New Uses for Coal

Sun (Auckland), Volume III, Issue 726, 27 July 1929, Page 10

New Uses for Coal

Fostering World-Wide Industries

WILL oil-ships go back ultimately to eoal burning? Some mining experts have excellent reasons for believing that they will. “Coal is going to be regarded more and more as something not to be wastefully consumed in the raw state.'’ declared one eminent English engineer recently—a statement which has particular significance in view of the newlyformed company to carbonise Waikato slack coal.

The treatment of New Zealand slack coal produces an entirely different result to a similar process applied to English coals, where the companies are compelled to rely upon the gas to support the undertaking. The newlyformed Waikato Carbonisation Company, Ltd., has promised a product with a calorific value equal to If not greater than the Newcastle coal now used on the New Zealand railways. Its association with similar concerns in England, backed by a capital of £45,000,000, ensures It against ultimate loss, while the process that has been chosen for carbonisation is one that has been thoroughly tried. In its way, New Zealand finds the disposal of its coal as important as England, with her vast coalfields running at part-time and keeping thousands of men, women and children below the bread-line of life, and If the brown coals on these fields can be successfully treated, a great fillip to industry must result. The future of the coal industry from the viewpoint of Great Britain, was discussed some time ago by Sir Richard Redmayne, the eminent consulting mining engineer, who talked of the expansion of the market with a view to greater consumption. GAS AND COKE

“We have heard a good deal of late with regard to low temperature carbonisation,” he. said. "Technologically it is an accomplished fact. Commercially ‘Yes’ in regard to some very few processes. It is not generally recognised that the number of processes which are being tried out in the experimental stage is very great; they run into scores, some of which will never be heard of again, and some may become commercially successful. “But what is not generally recognised is that certain processes are suited to certain classes of coal only, and to the meeting of a certain set of circumstances. It is for, instance, one thing to combine low temperature carbonisation with the generation of electrical power, and another to work a low temperature process with the object of disposing of the residual coke for domestic heating. In connection wit for domestic hea’ting. In connection with! power schemes, both the waste gas and the residual coke are consumed at the boilers for raising steam for the generation of electricity, and the by-product (oil) can be sold at a profit. “Where low temperature carbonisation of coal would help the coal trade," continued Sir Richard, “is in the fact that more coal would be required, inasmuch as one ton of coal carbonised would give probably not more than 13cwt or 14cwt of low temperature coke. Seeing that there are consumed for domestic purposes about

40,000,000 tons of coal per annum in England, the extent of the increase may be easily calculated In that direction alone, without taking into consideration the low temperature carbonisation in conjunction with power stations.

“At the power stations, it must be remembered, coal is consumed to the best possible advantage. A general electrification scheme in Great Britain, therefore, would mean at first a very considerable curtailment in the demand for coal at the outset. But cheap power ultimately invariably leads to an enhancement of the demand for coal, paradoxical as it may appear.”

With regard to the competition between oil and coal on board ship, Sir Richard said within a comparatively short time, the Mercantile Marine would use coal in preference to oil for the raising of steam. Using powdered coal to generate steam at, say, 7001 b pressure per square inch in turbines, with high-class steam coal at 20s to 23s a ton (and it was below this at the present time), it would not only not pay to burn oil for the generation of steam at sea, but it would be cheaper to use steam turbines under these conditions in preference to the internal combustion (Diesel) engine. This statement was more than warranted from the results that had been obtained. OIL FROM COAL “Coal," added Sir Richard, “is going to be regarded more and more as something not to be wastefully consumed in the raw state. I agree with Mr. Hodges that we should recover all the oil we can from coal, and by the process of ‘cracking’ render it suitable for use in automobiles, and in an uncracked state for other forms of internal combustion engines. The residual coke would be used for burning in the domestic grate and for central heating. It has yet to be definitely determined whether, in its pulverised form, the residual coke will be as suitable for raising steam as pulverised raw coal.” Little doubt remains as to the result of the product to be secured by the W alkato Carbonisation Company, which now has a few tons of briquettes obtained from the Waikato mines treated by the Lurgi process in Germany. This is to be tried out on the Government Railways within the next week or two, and also upon locomobelonging to the coal company at Waipa. The success of the tests is assured, as previous experiments have shown the intense calorific value of this product. When this is fully working, New Zealand will have takqp a definite share in the great work of getting the best out of the world’s coal supply.