US2078247A - Catalytic conversion of higherboiling hydrocarbons into lower-boiling hydrocarbons - Google Patents

Description

2,078,247 BONS Aprll 27, 1937. J. HoUDRY CATALYTIC CONVERSION OF HIGHER BOILING HYDROCAR INTO LOWER BOILING HYDROCARBONS Filed May ll, 1932 EUS HC HOUdTy Patented Apr. 27,- 1937 UNITED STATES ,PA'n-:NTY ori-ICE INTO LOWER-BOILING HYDROCARBONS Eugene J. lHoudry,

Houdry Paris, France, assignor to Process Corporation, Dover, Del., a

corporation of Delaware Application May 11, 1932, Serial No. 610,567

11 claims This Vinvention relates to improvements in processes of and apparatus for the conversion of higher boiling hydrocarbons into lower boiling hydrocarbons by contact with an active mass at an elevated temperatme and the subsequent refining in contact with another active mass at elevated temperature with the subsequent regeneration or reactivation of these respective active masses in situ.

One object of the invention is to devise improved ways and means for producing a motor fuel suitable for use'in high compression internal combustion engines which is characterized bya high yield of the lower boiling hydrocarbons from higher boiling hydrocarbons, by stability against undesirable oxidation, which often results in the production of objectionable products either in stcirage or in use, and by high antidetonating va ue.

The advantages of catalytic conversion ofV higher boiling hydrocarbons into lower boiling hydrocarbons in accordance with the present invention are indicated by a comparison with conventional thermal decompcsitionor pyrolytic cracking methods by which products having substantially the same antidetonating characteristics are secured. Thermal decomposition of high boiling hydrocarbons causes a non-selective acceleration of reactions at high temperatures with excessive losses due to high gas yields. The product which results is refined only with difliculty and even then the resulting product is inferior as far as stability against' undesirable oxidation is concerned. the present invention eiects a selective acceleration oi certain desirable reactions with losses which are not excessive, i. e. with low gas yields. The product requiresno further refining andhas very high stability against undesirable oxidation. In addition, Va much higher anti-knock rating can be obtained from the same charging stock than is possible with the conventional pyrolytic methods.

'I'he single gure is a diagrammatic disclosure of one form of apparatus for practising .the invention.

Referring to the drawing, the charge of 'material to be converted, such. as gas oil, preferably in a partially heated state, is admitted through valved line 2 and passed with or without admixture of vapor such as steam from valved line 4 into line 8 and thence into pipe vstill 8.' The vapors and atomized portion of the charge preferably pass from still 8 through vapor line '|0 into a separator l2 where the atomized portion Catalytic conversion byis extracted from the vapor and passes as liquid through valved line I4 through heat exchanger I6 through valved line I8 into vented storage tank 20. The vapors pass through line 22 into one of the two valved lines 24 or 28 leading to insulated catalyst chambers 28 and 30 respectively which contain suitable catalytic material for effecting the desired conversion. The resulting products, still in vapor phase, issue either through valved line 36 or 38 into vapor line 40 which includes heat exchangers 42 and 46 and discharges into fractionating column 50 where separation is eiected between lower boiling vapors and higher boiling l'quid. The higher boiling liquid is withdrawn through valved line 52, heat exchanger 54 and Yvalved line 58 into vented storage tank 58. The fractionation desired in the column is partially or wholly controlled by directing some or all of the charge through closed heat transfer system or by circulating a cooling medium through closed coil 62 located in the top of the column or by both such means. The vapors ofthe lower boiling hydrocarbons pass through vapor line 64, heat exchanger 42, vapor line 86 into one of the two valved lines 88 or 10 which discharges into catalyst chambers 12 and 14 respectively which contain suitable catalytic material for reiining and stabilizing the hydrocarbon vapors. The latter pass after treatment by valved line or 82 respectively into vapor line 84 which discharges into a. second fractionating column 86 where separation. again takes place, into lower boiling vapors and higher boiling liquid. The higher boiling liquid is withdrawn through valved line 88, heat exchanger 90 and valved line 02 into vented storage tank 94. The fractionation in column 88 is controlled by means of a distributor 98 in the top of the column to which a portion of the condensate of the inished product is returned. The uncondensed vapors from the. column pass through vapor line- 98 into condenser |00 and thenceby line |02 into gas separator |04. The gas is withdrawn through valved line |06 and the liquid condensate passes through line |08 into vented storage tank ||0. Condensate is withdrawn as needed through valved line |2 and is forced by pump ||4 through valved line ||8 into distributor 88.V s

