US1714453A - Oil-cracking process - Google Patents

Description

'May 2l, A. SCHWARZ 1,714,453

OIL GRACKING RocEss Filed March 25, 1925 PaMP /645 Pnooucfn. I 7

W XW, fjwuanc ranma May 21,1929.l

UNITED STATES .l 1,714,453 PATENT orner..

ALFRED SCHWARZ, OF QPPER MONTCLAIR, NEW JERSEY., ASSIGNOR TO COAL AND OIL PRODUCTS CORPORATION, A CORPORATION OF DELAWARE OIL-cnnoxING PROCESS.

applicati@ mea Marcil 25, 1925. sealan. 19,076.

This invention relates toa process of cracking oil thereby producing lighter oils and gas therefrom. It relates more parJ ticularly to a process by which theoils may be cracked and the carbon resulting therefrom can be utilized in the process.

In processes now commonly used for producing 'motor fuels from oils that have higher boiling points than those suitable for motor lfuels, which processes are called oil cracking processes, it is more or less common practice to crack the oils thereby producingresidues in the form of coke or heavy tarsof little commercial value which are oftentimes expensive to handle and hard to remove from the apparatus in which they are produced. Furthermore, in cracking oils the heat transfer isi usually made through the walls of receptacles which procedure is wasteful and frequently. causes deposition of carbonaceous matter upon the heating surfaces.

One of the objects of my invention is to crack oils in such a manner that Apractically all of the heat supplied to the oil is intro-v duced directly into the oil withoutpassing through the walls of the receptacle. An-

other object of my invention is to so control the chemical composition of the gases produced as to have a maximum of compounds of a hydrocarbon series other than the parahn series, and preferably those bf the benzol series. A further object of my invention is to consume the residue formed during the operation so as to generate heat and gases in order to eliminate the handling of residues and in order to be able to crack substantially all the oil and to convert -any such portion of the oil that may have a tendency to be precipitated as carbon,into y a fixed gas, this gas being a secondary product of the process.

The invention will be understood from the description in connection with the accompanying drawings, in which two arrangements of apparatus are shown by'which the process can be performed. Ingthe.draw

ingsFig. 1 is a somewhat diagrammatic view showing the arrangement of the apparatus, parts being shown in section, to carry out the process and Fig. 2 is a similar view showingA a modied arrangement of Aapparatus.

lIn the drawings, reference character 1 `indicates a gas producer somewhat similar to forced into the those commonly used, the same being modified, however, so as to adapt it especially for carrying out the present-invention. The producer 1 has a main chamber 2 which may be lined with fire-brick, and a superposed chamber 3 having a waste heat duct 4 extending therefromprovided with a valve 5. The chamber 3 is closed at the top by a cover 6 which carries a perforated plate to serve as an oil distributor: as indicated below. A coal hopper 7 controlled by a valve 8 leads to the chamber 3 andthe hopper 7 is supplied from a supply 9 that is provided with' a valve 10 that may be opened and closedat will for feeding a charge of coal to the hop er 7. c

T e producer 1 is also provided with a grate 11 below which steam may be introduced into the producer through the valve controlled inlet pipe 12 from any convenient source. A valved pipe 13 leads from the prodcer 1 tangentially into a settling cham- .y ber 14 that is provided with an outlet pipe 15 controlled by the valvel'. A pipe 17 leads from upper portion of the settler 14 to a rfractionating tower 18 which is rovided with the usual shelves 19. This filiactionating tower may also be filled, if desired, with porous material such as coke, broken brick or the like. Reflux pipes, one of which is shown at 22, lead from the shelves to the lower end of the fractionating tower and a valvedbranch pipe 23 leads from the pipe 22 into the tower and a valved branch 24 may lead to a storage or supply tank. A pipe 25 leads from the fractionateov ing tower 18 to a condenser 26 that may be thriougha pump 35 toa gas holder not` shown. If desired two producers l may be connectedl to the tower 18, the same being operated alternately.

A branch pipe 39 provided with'a valve 43- leads from the pipe 12 to the injector 40. The suction end offithe linjector 40 is connected by a valved pipe 41 to the suppl' tank 42 for` oil that is to be cracked. 105 pipe 46 leads from the injector 40 to the cover cap 6. They oil-i-from tank 42 ynay be isproducer 1 by means of the-injector 40 w en gravit feed is not provided'or a pump mayfee the same. The 1'10 starting the fire in the producer 1.

