USE OF THERMAL HEAT

Poverty Bay Herald, Volume LIX, Issue 17948, 28 November 1932, Page 4

USE OF THERMAL HEAT

INDUSTRIAL PROSPECTS ,T ‘. ... i. • v HARNESSING HOT SFRINGS lODINE AT MORERE AND COAST Prospects of harnessing natural .heat tor industrial and agricultural purposes are discussed in tho latest issue ul the Journal of Agriculture by Messrs. J. A. Bruce and F. B. Shorlantl, of tlie chemistry section of the Department ot Agriculture. They suggest that Morere and To Puia might give valuable yields of expensive iodine salts for pharmaceutical and agricultural purposes. bo far as the writers know, only three countries iu the world have harnessed thermal heat, these being Iceland, Tuscany (Italy) and California. Hot springs in Iceland provide steam, carried m pipes, for heating the soil for the growing of garden crops, for the heatiug of hot-houses, which grow many of the vegetables and fruits known in New Zealand, including tomatoes and strawberries, and the provision of heat for cooking, laundering and other household .purposes. Natural heat in Tuscany provides steam to drive low-pressure turbines. Steam from thermal activity in California also has been used, and four bored wells 'established by a company„ are estimated to represent a switchboard delivery of 4500'kilowatts:' ; One of the difficulties an.using natural (heat from New Zealand thermal regions jis the-corroding efffet some of iC.vyoulcl * {have off iroii or steel pipes, <as a ' raftllt of the acidity of the water in some of the springs. Also, the soil in the immediate vicinity of such springs, being of an acidic nature, would require special treatment before being adapted to horticultural purposes. FROST DANGER. REMOVED Continuing, the writers state “According to Dr. Herbert in ‘The Hot Springs of New Zealand’ (1921), the sanatorium gardens at Rotorua were set out by taking soil and placing it in a wilderness of sulphur beds and pumice. As the subsoil is warm, these gardens constitute an ideal forcing ground for flowers, which bloom in profusion. “It would seem that properly controlled warming of the ground by means of pipes from hot springs or the making of hotbeds in suitably chosen areas Would remove the dangers of the hard lrosts which are common at Rotorua in winter, thereby assisting in the early or out-of-season production of certain hothouse and other agricultural crops under the influence of the sunny climate. In many parts of the district the soil is of good texture and is remarkably responsive to phosphatic fertilisers in particular. “It appears that the hot spring localities in Iceland have already been carefully surveyed and mapped, and a similar complete compilation and correlation of recorded data cf the characteristics and locations of nil hot springs in New Zealand would be of considerable assistance in deciding the possibilities of exploitation of these natural resources from the industrial and agricultural standpoint. SALTS AND GASES

“A close study of the mineral content of the local thermal springs might possibly indicate the position in regard to the profitable recovery of certain, chemical substances by evaporation with trio abundant natural heat. In particular, the expensive iodine salts, which are held to be present in relatively large quantities in a number qf hot springs— Morere and Te Puia, for example—might possibly be utilised for pharmaceutical purposes and for iodised licks for farm animals.

“Some of the other salts present \ (notably common salt in abundance) might also in tho future be recovered and appropriately used. Some of the gases accompanying fumarole steam have commercial importance—for instance, carbon dioxide, the chief gaseous constituent of the volcanic steam of many thermal regions, has been successfully recovered in Tuscany. “In conclusion, it may be pointed out that the thermal region' of New Zealand compares favorably with that. of Iceland in several respects, including extent, power, adaptability and suitability of soil and climate for agricultural utilisation.”