US2076695A - Process of producing an improved motor fuel and solvent oil - Google Patents

Description

Aprll 3, 1937. J. c. BLACK 2,076,695

PROCESS OF PRODUCING AN IMPROVED MOTOR FUEL AND SOLVENT OIL Filed July 5, 1929 .5 I 5 srock 69 ECO/V- INVENTOR JOHN C ELflCk ATTORNEY Patented Apr. 13, 1937 PROCESS OF PRODUCING AN IMPROVED. MOTOR FUEL AND SOLVENT OIL John C. Black, Beverley Hills, Calif., assignor to Gasoline Products Company, Incorporated, Newark, N. J., a corporation of Delaware Application July 5, 1929, Serial lilo. 376,228

Claims.

This invention relates to a method of processing mineral oil products, such as petroleum oils, shale oils, or distillates of the same, to produce an improved motor fuel or gasoline stock suit- 5 able as a fuel for internal combustion engines with a high compression ratio, or as a solvent for the extraction of oils from vegetable products and the like; this product being lower in sulphur content and containing a higher percentage of carbocyclic hydrocarbons than is usually obtained by any of the well-known thermo cracking processes using super-atmospheric pressure.

Briefly stated, my invention comprises separating by fractionation and condensation, a r

higher boiling fraction and a lower boiling fraction from a vaporized naphtha stock derived by r cracking a higher boiling petroleum oil by any of the processes known in the art, or derived by the distillation of a crudepetroleum oil, then subjecting the said separated higher boiling naphtha fraction to a temperature sufiiciently high to dehydro-genate and convert a substan tial portion of the same into carbocyclic hydrocarbons, then separating by-fractionation, that portion of the said dehydrogenated hydrocarbons which have boiling points up to approximately 450 degrees F. or' any other end point desired, and then commingling the same with the lower boiling fraction separated from the said first naphtha stock, with or without the addition of casinghead gasoline stock, in quantities suificient to produce gasolinestocks having any desired range of boiling points within the limits 'of the stocks blended. In case a solvent for the extraction of oil from vegetable products,

or a cleaners solvent is desired, the dehydrogenated hydrocarbons having boiling points up to approximately 450 degrees may be employed after a purification and fractionation operation. 40 As an illustration of the process I will take a naphtha vapor from a pressure cracking proc ess, this vapor having passed through fractionating equipment to produce if it were condensed, a gasoline or naphtha stock having an end boiling point of 425 to as high as 500 degrees F., depending upon the degree of cracking or the quantity of carbocyclic hydrocarbons required in the finished blend. This vaporized naphtha stock is now further fractionated by any of the 5 well-known fractionating processes'but the one shown in the accompanying drawing is a wash tower equipment in which a portion of the separated or condensed oilafter cooling, is used as the condensing medium. The wash oil in this case is of the same character as the oil I wish to separate from the naphtha vapors and was previously a part of them. The separated or condensed portion consists of the higher boiling fractions of the vapor, say from 250 degrees F. up to the end boiling point of the naphtha 5 stock entering the fractionating equipment. The lower boiling fractions, or the uncondensed' portion of the naphtha vapors pass out of the tower and are separately condensed'to form the primary blending constituent of the final prod- 1 not. This primary portion of the naphtha vapors may have, as an illustration, boiling points of from 90 degrees F. to 250 degrees F. oreven higher, say to 284 degrees F. which is the boiling point of the 50'per cent fraction of the U. S. 5 motor gasoline. This primary fraction is already rich in hydrocarbons having non-detonating qualities and I have found it is not necessary to further process this fraction to get a satisfactory motor fuel when blended with the secondary 2o blending stock. The high boiling fractions separated by the wash oil are further treated and changed in the process into a range of boiling points starting as low as that. of the original. naphtha stock and as high or higher than in 25 the original stock. These processed or re-treated hydrocarbons are fractionated and the proper boiling point hydrocarbons are separated to form the secondary blending stock which may range in boiling points from 100 degrees F. or lower 30 to as high as 400 degrees F. or higher. The two stocks, the primary and the secondary blending stocks, when blended will form a gasoline or motor fuel entirely different from the original stock from which they were derived, as for instance, 5'