In the modification shown inV Fig. 2 many of the devices are identical with those already described i'n connection with Fig. 1 and such parts are indicated by the same reference character with the suiiix a. This arrangement differs in certain respects from that shown in Fig. 1. The outlet pi e 4a leads into a heating chamber 50 in whlch a still 53 is placed. This still is provided with tubes 51 which tubes lead to a stack 52. A valved pipe 55 leads from the still 53 to.the valved pipe 17, that leads directly from the gas producer 1u to the fractionating tower 18, .the tower 18? being provided with a vapor outlet 25a in the upper portion thereof. One or more valved reflux pipes 22 lead from the shelves 19 to points below the liquid level in still 53. Two ormore gas producers l may be connected to the still 53 and the fractionating tower 18a and operated alternately. A pipe 41a leadsfrom nearl the bottom of the still 53 through a pum 57l to an injector 40% Steam may be admitted to the injector 40a through the pipe 39a from any convenient source and a pipe 46a leads from the injector to the cap 6a of the gas producer.

The upper end of the tower 1 8 or 18a may be jacket'ed and the supply of water thereto may be controlled or regulated by means of valves as shown at' 6() so as to' introduce steam or water around the upper portion thereof. A

The process may be operated in two ways which may be termed continuous and intermittent respectively. In operating by the so-called continuous method, fire is started in the producer l onl the grate 11, coal or coke being then charged into the ,chamber 2 until it is filled nearly to the valve 8. The blower47 is started with the lvalve 5 open and the valves 8, 3G, 38, 43, 44

vand'superheated' steam is admitted through valve 44 into the injector 40, while oil is `admitted from the tank 42 into the injector 40 so that the atomized mixtures are sprayed through'the cap 6 into the chamber 2 where the coal in the upper part of the reducer acts as a temporary retainer for t e oil and the high temperature in this region will begin to crack the oil. Thevaporstherefrom will pass. downwardly into a hotter region where more cracking will take place and carbon will be deposited, the vapors or gaseous products ,finally passing into the pipe 13 and through the settling chamber 14 where suspended particles 4will be deposited and the vapors will then pass through a pipe 17 into the column 18 where the vapors are fractionated, the uncondensed portion passing through pipe 25Aand condenser 26 whereupon the uncondensed gases and the condensate-pass into the receiving tank 29 where the water settles to the bottoni and is Withdrawn through the pi e 30 while the oil is Vwithdrawn through t e pipe 31 and the fixed gases pass through the. pipe 34 and pump 35 to a place of Iconsumption or to a gas holder. The reflux pipe 22 is arranged to lead the reflux from a plate 19 to the base of the tower where it ican be introduced into the hotter'portion of the tower through the pipe 23, or it may be withdrawn through the pipe '24. When introduced into the hotter portion of the fractionating tower 18, the condensate comes into Contact with the hot gases from producer from separate plates 19, the condensates passed therethrourrh will be oils of differ# ent specific gravitles and different qualities which may be subjected to further treatment in the tower 18, or they may be withdrawn from the 'system for other uses. .The lighter oils will, of course, be drawn from the top shelves 19 of the fractionator and heavy oils from lower shelves. `The heavy oils that may be withdrawn through the pipe 2O may be passed through the system again by rst introducing the same into the supply tank 42. While operating the process as above described, air is constantly taken into the system which is first caused to produce carbon dioxide in the lower part of the gas pro-y ducer and when the proper amount of air is introduced this carbon dioxide is converted into carbon monoxide in upper layers of the incandescent coal or coke. Superheated steam is admitted through the pipe 12, and forms water gas in accordance with the Well known reaction and the combined gases meet the oil vapors that pass downwardly through the upper portion of -the producer and the mixture passes through the line 13 as above indicated. Reactions appear to take place between the ases and vapors,but on account ofthe fact t at there are so many different hydrocarbons present in the mineral oil vapors, the reactions of4 which are very com licated, it is not certain what the various c emical reactions are in the different reaction zones.

-Thefollowin is given as an illustration of results that i ave actually been obtaiii'edI with an installation of this character. With a gas producer' 1, about 7 high and 14 in internal diameter and a fractionating tower 18, about 14 high and 12 in diameter arranged as illustrated in Fig. 1, I charged the producerwith ordinary foundry coke and raised the temperature to about 800 F. and charged superheated steam through pipe 12 at a temperature of about 600 F. A vacuum pump of the eccentric piston type was set in operation as shown at and a small amount of air was admitted through the valve 49. Petroleum oil having a boiling point such that about 12% -could be distilled off between 500- F. and 600 F., the remainder boiling above 600 F., was introduced through the injector throughthe spray box 6. This oil was the residue from a pressure cracking operation Ycommonly called pressure still tar in the trade. The

process was operated for several hours and during that entire time gases obtained from the receiver 29 burned with a high caloriic value and distillates collected from the pipel 31 contained 65% of material that was distilled ofbetween 120 F. and 437 F. and

60% of the remainder distilled below 600 F.

