US1864686A - Process of cracking and coking - Google Patents

Description

June 28, 1932.

.1. D. FIELDS PROCESS OF CRACKING AND COKING Filed March 5, 1930 In 1/2 21 for :fafirz .Zf'z'eicls Patented June 28, 1932 JOHN D. FIELDS, OFLOS ANGELES, CALIFORNIA PROCESS OF CRACKING AND COKING Application filed L March 8,

This invention relates to a method of treating petroleum hydrocarbons together with vegetable substances for the production of essentialoils and acids from the organic substances, low boiling fractions from the petroleum hydrocarbons, and commercial carbon from both the vegetable substance and the hydrocarbon; the invention further embracing the composite carbon product (coke) An object of the invention is to provide a method whereby a hydrocarbonmay be distilled to effect its conversion into low boiling fractions and coke, producing a high percentage of low boiling carbon and whereby the carbon residue or coke product will be of such character as to enable its ready removal from the distilling apparatus and also have properties imparted thereto which will render it valuable as a carbon or coke product suitable for use in metallurgical and other operations.

Another object is to provide a method or process in which solid vegetable matter is destructively distilled in petroleum whereby as valuable essential oils and acids of the vegetable organic material, low boiling petroleum fractions and a-valuable coke are produced in a single operation.

Another object is to provide a composite A carbon product (or coke) containing both organic and mineral carbon, and to provide an effective and economical method of producing same. Under the term organic carbon I include charcoal from the vegetable matter, and under the term mineral carbon I include the carbon formed from the petroleum.

With the foregoing objects in view, together with such objects and advantages as 40 may subsequently appear, the invention resides in the steps and features hereinafter set forth and claimed. A manner of carrying the invention into effect is illustrated by way of example in the accompanying drawing, in

which:

fractions of the hydro- 1930. Serial No. 432,910.

Fig. l is a view in section and elevation of a pressure still of the boiler type; and

Fig. 2 is a detail in cross section of the boiler illustrating the manner in which carbon or coke is accumulated while efl'ecting its separation from the materials under treatment. While various types of stills and associated apparatus may be employed in carrying out the method and in the production of the carbon product and other products, a structure is here shown in the drawing which is suitable for the purpose and which embodies a boiler A constituting a still, a furnace B for heating the boiler, a hopper C constituting on feeding means for the vegetable matter in a comminuted state, a reservoir D constituting a source of hydrocarbon supply, and-valve controlled feed conduits E and F leading from the hopper and reservoir to the boiler through. which the boiler may be charged from time to time. A vapor discharge conduit G leads from the boiler A to a suitable condenser H, being here shown as leading from a dome 1' on the boiler fitted with a pressure gauge J and a temperature indicator K. p

In carrying out the invention a quantity of vegetable matter in a comminuted solid form together with a uantity of a petroleum hydrocarbon is place in a suitablestill, as in the boiler A, where it is subjected to suitable temperatures and pressure as will be hereinafter set forth.

The Vegetable matter employed is of such character as to produce, during distillation, 0 alcohol, acetic acid, acetone and phenols. An example of such organic material suitable for the purpose is sawdust, dried kelp, beet pulp and sugar-cane refuse, which substances are hereinafter included in the expression car- 35 bonizable carbohydrate vegetable matter. These substances carbonize to form charcoal without first melting. Various other vegetable substances obviously may be employed.

The hydrocarbon employed may be of any character desired to be converted according to the character of the product desired to be derived therefrom. However, a particular hydrocarbon which may be employed may be stated by way of example as comprising petroleum residuum having a high boiling point, for example, of approximately (S degrees Fahrenheit and which may be either of asphalt or paraffin base. The high boiling residuum may, in many cases, he a thick oily material containing a substantial amount of petrolatum-like material and/or some pitchy material in solution, which may need to be warmed up by steam or equivalent, before it can readily be pumped through pipe lines. It may contain a small percentage of free carbon, if it constitutes a residuum from cracking processes. But this material is readily distinguished from petroleum pitch which product, when at atmospheric temperature is a. somewhat brittle solid. I make no claim to coking pitch in a coke oven, either alone or mixtures made by mixing pitch as such, with other materials.

The vegetable matter and petroleum oil -ma v be combined in various proportions. A

desirable proportion is sufficient hydrocarbon to mix with a given quantity of the organic material and form a liquid, fiowable, pumpable mixture. A specific proportion of the vegetable substances is 15 to 20 percent by weight of the petroleum oil. However, a wide range of proportions of the hydrocarbon and the organic material may be emloyed according to the desired results to lie attained, but always the amount of oil is several times more than the amount of the vegetable matter. The mixture of the vegetable matter and hydrocarbon oil placed in the still is subjected to the combined action of a temperature and of a pressure sufficient to effect destructive distillation of the vegetable material and thereby drive off the essential oils and acids and also sufficient to effect separation of low boiling fractions from the hydrocarbon and also to produce a coke-like carbon residuum. A temperature of from 350 to 400 C. (662 to 752 F.) has been found highl' satisfactory but a higher temperature may e employed where heavier fractions are to be produced, it being evident that the higher the heat or temperature to which the materials are subjected, the greater separation 'of the heavier fractions from the hydrocarbon under treatment will result.

