US2354546A - Treating hydrocarbon fluids - Google Patents

Description

July 25, 1944. E. D. REEVES 2,354,546

TREATING HYDROCARBON FLUID Filed Aug. 27, 1941 ZEGENERAT/ON TLUE 25 I a i e 5m" f" 50 H54 nso 06N VE YO A raza /NLAT MPE ST1/.L t y tesuzvonz Patented July 25, 1944 2,354,546 TREATING nYnaocAanoN FLUms Edward D. Reeves, Cranford, N. J., assignor to Standard Oil Development Company, a corporation of Delaware Application August 27, 1941, Serial No. 408,424 y 11 Claims.

The present invention relates to improvements in the art of chemical reactions, and the said invention is fully described in the following description and claims, reference being had to the accompanying drawing.

One object of the present invention is to treat hydrocarbons in the presence of a solid contact -v material.

Another and more specific object of this invention is to provide a continuous viscosity-breaking process for conversion of heavy petroleum materials such as reduced crude into valuable products, such as gasoline, gas oil and coke, in the presence of a finely divided carrier which absorbs the unvaporized liquid constituents and the tar-like deposits resulting from the viscositybreaking operation so that the resulting mixture consists of gases and vapors and solid particles with no liquid present.

A further object of this invention is to subject a. heavy hydrocarbon oil to a viscosity reducing operation, a coking operation or the like at temperatures as high as 1050 F. to about 1200 F. It is generally known that if one carries out a hydrocarbon oil conversion process, such as a viscosty-breaking operation at temperatures above about 900 F. to 950 F., there are, in the ordinary thermal processes, such excessive deposits -of carbonaceous material inthe coil or reaction vessel that frequent shutdowns of the unit to clean out the solid carbonaceous deposit are required.

According to the present invention highv temperature conversion of relatively heavy hydrocarbons may be carried out in the presence of finely divided adsorbent material. The relatively heavy hydrocarbons are heatedto a temperature below cracking temperature so that it is notv completely vaporized and then mixed with a sumcient amount of powdered adsorbent material to adsorb unvaporized and residual cokeforming liquid constituents andthe resulting mixture consists of vapors and gases and solid adsorbent particles with no liquid constituents present. During heating in the conversion or reaction zone, the vapors are cracked and the adsorbed liquid constituents are cracked into gasoline, gas oil. gas and coke, the coke remaining on the adsorbent particles. During passage through the reaction zone, the adsorbent material due to its abrasive action maintains the lnner surfaces of the reaction zone free from carbonaceous or coky deposits. 'I'he advantage of operating at high temperature is that there is thus obtained a favorable product distribution.

Thus, when operating on a heavy viscous fuel oil at temperature of say -1050 to 1100 F., the fuel oil may be converted to gasoline, gas oil, some gas and coke and the coke forming constituents will be adsorbed by the adsorbent material and will not therefore deposit in the reactlon'coil, vesse? or the like. Ordinarily, when operating at temperatures as high as 1100 F. on avery viscous hydrocarbon, a film of the liquid adheres to thtr inner surfaces of the reaction coil or zone and eventually forms a solid deposit of carbonaceow or coky material.

Other and further objects will appear from the following description.

It will be understood that the present invention contemplates any heatconversion of hydrocarbons where the hydrocarbons are converted in the presence of powdered adsorbent material.

Referring to the drawing, the figure is a diagrammatic layout showing an arrangement of elements in which the present invention may be practiced.

In order to give more information regarding the present invention, a specific example describing the same shall now be given, but it will be understood that the precise details thereof do not impose a limitation on the invention such as to exclude obvious vmodifications which would readily occur to one skilled in this art.

An East Texas crude which had been topped to remove light naphtha, gasoline, kerosene, range oil and gas oil may be fed to the system through line I and then forcedthrough pipe still or other heater 2 where it is heated up to a temperature of about 600 F. to 850 F.

The topped or reduced crude which is at the temperature indicated is a mixture of liquid and vapors and this mixture passes from pipe still 2 through line I a where a fresh or regenerated solid carrier, such as pumice, clay or the like suspended in a gas, such as steam, hydrogen, hydrocarbon o r ythe like is added to the oil stream from vessel 3a through line 3 in a manner hereinafter more fully explained. The solid carrier which is preferably in powder form should be at a temperature about that of the reduced crude oil in line la. The particle size of the carrier should be such that most of it will pass through a screen of to 300 mesh. 'I'he ratio of solid carrier to oil will vary from about .05 to about 10 parts by weight of carrier to one part of oil.