When operating the process as just ndescribed, due to the continuous 'admission of air, there appears to be .a considerable amount of hydrocarbon derivatives formed of the fatty acid series. And this constitutes an important factor in the process. Such fatty'acids may be refined and used for many purposes, for example: Manufacture of soap requires large quantities.' If the process is operated with a view of making fatty acids as a by-product the continuous admission of air is desirable. If however the rocess is operated more for the purpose o making motor fuel, a large amount of fatty acids in the distillate is not desirable. desirable to avoid the production of fatty acids, the process maybe operatedintermittently'by first blowing' airV by means of the pump 47 through the gas roducer-l and permitting the products o pass out through the pipe 4 until the temperature has reached the proper point after which the air can be shutoff andthe oil sprayed in and steam admitted until the temperature needs to be increased a other'variation of my process is t at I may mix the oil with ordinary live steam and pass both of them through a superheater and then introduce this mixtureinto the distributor #6. When the rocess is operated without an air supply, during 'the time the oil is being admitted to the producer 1, the

production of fatty acids is very nominal but during the time that air is being blown into the producer to raise the temperature ofthe carbon therein to incandescence, a certain amount of heatA would be wastedlbut I utilize such heat, by arranging the apparatus .the A.pro ucing carbon monoxide gas and relying combustion to in. An-

as indicated in Fig. 2. The products of combustion pass in this arrangement of apparatus through the pipe 4a into the lire box 50 along the under side of thestill 53, which contains oil to be cracked, and these products then pass through the tubes 51 where they give up further heat to `the oil and these products of combustion finally pass out through the stack 52. Vapors from the oil in the still 53 pass through the pipe 55 to the tower 18a and uncondensed vapors issue from thetower through pipe 25u. Refiux condensate passes through the pipe or pipes 22a from the' tower 18a into the still belowy the liquid level therein. After the `air has been blown into gas producer 1- a sufficiently long time to bring the temperature to that of incandenscence, the air is shutfoi' ing conducted with the aid of steam which "is preferably superheated, I do not llimit myself to the use of steam as I may carry out rocess without using steam by merely upon the reactions among the hydrocarbon vapors, the gas being used as a medium of d,

heat transfer. The process is adaptable to many grades of oil and the reactions will vary with the sort of hydrocarbons used. Not only very heavy oils and residues may be used-as the stock to be cracked, but light oils such as kerosene and gas oil may also be treated 4by this process. At the same time other sorts of oils such as coke oven light oil, coal tar and the like may be introduced into the producer and ma be subjected to the treatment above descri ed. While the most logical method of sup plying heat to the oil vapors and water vapors for the purpose of inter-reaction, is to abstract saidheat from the gas producer, nothin herein contained shall be construed to limit the scope of this invention by the additional application of external heat on any portion of the apparatus. While I primarily intend to extract the combustible roducts from the fixed gases, in some cases may desire to conduct the mixed product to a burner or internal combustion engine .and use all the products direct.

I claim 1. The process which comprises heating portions of a mass of carbon to different temperatures by combustion, bringing steam into contact with a portion hot enough to form water gas, simultaneously bringing hydrocarbon oils into contact with portions suiiicientlyheated to form oil vapors, maintaining said vapors in contact with said mass of carbon, passing the same through zones of said mass of carbon of increasing ltemperatures suliciently hot to cracksaid -vapors and produce a substantial amount of condensible hydrocarbons and suiciently cool to avoid complete gasification, mixing the water gas and oil vapors at high temperatm-e and segregating the gaseous and lcondensible products.

2. The process which comprises heating a mass of carbonaceous material to an oil 'cracking temperature thereby producing .waste gases, utilizing said waste gases to heat a body of oil to a distilling temperature, removing vapors from said body of oil, introducinvr unvaporized oil from said body into said mass of carbonaceous material to eect vaporization thereof, passing ythe resultant vapors downwardly throu h zones of increasing temperature to crack t e same,

fractionating the resultant ',vapors and gases, and conductm heavier condensed fractions to said body o oil for retreatnient.

3. The process which com rises establishing a gas generating zone Ey blowin hot carbonaceous material -with air, heating a- ALFRED SCHWARZ.

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