US1299455A - Process of obtaining gasolene from hydrocarbon gases. - Google Patents

Description

l. B. GARNER. PROCESS 0F OBTAINING GASOLENE FROM HYDROCARBON GASES. APPLICATION FILED IAN. Is, I9I1. IIENEWED Aue.2e.1918.

1,299,455. l Patented Apr. 8,1919.

INVENTOR WITNESSES l`UNITED sTATus .PATENT ornrou.

JAMES B. GABNER, or PITTSBURGH, PENNSYLVANIA, AssIGNon fToHoPn NATURAL oAs COMPANY, or rITTsBUReH, PENNSYLVANIA, A CORPORATION or WEST vm I GINIA.

PROCESS OF OBTAINING GASOLENE FROM YDROGARBON GASES..

Specification of Letters Patent.

Patented Api. s, 1919.4

Application led .Tapuary 18, 1917, Serial No. 143,105. Renewed August 26, 1918. Serial No. 251,542.

To all whom t may concern: v

Be it known that I, JAMES B. GARNER, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improve- -ments in Processes of Obtaining Gasolene and of the paraiiin or olefin series or whether they are cyclic.

In United States Letters Patent No. 989,927, granted to G. M. Saybolt, there is disclosed a process for obtaining naphtha or `gisolene from combustible gas of natural origin and underground source, such method, briefly stated in the general terms Of the patent, consisting in subjecting the gas un- 'der pressure to a naphtha absorbing menstruum for the purpose of separating from the gas such naphtha as is liquid at atmospherie temperature and pressures, and Iin subsequently removing the naphtha from the menstruum.

While my inventioncontemplates the use of an absorption lrocess similar to that disclosed in the Say cated above, unlimited to the recovery of gasolene from natural gas, but extends' toits recovery from any gas or gases with which it may be intermingled. As an example of gases, other than natural, from which gasolene may be recovered, it has been found that large quantities of gas are formed in thel practice of the various processes for cracking petroleum to produce gasolene, and that such gases include gasolene hydrocarbons, that is, hydrocarbons whose boiling points lie within the above stated range.

vIn practising absorption processes, for the recovery of gasolene from hydrocarbon gases with which it is associated. one of the greatest sources of difficulty is the presence in the menstruum of the lighter constitu ents of the gas. Under the pressures which, to obtainsubstantial yields of gusk'ilene, it.

Olt patent, it is, as indi-I is necessary to place the gas when subjecting it to the absorbing menstruum, it has been found impossible to prevent some of the lighter lconstituents of the gas from be-v ing absorbed by the menstruum. When, for the purpose of distilling the menstruum, the highabsorption pressure is diminished or removed (as it must be to" practise the prooess in a practical and economic manner), the absorbed lighter constituents of the gas volatilize, choke up the apparatus, and prevent to a large extent the distillation of the gasolenev from the menstruum and also prejudicially eii'ect the subsequent condensation of the gasolene vapors.

' It is therefore the obj ect of my invention to provide a process for the purpose and of the general character described, whereby the lighter constituents of the gas absorbed by the menstruum may be eii'ectively -removed from the menstruum prior to the distillation thereof.

In the practice of my invention the gas to be treated is subjected to the absorbing menstruum under such high pressures as are required to eiiect the removal from the gas of large portions of its gasolene content. As already stated some of the lighter constituents of thej gas will be absorbed by the menstruum when the absorption step is per-.

formed under high gas pressure. To remove these lighter constituents I expose the menstruum, after it has been used for vhigh pressure absorption, to the gas at low presf sure and-before the gas has been subjected that the quantity Of lighter constituents ab- Y sorbed by the menstruum varies little if any with relation to the proportion of lighter constituents in the gas, so that the additmn to the gas of the lighter constituents previously absorbed by the menstruum willnot have the effect of subsequently increasin the amount of lighter constituents absorbe After the menstruum has been thus exposed to the low pressure incoming gas it is dis tilled for the removal of its absorbed gaso? iene constituents.

Manifestly this process is Well adapted to the treatment of gases of low pressure origin, such as casingehead and How-tank natural gases, these gases being usually obtained at, or at less than, atmospheric pressure. To recover substantial yields of gasolene from them, they must be compressed.

By effecting such compression at the absorption plant, the menstruum with its absorbed gasolene and lighter constituents may be exposed tothe incoming gas prior to its passage through the compressor, and this may be done without additional operating expense.

The menstruum may, for the removal of its lighter absorbed constituents, be exposed to the low pressure gas in any desired manner. However, this is preferably done by passing the low pressure gas through the menstruum when the menstruum is in the form of a spray. By such procedure the menstruum will, in addition to giving up its lighter constituents, further absorb some of .the heavier gasolene-forming constituents of the gas.

In the accompanying drawing there is diagrammatically shown an apparatus for practising the invention in the preferred manner just stated.

Referring to the drawing, the low pressure as, from whatever source of supply it may e taken, flows through a pipe 1 to a tank 2 in which there are aplurality of noz- 'zles 3 connected to a header 4, which header 1s in turn connected to aconduit leading from the body of menstruum through which the gas under high pressure has beenpassed to effect the absorption of gasolene-forming hydro-carbons. The pressure being thus removed from the menstruum while the menstruum is exposed to the low pressure gas, the lighter gaseous constituents previously absorbed by the menstruum become volatilized and intermingled with the gas. lFrom the tank 2 the gas and menstruum flow through a conduit 5 to a tank 6. To the end that the finely divided particles of menstruum carried by the`gas from the tank 2 may not enter the compressor, the conduit 5 extends to a point near the bottom of the tank 6 and the level of the menstruum within such tank is maintained above the outlet of the conduit, as indicated. From the tank 6 the gas is taken by a pipe 7 to a compressor 8, and is thereafter cooled by a cooler 9. Manifestly the compressor may, if desired, beused to create a partial vacuum in the pipe 1 for the purpose of drawing of the gas from, for example, a flow-tank, casing-head or still.