the original stock may have boiling points, having an initial of 95, degrees F. or less, 18 to 20 per cent boiling at 212 degrees F., the 50 per cent fraction boiling at approximately 284 degrees F. and a final boiling point of 437 degrees R, where- 40 as the blended stock may have an initial of 95 degrees F., 30 to 35 per cent boiling at 212 degrees F. and or per cent boiling at 284 degrees F., and the final boiling point may be 437 degrees F. or lower, this latter depending upon 45 tor fuel fulfill this requirement. This end is attained by the conversion of a portion of the higher boiling fractions into lower boiling fractions of the benzol series, or hydrocarbons of 5 similar characteristics, it being well-known that benzol gasoline mixtures make a most satisfactory non-detonating motor fuel.

The gasoline made by this process may be chemically treated and purified by any of the well-known vapor phase processes, or the blended stock may be treated and purified by any of the v well-known treating and sweetening processes.

Anobject of the invention is to produce gasoline boiling point stock or motor fuel for use in internal combustion engines with a high compression ratio.

Another object of the invention is to produce a motor fuel suitable for use in internal combustion engines with a high compression ratio without requiring the use of anti-knock compounds. I

Another object of the invention is to produce a solvent which may be employed to extract oils from vegetable products or may be used as a cleaning fluid.

Another object of the invention is to provide a continuous process for converting by a dehydrogenation operation a higher boiling fraction of a gasoline or naphtha stock into a non-detonating motor fuel containing a high percentage of carbocyclic hydrocarbons such as benzol, toluol, xylol, etc.

Another object of the inventionis to increase the non-detonating properties of cracked gasoline stocks by a continuous process, while the same is in the process of manufacture.

Various other objects and advantages 'of the present invention will be apparent from the description of the preferred form or example of the 40 process embodying the invention. For this purpose, reference is made to the accompanying drawing, in which there is illustrated a form of apparatus in which the invention may be performed.

The drawing represents a diagrammatic view of the apparatus in which the parts are in vertical section.

In the drawing, I represents generally a tank for holding the hydrocarbon oil to be processed,

which is termed charging stock", and may be any petroleum oil distillate such as a gas oil stock. Pipe 2, controlled by valve 3, connects charging stock tank I near the bottom to the inlet side of pump 4. Pipe 5 connects the discharge side of pump 4 to heat exchanger 6. Pipe 1 connects heat exchanger 6 to heater coil 8 which is stationed in the furnace 9. The furnace 9 is provided with a burner I2 which leads to a source of fuel supply not shown. Pipe I0 controlled by pressure relief valve |I connects heater coil 8 to fractionating tower I3. Fractionating tower I3 is provided with a separator plate I5, contact material I4, such as tile, and a spray pipe 28. Pipe I6 connects fractionating tower I3 just above the separator plate, to heat exchanger '6. Pipe II connects heat exchanger 6 to cooling coil I9, which is stationed in the condenser box I8. Pipe 26 connects cooling coil I9 to re-cycle stock tank 2|. Pipe 91, controlled by valve 22 connects re-cycle stock tank 2| to a storage not shown. Pipe 24, controlled by the valve 23, connects re-cycle stock tank 2| near the bottom to the inlet side of pump 25. Pipe 26 connects thedischarge side of pump 25 to spray pipe 28. Pipe 80, controlled by the valve 34, connects fracti0nthrough the pipe 91.

