Патент USA US2405660код для вставки
Allg. 1.3, 1945." v N_ F_ |_|NN ` l 2,405,660 METHOD OF PRODUCING'l TOLUENE Filed Oct. 17, 1942 „ ` I 5o mxocsn ~ mw 55 '_ ._ ~ . 1 ’ 7; . .if 2 Sheets-Sheet l -`--1 ‘ 88 N. F. LINN ' METHOD oF PRoDUcING @940,650 TOLUENE Filed oct. 17,1942 B3 v ' l 2 sheets-sheet 2 Patented Aug. 13, 1946 2,405,660 -UNITED STATES PATENT kOFFICE 2,405,660 METHOD OF PRODUCING TOLUENE Norman F. Linn, Mountainside, N. J., assignor to Standard Oil Development Company, a corpo ration of Delaware Application October 17, 1942, Serial No. 462,323 3 Claims. 1 (Cl. 26o-673.5) 2 The-present invention is directed toward the fraction is withdrawn through line 5, condensed in a cooler ‘I and thence discharged through line 8 into a naphtha storage Vessel l0. production of automotive fuel and, more par ticularly, it relates to a method of improving a hydrocarbon oil boiling in the naphtha and/or The bottoms from distillation zone 3 and boil gas oil range, particularly as regards octane number, which naphtha or gas oi1 is of the Fischer type. By “Fischer” type naphtha or gas and Hz in the presence of a known suitable cat ing say from 440-650o F. are Withdrawn through line I5, condensed in a cooler Il, thence dis charged through line I9 into a gas oil storage vessel 20. The overhead fraction and the gas oil bottoms alyst and under known conditions of tempera 10 from the distillation zone 3 are treated as will oil, I refer to hydrocarbons synthesized from CO ture, pressure, etc.` As is generally known, hydrocarbons may be “Fischer” synthesized in the presence of suitable be lmore fully explained hereinafter. At the out set it is explained that the- naphtha is sub jected to reforming in the presence of hydrogen, catalysts such as iron, nickel or cobalt either While the gas oil is cracked. ` The reforming op alone or deposited on a carrier such as kieselguhr 16. eration results in the production of aromatics or kaolin. This may be promoted and stabilized which may be solventl extracted to recover, for by alkalies and manganese and copper. These example, toluene with a degree of purity suit products, however, have a very low octane num able for nitration.. The gas oil cracking also re _ber since they are largely composed of normal sults in the production of an automotive fuel parafñns. Broadly speaking, my invention com 20 of high octane number, together with toluene of prises improving the octane rating of such a a high degree of purity. hydrocarbon oil by subjecting it to a combined Continuing the description of the process hydroforming, solvent extracting and catalytic shown in the drawings, the naphtha in storage cracking operation. It is also concerned with vessel I0 is 'Withdrawn through a line 35 and the production of substantially pure aromatics, 25 thence discharged into a heater 32, which may e. g. toluene of so-calledl “nitration grade’.’ by «be a furnace or other suitable heating means, subjecting selected fractions to a combination of Where _it is heated to reaction conditions, thence processes which will be more Vcompletely described below. By “hydroforming” I mean to imply an l discharged through line 35 into a reactor «45 >con taining a _catalyst ofthe type previously indi operation in which the treated oil is subjected 30 cated. Hydrogen from 50 is Withdrawn through to elevated temperatures, say of¥ the order of 900-1000° F. and pressures of 10D-400 lbs. per line 52, heated in a ñred coil or other heating means `53, and thence discharged through line square inch and in the presence of a catalyst, 55 into reactor 40 so it is present with the oil chromia or molybdena- alone or supported on undergoing treatment. vWith respect to operat activated alumina, orother VI group oxide or a 35 ing conditions, the following give good results: mixture of sulñdes, such as nickel and tungsten sulñdes, and also employed in the presence of added hydrogen. The hydroforming operation is, for the most part, one of dehydrogenation With the formation of aromatics and oleñns from 40 paraiiins, accompanied also by some cyclization of paraiiins, aromatization, isomerization and cracking of parafûns, but the operation generally is conducted under conditions such that there is a minimum changein the boiling range of 45 the _charging oil. In the accompanying drawings, vIl have indi cated diagrammatically a flow plan illustrating a preferred modification of my invention. Temperature _____ __ S50-1000’ F., with tempera tures of from about 925 950° F. preferred. Pressure _________ _- From 150-400 lbs. per sq. in. gauge, with about 250 lbs. pressure