US2457457A - Methods for treating bituminous shales - Google Patents

Description

Deel 2s, 194s.

J. L. M. FREJACQUES METHODS FOR TREATING BITUMINOUS SHALES AFiled April 24, 19415 Fractional Distilla'in @OSO/ine Fractional .Dz'tz' [lation Ihtermedzate Oils Eo/v MHH/WCE Fifa/4c a 05s, y

Arrow/y Patented Dec. 28, 1948 i1 Gasoline V:ma :lubricating :ons obtamdiirom rawoils.producedintnedistillation. of bituminous V.scl'iists "generally conta-infie. large "amount "ffsl- (phur Vand La "comparatively 'important proportion -of unsaturated"l'iy'drocarborisv whichrender' rflningsomewhatjdiiucult. ,'*Whenirenningaooofding ltothe 'conventional method,` Lie." by Washing' `xiil'th L'soda arid'with sulphurictacirl.thetreatmentvisjaccompamedby important losses, duep both`t'odis solution "avrrdto polymerization. The lubricants which cani begremoved ."rrom thel raw *oileregpro- (duced Witha grade.

The accompanying drawinglis 'a dia'gramiatic representationioffaflow 'sheetro'f they process.

Th'ej'present :invention 'has for .its object 5a method *for obtairling ra highfgrade slphurlfree lubricant,l starting frombituminous-schiste JAC- "c'ordin'g to-this m'e'thod'the `soliists `are;`ds'til1`e'din the "presence "of Voils of medium volatility lroduced `during a preceding operation, afte'rv which the oil thus obtained is submitte'dto vlratiti'onal distillation 'and the 'lighter fractions 'aretreatd Witlr a1cata1ys`tof theFriedel arid Crafttype'cnsisting :of a suitable 'anhydrous v'halide of "an v`:at least trivalent element (for instance aluminium ichloride') The-oil i thus vproduced is .fractionated `forV collectin'gzthe lubricant.

LIn orderthatithis 'production may bereallyof -tilled oils containing sufficiently 'important 1 vDro- 'portions of unsaturated hydrocarbons, say about '30 rtoL40% 1'or Peven more. Such percentages Toi olenes `can "be obtained. Yby providingffor a 'Silit- "able progress inthe distillation"ofthesohistsin- "dergoingtreatment. FoA this end, 'it is necessary to use retorts adapted to be heated in a comparatively rapid manner, `so as to bring the 4schist t0 40G-'500r-C. andiit is also ne'cessaryto recyoleiinside -the furnace 'those `fractions "of fthe raw oil whichform -neither vga'solin'enor lubricating Teils. The-distillation v"furnace should be'arrangelin 'a gmannerfsuchthatthis reintroduction 'can' be conveniently performed. This recycling than libe Vref- 2 The 1teinperattue Yat which distillation of the foilfresultin-g from e the vdistillation of schist fshould :bestopped{for-` obtainingthe fraotiontobetreatd withfazluminiumfchloride depends-on -tlie `nature it is desired to obtain. Generally aftemperature .comprisedbet-Ween 200 and 250 C.is-of acl-Vantage. l f

-When .thesdlstillation is -thus stopped, v'it v'is :poslsible to remove Tthrough subsequent distillation, from the remainingloil, pitch, lubricatingioils-and oilsoffmedium volatility. The :lubricatingwoils :maybe refined through Ythevusual :methods and -usedla'stsucn -but their Erefining is diflicult and `-it -is often of vadvantage =to treat them again in the Lfschistdistillin'g furnace Vtogether with lthe oils of medium volatility. Pitch may also be redistil-ledfinsid'e ithe furnace, but -it-generallyproduces only little oil with-large amounts `of `coke and 'of fga-sestandl'itis-generally'more advantageous to'use .it .,separately. y

f'I-hell-i-g'ht -oils robtained. .from the distillation of thetm'ix'tureof oils resulting Ifrom the distillation of Vshists may be submitted -to a slight refining ywith soda `or rwith sulphuric :acid vbefore they are vtreated Wthaluminium chloride. It isjthus poss'blelto reduce vthe .proportion of .aluminium chloil'e required. AThe latter is variable in accordahceitith the nature of the schist treated and ."shold be 'equal as an -average to 5 to 10% -in it/eight 'ofthe ole'nes contained in the oil.

Th'e viscosity "andthe different qualities of `the oils vobtained may be modied almost at Will :by a A`Il'l'ld'(lftil in th "COIldlt0-n`s '0f 'polylnzation. v At mornialroo'm 'temperature or "at even lower temperatures, "sa'y "beloiivOD C'., 'the viscositles 'obtainel are very high. At higher temperatures, stty 50580" C., `it is possible t0 'Obtain more fluid pils. 'It'may aisobeof'interest 'to begin the poly -iner-iation at "low temperature 'and to 'prosecute 'it then at `high temperature. All these conditions lha-ve obviously their "influence 'also "on the durat-o'n o'f 'theltreatmen't'which may be given out A'by way of indicationas lasting affev'v hours A'a't'high temperature or a Vfew days below l'freezing"'poi'nt. `'gfotfd stirring iis 'reqlliea 'throughout `the 'period of tret'ment.