ating tower 13 at the bottom to cooling coil 82 which is stationed in the condenser box 8|. Pipe 83 connects cooling coil 82 to primary resid uum tank 84. Pipe I9, controlled by valve 96. connects pipe 5 to pipe Ill. Pipe 21 connects fractionating tower I3 at the top to fractionating tower 29. Fractionating tower 29 is provided with contact material such as tile 3| and a spray pipe 39. Pipe 35, controlled by the valve 33, connects fractionating tower 29 at the bottom to exchanger 36. Pipe 31 connects exchanger 36 to cooling coil 39, which is stationed in the condenser box 38. Pipe 48 connects cooling coil 39 to heavy ends tank 4|. Pipe 42 connects heavy ends" tank 4| near the bottom to the inlet side of pump 43. Pipe 44 connects the discharge side of pump 43 to pipe 63. Pipe 63', controlled by valves and 46, connects the pipe 63 to exchanger 62. Pipe 63 connects the pipe 63-, to spray pipe 38 in the fractionating tower 29. Pipe 62 connects exchanger 62 to exchanger 60.; Pipe 6| connects exchanger 68 to exchanger 36. Pipe 59 connects exchanger 36 to heater coil 52. The heater coil 52 is stationed in the furnace 5| which is provided with a burner 53. Burner 53 leads to a source of fuel not shown. Pipe 32 connects fractionating tower 29 at the top to condenser coil 86 which is stationed in the condenser box 85. Pipe 89 connects cooling coil 86 to. "primary blending stock tank 81. Pipe 94 connects pipe 89 to an absorber not shown. Pipe 96, controlledby valve 98, connects primary blending stock tank 81 near the bottom to pump I03. Pipe I04, controlled by valve I96 connects pump I03 to a storage not shown. A branch pipe controlled by valve I connects pipe I04 to pipe 93. Pipe 49, controlled by valve 49, connects heater coil 52 to fractionating tower 54. Fractionating tower 54 is provided with a separator plate 56 and bubble trays 55. Pipe I6 connects fractionating tower 54 at the top to condenser coil I8, which is stationed in the condenser box 11. Pipe 9|; connects condenser coil I8 to gasoline tank 92. Pipe 93, controlled by the valve 93, connects gasoline tank 92, near the bottom, to a storage not shown. Pipe 51 connects fractionating tower 54 just above the separator plate 56 to exchanger 62. Pipe 64 connects exchanger 62 to cooling coil 65 which is stationed in the condenser box 66. Pipe 61 connects cooling coil 65 to re-cycle stock tank 68. Pipe 89, controlled by the valve 69, connects re-cycle stock tank 68 near the bottom to a storage not shown. Pipe 59, controlled by the valve 58, connects fractionating tower 54 at the bottom to exchanger 66. Pipe I6 connects the exchanger 60 to cooling coil II which is stationed in the condenser box I2. Pipe 13 connects cooling coil II to secondary residuum tank I4. Pipe I5, controlled by the valve I5, connects secondary residuum tank I4 near the bottom, to a storage not shown. Pipe 48, controlled by the valve 41, connects the discharge side of pump IIII to pipe 49. Pipe I82 connects the inlet side of pump IIII to pipe '98. Pipe 98, controlled by valves 98' and I98, connects charging stock tank I toi'ecycle stock tank 68. Pipe 99, controlled by valve 99', connects pipe 98 to re-cycle stock tank 2| Pipe connects pipe'9I to an absorber not shown by means of which the gasoline stock retained by the hydrocarbon gases may be separated and returned to the gasoline tank 92.

The preferred process as carried out in the apparatus just described is as follows:

Tank is filled with the petroleum oil to be processed, such as gas oil stock, from a source not shown. The gas oil stock, termed charging stock" contained in tank I-, is caused to pass in a regulated stream flow through pipe 2 into the in- 5 let side of pump 4, by operation of valve 3. Pump 4 continuously discharges the gas oil stock through pipe 5, heat exchanger 6, pipe I and heater coil 8, under a pressure suiilcient to prevent any substantial vaporization during the passage through heater coil 9, preferably using a terminal pressure of approximately 1000 pounds, although higher or lower pressure may be used, depending upon the stock to be. cracked and the temperature employed. This oil passing through heater coil 9 is heated to a temperature of approximate-- temperature by the continuous introduction of a bypassed portion of the charging stock coming through pipe 19, which connects pipe 5 to pipe I0, the flow, being regulated by operation of valve 96. This introduced oil not only cools the cracked oil stream to a temperature below an active cracking temperature of approximately 800 to 875 degrees F., depending upon the oil to be cracked, but

