POWER ALCOHOL PROSPECTS
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And the L.G.O.C. Tests of Alcohol-Benzole Mixtures.
WE REFERriED very recently to the" constitution of theEmpire Motor Fuels Committee of tho Imperial Motor Transport Council, and it is clear from information now available that this committee. has got to work promptly, and bids fair to replace recommendations arid advice by actual achievement.
Before endeavouring, however, to indicate the lines on which this. committee is first working, it may he well to .clear the air by explaining that it is not the only organization which is giving time to the study of alcohol as a fuel. In connection with the Fuel Board of the Department of Scientific and Industrial Research, there is a department for alcohol investigation. This is in the able hands of Sir Frederic L. Nathan. This department, as we understand it, is only directly concerned with the conduct of investigation and research, but, no doubt, will he. able to exercise considerable influence on more purely commercial matters, such as the various necessary developments which would affect the existing regulations of the Board of Customs and Excise. Of late, the Board ha,s shown a more friendly attitude) towards those who are anxious to developpower alcohol, supplies. This became apparent during the sittings of the recent Alcohol Motor Fuel Committee at the Petroleum Executive.
It will be remembered that, at the instance of that committee, the London General Omnibus Co. made arrangements to conduct prolonged road tests with alcohol mixtures and the necessary amount of fuel was made available to the company for that purpose. Simultaneously, Professor Dixon engaged to conduct important experimental work at Manchester, and the results of his investigation, which is not yet eomplete, will, DO doubt, throw considerable light on various matters connected with the eanibustion of fuel alcohol in the cylinder.
Who Will Father the Power Alcohol Movement?
Another interest obviously deeply concerned in the whole movement is that of the,existing distillers. It. is for them to decide whether they will father the power alcohol movement and take responsibility for the production of alcohol in huge quantities from alcohol crops grown in various parts of the world. The obvious alternative is that the movement from the first should be more or less directly controlled by those who now control the getting and distribution of petroleums, but all indications point to the probability that distillers will look well ahead and see that they are not crowded out of what must be regarded as their legitimate sphere of .)-tetion.
We have, then, a branch of a Government department and a, committee which, though not official, is strongly representative of official interests, and also of the practical and commercial interests concerned. The Empire Motor Fuels Committee is not forumlating a report but is getting straight to business. It is putting forward proposals with regard to the provision of bonding apace, the reception and handling of alcohol denatured Overseas, and the provision of facilities for denaturing at the port of arrival. It is evidently very necessary that a definite liaison should be established with the Dominions and Colonies, so that they can be kept advised and, in
return, advise others as. to the existing regulations and the changes made in them in any part of the Eng:lire. It is very desirable that a British denaturing specification should be drawn up. The policy of the committee is that such a specification, when prepared, should be transmitted Overseas, so that., when alcohol is exported from any country to Great Britain, it may be previously denatured according
to the British specification. This fact would be certified by officials of the Governments of exporting countries, and the spirit should then be landed in the United Kingdom, under simple regulations involving the minimum expenditure of time or money.
Permitting the Use of Power Alcohol.
The committee is also interesting itself in the references inade to power methylated spirits in the Finance Bill. It is provided that the payment of an allowance, in respect of spirits used for making industrial methylated spirits, shall applyto power methylated spirits similarly.. The inclusion of this clause is a hopeful sign, as indicating an official acknowledgment that such spirits may be used in considerable quantities for power generation. The clause would evidently be improved if the term "denatured " were substituted for the term "methylated," since the latter implies a specifie method of denaturing to the exclusion of other, and possibly better, schemes. The Bill does, however, indicate, that any substances may be used for denaturing that may be prescribed by the Commissioners of Customs and Exciee. It•would, however, be well to get the nomenclature clear and correct from the start, so as to eliminate the possibility of progress being held up by strict legal interpretation of the actual wording, as against the intention of Acts of Parliament.
It is felt that specially liberal treatment might quite safely be accorded to mixtures containing a comparatively smalIf proportion of alcohol, and a recommendation to that effect will no doubt be made.
At present, there are all sorts of difficulties in the way-of the distribution of power alcohol, and numberless regulations as to how it should be removed, warehoused, delivered, and so on. It is essential that it should be possible to convey it in tank barges, -or wagons, or in large containers, both before and after the processes of denaturing and mixing. It must be permissible to bring the spirit this country in tank vessels and to pump, or convey, it from the tanks,into bonded store at its arrival. The regulations for its reception, storage, and, if necessary', denatura,tion, must be simplified and made cheaply and easily Workable, and, in approved cases, the denaturing of plain spirits in any warehouse, or other approved place of storage, must be legalized_
Further Experimental Work Desirable.
We shall return later to the subject of the L.G.O. Co.'s tests of alcohol-benzole, but it must bp evident, in any case, that, before the general. suitT ability of such fuels can be regarded as having been finally demonstrated, they must be employed by a considerable number of users not possessing such ex.ceptional maintenance facilities.. For this reason, the Empire Motor Fuels Committee, having secured the generous support of the. distillers, hopes in the
near future to obtain, as wehave already stated in this journal, the release of several thousand gallpns of power alcohol weekly. This will be distributed to approved users representing two groups ; namely, the actual users of commercial motor vehicles, and the manufacturers of engines and carburetters desirous of experimenting with alcohol and its
mixtures. Those who wish to participate in the distribution of power alcohol for either of these purposes should communicate with the Secretary of the Empire Motor Fuels Committee of the .Imperial Motor Transport Council, at 50'.; Pall Mall, S.W.
