N.Z. BROWN COALS

Press, Volume LV, Issue 16422, 16 January 1919, Page 8

N.Z. BROWN COALS

RESULTS OF RESEARCH "WORK. Mr Lawrence Birks writes.— V verv important publication has recently been issued on the subXt Of New Zealand brown coa s Sch is "rtbr 1 •^ a r b j? notice than ''J'" Sse-Tod W 0. H. biUtag, M.A., BSc ' National Research scholars, cmhodvine the results of their researches S?--p'T b rr,ued h » scholarships, and .t 0 »sued as and -VV as Minister of Inter- - o , UAffairs The experimental investigaht s A&'tfsrs si sffi?s£ nor ton'e in New Zealand, owing to the K'fnS deposits of Waikato. Canterbury, Otago, ana W ticuHrlv in Southland, and the limited extent of the bituminous coals of the Th. ve. development of hvdro-electnc power will increase, rathor than reduce, the importance of tbe subject. For motive power and lighting purposes, hydro-electric energy wfll certainly replace coal fuel almost entirely, but for heating purposes on the large scale the direct use of fuel or fuel gas must bo more economical in most cases and for the production of tar, tar oils, fuel oils, pitch, coke and all the innumerable by-products of the distillation of tar. deluding explosives dvos, flavouring essences, hydro-electric power will onlv stimulate the demand for the scientific utilisation of our fuel resources. We must look forward to the time in the early futuvo when it will be regarded as a criminal waste to burn coal in a kitchen or boiler furnace, owingjUo the waste of these valuable tar praducts which simply go up the chimney and blacken the neighbourhood, while much bettor heating service is obtainable by the use of gas or coke after the recovery of the tar products. , The investigations under notice were dirocted towards two main considerations, both of fundamental importance.: (1) The use of New Zealarid brown coals in ijas producing; and (2\ The low temperature distillation of iNew Zealand brown coals. They do not claifti to be final investigations in any sense, but rather of a preliminary nature intended to' serve as an' inspiration and a starting point for fuller researches. Nevertheless, very thorough work was done, extending over several years. As an indication of the care and thoroughness, the authors state with regard to the tar distillation that "the work of the first three months, during which the many difficulties mentioned above were gradually being overcome, is omitted altogether as unreliable." Thd general results are worthy of careful study by those concerned in the industry. With regard to the use of brown coals in gas producers, although this is commercially quite general, the authors noint out important improvements wEich are immediately deducible from their experiments—particularly in the direction of-more regular feeding of tho fuel and the addition of water with the fuel. In the distillation of the coals they find a return of 4 to 8 per cent, of tar as the result of low temperature distillation, which was re-distillod into light oil, middle oil, heavy oil, and pitch, and again into seven fractions in the course of further purification. The separation of various commercial, products is for further investigation. The brown coal tars differ from those derived from bituminous coals in being lighter than water instead of heavier. The resultant coke is distinct from that obtained in gas manufacture, as it is not subjected to so high a temperature, and still contains comparatively large quantities of hydrocarbons. This characteristic should render it much freer burning, and thus more useful as a fuel for domestic and other purposes, though, of course, not so useful for electrochemical purposes for which, in any case, the high proportion of ash would reduce its value. The investigations deal with practically tho whole | of tho New Zealand brown coals, in- ' eluding Kaitangata, Nightcaps, Homebush, Taupiri, Benhar, Mataura, Christies, Freemans, Jubilee, Ml. Somers, Waikaka. Albur.y, and Conical Hill, and are thus of quite general value.. The matter is being followed up by Dr." Evans, finder a science research grant, made through the New Zealand Institute, and Mr Gilling lias been re-_ tained for two years' further work. It is to bo hoped that other research scholars will also, find opportunity to follow up the investigation, or what would be much more effective still, that tho coal-owners will combine to appoint a chemist at a reasonable salary and expenses to continue tho work indefinitely. The cost would'only be a few hundreds a year. The returns will certainly run to thousands, and will prob-1 ably , run to hundrbds of thousands of pounds worth per year, as the development of hydro-electric power forces on New Zealand the wider and more effective utilisation of our fuel resources