US2726196A

US2726196A - Gilsonite conversion

Info

Publication number: US2726196A
Application number: US328738A
Authority: US
Inventors: Ward J Bloomer
Original assignee: Lummus Co
Current assignee: Lummus Technology LLC
Priority date: 1952-12-30
Filing date: 1952-12-30
Publication date: 1955-12-06
Anticipated expiration: 1972-12-06

Description

Dec. 6, 1955 w. J. v BLOOMER GILSONITE CONVERSION Filed Dec. 30, 1952 w ,R m m lJ 1 United States Patent Ofifice 2,726,196 Patented: Bees 6, 1955 GILSONITE CONVERSION Ward J. Bloomer, Westfield, N. J., assignor to Lummus Company,- New" York,-N-.-Y.,- a corporation of Delaware Application Decemlier 30; 1952', Serial No; 322L738 Claims. (Cl. 196-50) This invention relates retire" recovery of available end p'r'oductsfrom the class of: material known as asphaltites of which gilsonite is ap'articular example.

It" is known that'the asph'alt'ites and gilsonite in particular, is a' solid bitumen which has a melting 'point'irrthe orderot270" F. toabout 400 F., normally contain's'less' than5 volatile matter and-has a fixed carbon content in the range of 10'3()%'. The most particular characteristic of-gilsonite, however, is' the fact that when heated to'a temperature above 500 F., there is formed aconsiderable quantityof gas' andtherelease of substantial quantities of heat which tend to convert the liquid gilsonite' directly into a solid' coke' material which has a relatively low value.

To -date, the difiicultiesin heating gilsonite to a necessary extenthave made it impossible to recover the 'valu-' able hydrocarbons on acontinuous commercial basis; I

have' found that if the gilsonite is heated in the presence of a liquid hydrocarbon of selectedboilingzrange insuch' ratios that'the' exothermic heat can'belargely dissipated byi'the vaporization of the hydrocarbon, it is possible'to' heat the gilsonite to a suificientlyhigh degree so that it can be-ultim'atelyreducedto a dry cokeby; chargingxitto of the liquid having suificiently high latent heat present so that enough of the exothermic heat is absorbed to pre vent excessive gassing and temperature rise of the mixture. F or-this purpose, I prefer to use a gas oil of about 700900 F. end point. Such a liquid has the advantage that it'will tendto partially dissolve the gilsonite and being an adjacent fraction may be readily handled not only in a cracking heater, but in fractional distillation-equipment and in a continuous coking operation; There are other liquids however, which could be'used solely for the ab-' sorption of the exothermic heat which would'permit the recovery of the low boiling end products following the preliminary cracking stage. a

My invention further contemplates the reductionof the liquid residue from the first fractional distillation step to a dry coke which may be effectively used as a circulating mediurnina continuous coking operation of the type described in the co-pending application of August'I-Ienry Schutte Serial No. 252,306, filed October 20-, 1951.

The attached drawingshows a schematic view of the complete equipment for the reduction of powdered gilsonite to its ultimate end products.

In accordance with a preferred form of embodiment of my invention, ground or pulverized gilsonite is collected ina hopper 1 from which it may be distributed at a; desir ed" rate by the conveying mechanism Zinto a dissolving 2' tank 5. Tank -5 is'providedwith lock gates 3--and 4 'tomaintain the tank in a closed manner.

The dissolving tank-5 is provided 'witha heating coil6 whichmay'be interconnected 'to a: steam or other heat: source to maintain -the tank at about 500- F., the-'rnix ture being in a generallyliquid mass resulting-from the addition of suitable diluent from the-line 7. Aheater s is provided in line 7 to bring the diluent'to the desiredsolution temperature. As heretofore described, this liquid-is preferably a high boiling hydrocarbon-ofithe general boilingrange of agas oil. Approximately /s :to /2 as much liquid is added to the tank aspowdered gilsonite. I

The gilsonite liquid mixture'is maintained as-aslurry or solution which is preferably agitatedby the agitator 9 and is drawn oif with-substantial uniformity through-the bottom drawoti 10 through the valve 10a andis-pumped by the pump 11 to the heater 12 Heater i2 is asuitable coilheater which may be provided'with a convection as well as a main heat section. The oil is introduced at about 500 F. and" is then heated to a temperature substantially above the tempera ture of incipient coking an'd preferably'to about 776 775 F. during which partial cracking-takes place.