The fresh feed or charge in storage tank II8 passes through valved line |20 and is discharged under pressure by pump |22 into valved line |24 through heat exchanger 80, line |26, heat transfer system 60, line |28. valved line |80, heat exchanger 54, line |82, heat exchanger 46, valved valved line line |34, heat exchanger I6 into valved line 2. The control offbeat transfer for proper operation of that-'System is maintained by the use of valved lines |36, |38, and |40 as required. 'Ihe charge may also be discharged from pump |22 in whole or in part through valved line |36 into 2. After the fresh feed in storage tank ||8-is exhausted, additional runs on reflux material may be made by connecting tanks 94 and 58V together or in succession to pump |22, until the ultimate yield of the original charging Stock is attained.

The catalytic chambers 28, 30 and 12, 74 are provided in pairs in order that the plant may be in continuous operation, one chamber of each pair being von stream; while the other is in regeneration, and each chamber alternating in function. 'Ihe catalyst used in chambers 28 and 30 may be of any known type which will effect the desired conversion of high boiling hydrocarbons into low boiling hydrocarbons, but must be in a form which will permit regeneration in situ. 'Ihus fragments of metalshaving selective adsorbtive or catalytic activity may be used, such as iron, nickel, cobalt or molybdenum, or oxides of such metals, especially when supported on a suitable carrier, or fullers earth or activated hydrosilicate of alumina in molded form, especially of restricted ferrie oxide content` (not more than 3%) as disclosed in my copending application Serial No. 600,581, filed March 23, 1932. Catalytic material having the necessary selective adsorptive properties to remove gum-forming constituents from the transformed vapors and to stabilize the Same may be taken from 'the above list for refining chambers i2, lli, but by preference it' comprises activated hydrosilicate of alumina of the composition described in my aforesaid copending application having admixed therewith a suitable metallic oxide, such as nickel oxide, and the mixture molded into rigid pieces of suitable siz'e and shape. By preference, regeneration of the catalytic mass in each of the aforesaid chambers is effected in situ by first admitting steam and then air with steam or with other inert material, such as flue gas, in order to control the temperature of regeneration, as disclosed in my copending application Serial No. 604,997, filed April 13, 1932. The regenerating medium may be admitted to catalytic cases 28 and j |40 and the fumes may be vented therefrom through valve outlets |42 and' |44 respectively. Similarly a regenerative medium to be followed later by a reducing gas may be supplied to the rening chambers 12, 14 by valved inlets |46 and |48, respectively, and the fumes may be vented therefrom by valved outlets |50 and |52, respectively- The operation of the apparatus for the conversion of higher boiling hydrocarbons into lower boiling Vhydrocarbons may be further described by giving the details of typical runs with two different charging stocks, including the approximative operating temperatures and pressures. A. fresh Coastal gas oil charging stock with a distillation range from 400 to 700 F. and a gravity of 28 AIP. I. was fed to pipe still 8 whose outlet temperature was maintained at about 850 F. Any unvaporized portion of the oil was segregated in tank 20. The vapors passed at about 845 F. into one of vthe two conversion chambers28, 30 in contact with the catalyst therein which was .maintained at a temperature of about 835 F. and

under a gauge pressure less than 15 lbs. per sq. in. The pressure was merely for the purpose of forc- 30 by valve inlets |38 and/"75%.