While a wide range of pressures may be employed in the still during the distilling operation, it has been found in practice that by subjecting the materials under treatment to a pressure of approximately 100 pounds per square inch with a temperature of approximately 400 degrees C., a maximum of carbon is produced and a distillate contaming a large proportion of cracked low boiling fractions.

' By distilling the vegetable matter and the hydrocarbon together the essential oils and acids of the organic matter come off as distillates, and also the low boiling fractions of the hydrocarbon, and to some extent distillates may be simultaneously formed during the distilling operation from both the vegetable matter and the hydrocarbon, which disti llates will collect together. conveyed from the still and subsequently condensed and separated in any suitable manner.

The distilling of the hydrocarbon and the vegetable materials results in the formation of a solid residue which consists in most part of carbon, including organic carbon or charcoal derived from the organic materials, and coke or mineral carbon derived from the cracking of the petroleum hydrocarbon with which other substances are combined, such as potash, forming a composite coke.

' An important feature of the invention resides in the fact that in subjecting the mixture of hydrocarbon and organic materials to the distilling temperatures a quantity of residue charcoal is formed before the formation of mineral carbon .or petroleum coke takes place which results in the depositin of a layer of the charcoal on the inner sur ace of the still as indicated at L in Fig. 2, thus coating the still surface with charcoal before any appreciable amount of mineral carbon or petroleum coke is formed in the still so that when such mineral carbon or coke is formed it is deposited on the layer of charcoal as indicated at M and, accordingly practically no accumulation of the mineral carbon or coke directly on the metallic walls of the still takes place. Such deposition of a hard petroleum coke, on the still bottom in both cracking stills and coking stills has heretofore been a great source of trouble, since the removal of such coke consumes a great amount of time, this usually requiring hand labor with chisels or similar tools, and of course has to be carefully and thoroughly done.

Thus, in the prior art, mineral carbon or petroleum coke has such an affinity for the heated metal, usually iron, forming the walls of the still and which ordinarily causes such adhesion of the carbon to the metal as to render its removal very difficult. By the formation of the charcoal' layer between the coke and the metallic walls of the still ready separation of the carbon residue is effected as the charcoal has very little, if any, tendency to adhere to the metallic surface of the still other than to rest thereon. A ready separation of the carbon body formedin the still may be effected after completion of the distilling operation which can safely be carried to such extent as to coke the carbon residue to dryness. The still or boiler is formed with an opening N through which the carbon residue may be removed.

The carbon thus formed will consist of an The vapors are admixture of organic carbon and mineral carbon together with such other solid substances as may result from distillation of the materials under treatment. Experience has shown that the carbon product produced by my method contains both mineral and organic carbon, (i. e. petroleum, coke and charcoal), and constitutes a carbon which is highly suitable for use in metallurgical operations.

I claim:

1. The method of simultaneously producing distillates and coke which comprises subjecting a substantially fluid mixture of several parts of petroleum oil containing high boiling constituents and one part of comminuted solid carbonizable carbohydrate vegetable matter, said mixture being capable of being pumped, to cracking, destructive distillation and coking, while maintaining a superatmospheric pressure of several atmospheres on said mixture, and continuing the distillation until a solid product containing carbon residue from both said oil and said vegetable matter remains, while condensing the vapors to form a distillate.

2. The method of simultaneously producing distillate and coke which comprises subjecting a mixture of one part of comminuted solid carbonizable carbohydrate vegetable matter and several parts of a normally liquid petroleum oil containing high boiling constituents, such mixture being sufliciently fluid to be capable of being pumped, to cracking and destructive distillation, while maintaining a superatmospheric pressure of several atmospheres thereupon, and continuing the heating for a sufiicient time to leave a carbonaceous solid mass composed largely of petroleum coke and carbon residue from said vegetable matter, continuing the heating until the carbonaceous mass is substantially dry, and condensing the vapors given off during the process.

3. The method of simultaneously producing distillate and a solid carbon product, which comprises subjectin a fluid mixture capable of being pumped, 0? one part of comminuted woody matter and at least four parts of high boiling petroleum oil to cracking and destructive distillation while maintaining a superatmospheric pressure of several atmospheres thereupon, and maintaining a temperevolved to obtain distillate oil.

JOHN D. FIELDS.

ature of about 350 to 400 0., during most of the cracking and destructive distillation process, and continuing the treatment until a solid mixture of carbon from the etroleum and containing carbon residue rom said .woody matter is formed, and condensing the vapors evolved.

4. The method of simultaneously producing distillate and coke which comprises carbonizing a mixture containing a high boiling petroleum oil and comminuated woody mattcrin such proportions as to form a substantially fluid mass by subjecting such mass to

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