US1832975A - Process for hydrocarbon oil conversion - Google Patents

Description

Nov. 24, 1931. O.\H. FAIRCHILD PROCESS FOR HYDROCARBON OIL CONVERSION Filed Jan. 14, 192

Patented Nov. 24, 1931 UNITED STATES PATENT OFFICE OSCAR H. FAIRCHILD, OF CHICAGO, ILLINOIS, ASSIGNOB TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PBOCESS FOB HYDROCARIBON OIli CONVERSION Application filed January 14, 1926. Serial No. 81,158.

' This invention relates to improvements in the process and apparatus for hydrocarbon oil conversion, and refers more particularly to the production of lighter gravity hydrocarbon products from heavy gravity hydrocarbons by subjecting the hydrocarbon oil to vapor phase cracking.

In the present vapor phase cracking processes now in use, one of the objections existing is that it is impossible to transmit the most efiicient high heat to the vapors due primaril to the loss ofheat units in passing through the metal container wall and the rapidity with which such metal. container wall burns out. Attempts have been made to utilize reiractory walls, but the same objection of ineficient heat transmittal through therefractory walls exists.

The present invention is primarily directed to the idea of subjecting the hydrocarbon'oil to cracking in the vapor phase by subjectin the vaporons roducts to the direct physiczfi contact of big ly heated gases.

Briefly, the invention in one specific embodiment comprises introducing the hydrocarbons, either in liquid form or vapor form, or in both liquid and vapor form, into the highly heated zone of a heat generator at a point immediately adjacent the fuel gasification zone, that is, the zone where the fuel, such as coke, for example, is gasified in the heat generating process. A bed of coke or similar carbonaceous fuel is maintained above the point at which the hydrocarbons are introduced. The hydrocarbons are thus subj ected to direct contact with the heated gases generated, and the vapors and gases mingle in the bed of carbonaceous fuel at a prolonged high temperature.

The introduction of the hydrocarbon material directly into the zone of highest heat allows a wide variation in temperatures to which the vapors may be subjected during the crackin reaction. By regulatin the agent intr need to accelerate or retar heat generation, it is possible to simultaneously control the temperature and regulate the percentage of saturants and unsaturants in the final product produced.

Many other advantages and objects will be more particularly brought out in the followmg description.

In the drawing, the single figure is a diagrammatic side elevational view, partly in vertical section, of the apparatus.

Referring more in detail to the drawing, 1 designates a vertical drum or chamber interiorly insulated with suitable refractory material as shown at 2. The upper end of the vertical chamber 1 may be closed by the top closure plate 3, on which is mounted a dome 4 having amovable door 5 through which charges of coke or similar carbonaceous ma terial may be introduced to the chamber. 011 one side of the dome 4 is a supporting bracket 6 in which is pivotally mounted an arm 7 having a movable weight 8. This arm 7 has pivotal engagement with a downwardly extending link 9 on which is mounted a valve 10, closed from the inside. Intermediate its length, the chamber 1 may be provided with any suitable number of peek holes or poke holes 11. They may be stationed at any height and in any number which may be desired. Also intermediate the height of the chamber 1 it tapers inwardly along the line 12 to provide a constricted portion 13, which constricted portion serves as a constricted orifice for the purpose of bringing the hydrocarbon vapors and hot gases into intimate admixture. Below the constricted portion 13, the drum tapers outwardly again along the line 14 until the tube reaches the diameter of the tube above, shown at 15. The portion of the drum 15 below the constricted portion 13 constitutes the heat generating zone, and there is mounted therein a grate 16, which may be of any construction, and which is shown diagrammatically. In some cases, the grate 16 may be omitted.

The drum is mounted on a base 17 and is provided with the ash pit 18 below the grate 16, where the latter is used, said ash pit 18 being cleaned through the door 19. Air under sufficient pressure to enetrate the entire mass may be introduced t rough the inlet 20, controlled b the valve 21. In addition to air, an endothermic agent such as steam, carbon dioxide, or other agent ma be introduced simultaneously with the air t rough the same highly inlet pipe 21, the proportion of air to endothermrc agent being regulated in an obvious manner at a point not s own on the drawing.

A bed of refractory material 22, which may be crushed firebrick or other refractory material, is maintained on the grate 16 for the purpose of protectin the grate from the intense heat generate in the chamber 15. Where it is not necessary to use the grate, for instance where utilizing the usual domestic or metallurgical coke, the grate 16 ma be dispensed with as well as the bed of re ractor material 22.

have shown the heat generating chamber 15 as an integral part of the chamber 1. It is to be understood, of course, that the heat generatin unit, it being desired only to bring a ighly heated gas into direct contact with the hydrocarbons in the presence of a carbonaceous material, such as coke. The coke or other carbonaceous material 23 may be maintained in a substantial body within the chamber 1.