ing the vapors through the system. 'Ihe vapors were cooled by passing through heat exchanger 42 umn 50 where they were separated into lower boiling hydrocarbons of approximately motor fuel distillation range and into higher boiling hydrocarbons which were collected as liquid in tank 58 and were subsequently used as a charging stock for another run. The fractionation in the column was controlled by the use of partially heated charging stock in line 60 and by cooling coil 62 in the top of the column. The vapor issuing from the top of. the column at about 335 was stepped up to about 650 F. in heat exchanger 42 and then passed into one of the two rening and stabilizing chambers l2, l@ where the temperature was maintained at about 650 F. The refined and stabilized vapors were then conducted to the second fractionating column 86 where nal separation of the hydrocarbon mixture having exactly the desired motor fuel distillation range was effected and the heavier portion passed to tank 94 for later use as charging stock for another run. 'I'he denser |00 and after separation of the uncondensable gas in element |04, the`condensate was run to the storage tank H0. A portion of this condensate was returned to the top of the second column to control fractionation. The pressures in the various elements of the system were kept as low as possible.

and 46 and discharged into fractionating col- After the exhaustion of the fresh feed, the botv toms of the two fractionating columns 50 and 86 were used as charging stock. The operation was the same as in the case of fresh charging stock except that the pipe still outlet temperature was raised to about 895 F. and that of conversion chambers 28 and-30 to about 875 F. The heavier hydrocarbon fractions obtained from the bottom of the two fractionating columns when using this stock was then accumulated for use as second rerun stock. The operation using this last -stock was the same as for the fresh charging stock with the exception that the pipe still outlet temperature was again raised to about 950 F. and that of the conversion chambers to about 92.5 F.

The ultimate yield of finished motor fuel with distillation range corresponding to U. S. motor fuel V from the fresh charging stock was above This motor fuel required no further treatment of any kind. Chemical and physical analyses and tests showed it to be of very high quality. Its high antiknock characteristics were indicated by its octane number and its chemical stability was' shown by the results obtained from several oxidation tests. The oxidation induction period for this motor fuel was 25 hours when exposed to an atmosphere of oxygen at a pressure of lbs. per sq. in. and at a temperature of 212.F. No residue was left after evaporation of 100 c'c. in either a glass dish or a copper dish.

A fresh Pennsylvania gas oil charging stock with a distillation range of 400 to 700 F. and a gravity of 40 A. P. I. when processed in exactly the same manner as the Coastal gas oil gave approximately the same yield; The-quality of the motor fuel of the same distillation range as that obtained from the Coastal gas oil was the Vsame with the exception that the octane number .was85.

The examples given are not intended injany Way to restrict the .effective operation of the process and apparatus over other temperature and pressure; A few of the moreimportant values for pressure and `temperature are as follows. The pipe still mayoperate at.presmission of air but where the activityof the cat-f alyst will not be destroyed or impaired. For supporting combustion it cannot drop much below 700 F., but its upper limit will depend largely upon the catalyst which is used. With hydrosilicate of alumina of the type disclosed in my aforesaid copending application Serial No. 600,581, which is the preferred catalyst, the temperature of regeneration should not be permitted to rise much above 1050 F. While the use of substantial pressure in the system may be desirable under certain conditions, it appears to reduce the antiknock qualities of the product and for this reason in the production of a gasoline for present day high compression engines the pressure in the system should be kept as low as possible, especially in the catalytic chambers.

I claim as my invention;

1. The process of producing completely refined low boiling hydrocarbons of superior stability and antiknock rating from high boiling hydrocarbons in a continuous operation which comprises continuously vaporizing the high boiling hydrocarbons by raising their temperature above 800 F., transforming the resulting vapors at a temperature, not over 1000 F., by the action of a contact mass having suitable selective adsorptive or catalytic properties comprising activated hydrosilicate of alumina in molded form, cooling and fractionating the resulting vapors to separate out the desired low boiling products, raising the desired low boiling products to a temperature above 500 F. by heat exchange with the vapor products of said transforming step while cooling said last named products, and rening and stabilizing the said desired low boiling products at a temperature between 500 and 700 F. by the action of contact material having suitable selectiveadsorptive or catalytic properties comprisin' e sentially activated hydrosilicate of alumina n molded pieces. u

