DE3529263A1 (en) * | 1985-08-16 | 1987-02-19 | Hoechst Ag | METHOD FOR PRODUCING 2-OXO-1,3-DIOXOLANES |
| US5212321A (en) * | 1989-10-07 | 1993-05-18 | Boehringer Ingelheim Gmbh | Process for the preparation of trimethylene carbonate |
| DE4030283A1 (en) * | 1990-09-25 | 1992-03-26 | Ruetgerswerke Ag | PROCESS FOR PREPARING CYCLIC CARBONATE |
| US5179214A (en) * | 1991-09-23 | 1993-01-12 | Texaco Chemical Company | Process for manufacturing alkylene carbonates |
| DE4141189A1 (en) * | 1991-12-13 | 1993-06-17 | Bayer Ag | METHOD FOR PRODUCING ETHYLENE GLYCOL CARBONATE |
| US5283356A (en) * | 1992-08-03 | 1994-02-01 | Texaco Chemical Company | Process for manufacturing alkylene carbonates using metal phthalocyanine catalysts |
| US5405977A (en) * | 1993-01-04 | 1995-04-11 | Huntsman Corporation | Process for removing organic halides from alkylene carbonates |
| US6594688B2 (en) | 1993-10-01 | 2003-07-15 | Collaboration Properties, Inc. | Dedicated echo canceler for a workstation |
| US5631386A (en) * | 1996-08-02 | 1997-05-20 | Arco Chemical Technology, L.P. | Alkylene carbonate recovery |
| RU2100355C1 (en) * | 1996-10-31 | 1997-12-27 | Институт физиологически активных веществ РАН | Method for catalytic binding of carbon dioxide |
| US6258962B1 (en) | 1999-06-14 | 2001-07-10 | Mobil Oil Corp. | Process for producing alkylene carbonates |
| US6407279B1 (en) | 1999-11-19 | 2002-06-18 | Exxonmobil Chemical Patents Inc. | Integrated process for preparing dialkyl carbonates and diols |
| KR100389459B1 (en) * | 2001-02-14 | 2003-06-27 | 한국과학기술연구원 | Production Method of Alkylene Carbonates |
| JP3823149B2 (en) * | 2002-03-06 | 2006-09-20 | 独立行政法人産業技術総合研究所 | Alkylene carbonate synthesis catalyst |
| US6696579B2 (en) * | 2002-05-08 | 2004-02-24 | Arco Chemical Technology, L.P. | Alkylene carbonate purification |
| US6586605B1 (en) | 2003-01-08 | 2003-07-01 | Arco Chemical Technology, L.P. | Purification of alkylene carbonate |
| US20080214386A1 (en) * | 2004-03-01 | 2008-09-04 | Toshikazu Takahashi | Catalyst for Cyclic Carbonate Synthesis |
| PE20070477A1 (en) * | 2005-08-02 | 2007-05-16 | Shell Int Research | PROCESS FOR THE PREPARATION OF ALKYLENE CARBONATES |
| PE20070478A1 (en) * | 2005-08-02 | 2007-05-18 | Shell Int Research | PREPARATION PROCESS OF ALKYLENE GLYCOLS |
| US7378540B2 (en) * | 2005-10-21 | 2008-05-27 | Catalytic Distillation Technologies | Process for producing organic carbonates |
| ATE506355T1 (en) * | 2006-08-03 | 2011-05-15 | Shell Int Research | METHOD FOR PRODUCING ALKYLENE CARBONATE |
| EP2066607B1 (en) * | 2006-09-15 | 2010-11-03 | Shell Internationale Research Maatschappij B.V. | Process for the preparation of alkylene glycols |
| WO2008031864A1 (en) * | 2006-09-15 | 2008-03-20 | Shell Internationale Research Maatschappij B.V. | Process for the preparation of alkylene carbonate |
| KR101546105B1 (en) * | 2007-07-20 | 2015-08-20 | 셀 인터나쵸나아레 레사아치 마아츠샤피 비이부이 | Process for the preparation of alkylene glycols |
