Unfortunately, the bibliography for the corresponding chapter in the biography by Nitske and Wilson (3) does not clarify where the authors obtained this information nor does it list references to the writings by Diesel discussed here. Thus, according to Nitske and Wilson, the peanut oil-powered diesel engine at the 1900 World’s Fair in Paris was built specifically to use that fuel, which is not consistent with the statements in Diesel’s book (1) and the literature cited below.
Furthermore, the above texts from the biography (3) and Diesel’s book (1) imply that it was not Diesel who conducted the demonstration and that he was not the source of the idea of using vegetable oils as fuel. According to Diesel, the idea for using peanut oil appears to have originated instead within the French government (see text below). However, Diesel conducted related tests in later years and appeared supportive of the concept. A Chemical Abstracts search yielded references to other papers by Diesel in which he reflected in greater detail on that event in 1900. Two references (4,5) relate to a presentation Diesel made to the Institution of Mechanical Engineers (of Great Britain) in March 1912. (Apparently in the last few years of his life, Diesel spent considerable time traveling to give presentations, according to the biography by Nitske and Wilson.) Diesel states in these papers (4,5) that “at the Paris Exhibition in 1900 there was shown by the Otto Company a small Diesel engine, which, at the request of the French Government, ran on Arachide (earth-nut or pea-nut) oil, and worked so smoothly that only very few people were aware of it. The engine was constructed for using mineral oil, and was then worked on vegetable oil without any alterations being made. The French Government at the time thought of testing the applicability to power production of the Arachide, or earth-nut, which grows in considerable quantities in their African colonies, and which can be easily cultivated there, because in this way the colonies could be supplied with power and industry from their own resources, without being compelled to buy and import coal or liquid fuel. This question has not been further developed in France owing to changes in the Ministry, but the author resumed the trials a few months ago. It has been proved that Diesel engines can be worked on earth-nut oil without any difficulty, and the author is in a position to publish, on this occasion for the first time, reliable figures obtained by tests: Consumption of earth-nut oil, 240 grammes (0.53 lb) per brake horsepower-hour; calorific power of the oil, 8600 calories (34,124 British thermal units) per kg, thus fully equal to tar oils; hydrogen 11.8 percent. This oil is almost as effective as the natural mineral oils, and as it can also be used for lubricating oil, the whole work can be carried out with a single kind of oil produced directly on the spot. Thus this engine becomes a really independent engine for the tropics.” Diesel continued that (note the prescient concluding statement), “similar successful experiments have also been made in St. Petersburg with castor oil; and animal oils, such as train-oil, have been used with excellent results. The fact that fat oils from vegetable sources can be used may seem insignificant today, but such oils may perhaps become in course of time of the same importance as some natural mineral oils and the tar products are now. Twelve years ago, the latter were not more developed than the fat oils are today, and yet how important they have since become. One cannot predict what part these oils will play in the Colonies in the future. In any case, they make it certain that motor-power can still be produced from the heat of the sun, which is always available for agricultural purposes, even when all our natural stores of solid and liquid fuels are exhausted.”
The following discussion is based on numerous references available mainly from searching Chemical Abstracts or from a publication summarizing literature before 1949 on fuels from agricultural sources (6). Because many of the older references are not readily available, the summaries in Chemical Abstracts were used as information source in these cases. By: Gerhard Knothe
The History of Vegetable Oil-Based Diesel Fuels (Part 2)
The History of Vegetable Oil-Based Diesel Fuels (Part 1)
It is generally known that vegetable oils and animal fats were investigated as diesel fuels well before the energy crises of the 1970s and early 1980s sparked renewed interest in alternative fuels. It is also known that Rudolf Diesel (1858-1913), the inventor of the engine that bears his name, had some interest in these fuels. However, the early history of vegetable oil-based diesel fuels is often presented inconsistently, and “facts” that are not compatible with Diesel’s own statements are encountered frequently.
Therefore, it is appropriate to begin this history with the words of Diesel himself in his book Die Entstehung des Dieselmotors (1) [The Development (or Creation or Rise or Coming) of the Diesel Engine] in which he describes when the first seed of developing what was to become the diesel engine was planted in his mind. In the first chapter of the book entitled “The Idea,” Diesel states: “When my highly respected teacher, Professor Linde, explained to his listeners during the lecture on thermodynamics in 1878 at the Polytechnikum in Munich (note: now the Technical University of Munich) that the steam engine only converts 6-10% of the available heat content of the fuel into work, when he explained Carnot’s theorem and elaborated that during the isothermal change of state of a gas all transferred heat is converted into work, I wrote in the margin of my notebook: ‘Study, if it isn’t possible to practically realize the isotherm!’ At that time I challenged myself! That was not yet an invention, not even the idea for it. From then on, the desire to realize the ideal Carnot process determined my existence. I left the school, joined the practical side, had to achieve my standing in life. The thought constantly pursued me.”
This statement by Diesel clearly shows that he approached the development of the diesel engine from a thermodynamic point of view. The objective was to develop an efficient engine. The relatively common assertion made today that Diesel developed “his” engine specifically to use vegetable oils as fuel is therefore incorrect.
In a later chapter of his book entitled “Liquid Fuels,” Diesel addresses the use of vegetable oils as a fuel: “For [the] sake of completeness it needs to be mentioned that already in the year 1900 plant oils were used successfully in a diesel engine. During the Paris Exposition in 1900, a small diesel engine was operated on arachide (peanut) oil by the French Otto Company. It worked so well that only a few insiders knew about this inconspicuous circumstance. The engine was built for petroleum and was used for the plant oil without any change. In this case also, the consumption experiments resulted in heat utilization identical to petroleum.” A total of five diesel engines were shown at the Paris Exposition, according to a biography (2) of Diesel by his son, Eugen Diesel, and one of them was apparently operating on peanut oil.
The statements in Diesel’s book can be compared to a relatively frequently cited source on the initial use of vegetable oils, a biography entitled Rudolf Diesel, Pioneer of the Age of Power (3). In this biography, the statement is made that “as the nineteenth century ended, it was obvious that the fate and scope of the internal-combustion engine were dependent on its fuel or fuels. At the Paris Exposition of 1900, a Diesel engine, built by the French Otto Company, ran wholly on peanut oil. Apparently none of the onlookers was aware of this. The engine, built especially for that type of fuel, operated exactly like those powered by other oils.”