SULPHUR CONTENT Appreciable sulphur content in a fuel oil is objectionable. However, a content of 4 per cent or less is not sufficiently objec tionable to cause the rejeCtion of a fuel oil for general purposes. (In general, experiments in burning fuel oils of various sulphur content have shown that the corrosive effects on the boiler tubes or heating surfaces are negligible. However, with steel stacks and low temperatures, considerable corrosion in the stack has been noted.) In handling these oils, prior to burning, the corrosive action of the sulphur on steel storage tanks, piping, etc., is quite apparent and should be considered. If the oil is to be used for special metallurgical or other purposes where sulphur fumes are decidedly objectionable, it is necessary to specify a limiting figure for the sulphur content of the oil. The sulphur content can be determined in the bomb calorimeter after the calorific value has been determined. The calorimeter is opened by gradually allowing the pressure to diminish and the bomb is carefully and thoroughly washed out with distilled water. The pan is placed in the beaker with the washings and about 10 cc. of hydrochloric acid is added. The contents of the beaker are treated with bromine, heated to boiling temperature for about 10 minutes, filtered and washed and the sulphur in the filtrate precipi tated with 10 cc. of barium chloride solution. The precipitated
barium sulphate is filtered, washed and weighed in the usual man ner. The weight of the barium sulphate X 13,733 and diyjded by oil.
Fuel oil in this country is purchased by volume and not by weight.:. Table 10 shows that a gallon of oil of high specific gravity has a higher calorific value than a gallon of oil of low specific gravity. This fact should be remembered by users of oil fuel, because in buying fuel calorific value is sodght. Indi vidual conditions and requirements at the points of consumption influence to a large degree the specifications for viscosity, flash point and sulphur content. Definite specifications can be drawn for a fuel oil which will meet practically all requirements, but it can readily be seen that such specifications will exclude much of the fuel oil now available, and for most purposes the requirements need not be severe. Hence, it is advised that in purchasing fuel oil the individual requirements be studied, and that as lenient specifications as possible be written, which will insure an oil that will be satisfactory for the conditions for which it is intended.