| ES2453615T3 (en) * | 2007-12-03 | 2014-04-08 | Asahi Glass Company, Limited | Procedure for the production of a carbonate compound |
| CN105294643B (en) * | 2014-07-24 | 2018-07-13 | 中国石油化工股份有限公司 | Ethylene oxide and carbon dioxide prepare the catalyst and its method of ethylene carbonate |
| WO2021115997A1 (en) * | 2019-12-11 | 2021-06-17 | Shell Internationale Research Maatschappij B.V. | Process for the preparation of ethylene glycol |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2667497A (en) * | 1951-12-12 | 1954-01-26 | Olin Mathieson | Process for the preparation of cyclic carbonates |
| US2766258A (en) * | 1952-05-15 | 1956-10-09 | Jefferson Chem Co Inc | Process for isolation of alkylene carbonates |
| US2773070A (en) * | 1952-10-31 | 1956-12-04 | Jefferson Chem Co Inc | Catalytic process for producing alkylene carbonates |
| US2773881A (en) * | 1953-02-09 | 1956-12-11 | Union Carbide & Carbon Corp | Glycol carbonates |
| US2994704A (en) * | 1958-11-19 | 1961-08-01 | Pure Oil Co | Preparation of cyclic alkylene carbonates |
| US2994705A (en) * | 1958-12-08 | 1961-08-01 | Pure Oil Co | Preparation of cyclic alkylene carbonates in the presence of organic phosphonium compounds |
| US2993908A (en) * | 1958-12-16 | 1961-07-25 | Pure Oil Co | Preparation of cyclic alkylene carbonates |
| US3535341A (en) * | 1968-02-07 | 1970-10-20 | Dow Chemical Co | Process for making alkylene carbonates |
| GB1177877A (en) * | 1968-08-26 | 1970-01-14 | Vnii Neftekhim Protsessov | Process for the Production of Alkylene Glycols |
| US3629343A (en) * | 1968-10-11 | 1971-12-21 | Vnii Neftekhim Protsessov | Process for the production of alkylene glycols |
| IT971363B (en) * | 1972-11-30 | 1974-04-30 | Sir Soc Italiana Resine Spa | PROCEDURE FOR THE PREPARATION OF ETHYLENE GLYCOL |
| IT1034323B (en) * | 1975-03-17 | 1979-09-10 | Anic Spa | PROCEDURE FOR THE PREPARATION OF ALKYLENCARBONATES |
| US4314945A (en) * | 1977-12-22 | 1982-02-09 | Union Carbide Corporation | Alkylene carbonate process |
| US4160116A (en) * | 1978-08-28 | 1979-07-03 | Showa Denko K.K. | Process for the production of alkylene glycols |
| JPS55122776A (en) * | 1979-03-14 | 1980-09-20 | Harukazu Matsuda | Synthetic method of carbonate |
| US4233221A (en) * | 1979-10-24 | 1980-11-11 | The Dow Chemical Company | Ethylene carbonate process |
| JPS5645426A (en) * | 1979-09-21 | 1981-04-25 | Nippon Shokubai Kagaku Kogyo Co Ltd | Preparation of alkylene glycol |
-
1982
- 1982-11-15 US US06/441,191 patent/US4786741A/en not_active Expired - Fee Related
- 1982-12-03 DD DD82245548A patent/DD207204A5/en not_active IP Right Cessation
- 1982-12-16 PL PL1982239558A patent/PL137366B1/en unknown
-
1983
- 1983-01-13 TR TR21898A patent/TR21898A/en unknown
- 1983-11-14 CA CA000441124A patent/CA1248119A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| TR21898A (en) | 1985-10-11 |
| DD207204A5 (en) | 1984-02-22 |
| PL137366B1 (en) | 1986-05-31 |
| PL239558A1 (en) | 1984-07-30 |
| US4786741A (en) | 1988-11-22 |
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