2. Process oflmanufacture of high-antimocx, low boiling hydocarbons from high boiling hygirocarbons comprising vaporizing the high boiling hydrocarbons by heating them to 8001020 F., contacting the vapors ata temperature of 800-to 1000 F. with either of two catalytic masses having A selective adsorptive properties and comprising essentially activatedhydrosilicate of alumina in molded pieces to effect a partial conversion, cooling the converted vapors, separating the latter into `low boiling vapors and high" boiling liquid, cooling the high boiling liquid, heating the low boiling vapors by heat exchange'with said con verted vapors, contacting the low boiling vapors at a temperature of 500 to 700 F. with either-oi adsorptive properties and comprising activated hydrosilicate of alumina mixed with metallic oxide -in molded pieces, separating the resulting products into lower boiling vapors and higher boiling liquid, condensing the lower boiling vapors to secure aV finished product Vand alternately regenerating the contact masses for each of said catalytic operations in order that the process may be operated continuously.

3. Process of manufacture of high antiknock, low boiling hydrocarbons from high boiling hydrocarbons comprising vaporizing the high boiling hydrocarbons by heating' them to approximately 850 F., contacting the vapors at approximately' 835 F. with either of two catalytic masses having selective adsorptive properties and comprising essentially activated hydrosilicate of aiumina in molded pieces to effect a partial conversion, cooling the converted vapors and eiecting a separation into low boiling vapors and high boiling liquid. cooling the high boiling liquid, heating the low boiling vapors by heat exchange with said .converted vapors during the cooling ot the latter, contacting the said low boiling vapors at approximately 650 F. with either ottwo refining catalytic masses having selective adsorptive propertles and comprising activated hydrosilicate of alumina mixed with metallic oxide in molded pieces, separating the resulting products into lower boiling' vapors and higher boiling liquid, cooling the higher boiling liquid, condensing the lower boiling vapors to secure a hnished product, maintaining continuous operation of the process by alternately regenerating the contact masses for each of said catalytic operations and effecting a partial heating oi the high boiling hydrocarbon charge by heat exchange selectively with the said separated liquids before saidrst named va.- porizing step.

4. Process of manufacture of high anti-knock stable low boiling hydrocarbons from high boiling hydrocarbons comprising vaporizing the high boiling hydrocarbons by heating them to a temperature above 800 F., separatingfentr'ained liquid yfrom the resulting vapors, cooling the separated verted vapors by heat exchange with the high boiling hydrocarbon charge, separating the converted vapors into low boiling vapors and high boiling liquid, cooling the high boiling liquid, contacting the low boiling vapors after heat exchange v with said converted vapors at a temperature of 500 to '700 F. with either of tworeiining catalytic masses having selective adsorptlve properties and comprising activated hydrosilicate of alumina and nickel oxide in molded pieces, separating the resulting products into lower boiling vapors Aand higher boiling liquid, cooling the higher boiling liquid, condensing the lower boiling vapors to secure a finished product, selectively heating said charge by heat exchange with the said separated liquids, and alternately regenerating the contact masses for each of said catalytic operations in order that the process may be operated continuously.

5. In the refining of low boiling hydrocarbons in the fgasoline boiling range, the process steps of heating low boiling gasoline materialsubstantially free or higher boiling 'material to a temperature above 500 F. and contacting the latter while in M vaporphase and ata temperature within the two refining catalytic masses having selective.

range of 500 to 700'? F. with a single catalytic mass having selective adsorptive properties and.

capable of rening and stabilizing said vapors,

saidl mass being subject to poisoning by sulphurous material and comprising activated hydrosiliby sulphurous materials, said mass being formed in molded pieces capable of regeneration in place.

