MANUFACTURE OF COAL CHAR

Southland Times, Issue 24769, 13 June 1942, Page 4

MANUFACTURE OF COAL CHAR

PRODUCTION AT CITY GASWORKS Producer gas fuel, or coal char, which has become so well known to thousands of motorists throughout the Dominion with the introduction of the petrol restrictions, has for the last 18 months been manufactured at the city gasworks. Until January of this yeai- there were only three places in the Dominion where this essential product was being manufactured, but within the last few months numerous smaller plants have begun operations. The Invercargill char has been thoroughly tested with the highest results. Until the winter-time the gas was being manufactured at the rate of about 70 tons a month, but now that the staff has had to concentrate on. a greater output of coke the production of char has fallen off slightly. In January 70 tons of the fuel were manufactured and in February the output was 130 tons. LINTON COAL USED Char can be manufactured only from the lignite type of coal, and the main sources of supply are Southland and the Waikato. The process of manufacture is similar to that of coke, the difference lying in the type of coal used. Bituminous coal from Westport is used for the manufacture of coke, and for producer fuel Linton coal, known as brown coal, is used. The coal is fed into the horizontal retorts as in the manufacture of coke, and goes through a process of carbonization. Carbon gas, different from household gas, and tar are given off, and when the retorts are emptied the product in its new form is available. In appearance the product is similar to the coal before treatment, but is much lighter in weight. The fuel is carefully sprayed with water and thoroughly dried. For the drying and screening operations plenty of space is required, and a new building will be erected in the near future for this purpose. GOOD RESULTS FROM FUEL Good results are generally obtained from a powerful car, and if a purifying plant is installed there is no damage to engine parts. Motorists who have used raw coal in their producer gas units have learned a hard lesson because the engine has to be taken down and cleaned after a very small mileage. An engine runs very smoothly on producer gas, and by some it is considered better than petrol gas. The output of household gas has increased considerably during the last few months, and so far this year has been the busiest for the staff for 14 years. Last month more than 6,000,000 cubic feet of gas was manufactured, an increase of 500,000 cubic feet over the same period last year. A large amount of credit goes to the members of the staff at the gasworks who have co-operated wholeheartedly > with the management since experiments were started two years ago. During the first three months of this year, when a large weekly output was maintained, the staff of stockers performed their duties under heat and grime without complaint.