A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

53 CHAPTER V. FUELS. General Remarks. 1. As the cost of obtaining the primary steam is involved in the economy of a distilling apparatus, it is well to consider the subject of fuel; its importance is most clearly manifested in the distillation of sea water, when carried out by means of compound or multiple distillation. The most usual fuels are coal, coke, wood, petroleum, and gas. Therefore, one has a variety of fuel, in a state or condition that is either solid or liquid, or gaseous. As coal is the fuel that is most common, we will begin with coal and coke. Note.—The experiments of Dulong show that 1 lb. of carbon is capable of emitting 12,906 B.T.U. when burnt, and that 1 lb. of hydrogen when consumed is capable of emitting 62,535 B.T.U. Therefore, the heat that various fuels of this class (hydrocarbons) are able to emit is the proportion in which these two combustibles are combined with each other. If, however, oxygen is also present in the fuel it will neutralise the hydrogen also present to the extent that it is combinable with that gas in forming water. Water consists of 2 atoms of hydrogen to 1 atom of oxygen, and as the atomic weight of oxygen is 16, whilst that of hydrogen is 1, it follows that in water oxygen has a preponderance of 8 to 1 over hydrogen as