US1250799A - Art of cracking petroleum hydrocarbons. - Google Patents

Description

" J. W. COAST, In. ART OF CRACKING PETROLEUM HYDROCARBONS.

4 Patented Dec.

APPLICATION FILED DEC. H 1916.

UNITED STATES PATENT OFFICE.

JOHN W. COAST, JR., OF TULSA, OKLAHOMA, ASSIGN OR, BY MESNE ASSIGNMENTS, TO THE PROCESS COMPANY, A CORPORATION OF MARYLAND.

ART OF CRACKING PETROLEUM HYDROCARBONS.

Specification of Letters Patent.-

Patented Dec. 18, 1917.

Application filed December 11, 1916. Serial No. 136,229.

To all whom it may concern:

Be it known that I, JOHN W. COAST, Jr. a, citizen of the United States of America, a resident of Tulsa, in the county of Tulsa, State of Oklahoma, have invented certain new and useful Improvements in the Art of Cracking Petroleum Hydrocarbons, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to improvements in the art of cracking petroleum hydrocarbons to obtain a gasolene substitute adapted for use in internal combustion engines. One of the objects is to improve the prior art by providing a method whereby high boiling petroleum distillates or residues, or a mixture including such distillates or residues, may be cracked, vaporized and condensed very rapidly, with the result of obtamlng a high grade low boiling product. In the preferred form of the invention, the highly desir-able product is obtained by a single crackproduct may, of course, be improved by fracing operation, it being unnecessary to subject the product to a multiplicity of dlstilling operations. However, the quality of the tional distillation.

More specifically stated, the preferred method comprises the step of condensing and returning to the retort, a large volume of high boiling hydrocarbons, and conducting the relatively small volume of low b011- ing hydrocarbons to the main condenser from which the low boiling product is recovered. The contents of the retort are subjected to such a high temperature that the liquid vaporize very rapidly, and a large volume of uncracked high boiling hydrocarbons, therefore, pass from the retort to the primary or reflux condenser where they are condensed and prevented from passing to the main condenser. The vaporized low boiling hydrocarbons pass from the primary or reflux condenser to a steam chamber where they are acted upon by a spray of relatively cool steam. The steam condenses an intermediate fraction, and almost entirely eliminates the objectionable odor and color usually present in cracked products. For reasons which at this time I am unable to fully explain, the product is otherwise very materially improved by the introduction of steam into the light hydrocarbon vapors which pass conduct the vapors from the retort, first through the primary condenser under a high pressure, thereby condensing and returning the high boiling fractions. The remaining vapors are then conducted, While under the high pressure, into the steam chamber where they are acted upon by the steam, the intermediate fractions being condensed by the relatively cool steam and returned to the primary condenser. After passing successively through the primary condenser and steam chamber, under a high pressure, the vaporized low boiling hydrocarbons are preferably conducted with the steam to a main condenser maintained at about atmospheric pressure.

Figure I is a diagrammatical view of an apparatus adapted for use in carrying out my method.

Fig. II is a fragmentary section of one of the air cooled condensers.

Fig. III is a transverse section of the condenser shown in Fig. I

To illustrate the invention I have shown a retort or still 1 arranged over a heating chamber 2. The primary condenser preferably comprises an air cooled vapor pipe 3 leading from the retort to an air cooled drum 4, the latter being connected by a short pipe 5 to another air cooled drum 4:. Each of these drums is provided with horizontal tubes, open at their ends and'communicating with a hot air flue 6. Dampers or valves 7, arranged in the air flues, may be adjusted to regulate the circulation of air through the tubes in the drums 4 and 4. 8 and 8 designate deflector plates arranged in the air cooled drums to direct the vapors in the direction indicated by arrows. An opening 9 is formed at the lower edge of each deflector plate 8 to allow the condensate to flow backwardly, toward the retort. A return pipe 10, leading from the condenser 4 to the retort 1, is provided with a trap 11 and a valve 12.

The vapors passing from the drum 4 are conducted into a steam chamber 18, and the vapor pipe 14: may be regulated to'ma-intain Y steam chamber.

a predetermined pressure in the Steam cham-- ber 13, also in the retort 1 and primary condensing elements 3, 1 and 4. A steam pipe 18 is connected to a discharge member 19 1n the steam chamber 13. The flow of steam may be regulated by adjusting a valve 20.

' Although I have shoWn and described a specific structure adapted for use in followlng my method, it is to be understood that the illustration is merely diagrammatical and that any suitable apparatus may be used in carrying out the method herein claimed.

