Biofuels: Alcohol, the Fuel of the Future? – Part 4 by Chris Meyer, Technical Journalist
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GENERATION Biofuels: Alcohol, the fuel of the future? – Part 4 by Chris Meyer, technical journalist Just after World War 1, it was thought that oil supplies in America would become exhausted in about twenty-five years. The idea of importing oil from the Middle East, then from Persia, or Russia, was considered positively dangerous. And the explosive growth in the number of people buying cars meant that known reserves would be depleted even sooner. Small wonder that alcohol was considered as a possible alternative fuel. “Midgley and Kettering's interest in ethyl that time, it was thought that oil supplies alcohol fuel did not fade once tetraethyl in America would become exhausted in lead was discovered as an antiknock in about twenty-five years [9]. The idea of December, 1921. In fact, not only was importing oil from the Middle East, then ethyl alcohol a source of continued from Persia, or Russia, which was then in interest as an antiknock agent, but more the throes of a civil war, was considered significantly, it was still considered to be positively dangerous. And, the explosive the fuel[for high compression engines] that growth in the number of people buying would eventually replace petroleum[when cars meant that known reserves would be supplies began to run out]” [9]. depleted even sooner. Today, Thomas Midgely is known as the Small wonder that alcohol was considered inventor of two chemical compounds as a possible alternative fuel. In fact, the that have caused the world problems: situation then was eerily similar to today, as A charcoal fuelled Opel Kapitan with an Imbert projections of millions of new motorists in gasifier, at the Automechanika show in tetraethyl lead, a poisonous anti-knock Frankfurt, 2006 (Photo: Courtesy Kack Rosebro, agent in petrol, and CFCs, claimed to be India and China now mean that current oil Green car Congress). responsible for damage to the ozone layer. supplies could be depleted even sooner than predicted. At first, Kettering, Midgely But Midgely's role in investigating ethyl discovered, there were two “ethyls” on and Boyd, another GM researcher, began alcohol's potential as a fuel has largely the horizon for General Motors: Ethyl been forgotten. to consider what would be involved in a total switch from petroleum to alcohol fuel. leaded gasoline, which would serve as a How Midgely came to discover and And, like current calculations, they showed transitional efficiency booster for gasoline, develop tetraethyl lead and CFCs is there was no way the US could grow and ethyl alcohol, the “fuel of the future” exceeding well told by Bill Bryson, in enough food to produce enough alcohol that would keep America's cars on the Chapter 10 (“Getting the lead out”) of fuel to completely replace all the oil used. roads no matter what happened to the his best seller, "A short history of nearly domestic or world oil supply” [9]. everything." In 1921, Kettering noted that were [alcohol] to take the place of gasoline, over half the In other words, the long-term goal of That cannot be repeated here, instead, total farm area of the United States would General Motors researchers was to we touch on something largely forgotten be needed to grow the vegetable matter introduce high-compression engines today: how and why Midgely and Charles required [9]. Since then, things have got that would and could use fuel more F. Kettering, Vice President of Research at noticeably worse. Now, even using 100% economically. At first, the fuel would be General Motors, believed in ethyl alcohol of the [American] nation's corn crop would gasoline, aided by lead additives to stop as the fuel of the future, even after supply [alcohol for] only 7% of the fuel knocking. And then, when gasoline started tetraethyl lead was discovered, and why a consumed by its vehicles [22]. to run out, those same high compression lot of research was done at General Motors engines could then switch to a fuel that did into this topic, and how General Motors, So, strangely enough, many of the not cause knocking, ethyl alcohol. conclusions being reached now – that it abruptly decided to drop ethyl alcohol only really makes economic sense to make What is knocking? It occurs when the burn and concentrate only on tetraethyl lead . alcohol from cellulose, and not from food or explosion of fuel spreads too irregularly after ignition. Instead of one flame front Cellulose, the fuel of the future – were already reached by General Motors researchers in 1921. So, what happened spreading uniformly in what is basically “From cellulose waste products on the to stop alcohol from being used as a fuel? a controlled explosion inside the piston, farm such as straw, corn-stalks, corn After all, most countries of the present-day several different flame fronts develop cobs and similar sorts of material that European Union were