preferred. ~ Feed rate of oil-____ From 0.5-2 volumes of oil per volume of catalyst per hour on a cold oil basis, with a feed rate of about t 1.2 volumes of oil per Vol um'e of catalyst per hour preferred. Referring tothe drawings fora better under 50 Hydrogen proportion is in the range of from say 2000-4000 cubic feet per barrel of cold oil. standing of my invention, a Fischer synthetic Under these conditions the naphtha undergoes Ahydrocarbon is introduced'into >_the present Sys tem through line >l_ and thence distilled in a fractionator 3 into anv overhead fraction boil-k reforming, and the reformed products are with drawn through line 60 and discharged through Within the- range of fromvlZS-fizeë 1F., which .5_5 a cooler 62. and thence discharged'through line 2,405,660 3 4 phase formed in extraction vessel ||5 and this is Withdrawn through line |69 and discharged into stripper |52 where the solvent is removed withdrawn through line l2 and pumped by by distillation, withdrawn through line |63 and pump l5 to hydrogen storage vessel 55 for fur 5 pumped by pump |54 into storage vessel I Hl. The ther use in the process. substantially solvent-free extract is Withdrawn The bottoms» from the separation drum 'l5 from stripper |62 through line |15 and discharged are Withdrawnthrough line 80 and discharged into.y a fractionating column |15.- The parafûns into fractionator 85 from which several fractions still remaining or associated with the toluene cut are recovered as follows: First, an overhead 621 into a separation drum it. Overhead from separation drum "i0 a hydrogen-enriched gas is fraction boiling within the range cf from about 10 . 13G-210° F. and representing about 44 volume' per cent of the oil in line >853 is withdrawn f through line 38 and discharged after cooling into condenser 90 and thencefintoa gasoline storage vessel |80. The bottoms fraction'repre senting about 39 volume per cent of the product are withdrawn through line |85, condensed in a condenser |32 and thence discharged through line |83 into paraniníc wash solvent storage |20. The toluene is recovered from fractionator |75 through line |90 and thence discharged into an acid treating vessel |92 where it is treated pref erably with sulfuric acid of polymerizing strength, fed to the fractionator 55 is Withdrawn'through ~ - such as about 65% by Weight, or it may be treated with` a polymerizing clay to polymerize the olei'lns line 55, condensed in a cooler 97 and thence dis- . charged into line 88 where it mixes with the to convert them to heavier polymers which may lighter ends from the iractionator and ñow's with the latter into gasoline storage vessel |00. Thus from the reforming omration, the lighter be separated from the toluene by distillation. The thus treated material is Withdrawn through line |95 and discharged into fractionator 28|] from which lighter ends may be withdrawn through line 2id, While the heavier polymers are withdrawn through line 2 | 2. The desired toluene and heavier ends are recovered as gasoline blend ing agents. - ~ Referring again to fractionator 85, a side cut ï is withdrawn as a side stream through line 265 and delivered into a toluene storage vessel 258. The toluene in 268 has a degree of purity suii'icient for making trìnitrotoluene or any other product representing about 17% of materialcharged to `85 and boiling within the range of >from about 21d-259° F. is withdrawn as a side stream through line 55; This " fraction is purified by solvent treatment, preferably, although other means may requiring a high degree of purity. A » Referring to the heavy bottoms of the original Fischer product, it will be recalled that these were collected in storage drum 25. ’This mate rial is to be subjected to-catalytic cracking and towards this end it is withdrawn through vline be employed. Thus, for example, thissfraction -contains normally not only the toluene, but also parailins boiling within the range of 21e-250° F. and a minor amount of oleiins also boiling within this range, although the' presence of hydrogenf _tends to saturate oleñns formed in reactor Ml, 350, discharged into a suitable fired coil or other heating means 3|0 where it is heated to cracking temperatures, say from S25-925° F. and thence tion is to producej paraf?ns andaromatics. »As withdrawn through line 3|2 and discharged into i indicated, these paraiiins in the vboiling range of from 210-250° F. may be removed',y for instance, 40 a catalytic cracking reactor 325 where it contacts a cracking catalyst such as an acid treated mont >by cracking them to products -which’will