When the polymerization vis at an end, thefoil rfavyfbe treated 'as disclosed hereinafter: the oil is edito 'rest or if required submitted to een- 'gatiii'for-fseparating the aluminum chloride whio fcontaiuedfin tn'efoilin the-form oi a dou- 'bl'e'lnslllble Combination The T011 ylistli lt'l 'With f. Vlittle fdisColoiiif-ig 4a'lth foi* atif' caboh or even simply charcoal. It is of interest that these filtration furthering means be suitably dried before use so as to avoid the action of moisture on aluminium chloride.` After filtration, the oil is washed with soda and then distilled for collect-- ing its different fractions. The fraction distilling'lbelow IBO-215 C. forms a verystablefuel which is completely colorless and shows absolutely Qnog-' tendency towards forming gums. It is sufficiently desulphurized to allow its use withoutdanger -in-v motors. 1

The treatment may moreover end with 'a last;

sulphuric refining which maythen be performed with very small losses. l v v i 1 l Y The fractions passing above 200 Cjunder'20 mm. of mercury form the lubricating oils. They v are of very slight color and generallyoshow a high gasoline and easily condensable gases; it is of "l interest to recover these and to polymerize them. The light gasoline thus recovered may be polymerized by means of aluminium chloride together with the other polymerzable fractions or` else separately from said last mentioned'ractions, which permits of obtaining different grades of oil.

The easily condensable gases which it is possible to recover for instance by means of a treatment with active carbon may be treated in different manners. It is possible merely to make them bubble through oil stirred with aluminium chloride, so that they undergo polymerization; the olenes they contain are absorbed and transformed into oil. It is also possible to treat the gases directly with solid aluminium chloride either at atmospheric pressure or under a higher pressure. Lastly it is also possible to polymerize them into gasoline in accordance with any known" method and then to polymerize this gasoline by means of aluminium chloride as in the case of light gasoline.

I will now give examples of the method according tothe present invention.

Example 1.--The bituminous schist that' A-is ktreated is a schist from the Aveyron yielding 4.5

per cent of oil in the Fischer retort. l

This schist is impregnated with 50 kgs. per ton of oil to be recycled resulting from a prior operation. The whole is distilled in a rotary furnace of the externally heated type. The matter remains about minutes in the furnace. The thickness of the layer of schist in the furnace is 80-99 mms. Thetemperature of this schist at the hottest point yis 480, which corresponds, on the outside of the furnace, to a temperature of the combustion gases of 800 C. on the side through which the mass of schist leaves the furnace and 540 on the opposite side. rIhe furnace` is swept with a stream of can be'extracted, by cooling at 40 C., 5.3,kgs.

pheric pressure 13.6

'f''Medium oil to be recycled passing below 170 C. under a pressure of 2 mm. of

mercury 50.5 Raw lubricating oil passing from 1'70 to 30520. under a pressure of 2 mm. of

`fiitlercury.. 21.5 f

Re's'idu'ary pitch 5.4

The 13.6-kgs. of gasoline thus obtained are vmixedwith'the 5.3 kgs. of light gasoline obtained from ,the gas, thus giving a total of 18.9 kgs. of

` gasolineto be polymerized. This gasoline conture is treated with water slightly acidulated with hydrochloric acid so as to permit of separating aluminium chloride by de'cantation. l The decanted oil is washed .witha 1 per cent vsolution-of soda and subjected to fractional distillationl This 'treatment yields 11.8 kgs. of gasoline passing below 215 C. under atmospheric pressure, A15 kgs.

ofl medium oil to be recycled passing below 170 C. undera pressure of 2 of mercury and 4.2

` rated from the `medium oil.

kgs. of residuaryoil which is mixed with the 21.5 kgs. of raw lubricating oil precedingly obtained, makingfa total of 25.7 kgs. of raw'lubricating oil tobe .renedg' The gasoline thuslobtained con- ,tains only a total'amou'nt of 0.3 per cent 'of sulphur. It no longercontains corrosive sulphur.

vIt is perfectly colorless, does not get yellow after a Acertain time and has no tendency to forni gums.

Its octane index is 72 y The raw lubricating oil can be rened through any known means. Treatment by selective solvvents permits for instance of extracting therefrom from 10 to 13 kgs. of oil suitable for conj sumption and which may be fractionated so'as to yield about 40 per cent ofiiuidA oil of -2- IEngler at 50 C., 40 per cent of oil of 2 Engler at 50C. and 20 per cent of viscous oil-'of 21 Engler at 50 C., havinga viscosity index of -60.

