PETROL FROM COAL

Dominion, Volume 27, Issue 70, 15 December 1933, Page 11

PETROL FROM COAL

Prospects in Dominion ARTIFICIAL METHODS Survey of Possibilities NATURAL OIL SUPPLIES . The production of oil in New Zealand is discussed by the Minister of Scientific and Industrial Research, Rt. Hon. G. W. Forbes, in a statement he presented in the House of Representatives yesterday afternoon. Reference was made to the three methods of obtaining petrol from coal—high-temperature carbonisation, low-temperature carbonisation, and hydrogenation—and the possibility of their use in the Dominion. Recovery of benzole from coal gas was considered to warrant some encouragement. Tlie chances of finding flow oil sufficient for New Zealand’s own requirements and possibly those of Australia were stated to be reasonably good. Details of New Zealand’s consumption of petrol since 1928 in millions of gallons were given as follow: —

“It is well known,” said Mr. Forbes, “that the demand for coal in New Zealand is decreasing, and while it) is possible that with the; general revival of trade the demand may rise, the industry has had to face the position that unless there is a large increase in population or unless new uses are found for coal the demand may not be so great as in the past Under New Zealand conditions, except when convenience is a very major factor, coal or gas is still pre-eriiinently the most economic source of domestic or industrial heating, but for conversion into mechanical power, particularly for a mobile unit, oil is undoubtedly the most satisfactory fuel.” High Temperature Process. Mr. Forbes stated that high-tempera-ture carbonisation was the usual process operated at gasworks, where coal was carbonised at temperatures of from 1000 degrees to 1400 degrees Centigrade. While gas and coke were the main products a small amount of light oil was obtained by distillation of the by-product tar. It was possible to recover a further quantity of benzole, suitable for use as motor-spirit, from the gas by the use of a wash oil, or by means of absorbent carbon. This further quantity did not exceed two to three gallons per ton of coal carbonised. The process was in operation in many places in Great Britain and the Continent but not yet in New Zealand. Only the largest gasworks in New Zealand could install the requisite plant, and if they did so approximately 400,000 gallons of benzole would be recovered per annum. Tar and Gas. After dealing with the low-tempera-ture carbonisation process Mr. Forbes stated that from the tar and the gas it was possible to obtain a spirit, which after refining was suitable as a motor fuel. The total yield of spirit from the tar and gas varied from two.to four gallons per ton of coal carbonised, and it’had proved itself under test to be an excellent motor-fuel. Much greater yields of tar spirit could be obtained, however, by hydrogenation of the tar and 20 gallons would produce 14 gallons of motor spirit and six gallons of Diesel oil. It was clear that if motor spirit was to be obtained in large quantities by the low temperature process it was in the hydrogenation of tar that it must be sought. Nevertheless the scale of production which would be possible in New Zealand owing to the limited market for the carbonised residue, either as coke or as briquettes, was such that the necessary capital costs of hydrogenation would not be justified. Cost of the Plant. Hydrogenation was a method by which hydrogen gas was made to unite chemically with the solid coal, giving a liquid oil. The complexity and cost of the plant and operations might be judged from the fact that of the total estimated production cost of petrol by this method in New-. Zealand only about one-seventh represented the cost of the raw coal. It was probable that the cost of production of petrol from coal in New Zealand b.y this method would be to the order of lid. to 1/- per gallon (New Zealand currency) for a plant of 20.000,000 gallons capacity per annum, one-third of New Zealand’s consumption, which was presumably as large a plant as it would be wise to install in any one place. The capital eost would be in excess of £3.500,000. The total coal used by such a unit would be of the order of 240,000 tons per year, which with modern methods of mining for regular production, . would hardly employ more than 800 men in the mines, though there would probably be anothey 350 employed in the works. The steady employment of this number of men would of course give occupation in other industries and services, but there was no data to show how many. It did not appear that these advantages would at present offset the enormous interest charge of the capital involved and obsolescence charges. Further Consideration. There was another consideration in connection with the success of such a project in New Zealand, namely, the development alongside of hydrogenation of other intimately associated chemical processes such as the production of ammonia for fertilisers and the economic utilisation of carbon dioxide which was a by-pro-duct of the production of hydrogenation. Judging by experience elsewhere hydrogenation could not well stand by itself. Taking the whole evidence into consideration. it would appear safest to wait tor a few years until experiments nt Billingham in England had been thoroughly, completed on the large scale at present under consideration. Tlie chances of finding "flow” oil in New Zealand, sufficient for her requirements and possibly also for those of Australia. were considered .reasonably good. Even if found, however, economic development under present world conditions is largely influenced by the cost of transport, presumably by pine-line. _ to the neearest port or centre of distribution. -Nevertheless, an extensive geological and geophysical programme was justified on the evidence available, the cost of

which would be extremely small compared with the interest on the capital cost involved in the production of oil bv other methods. The possibilities of finding flow oil must be considered in connection with any proposals for hydrogenation. and it was preferable _ that these possibilities should be investigated by an intensive programme during the next few vears.

By motor By other means (engines, Year. vehicles, aeroplanes, etc.). Total. 1928 .... 41.43 2.0 43.5 1929 .... 50.6 3.6 60.2 1930 .... 62.8 3.9 66.7 1931. .... 55.2 5.2 00.4 1932' .... 49.8 5.4 55.3 Value of Imports. The value of the imports of petrol and crude oil into New Zealand for the same period were i is follow, the values quoted representing the current domestic values in the countries of export plus 10 per cent. Crude petroleum, crude residual oil, once-run shale oil, Calendar Motor and crude distilyear. spirit. late of petroleum. 1928 .. .. £1,655,000 £447,000 1929 . .. £2,131.000 £328,000 1930 .. .. £2,090,000 £498,000 1931 . .. £ 1,243.000 £417,000 1932 . .. £1,116,000 £373,000