boil morillonite clay or a synthetic cracking catalyst lower` than the toluene so that after- cracking, so that the final result of the reforming opera the toluene maybeseparated kby simple distilla tion. In the drawings, however, I have shown ¿solvent treating employing SO2 as the selectiveV '~ consisting vof silica :and alumina or silica and 45 Normally good results are obtained by operating ‘ solvent >forthe aromatics. Toward _this end, the « ata temperature of 875° F; andat a relatively low ^- pressure and permitting Ycontact- between the - catalyst and- oil vapors at-reaction temperatures ¿_ of from 15-25 seconds or more. Under these ` SO2 is withdrawn from lthe source ilßland» dis chargedl intothe top of solvent extraction Vessel | |5 Where it flows-countercurrently to the hydro ' carbon oil fraction entering from 55. f Asa fur A- conditions the gas oil undergoes cracking to form >ther aid to the process, a paraftlnicwash solvent -catalytically cracked gasoline in good yields there of» amounting to 35-40‘70. The cracked products ~ such aspentane isV withdrawnffrom the storage >vessel |25- andv discharged-through line z$22 into solvent extraction tower H5» ofcourse, in sol "Vent -extraction tower ||5 the usual» formation ‘ are withdrawn through line 335 and discharged ' into fractionating column 335. ' Unconverted gas is withdrawn from fractionator 335 through line 34B and thence discharged into storage Vessel 20 for further treatment. However, a portion vof this - oil is Awithdrawn continuously through liney342, Yparticularly as it becomes’increasingly refrac tory, and the thus Withdrawn oil may be used’for . of raffinate and extract phases takes place. 4The raffinate phase is withdrawn through line |30 and discharged into a stripping tower |35. This _ rañinate is stripped to remove the SO2 which is withdrawn through line |45 and pumped by pump |1i2 to storage vessel lill. The bottoms from stripper |35 are withdrawn through line |45 and discharged into fractionating column |41. The overhead fraction comprising the paraiiinic wash vsolvent is Withdrawn _from the fractionator |47 »through line |49, condensed in condenser |55, vthence pumped backv through line |5| to the paraf?n storage .|2ll.. >The bottoms from frac magnesia. The catalysts,- as Well as cracking con ditions for this operation are known to the art. a ‘heating oil or for some other purpose. The normally gaseous constituents are Withdrawn i overhead from fractionator 335 through line 358. f 4`These gases contain butylene, isobutylene, normal butano and isobutane and they maybe processed `in means not illustrated to form by alkylation branchV k'chainV hydrocarbons boiling Within the gasoline range, or they may be'converted to syn 'discharged into line |51 leading to gasoline stor-` 70 'thetic rubber intermediates suchY as butadiene, or otherwise-rdisposedof.v ~ _' " q age vessel |55. The bottoms Withdrawn `from «A 'fraction boiling within the rangeïolB` from Yfractionator Ml through line |55 maybe dis charged through line |55 to- either the reforming "100e-40|lf’F. is withdrawn from fractionator 335 tionator |41 are Withdrawn through line |55 and lzone 4i) or the 'cracking zone 320. ~I ’ ‘ " ' As previouslyindicated, there is"an"'e'Xtract 75 `throughiine~360 and discharged into a'fractîon ating 'column‘ 310. ~ AThe product entering 310 is 2,405,660 6 divided preferably into three fractions as follows: first, an overhead fraction containing the lighter ends which is withdrawn through line 380 and condensed in a cooler 38| and thence discharged there will come a time when it is necessary to regenerate the catalyst in the reactionk zones. This may be accomplished, after discontinuing the flow of oil to the reaction Zones, by treating .the catalyst with an oxygen-containing gas, such into stream 88 where it flows with the overhead from the reforming operation into gasoline stor as air, or air diluted with fiue gas, at tempera tures elevated sufficiently to cause burning o-f the age vessel Iûû. The bottoms from fractionator 310 may be withdrawn .through line 390, con fouling deposits. This procedure is well known densed in cooler 39| and also discharged into in the art. Where the catalyst in powdered form gasoline storage vessel |00. Finally, an interme 10 moves in and out of the reactors, it may be re generated in separate regeneration zones and diate cut boiling from 21o-250° F. and represent ing about 10% of the material discharged into thus render the operation continuous. fractionator 310 is Withdrawn as a side stream Another ramification of my process as