As indicated in the drawing, steam or some other inert gas is preferably supplied to dispersing vessel 3a from line la, after having rst been passed through preheater 4b. 'Ihe temperature of the steam should be about 850 F. to 1100 F. and its gauge pressure about from to 150 lbs. per square inch as it enters vessel3a. The steam is introduced into vessel 3a preferably, as shown, at a point opposite the discharge end of screw conveyor 4c discharging fresh or regenerated adsorbent material or carrier into vessel 3a. The impingement of the steam against the carrier entering vessel 3a causes the suspension or dispersion of the carrier in the steam and the suspension is injected through line 3 into the heated oil stream moving in line Ia.

The adsorbent particles in admixture with the oil stream adsorb unvaporized coke-forming liquid constituents so that the mixture is substantially dry with no liquid present and only vapors and' gases and solid particles are in line Ib. The vapors and gases and solid particles-are passed through line Ib to heating and reaction zone or chamber 4 which is shown as a coil in the drawing but which may be of any desired form. During the reaction in reaction zone 4 the crude oil lwill be reduced in viscosity and during the reaction or conversion, gasoline, 'gas oil, some permanent gas and solid carbonaceous material will be formed. In the reaction zone the heavy hydrocarbon constituents adsorbed on the solid adsorbent particles will be broken down or cracked to gasoline, kerosene, gas oil, permanent gases and coke which will remain on the adsorbent material so that the products leaving reaction zone 4 will be substantially dry without any liquid being present.

The temperature and pressure within reaction coil 4 will vary according to the kind and character of the feed stock, but generally the temperature will lie within the range of from about 850 F. to about 1200 F. and the gauge pressure will lie within the range of from about 0 to 150 lbs. per square inch with 5 to 25 lbs. per square inch as the preferred pressure range.

The products passing through the reaction coil 4 may be maintained at the desired reaction temperature by circulating a heating fluid around the outside of the coll as shown diagrammatically on the drawing. y

The heavy coke-forming liquid material formed during the reaction will for the most part be absorbed by the carrier and will be converted to relatively dry coke material on the carrier. Any coke tending to deposit on the Walls of the coil or other heater will be scrubbed oi by the abrasive action of the carrier powder and swept through the coil or heater leaving the inner surfaces of the coil or heater free of adhering material. By this method of operation, it is possible to control closely both the reaction temperature and the reaction time, thus permitting optimum conditions of operation for the avoidance of excessive coke and normally gaseous products formation, and the maximum yield of products of the desired viscosity.

The hydrocarbon material reduced to a crackable stock, gasoline and coke is passed from reaction coil 4 through line Ic to a cyclone separator 5 to separate the solid carrier particles in a substantially dry condition from reaction products in vapor form. The carrier material is intended to serve as a carrier for the coke formed during the viscosity breaking treatment or conversion of heavy oil but the carrier material may be an adsorbent material which has some catalytic activity, such as natural clays, bentonites, and the like. In separator 5, which is of conventional design, the reaction products or converted hydrocarbon material is taken of! overhead as vapors through line Id and is conveyed through line Id into cooler 5a, thence through line Ie into water separator 5b and finally to a reservoir 5c or to fractionation equipment through conduit If.

'Ihe amount of coke formed per 1000 lbs. of reduced crude oil in the above described operation is about 50 lbs. and the amount of permanent gas is about 2% or 20 lbs. The yield of gasoline is about 9o lbs. and of gas oil about 840 lbs. As previously explained, of course, the amount and character of the products obtained will depend on the feed stock, but it will also depend upon the severity of the treatment in the reaction coil. Operating on the reduced crude above referred to, the product distribution set forth above may be obtained by subjecting the reduced crude to a temperature of 850 F. in the reaction coil 4 for 10 to 30 seconds or if a temperature of 1000 F. is employed, the treatment in the reaction coil would continue from 2 to 15 seconds.

The separated pumice or other adsorbent materia] falls into vessel 5d by gravity and then falls from baille to baille in vessel 5d. The separated adsorbent material collects in the bottom of vessel 5d from which it is fed by star conveyor i into screw conveyor 8 and from there into regeneration flue I4 for removing coke deposits. Steam is preferably introduced through line l into the lower portion of vessel 5d to purge the adsorbent particles. The steam passes overhead through line Id with the reaction products. Steam is introduced at a temperature of about 850 F. to 1100 F. and under a pressure of about 0 to 150 lbs. per square inch gauge.

A regeneration gas is introduced into the system through line I0, passes into line I2 and is then forced into ilue I4 by blower II operated by motor I3. The carrier particles are swept by the gas up the flue I4 through the top loop I4a, down the opposite leg I 4c to the neck portion 30a forming a cyclone separator of purging unit 30 where the regenerated carrier particles drop out and the regeneration gas either passes into conduit I2 for recycling or is rejected from the system in whole or part through line 21. The regeneration gas blown into flue I4 by fan I I has a free oxygen concentration of from about 1% to about 15% oxygen, the remainder of the gas being some inert gas, such as' steam, flue gas, CO2, N2 or mixtures of any of these.

