US1767341A - Process and apparatus for stabilizing crude petroleum - Google Patents

Description

June 24,1930. F. B. BlMEL PROCESS AND APPARATUS FOR STABILIZING CRUDE PETROLEUM Filed Aug. 19. 1926 FREuEmm B. B an.

gvwentoz Patented June 24, 1930 UNITED STATES PATENT OFFICE FREDERICK B. IBIMEL', OF WESTFIELD, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE PROCESS AND APPARATUS FOR STABILIZING CRUDE PETROLEUM Application filed August 19, 1926. Serial No. 130,167.

The present invention relates primarily to the prevention or reduction of losses by evaporation of crude oils during transportation and storage. A method of reducing losses of gasoline fractions from crude petroleum is provided whereby the gases in solution in the oil are removed by rectifying means and the stripped oil can then be stored or transported without the losses of gasoline normally attending the escape of such dissolved gas.

It is well known that crude petroleum as it is obtained from flowing or pumping wells contains dissolved gases, and that upon the gas escaping, normally liquid products are carried away with the gas. My invention includes the use of a rectifying column in which dissolved gases are removed with the least possible quantity of normally liquid material. In this manner the quantity of gasoline evaporated will be less than when the gas escapes by simple distillation as from a vent tank, and consequently subsequent loss by evaporation during transportation and storage will be reduced. In other words, the crude oil is stabilized by removing from it those gases that are incondensible in a pure state under ordinary atmospheric conditions of temperature and pressure, the presence of which normally gaseous constituents tends to cause excessive loss of valuable less volatile materials.

My invention will be fully understood from the following description and the drawing which is a semi-diagrammatic view in elevation of the preferred form of the apparatus constructed according to my invention.

In the drawing a feed line 1 carries crude oil fresh from the wellsto a preheater 2 provided to raise the temp rature of the oil before it is introduced into a rectifying or stripping tower 3 which is preferably furnished with bell-cap plates 4. and overflow pipes 5 for passage of vapor and liquid respectively. A heating coil 6 is located in the base of the t'ower 3, from which the stripped oil flows to pump 8 andto a cooler 9.

A cooling coil 7 is located at the top of the tower to condense gasoline which may be vaporized, and a line 10 provided with a condensate drum 10 conducts eflluent vapors to vacuum pump 11 and to the separator drum 12. Vapor from 12 is compressed in compressor 13 and is dischargedinto separator drum 14, from which the gas, deprived of its more readily condensible fractions, is sent by line 15 to boilers as fuel or to gas mains. Condensate drums 12 and 14 are connected by pipes to pump 16 so that each condensate may be withdrawn separately, or either or both may be mixed with the cold stripped oil flowing from cooler 9 to storage or pipe lines for transportation.

In the operation of my process it has been found that oil from different sources requires diflerent conditions of pressure and temperature. The best results are ordinarily obtained with vacua of 10 to 28 inches mercury 0 corresponding to absolute pressures of approximately 2 to 20 inches mercury and a preheat temperature of 100 to'250 F. for the crude oil. The temperature at the top of the tower will range from 7 5 to 200 F., and at the base of the tower from 150 to 300 F. It will be understood that these temperatures may vary considerably with the heating steam pressure available and the cooling water temperature. It is advantageous to have the 011 flowing from the base of the tower about to 100 F. higher than the enterlng crude, and eflluent gases will be 30 to 75 F. lower than the crude. It is advantageous to main- .tain the flow of oil as constant as possible,

and automatic control devices are preferred but not required.

There are several modifications of the above mentioned apparatus which lie within the scope of my invention. The tower 3 may be packed with broken coke, stones, or contact rings as is well known in the art. The preheater 2 may be a heat exchanger, heating the fresh crude at the expense of the heat of the oil flowing from tower 3 with obvious advantages. With careful rectification 11: should not be necessary to have the compressor 13, although it is preferred; any gasoline expelled may be recovered by absorption in oil or on charcoal, as is well known. Cooling at the top of tower 3 is preferably accomplished with cold water, but in certain circumstances, where the crude contains large quantities of gas, the cooling may be accomplished by allowing part. of the liquid from drums 12 and 14 to expand into thetower as is well known in the art.

It is generally the case that vacuum is ad- Lvantageous but for certain crudes which contain excessively large quantities of gaseous materials, rectification may be accomplished under atmospheric or even superatmospheric pressure.

My invention is not to be considered limited b any theory which may be ofl'ered as an ext p anation of the operation of the process but only by the appended claims, in which I intend to claim all novelt inherent in my invention and allowable in view of the priorart.

I claim:

o 1. Apparatus of the character described,

comprising a rectifier for crude petroleum, heating means in the lower portion of the rectifier, separate means for removing and cooling liquids and gases from the rectifier,

means for'compressing said gases, and means .for returning condensate from said compression means to the cooled oil flowing from the rectifier. v I 2. A process ,for stabilizing crude petroleso um, comprising rectifying the petroleum under reduced pressure and at a temperature .above that of the atmosphere, separately removing liquid and gas containing vapor, cooling said liquid, compressing the gas to condense normally liquid constituents therefrom, i1 nd (il'eturning the condensate to the cooled 3. A process for stabilizing crude petroleum, comprising rectifying the petroleum, 40 separate y .removing li uid and gas containing vapor, cooling said 'liquid, recovering normally liquid constituents from the gas containing vapor,- and returning said constituentstotliepooled-liquid'. r 4; Aprocess according to claim 3, in which iithe rectification; is carried out at a tempera- .tune below. 3( )0{ F, g;

5. -A;proces's.for stabilizing crude troleum,compris1ng recti ing the petro eum at a temperature above t at of the atmosphere,

separately removingsliquid and gas containing lightnormally liquid hydrocarbons,

cooling said liquid, and 'admixin therewith light normally liquid hydrocar ons freed from the ."FREDERICK B. BIMEL.

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