is itself partially cracked with the formation of gasoline stock. From ,pipe, I0 the cracked oil stream passes through pressure relief valve I I and into fractionating tower I3 wherein the naphtha having boiling points up to approximately 450 degrees-F, produced by the primary cracking operation, is separated from a primary higher boiling distillate termed "recycle stock". This primary "recycle stock passes. frOm 'i'ractIonatIng tower I3 through pipe I9, exchanger 9, pipe II,

cooling coil I9, which is stationed in the condenser box I8, then through pipe 20 and into rej-io cycle stock" tank 2|.

storage not shown and may be used for fuel pur-' poses or other purposes known in the art. I

The "recycle stock collecting in the tank 2I, is

55 employed as a wash oil to assist in the fractional separation of the naphtha vapors from the higher boiling oils, in which a regulated quantity of this stock continuously passes from tank 2| in a regulated stream flow, 'controlled'by valve 23,

60 through pipe 24 and into the suction side of pump 25. Pump 25 continuously discharges this recycle stock through pipe 26, which ends in a spray pipe 28 stationed in the top of fractionating tower I3. This spray oil or recycle stock" after passing through contactmaterial I4, collects on the separator plate I5 and is returned to tank 2I, as heretofore described. The excess "recycle stock which collects in,tank 2| may be employed 'alone.or mixed with charging stock as an in- 70 Jection oil, to lower the temperature of the cracked oil vapors leaving cracking .-'coil 52, in

which case the required amount is permitted to now continuously through pipe 99 and into pipe 90- by operation of valve 99'. Pipe 93 conducts this 75 recycle stock into branch pipe I02, which is con nected to the inlet side of pump IOI. Pump I0l discharges this recycle or injection oil through pipe and into pipe 49, the flow being controlled by operation of valve 41. By operation of valve I00 the secondary recycle stock in tank 69 may heater coil 52, as heretofore described; Pipe I59,

controlled by valve 99', conducts the excess recycle stock to a storage not shown, from whence this stock may be returned to the system along with other petroleum oil stock to be again processed. As illustrated, recycle stock may be drawn from the tank 69 by a pump I01 through linw 99 and I08 and conducted through line I09 to the charging tank I.

The naphtha vapors separated in fractionating be used as an injection oil. By a regulated opentower I3 pass through pipe 21 and into fractionating tower 29 wherein further fractionation is effected in which a higher boiling fraction termed "heavy ends is separated from the lower boiling naphtha vapors. The heavy ends separated in fractionating tower 29, pass out of tower 29 at the bottom through pipe 35, the rate of flow being controlled by operation of valve 33, and then pass through exchanger 36, pipe 31 and into cooling coil 39,- which is stationed in the condenser box 39. From cooling coil 39 the cooled "heavy ends pass through pipe 40 and are collected in "heavy ends tank 4 I. In order to facilitate the fractionation operation in tower 29a portion of the "heavy ends collecting in tank 4| are used as a wash oil. The heavy ends continuously collecting in tank 4I are continuously permitted to flow through pipe 42 and into'the inlet side of pump 43-which discharges the vsame through pipe 44 into pipe .33'.:. By means of regulated openings of valves 45 and 46, the flow of "heavy ends" passfrom pipe 63' through exchanger 62, pipe 62', ex-

changer 90, pipe 6|, exchanger 36, pipe and into cracking coil 52, which is stationed in the furnace 5L- That portion of the heavy ends which passes out through spray pipe 30 into fractionating tower 29, assists in the fractional separation' and condensation of the heavy ends" contained by'the naphtha vapors entering tower 29. The wash oil, together with the heavy ends separated from the naphtha vapors, pass out of tower 29 and into heavy ends tank 41, as heretofore described.