6. In'the rening of low boiling hydrocarbons in the gasoline boiling range, the process' steps of heating low boiling gasoline material substantially 5 free of higher boiling material to a temperature above 500 F. and contacting the latter while in vapor phase and at a temperature within the range of 500 to '700 F. with a single catalytic mass having selective adsorptive properties and capable 10 of renning and stabilizing said vapors, said mass comprising activated hydrosilicate of alumina mixed with nickel oxide and formed in molded pieces capable of regeneration in place.

7. in the refining of low boiling hydrocarbons l5 in the gasoline boiling range, the process steps of 20 having selective adsorptive properties for removing gum forming/constituents and for rening and stabilizing said vapors, said mass made up oi molded pies formed of activated hydrosilicate of alumina containing nickel oxide and intended for regeneration in place.

8. Apparatus for the catalytic conversion of higher boiling hydrocarbons into lower boiling hydrocarbons comprising a still, a plurality of catalyst chambers, means selectively to conduct vallors from lsaid still to said chambers, a fractionating column, a heat exchanger connected to the outlet of said chambers and to the top of said column, means to conduct vapors from said chambers through said heat exchanger to the bottom of said column, a plurality of rening catalyst chambers, means selectively to conduct vapors from said column through said heat exchanger to said reining chambers, a second fractionating column, condensing means for vapors issuing from said second column, and means for edecting regeneration of the catalytic masses in all of said chambers whereby each chamber maybe used alternately on stream and in regeneration icry continuous operation ci the apparatus.

9. Apparatus for the catalytic conversion of higher boiling hydrocarbons into stable lower boiling hydrocarbons comprising a still, a plurality of catalyst chambers maintained ata ternperature above 800 F., means selectively to conduct vapors from said still to said catalyst chambers, a fractionating column, a heat exchanger, means to conduct vapors from said chambers through said heat exchanger to the bottom of said column, a plurality of rening catalyst chambers maintained at 'a temperature not over 700 F., means selectively to conduct vapors from said column through said heat exchanger to said redning catalyst chambers, a second fractionating column, a condenser for vapors from said second column, discharge lines for liquid from both of said columns, means in said lines for cooling said liquids, means for selectively utilizing said last named means partially to heat the charge fed to said still, and means for edecting regeneration of the catalytic masses Within all of said chambers in situ whereby continuous operation of said apparatus may be eected.

10. Apparatus for the catalytic conversion of higher boiling hydrocarbons into high antiknock lower boiling hydrocarbons comprising a still, a separator for entrained liquid connected to said still, a plurality of catalyst chambers maintained at a temperature between 800 and 1000'J F., means selectively to conduct vapors from said separator to said catalyst chambers, a fractionating column, a heat exchanger,` means to conduct vapors from said chambers through said heat exchanger to the bottoms of said column, a plurality of refining catalyst chambers maintained at a temperature between 500 and 700 F., means selectively to conduct vapors from the top ci said column through said heat exchanger to said reiining catalyst chambers, a second fractionating column, a liquid discharge line from said separator having a heat exchanger therein, a liquid discharge line from said first column having a heat exchanger therein. a liquid discharge line from said second column having a heat exchanger therein, means for selectively conducting charge through said three last named heat exchangers to said still, means for selectively admitting a regenerating medium to each oi said chambers, and means for conducting the fumes oi regeneration from each of said chambers.`

ll. Apparatus for the catalytic conversion of higher boiling hydrocarbons into stable low boiling hydrocarbons comprising afstill, two catalyst chambers, means selectively to conduct vapors from said still to said catalyst chambers, a fractionating column, a heat exchanger, means to conduct vapors from said chambers through said heat exchanger to the bottom of said column, two refining catalyst chambers, means selectively to conduct vapors from the top of said column.

through said heat exchanger to said rening catalyst chambers, a second fractionating column, condensing means for the vapors issuing from said second column, discharge lines'or liquid from the bottom of both said columns, a heat exchanger in each line, means for selectively conducting charge for said still through said. last named heat exchangersvand means for eiecting regeneration in situ of the catalytic masses in all said chambers whereby continuous operation of the apparatus may be eiiected, by having one of each pair of chambers in operation while the other `is in regeneration.

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