By products of Coal Gas
Many important products besides illuminating gas are obtained from the distillation of soft coal. Ammonia is made from the liquids which collect in the condensers; anilin, the source of exquisite dyes, is made from the thick, tarry distillate, and coke is the residue left in the clay retorts. The coal tar yields not only anilin, but also carbolic acid and naphthalene, both of which are commercially valuable, the former as a widely used disinfectant, and the latter as a popular moth preventive.
From a ton of good gas-producing coal can be obtained about 10,000 cubic feet of illuminating gas, and as by-products 6 pounds of ammonia, 12 gallons of coal tar, and 1300 pounds of coke.