During the heating 7 period',- substantial quantities" of heat are released by the-"exothermic decomposition of the gilsonite? I have found that-if the diluent hasa sufficiently high latent heat and is'pre sent insuficient' quantities}. enough of the exothermic heat is absorbed to prevent the gilsonite changinginto-coke. intact, the appearance-of the efrluentfrom the heater 12'at13 appearsto be=of"a heavy gas-oil nature. This material is introdueed-at the outlet temperature through valve 1& into the fractionating.

column 17: Introduction of the eilluent into the column may result in some foaming. Thisfcan-be eifectivelyflm hibited by the addition of a small am'ount of an anti-foam agent, at the pointof introduction o'rat'somepo'inthigher up in the column. v

The column 17 is provided" with suitable 'fi actionating decks 18* and is preferably provided with l arelioiler'3 Column 17 may also be 'providedwithsteam stripping ldfor the purpose of driving the light' ends oVerhead through the line 19;-

The overhead vapors comprising:cohdensi-ble andnon condensible portions are withdrawn-- throughline 19: These may betreated in a conventional mannerto-separate condensible hydrocarbon vapors from the'prod-uctsof gasification which include valuable amine compounds. The production and recovery of the amine compounds from the raw gilsonite is one of the important features In a lower part of the tower"a-heavy-distillate-is-with drawn throughline 29 under the control of'valv'30I Th" heavy distillate withdrawn is returned by lines 7z-and 7 todissolvingtank-S. Some heavy distillate may appear in the asphalt bottoms in the lower part of the tower. While the presence of excess amounts of heavy distillate is not desirable in the asphalt bottoms since it will abstract heat from the coke-bed in the cokingi reactor, thepreseirce of some heavy distillate is desired to'maintai'n thecoker charge in partial dilution duringtransfer.-

It is generally desirable to reduce the gilsonite to its ultimate end products of gases, coker distillate and solid coke. This may be accomplished by pumping the asphalt bottoms in line 34 to the continuous coker indicated at 32 through which passes a continuous stream of relatively small, hard coke pebbles as disclosed in August H. Schuttes U. S. Patent 2,600,078.

The continuous coker 32 is maintained full of such carbon particles and the liquid asphalt solution in line 34 is injected onto the coke pebbles at 36. This results in a continuous vaporization of the lighter ends of the charge by the preheated coke. The vapors are removed through the vapor outlet 35 and the coke particles continue to move downward through the outlet zone 42. A steam purging ring is provided at 43 below the vapor take-off 35 and in such position as to insure dryness of the coke particles as they pass downward and out through the outlet conduit 44.

Pressure is maintained in the reactor 32 sufficient to discharge the coke particles through the line 44 to the vapor release chamber 45 from which the particles flow through control valve 46 and through the separator 47 with the desired size of particles passing into the reheater 51 through the inlet 52. Oversize particles may be removed from the bottom of the separator 47. Undersize particles may also be removed from the separator 47 and returned to the system through the line 48.

Reheater 51 is of a radiant type being provided with a series of burners 53 in the upper part of the reheater, such burners being supplied by gas and air from the lines 54-55 in a well known manner. Particles of coke are heated to the desired extent and continuously moved downward past the flue gas collector 57 with the flue gases removed at line 58 and passed to the stack at 60.

Outlet from the reheater is through a series of lock and forwarding

tanks

61 and 62 which are provided with suitable valves 63 and 64 that are in turn operated in cycle manner by the controller 65. The tanks are provided with steam inlets which are also controlled by the controller to permit the movement of the coke particles to the reactor 32 by line 37.