'I'he temperature of the regeneration gas entering the ue I4 is from about 850 F. to 1100 F. and is under a pressure of from 0 to 150 lbs. per square inch gauge, with 45 lbs. per square inch preferred. The temperature of the carrier particles discharged into I4 from 8 will be from about 850 F. to 1100 F., with higher or lower temperatures permissible. The hot oxygen-containing gas upon contact with the heated carrier will cause combustion of the carbonaceous or coky contaminants, converting the same to gaseous combustion products, and the carrier will be thus regenerated. Since the combustion of the contaminants is an exothermic reaction, the temperature prevailing within ilue I4 will normally be increased. In order, however, to prevent overheating, a bank of tubes 31 containing a cooling fluid is preferably provided to abstract a portion of the sensible heat of the gases. A convenient cooling uid is water, which may be introduced at inlet 24, the steam formed being removed at 25. This steam lmay be further heated, if necessary, and used in the process as a stripping agent invesselldorasadispersionmediuminvessel 3a for the carrier or for some other purpose.

The regenerated carrierfalls by gravity from baille to baule through vessel Il and at the same time, steam, flue gas and/or nitrogen and/or carbon dioxide or any mixture of the above', is forced upwardly through the falling carrier to purge the same and remove remaining oxygen. 'Ihe incrt purging gas is admitted through line 2l into the lowerl portion of the purging vessel lll. After traversing through the carrier, the purging gas. preferably steam. may be discharged from the system through line 21 or employed to dilute the gases entering the suction side of blower I I. The purging gas should be under a gaugepressure of from to 150 lbs. per square inch and the temperature should lie within the range of from about 850 F. to 1100 F.

In another modification of this invention, a heavy fuel oil fraction was subjected to the process outlined in the preceding example, except as below explained, togyield from 1000 lbs. of the fuel oil, 500 lbs. of gasoline, 400. lbs. pf gas oil, 60

lbs. of coke and 4Q lbs. of permanent gases.

In this operation the treatment of the fuel oil in the reaction coil is more severe than in the preceding example in that the fuel oil is subjected to a temperature of about 950 F. for a time of from 10 to 30 seconds. If a temperature as high as 1050 F. is employed, theV time of treatment should be from 5 to 20 seconds. It will be understood, of course, that the specific gures given in this and the preceding example are purely illustrative and do not place a limitation on the process, since numerous changes may be made in the details without departing from the spirit of the invention.

To recapitulate, this invention relates to improvements in the conversion of relatively heavy hydrocarbons to form products of lower viscosity and also includes processes wherein a heavy viscous hydrocarbon is heat treated at sufficiently high temperatures to form solid carbonaceous material instead of a tarry material, as well as hydrocarbon liquids lighter than the original material. invention is carried out in the presence of a solid adsorbent material which adsorbs the cokeforming constituents and also, by virtue of its abrasive activity in 'a moving stream of oil, scrubs the inner surfaces of reaction coils or other sur- The treatment according to the present faces during the reaction thus maintaining them free of carbonaceous deposits.

'I'he dry contaminated adsorbent material containing coke is regenerated after separation from the hydrocarbon material after the conversion and returned to the process. In other words, this present invention relates to a cyclic process for carrying out the heat treatment of hydrocarbon oils to form products of the desired properties in the presence of a solid adsorbent material in a continuous cycle of operations wherein the contaminated adsorbent material is regenerated and returned for reuse tothe reactor.

Instead of the coil reactor l, I may use a cylindrical vessel containing internal heating elements or tubes or it may be carried out in a cylindrical vessel containing mechanical means of agitation and dispersion and the heat for the reaction may be added through the walls of the vessel itself. In a like manner, regeneration of the adsorbent powder can also be carried out in a cylindrical vessel or in other types of equipment just described.

Numerous modifications of the present invention 'falling within the spint thereof wm be apparent to those skilled in the art and the invention is to be construed as broadly as the below claims permit. f

This case is illed as a continuation in part of my application Serial No. 267.993 filed April 15, 1939 for Chemical process.

I claim:

1. A continuous process for reducing the viscosity of a relatively heavy hydrocarbon oil which comprises impin'ging a stream of steam against a stream of solid carrier in order to cause dispersion of finely-divided carrier in said steam. introducing said steam containing said ilnelydivided carrier into said relatively heavy hydrocarbon oil, heating the mixture to a reaction temperatur separating hydrocarbons of viscosity lower an the original relatively heavy hydrocarbon oil with the aid of steam from the carrier containing a carbonaceous deposit and regenerating thev separated carrier by'combustion of the carbonaceous deposit contained therein and returning the regenerated adsorbent material to a fresh supply of relatively heavy hydrocarbon oil.

