Natural Gas

The liquefied hydrocarbons—whose critical temperatures are above the prevailing atmospheric temperatures—are ethane, pro pane, normal butane, and These are recovered in a high state of purity in plants generally associated with natural gasoline recovery plants.

Gasoline Recovery.

Natural gasoline is recovered by three processes : compression and cooling, oil absorption, and charcoal adsorption, and is marketed in a variety of grades, generally based upon two factors; the Reid Vapour Pressure Test at ioo° F., expressed in pounds per square inch pressure, and the per centage which is distillable and recoverable at 14o° F. Both methods are official and standardized by the U.S. Bureau of Mines'. The chemical composition of natural gasoline will vary with its grade of commercial quality. Generally speaking it is composed of normal butane, the pentanes, the hexanes, the hep tanes, and the octanes. Those gasolines which have Reid vapour pressures in excess of 22 pounds at 100° F. also contain variable quantities of iso-butane and may carry some propane. Practically all the marketed natural gasoline is processed to remove hydrogen sulphide and organic sulphur by some one of the following treat ments: dilute caustic soda, dilute sodium hypochlorite, cupric sulphate or monoethanolamine.

The deepest natural gas producing well in the U.S. was drilled to a depth of 15,004ft. at Wasco, Calif., in 1938. There are now over 54,00o gas wells operating in the U.S. The Candelaria Well No. 1 in Harris county, near Houston, Texas, has a "shut-in" pressure of 4,800 pounds gauge pressure. The depth of this well is 8,1o1 feet.

Major Uses of Natural Gas.

The following are statistical data for the United States in 1937: (I) As Fuel—(domestic, commercial, and industrial), 2,370,000, 000,00o cu.ft.

(2) As source of Carbon Black Manufacture-5i o,6o6,000lbs. produced.

(3) As source of Natural Gasoline Recovery-2,039,i oo,000gals.

(4) As source of Liquefied Petroleum Gas Recovery—I41,5o5, 000gals.

(5) As source of Helium Recovery-4,8o9,23o cu.ft.

(6) As source of Carbon Dioxide (Dry Ice )-2o,o0o,000lbs. Minor Uses of Natural Gas.—The following are data for the United States in 1937: (1) Pentane in the production of 5o synthetic chemicals of greater or less commercial importance.

(2) Mixtures of ethane, propane, and the butanes in the mass production of one hundred synthetic chemicals—alcohols, alcohol ethers, ketones, esters, acids, acid anhydrides, aldehydes, oxides, amines, ethers, and chlorinated derivatives.

(3) Mixtures of ethane, propane, and the butanes in the mass pro duction of "poly" gasoline—a motor fuel of high octane rating.

(4) Butane in the production of butadiene, synthetic rubber, and as a solvent for the extraction of oils, fats, resins, nicotine, and perfumes (5) Propane as fuel in isolated districts and as selective solvent in mass production of motor oils of low cold test, high viscosity in dex, better colour and bloom, and high resistance to oxidation and the formation of carbon and sludge.

(6) Ethane in the production of ethylene—useful in citrus fruit ripening, as an anaesthetic, as a refrigerant, and in the manufacture of mustard gas and ethylene bromide. Large quantities of the latter chemical are used in connection with tetraethyl lead to yield high octane (anti-knock) motor fuels. (J. B. G.)