herein through line 400, and this may be discharged into described involves -including the reproportionat ing of xylenes, formed during the reforming, with line 99 to recover with the product from the re benzene in the presence of a suitable catalyst forming operation, its toluene content, in a man such as AlCla whereby additional quantities of ner which has already been described. toluene may be produced. The details of this In an alternate modification, the intermediate cut boiling from 210-250° F. which is withdrawn process are generally known in the prior art. from fractionator 310y through line 400 Vmay-be 20 What I claim is: discharged into line |58 for ultimate reforming l. A method of producing toluene of high pur in zone G0 or passed through lines> |56 and 305 ity from a hydrocarbon product obtained by the to coil 3|û and thereafter cracked. hydrogenation of carbon monoxide which com prises fractionating the said hydrocarbon product Many modifications of the invention as above set forth may be made without departing from 25 into a naphtha fraction and a gas oil fraction, submitting the latter to a cracking treatment at the spirit thereof. I have shown solvent extract ing a toluene fraction with liquid sulfur dioxide. a temperature of the order o_f S25-925° F. in the presence of a catalyst suitable for promoting the Instead of using this method, I may use another cracking of aliphatic hydrocarbons, recovering a solvent such as phenol, in which operation the vapors to be extracted are treated with liquefied 30 fraction boiling at about 210° to about 250° F. anhydrous phenol. This process or the process from the product of said cracking treatment, com of extracting the liquid SO2 do not form per se bining such fraction With the naphtha fraction the gist of my invention and any known method obtained in the fractionation of the product of for recovering toluene by solvent extraction may the hydrogenation of carbon monoxide, subject be employed. If the solvent is SO2 the tempera 35 ing the combined `fractions to a reforming treat ture maintained in the extraction zone I I5 should ment at a temperature of the order of S50-1000“ be from O to --60° F. or lower. The flow of SO2 F. and under a pressure of the order of 1GO-400 with respect to the hydrocarbon should be from lbs/sq. in. in the presence of hydrogen and a 1-3 parts by Weight of SO2 per weight of hydro catalyst comprising an oxide of a group VI metal, carbons and the volume of paraffinic wash sol 40 recovering from the product of said treatment a vent, for example, pentane from |20 should be fraction boiling at about 210° to about 250° F. from 1/2 to 11/2 volumes of the wash solvent per and treating such fraction to selectively separate volume of liquid consisting of SO2 and the hydro therefrom its aromatic content. carbon in the extractor ||5.v Of course, it will 2. A process according to claim 1 in which the be appreciated that in reactors 40 and 320 the 45 aromatic content of the fraction produced in the reactions therein taking place result in the dep reforming treatment is separated therefrom by osition of cokey or tarry deposits on the catalyst extraction with a solvent, followed by treatment and these operations must be interrupted inter of the extract phase with a parañinic hydrocar mittently to remove these deposits since they de bon solvent lighter than the parafìnic hydro activate the catalyst. This can be accomplished 50 carbon remaining in said extract phase to dis in known manner by burning off the tarry or place the latter, and distillation toÍ remove the cokey deposits with an oxygen-containing gas. said lighter parafñnic hydrocarbon solvent from In the foregoing disclosure, I have described the aromatic hydrocarbon product. my process in terms of fixed or stationary beds 3. A'process according to claim 1 in which the of catalyst. My process may be carried out using aromatic content of the fraction produced in the 55 a suitable powdered catalyst suspended in the reforming treatment is separated therefrom by reaction vapors in the several reaction Zones. extraction with a solvent, followed by treatment Thus, the reforming and/or cracking operations of the extract phase with pentane to displace the may be carried out by flowing the vapors to be parafiinic hydrocarbon remaining in said extract cracked or reformed through a zone where they phase, and distillation to remove the pentane contact a ñuidized powdered catalyst which is from the aromatic hydrocarbon product. suspended in said vapors. Also, of course, in the operationsl described NORMAN F. LINN.