PATENT FUEL

Hawke's Bay Tribune, Volume XVIII, Issue 82, 19 March 1928, Page 7

PATENT FUEL

WAIKATO COAL TESTS MANUFACTURE OF BRIQUETTES. REPORT OF AN EXPERT. A report on the Carbonisation and Briquetting of Waikato Lignites ” by Sir Ricard Redmayne. M.lnst.C.E., received by the Board of Scientific Industrial Research, has an important bearing on all lignite production in New Zealand. Sir Ricard Redmayne was for some years director of one of the' largest patent fuel works in Britain. He describes the processes of utilisation of brown coals in Saxony and tests with Waikato lignites ou a commercial scale, seven tons being utilsed on each occasion. The results were superior to those from German brown coal, but the latter is available at 3s per ton, compared with Waikato at about 13s 6d. Briquetting tests were conducted with Waikato coal at Belgian fuel works with satisfactory results. The conclusion stated in the report is: “We may safely reckon on one ton of Waikato coal oi the quality and character in Saxony yielding 12 cwt. of semi-coke containing 7 J per cent volatile matter. 10.8 gallons of tar oil by condensation (which is equal to a yield of 4.6 per cent on the coal). 1.69 gallon of light oil, the calorific value of semi-coke being 7180 calories, or 12,924 British therm units which is equal to that of an average bituminous coal from Great Britain.'.’

CAN BE A COMMERCIAI SUCCESS.

Sir Richard Redmayne, on the assumption that the latter cost £2 4s per ton. is of the opinion that Waikato briquetting can be a commercial success. On the assumption that lignite is delivered at a cost of 13s 6<l and pitch at £7 per ton, the cost of treatment would be £2 7s 8d a ton, while £2 4s would be realisable on the sale of briquettes, leaving 3s 8d to bo obtained from by-products—tar oil, 18 gallons; light oil, 1.69 gallons. This should produce a satisfactory pro fit. The report suggests that commercial operations be supervised by persons having an intimate knowledge of German working. As to the capital expenditure involved in erecting a carbonisation plant distillation nnd zenzol recovery plat, and briquetting works, on the supposition that a favourable site is available such as would not necessitate heavy earthwork for foundations and sidings, this would probably amount to from £400,000 to £450,000 in case of plant sufficient to deal with 1200 tons of lignite a day to produce 720 tons of briquettes.