The heavy ends" produced by the aforesaid fractionation operation pass through heater coil 52 under a pressure suflicient to obtain the desired rate of flow and to control the volume of vapors passing therethrough, which may range from approximately atmospheric up to 100 pounds terminal pressure. The: heavy ends" passing throughthis coil 52 are vaporized and. heated in a vapor state to a temperature of aprecycie" stock tank 2| and/or tanix: 98, or

charging stock tank i, as heretofore described.

The regulated amount of cool oil introduced into the cracked oil vapors leaving heating coil 52v is suillcient to cool the products of the cracking re- 5 action below an active cracking temperature and .at the same time partially crack the introduced oil. The products of the secondary cracking operation pass through pipe pressure reducing valve 49' and into fractionating tower N wherein the gasoline boiling point stock produced is separated from the 'higher boiling oil and passes in a vapor state out of fractionating tower 54 through pipe 16, and into condenser coil 18 wherein the gasoline boiling point stock is condensed to a liquid and collected in tank'tl'passing from the said condenser coil It through pipe 9i which is connected to tank 92. The "gas'oline stock collected in tank 92 may be conducted to a storage not shown, through the pipe 93, con-. BO-trolled by the valve 91' and may be thereafter commingled with the primary blending stock and purified by methods known in the art to produce a motor fuel having a desired range of boiling points and containing ahigh percentage of carbocyclic hydrocarbons in quantities suflicient to render the blended gasoline stock suitable-for use in motors witha high compression ratio.

- Pipe 59, controlled by thevalve 58, conducts the residual. oil separated by the fractionation operation in tower 64, 'through exchanger 60, pipe", cooling coil Ii, pipe I3 andintotank ll termed secondary residuum". This secondary residuum which collects in the tank 14 may be conducted to a storage not shown by opening valve 15' in the pipe II, and may thereafter be utilized as a fuel oil, or for other purposes known in the art. The higher boiling distillate resulting from the fractionation operation in tower, N which collects above the- separator plate 58, 40 passes out through pipe 51, heat exchanger-62, pipe 84, cooling coil 65' and into re-cycle stock tank 68. The recycle stock tank 68 contains the higher boiling distillate from the secondary cracking operations and as heretofore stated,

. this stock maybe used as an injection oil to cool down the products of reaction leaving the cracking coil 52, either alone or in conjunction.

with the charging stock from; tank .I; or the recycle stock may be conducted to a storage not shown by opening valve 69' in the pipe II, and

latter fraction is subjected to a cracking treatment at high temperature-and the resultant gas- 5 oline fractions are blended with'the first mentioned low boiling fractions which are not trea .tedv

with the higher heat-as are the high boiling fractions; in this way a great economy is effected as practically one half of the hydrocarbons are elim'- 7 inated from the highheat-treatment and yet the final product inboth processes will, result in a motor fuel of high non-detonating qualities which is the object of the two inventions.

Furthermore, I have discovered that by the elimination of the low boiling fractions that the 1.4 In the conversion of higherboiling hydrohigher boiling fractions are more readily cracked at the elevated temperature employed and a greater yield of carbocyclic hydrocarbons are produced than if the low boiling fractions were present, during the cracking operation. a 5

The primary blendingstock collected in tank 81 may be mixed with' the secondary blending stock-in tank 02; or tanks .1 and 02 may be the same tank and the blending of the stocks could be made as the stocks are produced, but for sim- 10 plicity and clearness of the operation, I have shown the two tanks separately; also if theprimary and secondary blending stocks should require separate chemical treatments, the two stocks maybe kept separate." Furthermore, it 15 may be desired to use the secondary blending "stocks as a motor fuel by itself without being as the use of various heat exchangers or fraction- 1 ating devices known in the art, and the invention includes all such modifications and changes as appear within the scope of the appended claims.

