US1391569A

US1391569A - Process for the cracking of hydrocarbon oils and the like

Info

Publication number: US1391569A
Application number: US346990A
Authority: US
Inventors: Nelson John
Original assignee: Individual
Current assignee: Individual
Priority date: 1919-12-23
Filing date: 1919-12-23
Publication date: 1921-09-20
Anticipated expiration: 1938-09-20

Description

J. NELSON. PROCESS FOR THE CRACKING OF HYDROCARBON} OILS AND THE LIKE. APPLICATION FILED DEC.23, 1919.

1,391,5 9, Patntedsept. 20,1921.

INVENTOR J. NELSON. PROCESS FOR THE CRACKING OF HYDROCARBON 0|LS AND THE LIKE. APPLICATION FILED DEC.23| 1919.

1,391,569 Patented Sept. 20, 1921.

2 SHEETS-SHEET 2.

INVENTOR UNITED. STATES PATENT orrlcs.

- JOHN NELSON, 0F GLASGOW, SCOTLAND.

' rnocns's non THE cnncx'me or HYDROCARBON OILS AND THE LIKE.

Specification of Letters Patent. Pate t d S t 20 1921 Application filed December 23, 1919. Serial No. 346,990.

To all whom it met concern:

Be it known that J 0111s NELSON, a subject of the King of England, residing in Glasgow, Scotland, have invented certain new and useful Improvements in a Process for the Cracking of Hydrocarbon Oils and the like, of which the following is a speci- "contact-substance, and cooling the vapors prior to further treatment with the contact material. Preferably, the vapors are cooled to a temperature just above that of condensation before the succeeding cracking step. For many oils, the temperature throughout the process does not substantially exceed 620 C. and is preferably about 500550, and the maximum cooling of the vapors between successive treatments is re resented by a temperature of about 375. T e degree of cooling between successive steps need not be the same, but may be .varied according to circumstances, for example, the extent o which the vapors have been already cracked. It is preferred to effect the cracking of the oil in a series of steps, each step being of comparatively short duration. 1 The temperature of the contact-substance may be the same for each period of contact, or a decreasing or increasing temperature may be employed. The contact material is kept agitated during the process as, for'example, by the passage of the hydrocarbon. According to a modification of the invention, the oil or its vapors are submitted to the action of the liquid contact-substance in conj unction with steam;

If the oil to be cracked'contains tarry or other objectionable products which cannot be eliminated during the cracking process,

the oil may be distilled from an auxiliary vessel, and the distillate or vapors subjected to the cracking operation.

The contact material may be a .molten metal, or alloy, for example, molten lead,

or a fused salt, or mixture of salts, as sodium mtrate, or sodium hydroxid, but the invention is, of course, not restricted in re- Y spect to the use of a particular liquid contact-substance. I I

The extent of the cracking may be varied wlthln certain limits by varying the depth at wh ch the hydrocarbon or its vapors are dellvered beneath the surface of the contact substance, and by the number of contact periods. As one object of the invention is to avo1d production of much carbonaceous matter, 1t is material not to subject the oil or 1ts vapors to the cracking temperature in constricted channels The apparatus which forms the subject of my prior application affords special provision against this, as well as providing a means of operation of the process herein set forth.

The accompanying drawings show one form in sectional elevation of such apparatus set for the treatment of two different kinds of oil.

Figure 1 shows diagrammatically the arrangement when heavy oils of high boilingpoint, such as petroleum fuel oils, are to be treated, and

Fig. 2 shows the setting for the treatment of lighter oils, such as coal-tar naphthas,

boiling say, above 160 and under 240 C.