The vaporous material removed from the reactor 32 which is recovered through line 40 is quenched by oil entering line 39, partially condensed and passed into the fractionator 41 from which a heavy gas oil is removed at 72 and is used to supplement, if necessary, the hydrocarbon used as the gilsonite diluent. A lighter overhead material may be removed at 71 and a heavier product may be removed at 73. The material in line 73 may be recycled to the coker 32 if desired. 4

Example I In accordance with my invention a mixture of 75 weight per cent of gilsonite, and weight per cent of a 100 neutral distillate blend were heated in a lead bath type heater and introduced into an atmospheric flash chamber with the following results:

In an experiment carried out at 100 mm. Hg abs. in which a waxy gas oil blend was used as solvent and 100 parts per million of an effective anti-foam agent was added, the following results were obtained.

5 3 Heater Heater Overhead Run No res Bath Outlet Temp., Temp.,

Hg 5 F. F. Percent Example III In a further experiment carried out at 100 mm. abs. in which a topped coker distillate recycled from batch coking of gilsonite was used as solvent, with 100 parts per million of an anti-foam agent added, the following results were obtained:

In all the foregoing runs, it will be noted that the heater temperature was maintained considerably above the normal coking temperature of gilsonite with no coking of gilsonite occurring.

While I have found it desirable to direct the flow of heater effluent into a flash or distillation tower as previously described, I also contemplate charging the heater eflluent directly to the coking reactor by line 13a, by-passing tower 17. The presence of considerable quantities of diluent along with other gasiflcation products will abstract some heat from the coking reactor bed and the end product distribution obtained in the coking reactor will vary somewhat from that obtained in the heater-tower system because of temperature and processing diiferences. The desired arnine compounds can be recovered along with the diluent in the coking distillate tower 41. Condensed reaction product with desired diluent properties may be returned to the dissolving tank along with the original diluent.

It is apparent that my invention provides a simple method of treating gilsonite to obtain valuable products therefrom by effectively avoiding exothermic heat and the accompanying formation of coke.

It will be evident to those skilled in the art that various modifications of this invention can be made in view of the foregoing description without departing from the spirit or scope of the disclosure or from the scope of the appended claims.

I claim:

1. The method of recovering valuable hydrocarbon constituents of a normally solid asphaltite, which comprises forming a solution of ground asphaltite together with a high boiling hydrocarbon liquid having an end point of between 700 to 900 F. and directly heating such mixture to a cracking temperature above the incipient coking temperature of the asphaltite in the absence of coke formation, the quantity of liquid and its latent heat being such that the exothermic heat given ofi by the asphaltite during heating and cracking is largely dissipated in the vaporization of the high boiling liquid.

2. The method of recovering valuable hydrocarbon constituents of a normally solid asphaltite which comprises forming a solution of ground asphaltite with a high boiling liquid hydrocarbon, heating the mixture directly to a cracking temperature above normal coking temperature of the asphaltite in the absence of coking, the quantity of liquid and its latent heat being such that exothermic heat given off by the asphaltite is dissipated in the vaporization of the high boiling hydrocarbon and coking of the asphalitc during heating is prevented, and introducing the efiluent from the heating step into a fractionator to recover valuable overhead and bottoms products.

3. The method of recovering valuable constituents of a normally solid asphaltite as claimed in claim 2 in which the bottoms from the fractionator are converted to dry coke and vaporous overhead and said overhead is condensed and used in part as the liquid solvent for the asphaltite.

4. The method of recovering valuable constituents of a normally solid asphaltite which comprises forming a solution of ground asphaltite with a high boiling liquid hydrocarbon diluent, heating the mixture directly to a temperature above which the asphaltite normally cokes and at which some cracking of the asphaltite occurs, absorbing exothermic heat from the asphaltite during cracking by direct vaporization of the high boiling liquid hydrocarbonate diluent and preventing the formation of coke during said heating, introducing the vaporized hydrocarbon diluent and cracking products of the asphaltite into a distillation tower, recovering an overhead product including amines and condensible hydrocarbons, withdrawing a side cut of a high boiling hydrocarbon from said tower suitable as the asphaltite diluent, withdrawing asphalt bottoms from said tower and converting said bottoms to a valuable coke product.