The new method may be followed in cracking various heavy hydrocarbon products resulting from the treatment of crude petroleum, particularly such inexpensive hydrocarbons having a boiling point higher than 350 F., the most beneficial results being obtained from hydrocarbons having a boiling point ranging from 450 F. to 700 F. The substances to be treated are introduced into the retort in any suitable manner, and .the valve 17 is adjusted to obtain the desired pressure in the retort, primary condenser and steam chamber 13. The pressure may range from 50 to 150 pounds per square inch, or even higher, but'it is preferably maintained at about 80 pounds per square inch. The contents of the retort are subjected to such a high degree of heat that the liquid will vaporize rapidly. This tem' perature may range from about 600 F. to 800 F., and is preferably maintained at about 715 F. to 750 F. The pressure in the apparatus is due to the expansive force of the vapors.

Owing to the intense heat and the rapid vaporization, a large volume of high boiling hydrocarbons flow from the retort into the primary condensing devices 3, 4 and 4:, and since these devices are in a higher plane than the retort, a large volume of condensate will return, by gravity, through the inclined pipe 3 to the retort. If desired, the valve 12 may be opened to permit the fiow of condensate from the air cooled drums .4' and 4: to the retort. To obtain the desired low boiling product, about one-half of the vapors may be condensed in the air cooled primary condensing devices, and additional condensation will take place in the steam chamber 13 above the air cooled drum 4. Relatively cool steam, preferably saturated steam, is discharged from the steam pipe 18 into the discharge member 19, the latter having a number of small discharge ports so as to discharge a multitude of fine streams of steam into the stream of vapors in the by the vapors, and the relatively heavy hydrocarbons are condensed by the cooling The steam is superheated action of the steam. The steamcommingles with and acts upon the light hydrocarbon vapors which pass entirely through the primary condensing .devices, the high boiling hydrocarbons being condensed before the vapors reach the steam chamber. It is also important to note that the steam is introduced into the vapors at a point where the vapors are under the high degree of pressure maintained between the valve 17 and the retort.

The mixture of steam and hydrocarbon vapors, under pressure, passes from the steam chamber 13 to the vapor pipe 14:. The pressure is relieved at the pressure regulating valve 17 and the mixed vapors are afterward condensed, under about atmospheric pressure, in the main condenser 15. The water and low boiling hydrocarbon product, recovered from the condenser 15, may be separated from each other in any suitable manner.

The return conductor 10 passes through a heating chamber H so as to heat the condensate before it reaches the hot liquid in the still.

tents of the still or retort 1.

The apparatus herein shown is claimed in an application for patent filed by me on Dec. 18, 1916, Serial Number 137,578. The

air cooled condenser per se and.the partic-,

ular method of conducting air and vapor through a condenser of this kind, are claimed in applications for patents filed by me May 31, 1917, Serial Number 172,037, and May 22, 1917, Serial Number 170,150, re-

spectively. The use of steam as herein dissultant vapors under a pressure greater thantwo atmospheres, conducting said vapors, while under pressure, through a condenser, thereafter introducing steam into 'the remaining vapors while said vapors are confined under pressure, and condensing the steam and low boiling hydrocarbons.

This condensate is preferably heated to about the temperature of-the con-' 2. In the art of cracking high boiling pe Y troleum hydrocarbons to obtain .a substitute for gasolene, the method which comprises cracking such hydrocarbons in a retort under a pressure greater than 50 pounds per square inch, condensing the vaporized high boiling fractions under a pressure greater than 50 pounds per square inch, thereafter lntroduclng relatively cool steam into the remalnmg vapors while said vapors are confined under a pressure greater than 50' pounds per square inch, conducting the mixture of steam and hydrocarbon vapors to a main condenser, and maintaining the contents of said main condenser under a pressure of about one atmosphere. v

3. In the art of cracking high boiling petroleum hydrocarbons to obtain asubstitute for gasolene, the method which comprises cracking such hydrocarbons'in a retort under a pressure greater than 50 pounds per square inch, condensing the vaporized high boiling fractions under a pressure greater than 50 pounds per square inch, thereafter returning vthe highboiling fractions to the retort and introducing relatively cool steam into the remalning vapors While said vapors are confined under a pressure greater than 50 pounds per square inch, conducting'the mixture of steam and hydrocarbon vapors to a main condenser, and maintaining the contents of said main condenser under a pressure of about oneatmosphere.

4. In the art of cracking high boiling petroleum hydrocarbons to obtain a substitute for gasolene, the method which comprises heating such high boiling hydrocarbons in a retort, conducting vapors from said retort first through an air cooled reflux condenser, and then through a steam chamber, conduct ing saturated steam to said steam chamber and introducing the steam into the stream of vapors in'the steam chamber, thus condensing high boiling fractionsand at the same time superheating the steam, returning high boiling hydrocarbons, in the form of condensate, from said steam chamber to said air cooled reflux condenser and from the last mentioned condenser to the retort, at the same time maintaining the contents of said retort, condenser and steam chamber under a pressuregreater than 50 pounds per square inch, conductin the mixture ofsteamand low boiling hy rocarbons from said steam chamber to a main condenser, and maintaining the contents of said main condenser under about atmospheric pressure.

JOHN W. COAST, Jr.

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