US1954477A - Treatment of hydrocarbon oils - Google Patents

Description

Patented Apr. 10, 1934 PATENT OFFICE TREATMENT OF HYDROCAR-BON OILS Gustav Eglofi', Chicago, 111., assignor to Universal Oil Products Company, Chicago, 111., a corporation of South Dakota No Drawing. Application February 14, 1930, Serial No. 428,519

1 Claim.

This invention relates to a process for the treatment of hydrocarbon oils and refers more particularly to a process for the hydrogenation of oils and of products of conversion of elevated temperatures. Among the objects of the process is to reduce the amount of coke and pitchy matter made during the crackingreaction thus increasing the yield of gasoline; to saturate the 7 more highly unsaturated hydrocarbons which substances form gums, polymers, and other undesirable materials in the motor fuel; and to desulphurize the hydrocarbons so as to render them more suitable for motor fuels and facilitate refining. It is not the purpose necessarily in carrying out the process of the invention to completely saturate the hydrocarbons cf the olefine series as such to produce parafin hydrocarbons, but rather to add hydrogen in regulated amounts to the highly unsaturated hydrocarbons such as diolefines for the purpose of facilitating refining and improving the anti-knock properties of the motor fuel resulting from the cracking operation.

In the cracking or conversion of relatively high boiling hydrocarbon oils into low boiling products suitable for motor fuel, considerable quantitles of coke and/ or asphaltic or pitch-like products may be formed. When the cracking oper- I ation is controlled to produce coke and distillate only, a fuel oil may produce from 25 pounds of coke upward ber barrel of oil charged and even when the cracking operation is carried on so as to produce fuel oil as one of the products, large amounts of coke may be formed and the cracked fuel oil or residuum may contain a relatively high percentage of suspended carbonaceous or pitch-like material. It is among the objects of this invention to reduce the amount of this sus pended material in order to improve the quality of the cracked residuum for fuel oil purposes.

The cracked distillate which contains the gasoline and which is the major product of the process generally contains highly unsaturated hydrocarbons which upon standing tend to polymerize and form gums, tars, and other undesirable substances. It is another object of the invention to reduce or prevent the formation of these deleterious materials.

The presence of sulphur compounds in a motor fuel may result in corrosion of the crankcase and other automotive parts during combustion and may also result in the corrosion of the cracking or distillation equipment. To reduce the of the present invention.

My invention comprises mixing the interme-. diate condensed hydrocarbon oil products of the cracking process referred to as reflux condensate with a metallic hydride or mixture of hydrides made by heating metalsof the alkali or alkali earth series such as sodium, potassium, calcium, barium, strontium, magnesium, etc., with hydrogen. The mixture of oil and hydride may then be subjected to treatment with steam at an elevated temperature. The hydride reacts with the steam forming hydrogen and the corresponding oxides of the metals which may have a catalytic effect in the reaction including the hydrogenation and the conversion or cracking.

The mixture passes through a gradually rising temperature and during the heating process the steam will react with the hydrides, producing hydrogen which in turn may react with the highly unsaturated products of conversion as well as with the coky, pitchy or asphaltic materials formed and also with sulphur compounds, thus bringing about the desired results.

It is generally recognized by those skilled in the art that hydrides in a finely divided state react at a greater velocity or rate of reaction 8 with steam than in bulk or mass form. This is mainly due to the enlarged surface of the hydride when finely divided. It is also thought that newly formed hydrogen in the so-called nascent state is much more active than molecular hydrogen. In carrying out my process, I make use in a novel Way of both of these principles.

In addition to the above I may also add molecular hydrogen to the materials undergoing reaction in order to assist in the reaction, or gases 9 containing hydrogen such as producer gas, natural gas, gas from the cracking process, etc.

In carrying out the present process, I may make use of any apparatus suitable for cracking, or apparatus or equipment which permits heating 5 the oil in the presence of hydrides and steam, but preferably I make use of heating tubes or an elongated pipe or heating coil into which the mixture of oil, consisting of the reflux condensate or intermediate insufficiently cracked fractions from the process, the hydride and steam is introduced. Preferably, the oil is heated to a cracking temperature under pressure, although my invention contemplates operating the process at lower temperatures also, and at reduced pressures.

The mixture of oil, finely divided unused hydrides (if excess is added), and products of the reaction may be passed to a chamber or vessel where the cracking reaction continues. Any coke which forms may accumulate in the chamber or if liquid residual products are desired, they are removed either continuously or semi-continuously from the chamber and the vaporized products may be removed through a suitable vapor line.

I do not wish to limit myself to any form of apparatus as there are many forms which are suitable for the purpose. For example, the modern cracking process is well adapted to the application of my invention which may consist, in addition to the heating tubes and reaction chamber, of dephlegmators, fractionating columns, coolingand condensing zones, receivers, flash chambers and other auxiliary equipment necessary or desirable for the operation of a cracking process including auxiliary heating elements for the mixture of reflux condensate and the hydride.

My process may be operated at atmospheric pressure or at super-atmospheric pressure and may also be operated at sub-atmospheric pressure.

As an example of my process, the mixture of hydrocarbon oil, steam and hydrides may be heated to temperatures of from approximately 400 degrees F. to 1400 degrees F., more or less, under atmospheric, super-atmospheric or subatmospheric pressures, e. g. from '75 pounds per square inch to 3000 pounds per square inch. At a transfer temperature of approximately 925 degrees F., and a pressure of approximately 1000 pounds, I may obtain a yield of gasoline in excess of 60%. This gasoline may require from approximately 25 to 50 percent less acid to refine to a marketable product and contain approximately from 25 to 50% less sulphur than gasoline produced by ordinary cracking.

The amount of coke formed is much less than that produced by ordinary cracking for a given yield of gasoline and the quality of the fuel oil when produced with regard to pitchy and carbonaceous material is much better, showing a relatively lower viscosity and lower cold test for the same yield of gasoline.

While. I have shown specific examples of yields and operating conditions, these examples are purely illustrative and are not to be construed as limitations upon my invention.

I claim as my invention:

In the cracking of hydrocarbon oils wherein the cracked vapors are dephlegmated to condense insufficiently cracked fractions thereof and resultant reflux condensate subjected to further conversion into lighter hydrocarbons, the method which comprises adding a finely divided metallic hydride to the reflux condensate and effecting the further conversion thereof in the presence of steam whereby the latter reacts with the hydride to form hydrogen in contact with the reflux condensate being converted.

GUSTAV EGLOFF.