Coal-gas, Coke, and Benzole.
Page 12
If you've noticed an error in this article please click here to report it so we can fix it.
The Gaseous, Solid and Liquid Motor Fuels of the Future.
By E. W. L. Nicol, Engineer and Fuel Expert to the London Coke Committee.
The fact that existing types of industrial motor vehicles have, in the present exceptional circumstances, been more or less easily adapted to the use of fuels other than those for which they were designed and rated, is a matter of accident which reflects little or no credit upon the designers. They, in following the line of least eesistance, have usually, as a matter of course, taken imported liquid fuels and relatively scarce and expensive smokeless coal as the bases upon which to develop the various types of petrol-driVen and steam-driven wagons. The incidence of the war has so diverted the available supplies of these hitherto staple fuels that many vehicles of the petrol-driven type are now of considerably reduced utility to their owners, while many of the other class are used only subject to the benevolent indulgence of the police authorities in not enforcing the strict observance of regulations as to the emission of smoke arising from the use of bituminous coal. This concession is, of course, exercised largely at the expense and annoyance of an equally indulgent public, for whose protection the regniations were framed ; but, it is submitted, the continued emission of dense and malodorous smoke from steam wagons and tractors, without effort being made to eliminate the nuisance, may result in bringing a growing branch of the motor industry into disrepute.
The "Re-discovery" of Coal-gas as a Fuel to Displace Pe1rol.
A keener appreciation of the advantages and possibilities of gaseous, solid and liquid fuels of native origin, as evidenced by the " re-discovery " of coalgas as a motor fuel, is at least one beneficent fact that has arisen out of the war. Experiments with coalge,s as fuel, conducted in the light of modern knowledge and wider experience of internal-combustion engines, and also with the fuller appreciation of exact requirements in the matter of fuel storage capacity, have clearly, demonstrated that the use of fuel in the gaseous form may largely influence the design of commercial motor vehicles for -the future. The incentive of much lower running cost favours this. Nor is evidence lacking as to the probable trend of events in steam wagon and tractor• design; following upon the practical failure of smokeless coal supplies. The influence of adverse 'circumstances in this connection has already become evident, through recent announcements of more than one new type of vehicle specially designed for "coke firing." This also is in the nature of a re-discoVery " of the advantages of a fuel once favoured by designers,.as those familiar with pioneer work in motor transport will easily recollect. The earliest services in Lancashire were run almost exclusively with coke as the fuel.
Coke Once the Staple Fuel in Railway • Locomotives.
It may be news to some that on several of the Louden railways coke was the original, and for some years, the staple locomotive fuel. Development in loco—boiler design and capacity was, no doubt, overtaken by the necessity for speeding-up running schedules, and coke fuel had to give way to (picker steaming, though less efficient coal, which is now being used in some of the larger express locomotives at hourly rates which often exceed 150 lb. per sq. ft. of grate area, the evaporative duty realized at this rate being only some 7 lb. of water per lb. of coal, which,: more economically Used, would be capable of evaporating 10 lb. to 12 lb. In the ease of the road
c40
loco. the partial abandonment of coke as fuel can be , traced to the Heavy Motor Car Order of 1904, limiting the tare weight of vehicles to five tons. This limitation has been largely responsible for the unnecessarily high fuel cost of running such vehicles. To comply with the. regulations, designers are still obliged to cut down weight by curtailing fire-box dimensions to the lowest practicable limits. In order to realize the rated capacity of their wagons having such restricted grate area, the use of coke had to be abandoned, and the most concentrated and expensive coal fuel available became necessary. In various present-day loco.-type wagons, the maximum average hourly rate of fuel combustion may reach 45 lb. to 50 lb. per sq. ft. of grate, at which rate the average evaporation realized, as shown by various statements of coal and water consumptions. is. only some 6 lb. to 7 lb. of water per lb. of best quality Welsh coal capable, under more favourable conditions, of evaporating 12 lb. to 14 lb. These figureS represent thermal efficiencies of about 50 per cent, or less, whereas, in boilers having a more liberal allowance of grate area, efficiencies of 78 per cent. to 80 per cent. are often realized, while the cheapest smokeless fuel available can be used to advantage. From the national economic standpoint these latter figures are significant, and it is to be hoped that the authorities charged with the framing of the new road-traffic regulations will take due cognizance. From the personal point of view, the advantages accruing to the owner who selects motor .vehicles designed and rated on a relatively low-grade fuel basis are obvious. In the case of a so-called petrol motor, rated on a paraffin basis or a coal-gas basis, the margin of power available, if and when it becomes desirable or cheaper to use imported spirit, will be a real asset ; while a steam wagon or tractor, provided from the outset with grate area sufficient normally to develop its full rated capacity with relatively cheap coke or coke breeze briquettes as fuel, should possess a very considerable margin of power when fired with Welsh coal.
Military "Preparedness" Demands Benzoic in the Future, and Therefore Coke.
• As to the future supplies of benzole, the full development of benzole supplies clerked from native mineral products is highly desirable from every point of view, including that of ` preparedness " for possible future events of a military character. ffany of the more important gas and colliery undertakings, which have installed benzoic recovery plant for meeting the urgent demands for war purposes, have been approached by representatives of the motor industry as to their probable future production of benzole. Benzoie is recoverable to the extent of about 1 to 14 gallon per ton of coal carbonized in the process of coal-gas manufacture, and future supplies may largely depend upon a sufficient outlet for the resultant coke (about 11 cwt. per ton of coal carbonized) being obtained. In the past, surplus coke has been extensively used in the manufacture of farburetted water gas, which Contains little or no benzole, and, moreover, is dependent upon imported solar oil, now much enhanced in price owing to shortage of tank tonnage. It will therefore, be seen that, while it is to the national advantage, and also to the interest of both the gas and the motor industries, to minimize so far as possible the use of imported fuels, it is incumbent upon the motor interest, which desires to see abundant supplies of benzoic, to assist, by making the fullest possible use of the residual fuel, gas coke.