As one of the features of the present invention, a header 24 is positioned adjacent the constricted portion 13 and is rovided with a plurality of discharges 25. be header 24 receives the hydrocarbons which may be in liquid form, or in liqui and vapor form, from any suitable source of shpply, such, for instance, as from storage or from a concurrentl operated distilling or cracking process. he object of provi mg a number of discharge ipes 25 is to uniformly distribute the intro uced hydrocarbon material in order that there may be a maximum efliciency of contact between said hydrocarbons and said hot gases. pipes 25 as discharging at a point below the constricted ortion 13. It is obvious, of course, that may introduce said hydrocarbons directly into the constricted zone. Tmniediately upon being introduced into the drum, the hydrocarbons, whether in vapor or liquid form,will be subjected to physical contact with 7 the highly heated gases generated as before described, and by means of the constricted ortion 13, athorough interminglin and e using will take place. This eated mixture will pass upwardly through the body of carbonaceous material 23, eventuall causing said body to be maintained in ahighly heated state.

The vapors and gases passing out through the vapor gas pipe26, controlled b valve 27, pass to any suitable forrn of scrub er or condenser 28, the condensate being withdrawn through the line 29, Lcontrolled by valve 30. Two chambers 28 and 31 are shown, but their use is optional. The vapors passing through the pipe 26 may be subjected to any form of treatment, such as dephlegmation, condensation, absorption, or the like.

The carbon particles precipitated in the upper section 32 of the chamber 1 will bechamber 15 may be a se arate- I have shown the discharge come a part of the carbonaceous fuel 23, and the non-combustible part thereof Wlll eventually be withdrawn as ash.

The rocess may be operated either continuous or as a batch operation.

The introduction of the hydrocarbons through the branches 25 into the heated zone 15 permits of wide variations in the range of temperature to which the vapors may be subjected during cracking reaction, for instance, between, say, 1000 1. to 2400 F. more or less. These temperatures are merely illustrative, and higher temperatures may be attained as follows: with the employment of pro-heated dry air, the temperature may reach 2400 F. plus the temperature of the pre-heated air; using cold dry air, the temperature may reach approximately 2400 F. more or less; if an endothermic agent, such as steam or carbon dioxide gas, is used simultaneously with the air, the temperature may range between 2400 F. more or less as a maximum, and 1200 F. more or less as a minimum. In any case, the temperature chosen as proper for a given effect can be controlled within close limits in actual operation.

By controlling the amount of air and other agent introduced through the line 20, it is possible to control the percentage of fixed, permanent gas and condensible vapors.

In using steam with the air blast, free hydrogen Wlll be liberated and become an important fraction of the vapor and gas mixture.-

A practical source of carbon diox'de gas for use as an endothermioagent me; be any flue gas. This will be desirable w men the presence of hydrogen in large volumes, such as would be the case when using steam is ob- Ectionable in the up "r chamber 32. it may pointed out that t is chamber 32 is, in effeet, a reaction chamber.

From the foregoing, it will be observed that I may provide a source of heat within the reaction zone, the hydrocarbons being brought into direct contact with the hot gases which bring about the desired reaction. I also provide a constricted zone to cause an eflicient intermin' ling of the hot gases and hydrocarbon. T ere is also provided a reaction zone which allows the gases and vapors a maximum time to react while simultaneously holding the vapors at an elevated temperature in the pgesence of the highlyheated carbonaceous dy 23.

As another feature of the invention, in case it is desired to use a catalyst, it may be introduced into the carbonaceous body- 23. The temperaturesnsed may be very accurately controlled, and the chemical composition of the generated gas may be controlled by regulating the volume of free hydrogen produced.

I claim as my invention:

A. vapor phase-cracking process for conill) Mill

verting heavy hydrocarbon oils into lower boiling roducts which comprises maintaining com ustion at the lower portion of a vertical columnof solid carbonaceous material 6 and passing the resultant hot gases upwardly through said column, restrictin the path of said hot gases to form a region 0 increased velocit above the zone of combustion, introducmg the heavy oil to be cracked in m va or form adjacent saidregion of increased ve ocity and at a substantial distance below the top of said column, causing the oil vapors to pass u wardly through said column in intimate a mixture with said hot gases 15 whereby the oil is cracked in the vagor phase and the result-ant carbon deposite in said carbonaceous material, so controlling the cracking conditions in said column that complete gasification of the oil is prevented and substantial amounts of condensible lighter hydrocarbons are formed therein, removing said gases and the vapors of said condensible lighter hydrocarbons from the upper portion of said column, and condensing said 25 vapors as the finalAfiroduct of the process.

OSC H. FAIRCHILD.

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