5. The method of recovering valuable constituents of a normally solid asphaltite as claimed in claim 4 wherein the withdrawn asphalt bottoms are in the presence of at least a portion of the hydrocarbon diluent.

6. The method of recovering valuable constituents of a normally solid asphaltite as claimed in claim 4 wherein at least a portion of the condensible hydrocarbons are condensed and returned to the tower as a reflux.

7. The method of recovering valuable hydrocarbon constituents and amines from normally solid asphaltites which comprises mixing ground asphaltite with a high boiling liquid diluent, heating the mixture to a temperature above the incipient coking temperature of the asphaltite at which cracking of the asphaltite will occur, removing exothermic heat released by the asphaltite during heating by direct vaporization of the high boiling liquid diluent so that no coking of the asphaltite occurs during cracking, passing heated effluent to a vacuum distillation tower, removing tower overhead comprising amines and hydrocarbon vapors, separating the amines and condensed hydrocarbon vapors and returning at least a portion of the condensed hydrocarbons as tower reflux, withdrawing an intermediate cut from said tower having a high boiling point and suitable as asphaltite solvent, returning said side out to be mixed with ground.

8. The method of recovering valuable hydrocarbon constituents from normally solid gilsonite which comprises mixing ground gilsonite with a high boiling liquid hydrocarbon diluent, heating the mixture to a temperature above the incipient coking temperature of the gilsonite in the absence of coke formation with partial cracking of the gilsonite, removing exothermic heat released by the asphalt during heating by direct vaporization of the high boiling liquid hydrocarbon diluent, passing the vaporous products of heating which include the vaporized diluent to a coking reactor, coking the efiiuent therein, passing vapors from the coking reaction to a coking distillate recovery tower, withdrawing an overhead product from said recovery tower comprising amines and condensible hydrocarbons, withdrawing a side out suitable as a gilsonite solvent and withdrawing an asphalt bottoms as product.

9. The method of recovering valuable hydrocarbon constituents of normally solid gilsonite as claimed in claim 8 wherein the amines and hydrocarbons present in the overhead from the distillate recovery tower are separated and at least a portion of the condensed hydrocarbons is returned to the distillate recovery tower.

10. The method of recovering valuable hydrocarbon constituents of normally solid gilsonite as claimed in claim 8 wherein the withdrawn side out is returned as ground gilsonite diluent and the asphalt bottoms from the distillate recovery tower are returned to the coking reactor.

References Cited in the file of this patent UNITED STATES PATENTS 1,940,725 Morrell Dec. 26, 1933 2,006,186 Stines June 25, 1935 2,067,810 Angell Jan. 12, 1937 2,105,874 Aldridge et a1. Jan. 18, 1938

Claims

1. THE METHOD RECOVERING VALUABLE HYDROCARBON CONSTITUENTS OF A NORMALLY SOLID ASPHALTITE, WHICH COMPRISES FORMING A SOLUTION OF GROUND ASPHALTITE TOGETHER WITH A HIGH BOILING HYDROCARBON LIQUID HAVING AN END POINT OF BETWEEN 700 TO 900* F. AND DIRECTLY HEATING SUCH MIXTURE TO A CRACKING TEMPERATURE ABOVE THE INCIPIENT COKING TEMPERATURE OF THE ASPHALTITE IN THE ABSENCE OF COKE FORMATION, THE QUANTITY OF LIQUID AND ITS LATENT HEAT BEING SUCH THAT THE EXOTHERMIC HEAT GIVEN OFF BY THE ASPHALTITE DURING HEATING AND CRACKING IS LARGELY DISSIPATED IN THE VAPORIZATION OF THE HIGH BOILING LIQUID.