Coal Gases For Fuel

Sun (Auckland), Volume I, Issue 296, 6 March 1928, Page 6

Coal Gases For Fuel

French Experimenting for Petrol Substitute

French scientists declare that the utilisation of various gases, and particularly coal gas, as fuels for motor vehicles is not only technically possible, but that they are likely to become serious competitors to petrol. Recent research work in France on cheap home-produced fuels has included tests of various gases as fuels for motor vehicles.

These have been divided into two classes—producer gas, or that produced on the vehicle itself while in motion, and stored gas carried in receptacles on the vehicles.

Tests of carbide—a producer gas—show that acetylene gas made in a generator must be freed from various

impurities before it is satisfactory. It can be used only in engines of low compression ratio (3.5 to 4) without troubles from pre-ignition and detonation. As the thermodynamic efficiency of engines using this gas is low, it has not been possible to bring it into general use. Producer gas, formed by the combustion of wood or wood charcoal, is rendered rather complex—in the case of wood—by the presence of various products of distillation. It is a mixture of carbon monoxide and hydrogen. Impurities are eliminated by suction, scrubber tubes and cotton filters, and carburation is effected by a very simple mixer, which usually embodies a gas inlet connected to the accelerator pedal and air inlet sfljusted by hand. e Use Recommended Attempts are being made to compensate for the low calorific value of this mixture by increasing compression ratios and stroke capacities, or feeding the mixture under pressure. Producer plants have now been brought to such a state of perfecton that their general use on motor vehicles is recommended by the French authorities. Of the stored gases, coal gas, cokeoven gas, methane, hydrogen, carbon monoxide and the residual gases from the process of cracking, low temperature distillation and the manufacture of synthetic products have all proved worthy of consideration. Flexible low-pressure containers and high-pressure rubber recipients which were originally used for storing these gases on the vehicles, have been superseded in favour of metal cylinders. The latest type is of electrolytic iron, bound with piano wire. Gases of this type are expanded before admission to the carburettor. An expander of the diaphragm type is used. Automatic mixers have been perfected for satisfactory carburation. Coal is Anti-Knock Coal gas, which is readily obtainable in industrial areas, acts satisfactorily in motors with compression ratios of 5 or 6 to 1. Very good results were obtained from the use of ordinary town gas, especially on motor-trucks. For power developed and distance travelled town gas proved 10 per cent, more economical than liquid fuel Linder exactly similar conditions. A lorry weighing nearly eight tons covered 40 miles on 42 cubic metres of town gas. In order to make the use of this fuel commercially possible for buses, experiments are being made with the installation of, compressor sets at termini, with detachable cylinders stored there, and with special piping from gas mains.