What I claim is:

carbon oils into lower boiling ones, process that comprises subjecting higher boiling oil in a primary reaction zone to cracking temperature to effect cracking, primarily separating"the-re- 35' sultant naphtha stock from higher boiling materials, secondarily separating by fractionation the higher boiling portions of said naphtha stock consisting mainly of hydrocarbons in the gasoline boiling range from the lower boiling portion thereof, passing the said separated gasoline hydrocarbons through a heating coil wherein the gasoline constituents, are subjected to a temperature-suillcient to elect conversion into products of increased anti-knock value. passing the resultant products from said heating coil to a fractionating zone wherein said products are fractionated. to separate out a gasoline stock and a higher boiling" oil and introducing" said higher boiling oil into contact with" the products passing to said fractionating zone to subject the higher boiling oil thus introduced to cracking. g 1

2.'In the conversion'of higher boiling hydrocarbon oils-into lower boiling ones, the process 5 that comprises subjecting higher boiling oil in a primary reaction zone to'cracking temperature to effect cracking, subjecting the resultantcracked products to --fractionation to separate out a gasoline fraction, a higher boiling cone, densate and a residual stock, passing said gasolinefraction through aheating coil wherein the gasoline constituents are-subjected to a temperature sumcient to effect conversion into products of increased anti-knock value, passing the resultant products from said heating coil to a fractionating zone ,wherein said products'are fractionated to separate out a gasoline stock and introducing at least a portion of aforesaid higher boiling condensate into'contact with the prbd- 70 ucts passing to said fractionating zone to lower the temperature 'of the stream of products '"entering therein.

3.- in the conversion of higher boiling hydro- 1 carbon oils into lower boiling ones. the process sate and a residual stock, passing said gasoline fraction through a heating coil wherein the gasoline constituents are subjected to a temperature suflicient to effect conversion into prod- 10 ucts of increased anti-knock value, passing the resultant products from said heating coil to a fractionating zone wherein said products are fractionated to separate out a gasoline stock and ahigher boiling oil and introducing at least 15 portions of aforesaid higher boiling condensate and of said higher boiling oil into contact with the products passing to said fractionating zone to lower the temperature of the stream of products entering therein.

4. In a process for the conversion of hydrocarbon oil wherein a hydrocarbon mixture containing gasoline components and higher-boiling components is fractionated to separate there from a light fraction containing gasoline components and a higher-boiling fraction, said light fraction is passed through a heating zone and therein heated to a temperature adequate to increase the anti-knock value of its gasoline components, the products are separated into vapors and residue, the vapors are subjected to fractionation in a second fractionating zone for the removal of their insufliciently converted highboiling fractions which are condensed as-reflux condensate, fractionated vapors of the desired end boiling point are subjected to condensation and the resulting distillate and gas are collected,

the improvement which comprises commingling at least a portion of said higher-boiling fraction 1 and said reflux condensate and introducing thethereby commingled oils into the stream of heated oil from the heating zone prior to the separation of vaporous and residual conversion products and efiecting cracking of the commingled oils thus introduced by the heat of the heated oil from the heating zone, whereby the commingled oils are subjected to somewhat milder conversion conditions than those employed in said heating zone;

5. In a process for the conversion of hydrocarbon oil wherein a hydrocarbon mixture containing gasoline components and higher-boiling components is fractionated to separate therefrom a light fraction containing gasoline components and a higher boiling fraction, said light fraction is passed through a heating zone and therein heated to a temperature adequate to increase the anti-knock value of its gasoline components, the products are separated into vapors and residue, the vapors are subjected to fractionation in a second fractionating zone for the removal of their insufliciently converted high-boiling fractions which are condensed as reflux condensate, fractionated vapors of the desired end boiling point are subjected to condensation and the resulting distillate and gas are collected, the improvement which comprises introducing at -least a portion of said higher-boiling fraction into the heated oil'from said heating zone prior to the separation of vaporous and residual conversion products and effecting cracking of the oil thus introduced by the heat of the heated oil from said heating zone, whereby the oil thus introduced is subjected to somewhat milder conversion conditions than those employed in said heating zone.

JOHN C. BLACK.

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