2. The continuous process of reducing the viscosity of a topped crude hydrocarbon oil, which comprises injecting into a confined stream of said crude a solid adsorbent carrier suspended in a gas and passing the stream of hydrocarbon oil to iiow through a lreaction zone at a temperature of about 850 F. to 1150 F., whereby a hydrocarbon oil of reduced viscosity is formed together with a carbonaceous material which is adsorbed. and held by the solid adsorbent carrier and separating substantially dry solidadsorbent material from vaporous hydrocarbon oil of reduced viscosity.

3. A continuous process for converting relatively heavy hydrocarbon oil which comprises impinging a stream of inert gas against a stream of solid absorbent carrier material under a pressure suillcient to cause substantiallyy complete dispersion of said solid absorbent material in said inert gas. forcing the dispersion of inert gas and solid absorbent material under a positive pressure into a moving stream of heavy hydrocarbon oil, passing the resulting mixture through a reaction zone maintained at active cracking temperature, keeping the oil in contact with said absorbent material while at active cracking temperature for a period suflicient to convert said oil into vapors and solid carbonaceous residue to thereby form a relatively dry suspension of cracked vapor products and solid material comprising solid carbonaceous residue and absorbent material, separating the solid material from the cracked vapors, burning the solid carbonaceous residue from said absorbent carrier material to thereby regenerate said carrier and impinging the regenerated carrier material into said firstnamed inert gas.

4. The process set forth in claim 3 in which the gas containing the dispersed carrier is steam.

5. The process set forth in claim 3 in which pumice is dispersed in steam and injected into the hydrocarbon oil.

6. A continuous process for reducing the viscosity of topped crude oil'which comprises injecting iinely divided pumice into the topped crude oil, causing the mixture of pumice and oil to flow through a reaction zone maintained under reaction temperature and pressure, keeping said oil in contact with said pumice within said reaction zone for a period suillcient'to completely convert said oil into vapors and solid 4residue to thereby form a relatively dry suspension of hydrocarbons which comprises heating therelatively heavy oil toa temperature below cracking temperature and below a temperature which will completely vaporize said oil, mixing iinely divided' solid absorbent material with the heated oil and passing the mixture of heated oil and absorbent material through a cracking zone maintained at cracking temperature, maintaining said mixture within said cracking zone for a period suiiicient to convert all of the unvaporized constituents of said hydrocarbons into solid residue and vapors to thereby form a dry suspension of carbonized solids and vapors and thereafter separating the gaseous conversion products from said sorbent and unvaporized residue. s

9. LA method of converting relatively heavy oil into lower boiling hydrocarbons which comprises heating said'relatively heavy oil to a temperature below cracking temperature and below a temperature which will completely vaporize said oil. mixing iinely divided absorbent catalytic material with the heated oil, passing the mixture of finely divided absorbent catalytic material and heated oil through a cracking zone maintained under conversion temperature, keeping said oil within said zone for a period suiiicient to convert all of the unvaporized constituents into vapors solid absand solid residue to thereby form a dry suspension of oil vapors and carbonized absorbent catalytic material and thereafter separating the gaseous conversion products from the carbonized absorbent material.

' 10. A process for reducing the viscosity of a topped crude oil which comprises continuously injecting a finely divided absorbent material into a stream of said crude oil, passing the stream of oil and absorbent material through a cracking zone maintained under cracking temperature and pressure, keeping said oil in contact with said absorbent material while at active cracking ltemperature for a period sufilcient to convert said crude oil completely into vapors and solid residue vto thereby form a relatively dry suspension oi' gaseous conversion products and carbonized solid absorbent material, and separating the conversion products from said carbonized solid ab sorbent material.

l1'. A process of converting a relatively heavy hydrocarbon oil containing vaporizable constituents and constituents unvaporizable without substantial decomposition under; normal pressure conditions to form lower boiling hydrocarbons which comprises injecting a relatively large amount of solid absorbent catalytic material in powder form into a stream of said heavy hydrocarbon oil, passing the mixture of oil and catalytic material through a cracking zone maintained at active cracking temperature, keeping said oil in contact with said catalytic material within said cracking zone for a period suiiicient to completely convert the unvaporizable constituents of said oil into vapors and carbonaceous residue to thereby form a dry suspension of oil vapors and solid-material comprising a mixture of catalytic material and solid carbonaceous residue, and separating the solid material from the cracked vapors.

EDWARD D. REEVES.

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