LIQUID FUELS

Taranaki Daily News, Volume LV, Issue 209, 5 April 1913, Page 10

LIQUID FUELS

'' THKIJI ORIGIN AND USE.

A SCIENTIST'S OPINIONS.

Jn view of the ever-increasing importance of the subject of liquid fuel, it is not surprising that Professor Vivian B. Lewes' course of Cantor lectures on this subject before the Royal Society of Arts, is being keenly followed by engineers and others, says an English file. Professor Lewes deals with such points as the factors which influence the liquid fuel supply, the probable life of the world's supply, and liquid fuels that can be used to increase the supply. He also discusses shale oil and its preparation, tar oil, alcohol, the "cracking" of heavy, oil fractions to supply motor spirit, and the production of the latter from residual oils and the influence this will have on supply, with the fascinating problem of the with the facinating problem of the origin of petroleum, he said it was just twenty-five years ago since petroleum was vised almost entirely for illuminating purposes. Since then the whole situation has been changed by the coming of electricity and of the motor-car, aeroplane, motor-boat, and oil-driven ship, so that nowadays petroleum is not regarded primarily as an illuminant, but as a power producer. In 1873 the world's total oil production was but 1,000,000 tons, whereas ten years ago it was 24,000,000 tons, and ' last year 50,000,000 tons. The petrol consumed in England lias increased from 40,000,000 gallons to 80.000.000 within the last four years. Petroleum was undoubtedly the chief liquid fuel, though in England they had oils obtainable from the shales of the Lothians and of Dorset, and also from the destructive distillation of coal. But all these would end, and then they would have to fall back on alcohol, a fuel that could be produced from vegetables in unlimited quantities, and which would be in use to-day but for the excise duties and restrictions. PETROLEUM FROM SEAWEED.

Coming to the theories regarding the formation of petroleum, Professor Lewes said that which went to provo the organic origin of fuel, dismissing as untenable the 'inorganic" theory of Moissan, Berthollet, and others, who held that petroleum was the product of disintegrated metallic carbides, some of which had been found experimentally to give products resembling crude oils. There was no evidence to prove that the earth contained enough carbides to give such vast quantities of petroleum as occurred in nature. On the other hand, the vegetable origin of petroleum was more understandable, said Professor Lewes, who supported the view that petroleum was formed originally from seaweed, which must have existed in immense quantities in the warm waters of the early geological period when the formation of petroleum might be expected to have begun. As proving that seaweed did contain petroleum products, the lecturer gave figures showing that 0.7 gallons of petroleum products could be obtained by the destructive distillation of one ton of dried seaweed, there being produced 354 oz. of volatile oil. 22 oz. of naptha, and 5150z. of paraffin. One might be inclined to suggest, from this that seaj weed should be used to-da.v as a source |of petrol, but the cost of drying the weed would be quite prohibitive.

EFFICIENT COMBUSTION OF PETROLEUM.

Professor Lewes next dealt with the burning of liquid fuel for production of power, and showed how widely the calorific value of such fuels varied. Thus the figure for petroleum was 10,904, this being lower than that of petrol, which was 11,524, shale oil being 10.124, blast furnace oil 8933. heavy tar oil 891(1. alcohol (absolute) 7184. and methylated spirit 0200. Coming to the early uses of petroleum for steam raising, he j referred to the use of Nobel's troughs in Russia, good results being obtained by | placing a series of troughs, one above the other, across the mouth of the furnace of a Lancashire boiler. The crude oil overflowed from the top trough down through the series, and as the oil contained a high percentage of volatile constituents, these burnt fiercely, and the (lames were sucked into the boiler space by the chimney draught, enabling evaporation to be obtained as high as 141b. of water per lb. of petroleum. Another earlv experiment was that of Colonel Footc, of the U.S.A.. who converted oil into gas before it was burnt under the boiler of the s.s. Palos. thus raising the I speed of the ship from eight knots to fourteen knots, though when the petroleum was injected by steam, as the furnace space and combustion area were so restricted, conditions that did not prevail on a tramp steamer, good results were more readily obtainable. To work the injector .21b. of steam per indicated horse-power was required, and this pointed the way to the desirability of using oil itself under pressure, this pressure ranging from 150-200fb. per square inch. THE DIESEL ENGINE.

The next step was to use the energy uf the petroleum direct, and not to cause it first to generate steam in a boiler, which led to a discussion of the phase of liquid fuel consumption that is attracting the greatest amount of attention at present, namely, the internal combustion engine. It was pointed out that before the Diesel engine could supplant the steam engine for marine purposes, it would be necessary for the worlds' production of petroleum to be doubled, and for the whole of the supply to be devoted for this purpose. Though the Diesel type consumed but one-third of the' fuel used bv the best

type of super-heated condensing steam plant, for a given power, with coal at about £1 per ton and fuel oil at 425.

per ton, the steam plant could be operated at a lower cost that the 'Diesel plant when all items of expense were considered. But Diesel fuel-oil would soon be 60s. per ton. and then the position would, of course, be still better for the steam engine. Tt was hardly likely that the outside owner would "scrap" his steam plant to replace, it bv Diesel engines until be was sure that •cheaper supplies of suitable fuel were in view. Tn conclusion. Professor Lewes dealt

briefly with the Bonecourt system of surface combustion, this being specially adaplable for use with liquid fuels. Tn this an explosive mixture of pus «ind air was forced bv a fan through a porous diaphragm of asbestos and fireclay on the surface of which it burnt without a (lame, but could not "bum back," so there was no dancer of explosion. The heat of combustion was very intense, causing Hie refractory material to become incandeseenf and give out a large quantity of radiant heat.