SEPTEMBER,
1943
443
and allowed to remain for two minutes. At the end of this period, three or four drops of distilled water should be added slowly, one drop at a time, to the solution on the metal. The solution may then be washed off. If the sample is 18-8 stainless steel, the copper in
the cupric chloride solution will be deposited on the metal surface, appearing as a copper-colored spot. If the sample is Inconel there will be no deposition of copper. Only a white spot will be left to indicate where the testing solution was applied.
King Coal's New KingdOlll
COAL supplies more than half the total energy used in the United States. The rapid increase in use of petroleum, natural gas, and water power in this century, however, reduced this proportion from 90 per cent in 1900. Coal is usually the cheapest source for steam and for space-heating requirements, but in its native state lacks the convenience of the competitive fluid fuels. Present acute difficulties in transportation of oil afford some opportunity for coal to regain some of its lost markets, and a portion of them perhaps permanently through results of expanded research. A few years ago it was said that although ten to twelve million dollars were spent annually on research and development in refining petroleum, even more should be expended on the preparation and direct utilization of coal. Germany, England, and Russia have been conducting coal research for years. More recently such research has been actively pursued in the United States, by the U. S. Bureau of Mines, Battelle Memorial Institute, Mellon Institute, several state geological surveys, and at least seven universities. Steel manufacturers, other metallurgical and alloy companies, power companies, railroads, and coal companies, all large consumers or distributors of coal, are increasing their coal research activities, but the total amount of industrial research in this field remains comparatively small at this time. One of the prime functions of an industry is to inform consumers of the best utilization of the industry's product. Compared with oil and gas industries, the coal industry is at a serious disadvantage because of the unknown and so far largely indeterminable chemical constitution of coal; research must overcome this handicap. Furthermore, since freight costs often constitute 50 per cent of the value of the delivered fuel, there is need to use the coal nearest at hand, even though not of the best quality, to the highest degree of efficiency. Research in coal is mainly in the three principal current and future fields of its use--combustion, carbonization, and hydrogenation. Since about 85 per cent of the coal which we mine is burned for fuel, it is natural that greatest research should be on combustion, in the study of coals for specific purposes, ascertainment of best combustion conditions and improvements of coal-burning equipment for various purposes. Many principles of combustion and heat transfer and problems of storage, handling, and grading and other physi-
cal aspects of coals of different ranks still remain to be investigated in the future. The amount of coal required to produce a kilowatt hour of electricity has been reduced from an average of 3.5 pounds in 1917 to 1.4 in 1940. Production of a ton of pig iron required 2846 pounds of coke in 1940, compared with 3500 pounds in 1917. In 1940, 115 pounds of coal were required to move 1000 tons of freight and equipment one mile; in 1917,175 pounds. In an effort to regain some of the markets lost to oil and gas heating, intense research is now under way to perfect small automatic stokers, smokeless stoves, and water heaters for homes. The use of coal for firing metallurgical and forge furnaces and further development of equipment for burning pulverized coal are also being investigated. Although carbonization of coal consumes only about 15 per cent of our coal output, this branch of the coal industry, exemplified by the by-products coke industry, is technically more advanced than others, largely because of the obvious advantage of the process over that of old beehive ovens. Nevertheless, full understanding of carbonization is incomplete. Steel companies and tar distillers have improved the value of by-products by finding new markets and developing new products or derivatives. Yet the demand for the various products is still unbalanced, so that phenol and various other valuable constituents are wasted, while synthetic phenol must be produced from benzene, another coal-tar product. Although coal is not commercially hydrogenated as a source of liquid fuel in America because of present abundant oil and gas, it is being done on a large scale in Germany and England. The importance of anticipating exhaustion of these reserves is obvious. Ultimately, liquid fuel from coal may afford a market approaching in magnitude that of present total coal production. A major research program on the suitabili ty of various American coals for hydrogenation has been begun. European experience in hydrogenation should prove invaluable, but further studies should also be made of the nature of the process itself, pre-treatment of coal, and other possibly cheaper processes. By-products of hydrogenation may open up new markets for coal as a raw material for valuable chemicals.
-Industrial Bulletin, Arthur D. Little, Inc.
