OIL GAS. The inflammable gases and vapors (chiefly hydrocarbons) which are obtained by passing fixed oils through red-hot tubes, and which may be used as coal gas, for the purposes of illumination; it yields a more brilliant light than the latter ; but is, in most instances, too ex pensive to be generally adopted. Brande states that a gallon of common whale oil yields from 90 to 100 cubical feet of has ; and an Argand burner, giving the light of six or seven wax candles, consumes from to 2 cubical feet per hour ; whereas, to produce the same light, from 5 to 6 cubic feet of coal gas are required. Another estimate is given below.
Purified oil is never used, as gas can be obtained from impure oils, train oil, or refuse feet, with as much ease as from the purer kinds. It is a good means for using up such materials. The results obtained by Henry, show the following results in 100 parts of illuminating gas:— From the above, it appears that oil gas is superior to that obtained from coal, as shown by its gravity, and that the pro duce is of the best quality when obtained at a low red heat. This temperature is
sufficient to convert the oil into gas, but is not sufficiently high to decarbonize the gas to any great extent. The apparatus for obtaining gas is simple: a retort is filled with bricks, or lumps of coke, so as to extend the surface when heated. The oils flow in a thin and constant stream upon the red hot bricks, when it is almost immediately purified ; the gas is carried on to the hydraulic main, and from thence through the purifiers to the gasometer. Cast iron retorts are used ; and 1 cubic foot, or 4 gallons of oil, pro duce from 600 to 700 cubic feet of gas, which is equivalent to from 90 to 96 per cent. by weight. The remainder is de posited carbon. Oil gas contains much more oleflant gas and naptha vapors than coal gas, and is hence more valuable as an illuminating event.