Example yII.-'The operation is lconducted as above, but the first fractionating of the oil ob- `tained`from the treatment ofV schist in the furnace takes place at a temperature of 250.C. instead of ,215 C. and the lubricating oil is not sepa- TheF resulting vproducts are:

. k Kgs.

-Light oil passingv below 250 under atmospheric pressure 36.5

lMedium oil to be recycled 50 Pit-cn 5.5

The 36.5 kgs. of light oil passing below 250 C. are treated with 1.2-2 kgs. of anhydrous alumin- During this time the gases flowing out vvfrom the. schist furnace are caused to bubble through this mixture. These gases are subsequently cooled kdown to a'temperature of .-40" C. for extracting 'therefrom the gasoline that has been driven along. Abouti kgs.` of. light gasoline are thus collected. The mixture rof @i1 and aluminium chloride is then brought to a temperature of C. as inf'the '"-jjabove example; 'After separationo'f--the'aluminium chloride, the polymerized oil fis* fractionated,

yielding 7.5 kgs. of refined gasoline, 17.8 kgs. of medium oil and 13.5 kgs. of lubricating oil which can be refined with an excellent yield through a mere treatment with sulphuric acid followed with a filtration with discolouring earth. The medium oil that is obtained is very little coloured and very well rened. It can also be recycled but it is preferable to use it as such.

Of course, processes intermediate between those indicated in the two above examples can be utilized. For instance only a portion of the lubricating oils and a portion of the medium oils resulting from polymerization might be recycled.

Various modications may be brought to this method without widening the scope of the present invention. For instance, it is often of interest to add to the aluminium chloride used a certain amount of powder of aluminium. It is also possible to use for instance zinc chloride, ferric chloride, boron fluoride, stannic chloride or a mixture of such catalysers.

What I claim is:

1. A method for producing a sulfur-free high grade lubricant from bituminous schists, which comprises initially distilling said schists in the presence of a recycle oil fraction of boiling range intermediate lubricating oil and gasoline and obtained from a prior fractional distillation operation, to produce a distillate oil, subjecting the distillate oil so produced to fractional distillation to obtain a lighter fraction and a heavier fraction, subjecting the lighter fraction to a polymerization treatment with a metal halide catalyst of the Friedel and Crafts type to produce a polymerization product, fractionating the polymerization product to obtain a plurality of fractions including a lubricating oil fraction and a recycle oil fraction of boiling range intermediate lubricating oil and gasoline, and recycling said recycle oil fraction to the initial distillation operation 2. A method for producing a sulfur-free high grade lubricant from bituminous schists, which comprise initially distilling said schists in the presence of a recycle oil fraction of boiling range intermediate lubricating oil and gasoline and obtained from a prior fractional distillation operation, to produce a distillate oil, subjecting the distillate oil so produced to fractional distillation to obtain a lighter fraction and a heavier fraction, subjecting the lighter fraction to a polymerization treatment with a metal halide catalyst of the Friedel and Crafts type to produce a polymerization product, fractionating the polymerization product to obtain a plurality of fractions including a lubricating oil fraction and a recycle oil fraction of boiling range intermediate lubricating oil and gasoline, and recycling said recycle oil fraction together with the heavier fraction of the prior fractional distillation to the initial distillation operation.

3. A method for producing a sulfur-free high grade lubricant from bituminous schists, which comprises initially distilling said schists in the presence of a recycle oil fraction of boiling range intermediate lubricating oil and gasoline and obtained from a prior fractional distillation operation, to produce a distillate oil, subjecting the distillate oil so produced to fractional distillation to obtain a lighter fraction and a heavier fraction, subjecting the lighter fraction to a polymerization treatment with a metal halide catalyst of the Friedel and Crafts type to produce a polymerization product, fractionating the polymerization product to obtain a plurality of fractions including a lubricating oil fraction and a. recycle oil fraction of boiling range intermediate lubricating oil and gasoline, and recovering and polymerizing the gasoline vapours and the easily condensable gases formed in the distillation of the schists.

4. A method for producing a sulfur-free high grade lubricant from bituminous schists, which comprises initially distilling said schists in the presence of a recycle oil fraction of boiling range intermediate lubricating oil and gasoline and obtaining from a prior fractional distillation operation, to produce a distillate oil, subjecting the distillate oil so produced to fractional distillation to obtain a lighter fraction and a heavier fraction, subjecting the lighter fraction under constant stirring at adjustable temperature to a polymerization treatment with a metal halide catalyst of the Friedel and Crafts type to produce a polymerization product, fractionating the polymerization product to obtain a plurality of fractions including a lubricating oil fraction and a recycle oil fraction of boiling range intermediate lubricating oil and gasoline, and recycling said recycle oil fraction to the `initial distillation operation.

JEAN LON MAURICE FREJACQUES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS

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