Referring to the drawings, A represents the heating chamber having four crackin pots B, set in the flue C, of the furnace As shown, the arrangement is such that the chamber in which the pots are set is surrounded by the hot gases from the furnace. The flue C in which the cracking-pots are set may be divided above the level of the contact-substance in the pots with a transverse partition, as indicated by the chain lines in Fig. 1, to restrict theheating area in the pots. E is the inlet for the hydrocarbon, and F are the pipes which lead the vapors from one pot to the next. f-g represents the-level of the molten contact-substance, "gh the zone of partial cooling, and

are shown touching the crown G, of the furnace, the cooling area in this case being merely that derived from the depth of the furnace crown added to theheight above the latter of the pipe, and, to a lesser degree, to the distance from the crown to the surface of the contact-substance. The figure illustrates, therefore, the minimum degree of intermediate cooling for heavy hydrocarbon vapors between successive stages of treatment.

In the case of lighter oils, such as the coal-tar naphthas mentioned, the flanges of the cracking-pots are not flush with the furnace-crown setting, but extend out of the furnace as shown in Fig. 2. In the case of petroleum solar-oil, a similar variation would be made in order to secure the maximum cracking results. It is, of course, to be understood that there is necessarily a limit beyond which the communicating pipes between the cracking pots project beyond the sphere of heat, and the distance must never be so great that condensation to liquid of'the hydrocarbon vapors can take place between successive treatments. The cooling is preferably the maximum possible in order to obtain the greatest temperature difference between the vapor and the contact-substance. The selection of the particular contactsubstance to be used depends, among other considerations, upon the working temperature employed. In operating at moderate temperatures (such as are utilized in the production of volatile spirits for use in petrol engines) it is preferred to make use of a bath of molten lead or of salts of suitable melting point, and to pass the hydrocarbon or itsvapors into the bath at a suitable distance below its surface. If temperatures exceeding those at which lead can be satisfactorily employed are required, metals or alloys of higher melting point than lead may, of course, be used.

It has been found that if oil be cracked by the aid of a liquid contact-substance in a series of successive steps, each step being of comparatively short duration, and the oil vapors be subjected to a cooling action prior to treatment in one or more further 7 steps, a much more satisfactory conversion of the oil can be obtained than has hitherto been the case. It is to be understood, however, that the total period of contact between the oil and the contact-substance is not necessarily short; it maybe prolonged as desired to secure the maximum degree of conversion under the particular conditions of working; it is each step of'contact which is short.

As the time during which the hydrocarbon and its product remain in contact with-the hot liquid substance is brief, the whole product or any desired fraction thereof, may be subjected to one or more re-treatments;

and desire vapors to a point just above that atwhichthey condense. 1

2. The herein described process for 'crack ing hydrocarbon oils and the like which comprises introducingthe hydrocarbon into a liquid metallic contact substance in a series .of steps and between two successive steps cooling the vapors to a point just above that at which they condense.

3. The herein described process for cracking hydrocarbon oils and the like which comprises introducing thehydrocarbon and steam into a liquid contact substance in a series of steps and between two successive steps cooling the vapors to a point just above that at which they condense.

4E. The hereinjdescribed process for cracking hydrocarbon oils and the like which com"- prises introducing the hydrocarbon into a liquid contact substance in a series of steps of brief contact period and between two successive steps cooling the vapors to a point just above that at which they'condense.

i 5. The herein described process for cracking hydracarbon oils and the like which comprises introducing the hydrocarbon into a liquid contact substance at a temperature of v between two successive steps cooling the vapprs t8 a temperature not substantially below 7. The herein described process for cracking hydrocarbon oils and the like which comprises introducing the hydrocarbon into a, liquid metallic contact substance at a temperature of 500550 in a series of steps and between two successive steps cooling the vapors to a point just above that at which they condense.

8. The herein described process for cracking hydrocarbon oils and the like which comprises introducing the hydrocarbon into a liquid metallic contact substance at a temperature not exceeding 620 in a series of.

steps and between two successive steps cooling the vapors to a temperature not subvapors of the h drocarbon to a point just stantially below 375 0. above that at which they condense, and vary- 9. The herein described rocess for crack ing the temperature of the contact substance 10 ing hydrocarbon oils an the like which at difierent steps. 5 comprises introducing the hydrocarbon into In testimony whereof I afiix my signature.

a liquid contact substance in a series of steps and between two successive steps cooling the J NO. NELSON.