already using a 5% where they shouldn't, and cause the we throw away, we can get, by present blend of alcohol with their gasoline in the explosion to proceed far more quickly – known methods, enough alcohol to run 1930s, long before most people had even and unpredictably – than planned for. our automotive equipment in the United heard the word “biofuels”. The result is a sudden down thrust of a States” [9]. The answer comes down to two words: piston, which ruins the steady, regular At first glance, this doesn't seem to be Standard Oil. But before we look at the thrusts essential to spinning a crankshaft something that Thomas Midgely would decision to switch to leaded gasoline, let smoothly. And, if not stopped, knocking ever say. After all, he invented tetraethyl us first sum up where General Motors was can soon ruin the engine as well. Knocking lead, and a few years later, he and going: or though they were going, and why. is not a problem with a low-compression Kettering were saying the exact opposite: engine, or with a diesel engine. But it is that alcohol was not suitable for large- Two ethyls on the horizon a huge problem when one is trying to scale automotive use. What happened to improve the fuel efficiency of an engine “Thus, during the time Kettering and cause the sudden change? by increasing the compression. Midgley researched anti-knock fuels, The first thing we must realise is that, at and especially after tetraethyl lead was As Kettering and Midgely had discovered energize - May 2010 - Page 19 GENERATION through their pioneering research, there that consumed ever more cheap, leaded Sweden, Germany [the United Kingdom] were two ways to solve it. One, the petrol, that became the quickest way for and Czechoslovakia [9]. high percentage direction, was to add the automotive industry to make profits. France and Germany, two key members alcohol to the gasoline, mixing it in various Alcohol as the fuel of the future had joined proportions of 5% or higher or even use electric cars, hybrid cars, and a need for of the European Union, had both known pure alcohol (methanol or ethanol) as better fuel efficiency as things that no insecure oil supplies during World War I. a fuel, as no knocking resulted. Modern longer really mattered. Germany had gone further, with alcohol lead-free petrol typically uses methanol, obtained from agriculture providing fuel ethanol or even benzene to stop knocking. While the USA turned increasingly to leaded for every motor car in the empire and petrol after 1925, most other industrialised most of the German transportation system Or, one could use far smaller concentrations nations turned to bio-alcohol.This was of a special additive compound, the low- after 1915 [9]. especially true for Europe, where most percentage direction.This compound, But it was the Second World War that countries routinely blended bio-alcohol originally iodine (far too expensive) and showed that burning wood could do with their gasoline between 1925 and later tetraethyl lead, effectively dampens far more than generate heat. It could 1937. And this brief period is worth looking the smaller, irregular explosions and allows also be used to drive cars and trucks: one steady burn to develop properly. at, for it shows how bio-alcohol was used an idea, strangely enough, that is being extensively in industrialised countries as a In chemical terms, this compound absorbs rediscovered as research into advanced fuel, without affecting food prices in the just enough of the free radicals, particularly biofuels continues. slightest. oxygen radicals that developed during Running on empty burning to prevent irregular explosions. How to produce bio-alcohol without Too little additive allows knocking to “In occupied Denmark during World War affecting food prices? develop, while too much additive, and II, 95% of all mobile farm machinery, the engine looses power, and eventually “By the mid-1920s ethyl alcohol was tractors, trucks, stationary engines, and dies completely. Then, the additive has routinely blended with gasoline in every fishing and ferry boats were powered by become a fire extinguisher. industrialised nation except the United wood gas generator units. Even in neutral States. 10% to 25% alcohol blends were Sweden, 40% of all motor traffic operated An abrupt change of direction common in the Scandinavian countries, on gas derived from wood or charcoal. All “By the mid-1930s, the alliance between where alcohol was made from paper over Europe, Asia and Australia, millions of General Motors, DuPont Corporation mill wastes; in France, Germany and gas generators were in operation between and Standard Oil to produce Ethyl throughout continental Europe, where 1940 and 1946” [15]. leaded gasoline succeeded beyond alcohol was made from surplus grapes, potatoes and other crops; and in Australia, What do you do when, suddenly, no petrol all expectations: 90% of all gasoline is available and you somehow have to contained lead” [9].