It will be seen that, altogether, there is good promise of progress in engine and carburetter design, much wider experience in the ernPloyment of alcohol mixtures under service conditions, and the relaxation of those restrictions which, at present, make hulk import of power alcohol impossible, or, at any rate, a very expensive and. slow process. As we have already pointed out, the strength of the Empire Motor Fuels Committee lies in its unofficial constitution, coupled -with its close official connections, by reason of which there is, at last, some real prospect of collaboration, with a view to progress, between potential growers of alcohol crops, distillers, engine -and carburetter designers, motor users, and, last, but not least, the Government and, particularly, the Board of Customs and Excise.
Turning now to the tests recently conducted, a brief. referenee may be made to " Natalite," which is a spirit composed of alcohol and ether. It is established that, when this spirit is used, there is no difficulty in starting from cold. To get full power from an ergine designed for petrel, the jet must be enlarged, and better efficiency can also be obtained by employing a vaporizer. The spirit has a slight action on brass, but, apparently, not enough to eouetitute a serious drawback. From the point of view of fire risk, it is much to be preferred as against petrol. From the point of view of engine flexibility, it is quite satisfactory, and does not appear to introduce any difficulties in respect of engine lubrication.
Information Obtained in L.G.O.C. Tests.
The L.G.O. Co. tests have been mainly made with a mixture of 50 per cent. benzole and 50 per cent. alcohol. These are. both slow burning fuels and, to get the best results, certain modifications in. the construction of the engine are desirable. Not-ably the compression should be increased ; also it is important that the induction pipe should be kept at the right temperature. A hot air supply to the carburetter is found beneficial, and very good results have been obtained when this has been used in conjunction with hot water 'jacketed induction pipe. During the tests, high compression aluminium pistons were employed, giving a compression of 114 lb. per square inch. To lower this, packing was placed under the cylinders, and, to increase it, plates,. were riveted to the crowns of the pistons. In this way, various compressions from 90 lb. to 133, lb. per square inch were tried. The thermal efficiency of the mixture with a compression of 114 lb. and also of 123 lb. was found to be better than that obtained with petrol, the advantage becoming greater as the load decreased.
The mixture gives far better horse-power than pstrol at low speeds, tho consumption of fuel per (brake horse-power being nearlyconstant for different engine speeds. This is peculiarly important in connection with bus work, but is a valuable quality in the fuel of any motor vehicle. A compression of about 123 lb. was found to be the best for bus work. Analysis of exhaust gases showed that combustion was very complete, As to the temperature of the mixture, the best results were obtained with a hot ..e16 water jacketed induction pipe, the water being at about 160 degrees Fehr. Road teats with regular set vice buses without any engine modification resulted in frequent trouble, due to choking of carburetter jets by particles that wore found to be metallic. Also heavy carbon deposits formed in the induction pipes, probably owing to the compression being to low tor a -slow burning mixture.
With the modified engine road tests were successful, but it was found that, after a month, the fuel tank became porous and corroded. lion and copper were both badly affected. Brass, aluminium, zinc, and tin were affected to a slight degree, but lead was not affected at all. It. is, therefore, necessary that tanks and pipes sh.ould be lead coated. The action on brass is, however'' so slight that the carburetter can still be made of that metal,
Comparison between Petrol aid Alcohol Benzole.
Fuel consumptions in miles per gallon were found to be slightly inferior to those obtained with petrol. The 50 per cent. Mixture gave seven miles to the ggllon as agat118'; 7.55 with petrol. When the percentage of benzole was increased, the difference mileage per gallon was diminished. In respect of thermal efficiency-, however, the 50 per cent. mixture showed itself superior to petrol or to mixtures with higher pereentag-er; of benzole. _Examination of the engine after six weeks' service showed a slight increase in fuel consumption and decrease in horse-power, and a coating partially. choking up the inlet passages. The exhaust valves were clean, and there was not much deposit on the pistons. This indicates that the periodical examination of valves and induction pipe is advisable.
On the whole, the tests were very satisfactory as indicating ease of starting, good acceleration, and flexibility, good pulling power at low speeds, and no knocking When travelling slowly on hills. In the matter of costs, it is impossible as yet to institute fair comparisons, because the commercial cost of power alcohol is not yet a known figure. All We can say is that the average cost of bonze& and alcohol must be somewhat lower than, that of petrol for the half and half mixture to show an advantage in this respect. After these first, tests, more extensive service use of the mixture was tried, -and, latterly, as many as 14 louses have been running on it. During the winter, the consurnption results deteriorated slightly, the average with the mixture being 6.05miles per gallon as against 7.19 miles per gallon with petrol. The running of the engines was, however, very good, a high torque being sustained at low speeds, and no difficulty experienced in starting up.
The Benefit of Special Engine Design.
Experiments with larger percentages of alcohol showed that, with the compression used, there is. a tendency fer-.consumption to be hart under small loads, due to the low compression then attained in the cylinder, • One is led to the. conclusion that, with high percentages of alcohol, the engine should be specially designed., and Should have overhead valves, valve pockets being eliminated, and compression ratio incyeased. Summing up results, the experiments and road trials prove the seAdceability of alcohol Mixtures, and particularly emphasize certain points, the chief of which are the following: The greater the percentage of alcohol, the higher is the possible thermal efficiency for the same compression, and the higher the compression the greater is the further rise in thermal efficiency. With high compression, the bad effects of valve pockets are more noticeable at small throttle openings than with low compression. It is understood -that the L.G.O. Co. is now conducting tests with alcohol-ether fuels, and with other alcohol mixtures, some of which are giving extraordinarily pronaiehz results.