COAL UTILISATION

Greymouth Evening Star, 9 July 1931, Page 6

COAL UTILISATION

NEW ZEALAND’S RESOURCES. A survey of New Zealand coal iesources and modern utilisation formed the subject of an address to the Wellington Philosophical Society last week by Mr W. A. Joiner, of the fuel research station of the Department of Scientific and Industrial Research. He said the Dominion’s present output was 2$ million tons a year and the probable resources had been estimated in 1927 at 1631 million tons. The supplies of lower grade coals were considerably in excess of those of higher grades, and the aim should therefore be to develop the former to the maximum.

Briquetting was one method of using small coal, and up to the present coal tar pitch arid asphalt had been the most satisfactory binders. Mr Joiner said. In 1906 a briquetting plant had been installed at Westport, but it was abandoned probably on account of the cost of the binder. To-day there seemed to be a distinct field for briquetting. The lecturer dealt with the use of pulverised fuel—coal reduped to a fine powder so that 90 per cent, of the particles ranged from 1-200 inch to l-1000inch in diameter. He said this fuel was used with excellent results in large steam-driven electric generating plants. Some advances had also been made with marine installations.

“With regard to the use of pulverised fuel in this country, it should be noted that the generation of electricity by its use has l reached a high stage of efficiency, and in any future plants powdered coal firing should certainly be considered,” he said. “A modern steam generating plant can be erected for a very much less initial outlay than is required for hydro-electric installations, besides giving employment to large numbers of men.

NEW MOTOR FUEL. Mr Joiner also described the process of carbonisation of coal by which gas, tar, water, nitrogen and sulphur compounds were collected. Low temperature carbonisation was regarded as a possible source of oil and motor spirit production. An instance of enterprise was the establishment in the Waikato of a plant for dealing with slack coal.

Dealing with the production of oils front coal by the hydrogenation process, Mr Joiner quoted Birmingham figures for the yield per ton. The motor spirit yield was 0.15 tons, valued at £2/2/-, and 0.45 tons of fuel oil valued at £l/16/- was derived, making a total yield of £3/18/- from the ton of coal. With coal at 15/- a ton, and allowing 30/- for hydrogen, a sum of 33/- remained to provide interest on capital and working labour, depreciation and repair charges. Results obtained by the British Fuel Research Board showed that a total yield of from 120 to 130 gallons of motor

spirit could be obtained from one ton of coal. Mr Joiner referred to a recent estimate for a coal hydrogenation plant with a capital cost of £2,748,200. The manufacturing cost of motor spirit was estimated at 9.2 d per gallon. Additional expenses would be interest on capital, profit, royalties, and selling and distribution costs. Such a plant would supply a little over 23 per cent, of New Zealand’s present petrol imports.