The compressed gas may be subjected to the absorbmg menstruum in any desired manner. Preferably it is passed rst through a spray absorber and then through a liquid-body absorber. The spray absorber,

the gas percolates through the liquid body of menstruum, the unabsorbed. constituents being caught in a header 16 and carried through a line 17 to any desired point of consumption. The purpose of the liquidbody absorber is twofold, first to remove from the gas the finely divided particles of menstruum carried by the gas from the spray absorber, and secondly, to effect further absorption by the menstruum of the gasolene constituents of the gas.

Considering the entire apparatus as a whole, the gas and menstruum flow in counter currents through it. The menstruum, substantially free from absorbed gas constituents, enters one end of the tank l5 through a pipe 18, Hows slowly through such tank, and is taken from it through a pipe 19. The pressure ofthe gas in the tanks 10 and 15 being substantially the same, a pump 20 is placed in the line 19 to cause the menstruum to properly flow through such line to the header, and from thence through the spray nozzles 11 Within the tank 10. The menstruum collected in the trap portion of the tank 10 is conducted through pipes 21 and 36 to the header 4, the valves 100 22 and 23 of these pipes being open. The latter of these valves is placed adjacent to' the header 'to prevent, as far as possible, the foaming of the menstruum in the pipes 21 and 36 when the pressure is relieved from 105 'tank 2 to the low pressure gas, and the consequent removal of the absorbed lighter gas constituents, have already been explained. The next step in the process is the removal from the menstruum of its absorbed gasolene. For this purpose the. menstruum is conducted through a pipe 24 to a still 25, in which it is heated to the required temperature to vaporize the absorbed gasolene. The vapors generated in the still are carried therefrom through a pipe 26 to a condenser (not shown) which may be of any well known" or desired construction. As indicated, thel pipe-18 for conducting the distilled menstruum from the still to the absorbing tank 15, and the pipe 24 for conducting the menstruum to the still pass through a suitable heat exchanger 27 which also may be of any preferred construction. The menstruum flowing to the tank 15 may be 130 further cooled by a cooler 28, and both the pipes 18 and 24 may be provided, respectively, with pumps 38 and 29. I

In case it is desired to use only'the liquidbody absorber, the gas, after being compressed, may be conducted through a. pipe 30 from the pipe 7 to the pipe 13, and the menstruum may be conducted through a pipe 31 from the pipe 19 to the pipe 36, thus bypassing the spray absorber. For this purose it is only necessary to close the valves 22, 32 and 33 of pipes 21, 7 and 19, respectively, and to open the valves 34 and 35 of pipes 30 and 31.

While my invention is,-in its broader aspects, unlimited to the relative or absolute pressures of the gas in the gasolene-absorbing and 4menstruum-exposing step of the process, the 'best results are obtained when the incoming low-pressure gas is at substantially atmospheric pressure, and when., for gasolene-absorption, the gas is compressed to thirty or more pounds per square inch.

Vith respect to the absorbin menstruum,l

various liquids having an a nity 'for the gasolene-forming hydrocarbons may be used. However, the preferred liquid is petroleum hydrocarbons having an initial specific gravity of from 28 to 55 Baum at 60 F.

It is apparent that other forms of apparatus than -those specifically shown and described may be used in thepractice of my invention.

I claim as my invention: l

l. The process of obtaining gasolene from hydrocarbon gases containing 1t, which consists in subjecting the gas under a pressure substantially greater than atmospheric pressure toa gasolene-absorbing menstruum; thereafter, for the removal from the menstruum of the lighter constituents absorbed thereby, exposing the menstruum to the gas at a pressure substantially lower than'said first named pressure and prior-to-said higher pressure subjection of the gas to the menstruum; and thereafter removing the gasolene from the menstruum.

, to the ga 3. The process of obtaining solene from hydrocarbon gases containing 1t, which consists in subjecting the gas under a pressure substantially greater than atmospheric pressure to a gasolene-absorbing menstruum; thereafter for the removal from the menstruum of the lighter constituents absorbed thereby, spraying the menstruum into the line of flow of the incoming gas at a pressure substantially lower lthan said first named pressure; and thereafter subj ec-tin the menstruum to a distilling operation or the removal of its absorbed gasolene.

1. The process of obtaining gasolene from hydro-carbon gases containing it, which con- .sists in subjecting the gas under a pressure not less than about thirty pounds to the square inch to a gasolene-absorbing menstruum; thereafter, for the removal from the menstruum of the lighter constituents absorbed thereby, spraying the menstruum into the line of flow of the incoming gas at substantially atmospheric pressure; and thereafter subjecting the menstruum' to a distilling operation for the removal of lits,

absorbed gasolene.

In testimony whereof I have hereunto set my hand.

JAMES B. JGARNER.

Witnesses: i

APAUL N. CBITGHLOW,

FRANCIS J. ToMAssoN.

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