FIGURE 10.-Compression type of plant for making gasoline from natural gas. Elevation.

The condensate is trapped into the accumulator tank b, and the residual gas may again be passed back into the compressors through a conducting pipe line. The authors believe that this latter arrangement results in the obtaining of no more condensate, for the residual gas is subjected to the same treatment to which it has already been subjected. In fact the method appears to be wasteful, because the residual gas simply takes the place in the compressors of some gas direct from the wells that could be profitably treated. However the authors have made no experiments to determine this point.

In Plate I, A, is shown an exterior view of a gasoline plant at Sistersville, W. Va. The small cooling coils for water cooling and the larger pipes for expansion cooling are shown distinctly.

Plate I, B, shows a plant in process of erection in the Glenn pool district, Okla. The expansion coils are jacketed. Plate I, C, shows a small plant at Reno, W. Va. There are many of the smaller plants of this type throughout the Appalachian fields. Plate II, A, shows the cooling coils and accumulator tanks of another gasoline plant.

Plate II, B, shows the interior view of an accumulator-tank house.

Plate III, A, shows a gas engine and belt-driven compressor of another gasoline plant.

Plate III, B, shows an interior view of a plant having both a lowstage and a high-stage belt-driven compressor.

Plate IV, A, shows the ruins of a natural-gas gasoline plant that was destroyed by an explosion.

Plate IV, B, and Plate IV, C, show views of a plant in California that is operated by an ammonia refrigerative system.

Plate V, A, shows an oil well from which casing-head gas is drawn for a near-by gasoline plant. The pump shown in the foreground to the left of the picture for pumping the gas from the well is connected to several other wells besides that one shown to the right of the figure. The gas-pipe connection to the oil well is not shown in the view, because it is on the other side of the casing.

Plate V, B, shows an exterior view of another gasoline plant in the Glenn pool district. Cooling and storage tanks and oil-well derricks and oil tanks are shown. Ice may be seen on two of the gasoline storage tanks.

Plate VI shows the interior view of the compressor building. Six 50-horsepower direct-driven gas compressors are contained in this Such an outfit can handle about 2,500,000 cubic feet of gas

room.

per 24 hours.

PLANT TESTS TO DETERMINE EFFECT OF DIFFERENT PRESSURES ON YIELD OF GASOLINE.

Some tests were conducted by the authors to show the grade and quantity of gasoline produced when the crude natural gas was subjected to different pressures during actual plant operation. The natural gas issued from the wells under slight pressure. Meters were being used constantly to measure the gas. The pressure to which the gas is ordinarily subjected is about 140 to 150 pounds per square inch. The following table shows the results of the authors' experi

ments:

Results of tests of the grade and quantity of gasoline produced when crude natural gas is subjected to different pressures.

It had been found by experiment at this plant that pressures of 140 to 150 pounds per square inch produced the most marketable gasoline. It will be observed that a pressure of 190 pounds produced

more gasoline. The extra 1 gallons, however, was of such a volatile character that it only escaped into the atmosphere upon exposure to the air; hence high pressures at this plant were unnecessary. Gasoline could be obtained by the application of pressures as little as 50 pounds per square inch, but the yield was small.

As natural gas is of different character in many different sections of the country and even in the same oil field, data obtained at one plant can not always be used as a basis for operating other plants— that is, as far as the pressures that should be used are concerned. Each operator should thoroughly test his own gas. Different pressures should be applied and the quantity and character of the gasoline noted. A reliable meter for measuring the gas becomes indispensable. If, in certain plants operating to-day, meters were installed and a series of tests conducted as above outlined much greater efficiency of operation could be attained. Other apparatus that could be used to advantage are thermometers, graduated vessels for measuring the gasoline, hydrometers for determining the specific gravity of the gasoline, and gas-analysis apparatus, especially an apparatus for detecting air leaks in pipes through analyses of the gas for oxygen. COMMENTS ON METHODS AND EQUIPMENT OF VARIOUS PLANTS.

One plant in McKean County, Pa., obtains only about 72,000 cubic feet per 24 hours from 91 producing oil wells subjected to a reduced pressure of only 1 or 2 inches of mercury. About 4 gallons of gasoline per 1,000 cubic feet of gas is obtained.

Another plant, about 2 miles distant, obtains about 30,000 cubic feet of gas per hour from 57 wells under a similar reduced pressure. The only plant in New York situated in the same field as those mentioned above is about 10 miles distant and obtains about 72,000 cubic feet of gas from 60 wells in 24 hours. The wells are drilled in what is known as the third sand. The sand in this locality is spoken of as being "close." At a compression of 250 pounds per square inch and with cooling to about 20° C. (68° F.), the yield of gasoline approximates closely 4 gallons per 1,000 cubic feet of gas. The specific gravity of the condensate is 90° to 95° B.

In the region around Tidioute, Warren County, Pa., there is a condition that exists in no other field in the United States as far as the authors are aware. The producing wells tap the third sand, and are subjected to a reduced pressure of about 20 inches of mercury. Any gases and vapors obtained are simply cooled in water and the condensate collected. The amount of vapors obtained per well is rather small and the methods of extraction of gasoline are crude. At only two "plants" is any attempt made to compress the gas, but connected to these are 50 or 60 wells. The majority of the producers in this region pump only a few wells.