Encouraging the Use of Coal
Page 49
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Pointers On the Efforts Which Are Being Made to Develop the Production of Our National Fuel
A PARTICULARLY interesting paper on the utilization of coal was read before the Royal Society of Arts, on Wednesday, by Mr. W. R. Gordon, director of the Coal Utilization Council.
We deal here with only those parts of the paper concerning the employment of this fuel and its derivatives for commercial vehicles. The author states that in the past few years there has been a great improvement in the design of steam vehicles. The new models using smokeless coat, low-temperature semi-coke and ordinary coke, are highly efficient. The fuel is sometimes handled automatically by mechanical stoker and crushed to the correct size on the way. These vehicles will run for a mile on 4 lb. of coal, -costing less than /d.
Perhaps the most ambitious scientifie project for the utilization of coal is the hydrogenation process, which provides both motor spirit and heavy oils. At present, the process is expensive. It has been calculated that petrol can be made direct from coal for 7d. per gallon, but this rate may be reduced.
The yield of petrol per ton of coal actually treated is about 62 per cent, by weight, calculated on the coal being dry and ash-free, but in the whole process from 3 to 34tons are required to produce a ton of petrol. Our annual consumption of petrol is over 3/ million tons, and if this were to be produced from British coal, over 10 million tons would be required, giving , employment to 40,000 miners.
The plant which is in course of erection by Imperial Chemical Industries, Ltd., aims at a production of 100,000 tons of petrol per annum, but with the experience thus gained other plants may be constructed.
An earlier method of using coal is that somewhat vaguely described as low-temperature carbonization. About 700 different processes of this type are known, of which some 120 have been tried here, The coal is carbonized in a temperature not exceeding 600 degrees C. It produces an easily ignited, smokeless, domestic fuel, and at the MetroCoalite plant at the South Metropolitan Gas Company's works at East Greenwich, where the process is operated by Low Temperature Carbonization, Ltd., the coal treated per day is approximately 320 tons. It gives 12/ to 13 cwt. of solid fuel per ton of coal, and about 2.75 gallons of unrefined motor spirit are obtained by stripping. The company supplies oil fuel to the Navy and coal petrol to the R.A.F., seven squadrons being supplied this year.
Another motor spirit produced from British coal is bensole, a product of high-temperature carbonization produced by stripping the gas and distilling the light fractions from the tars. The annual production is about 30 million gallons. It is estimated, however, that if every gas company carbonizing upwards of 20,000 tons of coal per annum would put down recovery plants, an additional 20 million gallons of benzole would be available.
Interesting experiments are being carried out with coal gas as a fuel for road vehicles. The comparative costs are interesting. The cost of compression varies, but is approximately 11d, per thousand cubic ft. With gas at Is. 7d., the cost compressed would be 2s. 6d. per thousand cubic ft., or the equivalent of petrol at 7.9d. per gallon. On a Birmingham gas department's vehicle the results given were 12 m.p.g. on petrol and a mile per 21 cubic ft. of gas. With petrol at 11d per gallon and compressed gas at 2s. 6d. per thousand cubic ft., this equals 0.916d, for petrol and 0.63d per mile for gas.
The Whitwood Chemical-Co. is using a system by which coal-gas is enriched with creosote.
If 20 cubic ft. per mile he taken as a fair consumption and 15,000 cubic ft. per ton of coal is normally produced, 100 vehicles, each running 20,000 miles per annum and Consuming 40 million cubic ft. of gas, require the carbonization of about 2,700 tons of coal.
A further use for coal is in connection with suction-gas producers employed in connection with agrimotors and commercial vehicles. More than 100 vehicles thus equipped have been sold for export by one maker alone.
The author is favourable to the replacement of tramcars by trolleybuses, the electricity required for which will still involve the consumption of coal with consequent employment to many miners.