US1708303A - Process of cracking petroleum hydrocarbons - Google Patents

Description

C. R. DOWNS April 9,1929. I

. PROCESS OF CRACKING PETROLEUM HYDROCARBONS Filed Dec. 1, 1925 Magi flbyw-z/ wf 731. M 4 A fl'orhey Patented Apr. 9, 1929.

-UNITED STATES PATENT OFF-ICE.

"CHARLES RAYMOND DOWNS, OF NEW HAVEN; CONNECTICUT, ASSIGNOR TO WEISS AND DOE/NS, ING, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF GRACKING PETROLEUM HYDROCARBONS A lication. filed December 1, 1925. Serial No. 72,422.

In a copending application, Serial No.

- 692,223, filed February 12, 1924, I have dis closed the use of boiling sulphur as-a method of heating bituminous materials such as tars or'petroleums or their distillates in such a way that distillation will take place with the least amount of superheating and cracking. This process was based on the fact that the use ofa boiling liquid as a heating means, especially where the heat transfer takes place through the medium of condensation of the vapors of the boiling liquid, gives a high rate of heat input without a large temperature differential.

In the petroleum industry much use is made of the type of distillation, destructive in character, which is known as cracking. This involves the subjection of selected frac tions'of the oil to such temperatures as will decompose tliem into lighter hydrocarbons, preferably of the gasoline type. In these processes the control of the temperature of the oil beingcracked is important as it must be high enough to enable decomposition to take place but not so high as to cause further decomposition into. excessive amounts of permanent gases, aromatic hydrocarbons, tar, etc.

i The invention herein described comprises the extension of the principle described in Serial No. 692,223 to cover the use of boiling sulphur as a means of heating in processes designed for the cracking distillation of petroleum products. many various types and I do not confine myself to the application of the boiling sulphur-heating means to any one type. Those processes in commercial use to-day operate most efliciently over a range of temperature from 750 F. to 950 F., or thereabouts, the optimum temperature for any specific case varying. with the particular oil fraction be-'- ing treated, the nature of thecrude petro leum from which it was obtained, thepres-u sure under which the on, etc; V

Over this range of temperature, sulphur -with a boiling point at sea lever of 832 F.

can be made to maintain a constant and unioperation is carried form temperature by regulation ofthe pressure on the sulphur system, being varied above, {at or below atmospheric pressure, according to the particular temperature desired. Ingene'ral, the use of absolute pressures between 9 lbs. and 50 lbs. per sq. in.

These are of gives a suflicient range for practical operation. .The use of the latent heat of condensation of sulphur vapor as a heat'supply renders it possible t'o obta'in high rates of heat flow without high temperature differ- .entials, thereby enabling the cracking temperature to be maintained at. the optimum, point desired, without thepossibility of excessive temperatures and further decomposition into undesirable products.

In order to describe the invention I give the following example accompanied by the drawing which is diagrammatic only. The example is for illustrative purposes only and I do not intend to limit myself thereby.

Numeral 1 represents a sulphur boiler. The boiler is set in a furnace 2 with firebox 3" and exit 4 to a stack (not shown) to al low the escape of the combustion products. The boiler connects by a pipe 5 to a jacket 6 containing the oil heatingelement 7 which may, for exa u'lple, be a pipe coil. The jacket 7 connects by a pipe 8 to a pressure regulating tank 9 with gauge l0 and pipe 11 for the introduction of an inert gas from a .pump or other pressure source;

In operation, the oil to be cracked enters in the" direction of the arrow at 12 and if desired may pass througha preheating coil 13 set in the cooler portion pf the furnace2, or be preheated in any other convenient way.

It thenpasses to the coil 7 in the sulphur 1 heating jacket 6 and exits inthe direction of the arrow at 14 dischargingto condensers,

reaction chambers pressure reducing valves, vapor boxes, bubble towers, or whatever dewoe is used 1n the part cular cracking system to which this heating means is applied.

Sulphur is boiled in "the boiler 1, the vapors pass ng by the pipe 5 to the jacket 6 where by condensing they give u'p their heat to the oil passing through the 001i 7 The conclensed sulphur returns through the pipe 5 to the boiler 1. n By maintaining a suitable inert gas pressure on'the tank 9, the boiling point of the sulphur may be fixed at a predetermined point, above which the oil in the pipe 7 cannot be heated. 'The tank 9 1s not essential to the invention as the jacket 6 may carry a pressure gauge and inert gas from a pressure source applied directly tothe jacketj In this process the vapors of the sulphur do not comeinto direct contact with the oil to be heated but are separated from it by metal or other malace.

- heating of the oil ma be in containers other than coil-shaped an in general, Ido not intend to limit myself in any way by the specific details of the construction shown. It is my intention to cover broadly the use of boiling sulphur-tor condensing sulphur vapor as a means of heating oils of any kind, but more especially petroleum oils to a term perature suitable for cracking the oil. The oil cracking itself maybe carried on at,

above or below atmospheric pressure, de-

pending on the particular cracking system 'to which my method of heating is ap lied.

Having described my invention, I c aim: 1. In cracking petroleum products, the

step which comprises heating them by means f of the vaporsof boiling su The boiler used may 'be of any type, the

temperature of the said sulphur vapors by the pressure applied thereto.

2 In cracking petroleum roducts, the step which comprises heatin t cm by means of the vapors of boiling suIphur' out of direct contact therewith but in heat transferring relation thereto-and regulating the tem Y perature of the said sulphur vapors by the pressure applied thereto by means of a' neutral fixed gas.

3. In cracking petroleum ring relation thereto and regulating the temperature of the said sulphur vapors by the pressure applied thereto by means of a neutral fixed gas at greater than atmospheric press e.

rect contact-therewith but in heat transfersignature.

ring relation thereto and regulating the CHARLES Ramona DOWNS.

roducts, the step which comprises heatin t em by means phur out of di; In testimony whereof, I hereby aflix my I

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