From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Reply to criticisms on the use of alcohol as a motor fuel, focusing on issues of corrosion and flame propagation.
| Identifier | ExFiles\Box 32\1\ Scan030 | |
| Date | 8th November 1913 | |
| THE AUTOCAR, November 8th, 1913. The Fuel Question. A Reply to Dr. Ormandy's Criticisms by the President of the Institution of Automobile Engineers, Mr. J.{Mr Johnson W.M.} S. Critchley, M.I.Mech.E. DR. ORMANDY has thought fit to criticise some portions of my recent presidential address to the Institution of Automobile Engineers. He fears that some opinions I am alleged by him to have expressed might be taken as representing the views of the Institution as a whole. It would indeed be strange if a presidential address met with the unanimous approval of the whole body of its members. An address to accomplish this end could only be a record of past events or a string of platitudes. I selected the fuel question in order to bring before the members the critical state of affairs in regard to the present and future prospects of obtaining a reliable and cheap fuel, having in view the urgent calls in connection with the proper development of the commercial vehicle. I stated that the fuel problem was the "greatest difficulty we have to face." I also had the desire to draw attention to the necessity for the constitution of a body to thoroughly investigate the problems before us. The present time is not one for cavil or "hair splitting" arguments, although some of Dr. Ormandy's comments would almost lead one to that conclusion. Alcohol.—Dealing firstly with alcohol. Dr. Ormandy disputes my contention with regard to the effects of acetic acid. Let us see what is the evidence on this point. In the report of the Departmental Committee on Industrial Alcohol, on which Lord Montagu represented the motoring interests and in connection with which Sir Henry Primrose, K.C.B., C.S.I., I.S.O., and Dr. T. E.{Mr Elliott - Chief Engineer} Thorpe were appointed a sub-committee to investigate personally the use of industrial alcohol in Germany, I find that the Committee came to the following conclusion in regard to the use of methylated spirit for motors: "Spirit is not used at present in this country for motor vehicles, nor is it used to any great extent either in Germany or France, in spite of the fact that both these countries are most desirous of encouraging the use of a material that is indigenous in preference to a material like petrol that has to be imported. Where spirit is used for motor or other engines in those countries, it is almost entirely for agricultural engines. For motor cars spirit presents certain special difficulties which require to be overcome, the principal being the behaviour of alcohol in very cold weather and the tendency of the acids generated by its combustion to cause corrosion of the metal surfaces with which they come in contact." Referring to Dr. Ormandy's evidence before that Committee, the following question was put to him: "Do you consider that in the present methylated spirit taken by itself there are elements that are seriously prejudicial to its use for motor purposes?" Dr. Ormandy replied: "How seriously prejudicial one cannot say, because so little work has been done with motors running with alcohol of the composition used in methylated spirits in this country. What is known is this, that the greater the percentage of acetic acid which is formed in the by-products resulting from the explosive mixture, consequently the greater the wear and tear on the valves and the moving parts in the cylinder. But it is not only the acetone which is present. It has been proved that methyl alcohol in the presence of air at such temperatures as 250° C. forms acetone or by-products such as formaldehyde and other substances which readily give rise to acetic acid on their combustion or their partial combustion. This temperature of 250° C. is one which is attained by the mechanical compression of the gases in a motor built to work with alcohol, since ten atmospheres to fifteen atmospheres are common compressions. By compressing a gas containing methyl alcohol to ten or fifteen atmospheres its temperature is raised without explosion to more than 250° C., and at that temperature methyl alcohol readily splits into compounds which, on ignition with air, tend to form acetic acid. The presence of methyl alcohol without acetone is more or less of a drawback—how far it is a drawback it is impossible to say without rather prolonged trials, since in Germany, where the longest trials have been made, there is only 1¼% of the general denaturing agent present in the motor spirit." Dr. Thorpe stated: "We were informed that even in the case of motors which are used for general service pressure has been brought to bear by the police of Berlin as far as they were able to in order to compel the use of alcohol; but we were further given to understand that as a matter of fact this pressure had been nugatory from the inherent difficulties of the application of alcohol. In the first place, the corrosion of the machinery was so great, and therefore the bill for repairs was so considerable, that that of itself was a very serious matter. We were told that all the running parts of the machinery were very quickly corroded, and that that was due to the relatively large quantities of aldehyde, and eventually of acetic acid, which were produced." In face of his own statement and that of Mr. Thorpe, how can Dr. Ormandy now contend that the acid products can do no harm to the motor? There is, moreover, further evidence before us, of the tendency of methylated spirit vapour when burned to corrode the interior of cylinders. The experiments with alcohol in Paris were given up partly on this account, and for the further reason that alcohol unless mixed with a large admixture of benzole or petrol did not explode with sufficient rapidity to meet the requirements of automobile practice. Dr. Ormandy joins issue with me in regard to the rapidity of flame propagation. Alcohol alone, I stated, is a slow-burning fuel, and is so described by Dr. Ormandy himself. At a lecture at the Royal Automobile Club he stated, "That while the explosion of petrol resembles that of dynamite, that of alcohol was like a slow grain powder and gave a big steady expansion." One may ask if the chemical composition has changed in recent years. With regard to the cost of alcohol let us see what Dr. Ormandy has to say on this point. At a lecture given by him at Glasgow before the Scottish A.{Mr Adams} C. (The Autocar, March 11th, 1905), he stated: "It is a well-know fact that a plant could be put down for the manufacture of alcohol on a large scale from the cheapest possible material, such as damaged grain, potatoes, and the like, which would make alcohol at about 8d. to 9d. per gallon." Now refer to The Autocar, March 1st, 1913, in which he states: "Once more the daily press, with a boldness only exceeded by its ignorance, has pointed out to the motorist the only way to salvation. We have | ||