Doing Without Petrol

Franklin Times, Volume XXIX, Issue 43, 19 April 1940, Page 2

Doing Without Petrol

Not long ago a double-deck bus pulling a trailer which carried a boilerlike contraption appeared in the streets of London, writes Greer Williams in the “Chicago Tribune.” The trailer was what is known as a portable gas producer. It replaced the bus’s gasoline tank. Likewise, coal gas from the generator replaced the petrol which' the motor previously burned. It was a strange sight to Londoners, but would have been a stranger sight on the streets of Chicago. The United Slates produces more petroleum than all other countries combined, and hence has never felt a ecessity of developing substitutes. Great Britain, in contrast, must import almost all its petroleum products. Even so, during peacetime it is more economical to depend on imported oil. But Britain is at war, which simultaneously increases the demand and, through blockade, restricts the supply. Hence it becomes worth wl: to develop substitute motor fuels from domestic sources.

The substitutes used depend on the country’s natural resources. Wood is the most popular source for producer gas in Germany and France which have far more forest land Ihan Great Britain.

Germany is rich in coal and hence in peacetime has been able to supply a large portion of its motor fuels by making petrol and oil from coat. Great Britain, whose Welsh coal mines have lacked sufficient outlet to keep them busy, manufactures a much smaller quantity of gasoline from coal. After two years’ experimentation in Britain it has now been demonstrated that gas from the partial combustion of coal —producer gas—is an economical source of motor fuel. Any number of other fuels may be used to manufacture ibis gas —peat, coke, charcoal, lignite, garbage, sewage, cot-ton-seed, straw, etc. At present all substitute motor fuels comprise an estimated 25 per cent, of Europe’s motor fuel consumption, producer gas constituting a minor part of the 25 per cent. Probably no more than i per cent of Europe’s 9,000,000 vehicles operate on gas. Producer gas may be generated while the vehicle is in operation or supplied from steel cylinders or balloons which are replaced or refilled at service stations. The balloon is a rectangular bag mounted on a superstructure over the truck. Steel cylinders, usually mounted on racks under the chassis but sometimes' lowed on trailers, may supply under compression the equivalent of anywhere from two to eighteen gallons of gasoline, depending on the type of gas used and the size of the tank. The principle of this advantage is the added weight of the tanks, which must withstand pressures up to -1000 pounds per square inch. The portable gas produce]' was exhibited in London at the same time that Mr Geoffrey Lloyd, Secretary of Alines, announced that the British Government recommended their manufacture as a wartime measure for the conservation of motor fuel. He said producer gas, unlike gasoline, would be favoured by freedom from taxation.

There was nothing- particularly origii a! about the portable gas producer. A survey made early in 1938 by Dr. Gustav Egloff, a Chicago oil chemist and authority on motor fuels, showed about 35,000 gas-driven motor vehicles in operation in Europe, some 9000 of them carrying their own gas genera-

tors. Most of these generators were designed as part of the body, being built in a trunk on passenger cars and behind or beside the cab on trucks. Largely found in France, Germany, and Italy, all 9000 burned wood or charcoal.

The generator system employed is thi same as that of the new British P'-rtage type, according to Dr. Egloff. The machinery consists, in the first place, of a cylindrical metal hopper sealed by hatches at both ends. The lv. pper is filled from the top with whatever fuel is used. An air inlet, connecting with a vent pipe running

up the side of the cylinder, is situated at the base of the hopper.

A small fire is started in the fuel 1 1 opposite the air inlet by means of a 1 torch and. blower. A temperature of < 2500 degrees Fahrenheit is produced, i which necessitates a water-cooling i jacket around ihe air inlet. The fire 1 is prevented from rising up through the entire mass of fuel by regulation of the amount of air taken in. Instead, as the burning continues fresh fuel drops down. The major products of combustion art carbon dioxide gas and water, neither of which is inflammable. But limitation of tlie air supply prevents ; complete combustion and results instead in tiie production of inflammable | gases, including carbon monoxide, hydrogen, and methane. These make up anywhere from 50 to GO per cent, of the total gases given off, the largest portion usually being non-inflammable nitrogen. The gas is conducted at a tempera l ti.re of about 1500 degrees through jan oullet into a dust collector tank | where the -.larger particles of soot are removed. It is then piped through a radiator which cools it to about 100 degrees and condenses out the water and acids contained in the gas. The gas then flows on into a cylindrical filter tank, rising through a succession of screens and cloths designed lo iemove the fine dust which otherwise would foul the motor. From there the gas is piped lo the motor at a temperature of about 105 degrees. Just as vaporised gasoline is mixed with air so that it will explode in Ihe motor's cylinders, so Hie gas is oxygenated as it passes into the manifold. The need of a carburetter is eliminated, however, although it may be retained for starting the engine on gasoline, since the gas lacks gasoline’s quick-firing capacity. Producer gas has a low heat eon- | tent, supplying only 200 British therj rnal units per cubic foot, compared i ! with 7000 for a regular grade of gaso- , ! line. Producer gas is far inferior fo ! gi-soline in the speed and flexibility of • molor performance. This is offset i lo some extent by reconstructing the ‘ cylinder head !o provide a higher eom- • | pression. The speed as well as the , eairying load, is further reduced by s the weight of the generator, which i ranges between 1500 and 2000 pounds for a five-ton truck. L Studies made in Great Britain show . that it costs around 10 per cent, less t-» operate a motor vehicle on producer I gas than on gasoline. Fuel .and t lubrication costs for producer gas are lower, but wages, maintenance, and depreciation are higher than for gaso- , line. The comparative cheapness of ( producer gas may be traced to its exemption from taxation, however. A considerable part of gasoline cost is tax. J As for fuel capacity, it was found that a 32-seat bus could travel 180 miles on 200 pounds of hard coal, a five-ton truck getting about 20 miles , less on that amount. Their hoppers will hold 500 pounds. While no comparative figures are I available on coal, Dr. Egloff found ■ that one gallon of gasoline was equal to about 25 pounds of wood or J2 pounds of charcoal. The coal ratio is believed to be in the vicinity of the lower weight.