The Fuel of the Future

"Gasoline is growing scarcer, and therefore dearer, all the time... Automobiles cannot use gasoline for all time, of that I am sure, and alcohol seems to be the best substitute that has yet appeared." (US House and Senate hearings on the "Free Alcohol" bill, 1906)

The development of the internal combustion engine can be traced back to the early 19th century when at least a dozen inventors were involved with development of  prototypes. Two early pioneers, Samual Morey and Nicholas Otto, used ethyl alcohol to fuel their internal combustion engine prototypes.  Samuel Morey developed the first internal combustion engine in America in 1826.  Nicholas Otto, who eventually invented the "Otto-cycle" engine used ethyl alcohol on his early prototype of the internal combustion engine.  Progressing into the early 20th century there was much concern over the supply of gasoline.  President Roosevelt, a foe of the oil industry, initiated the repeal of the alcohol sales tax in 1906.  In theory, industrial alcohol would be a new market for American farmers and an alternative to the oil trust.  At the same time, British, French and German scientists were busily designing engines that could handle a variety of fuels, including ethyl alcohol.  These countries were not only worried about the longevity of oil supplies but also the erratic oil supply from Russia and America.  Oil trust battles between the Rothschilds, the Nobels, Rockefeller and Marcus Samuel (Shell)  resulted in significant oil price volatility.  France and Germany were particularly eager to develop a fuel that could be distilled from farm products as neither country had a domestic oil supply. Studies of alcohol as a fuel for internal combustion engines began in 1906 where it was found that significantly higher engine compression ratios could be achieved with alcohol but at lower B.T.U.  The fuel economy was virtually equal for alcohol and gasoline.  The U.S. Geological Service (USGS) later concluded that alcohol was "a more ideal fuel than gasoline" with better efficiency albeit with higher cost.  Alcohol had many advantages over gasoline with no smoke or disagreeable odors. By 1925, most people in the automotive industry, including Henry Ford, believed that ethyl alcohol was the "fuel of the future".  There were at least two events in history that prevented the widespread use of ethyl alcohol as an engine fuel.  The first event was the introduction of prohibition in the United States in 1919.  During prohibition the manufacture, transportation, import, export, and sale of alcoholic beverages was prohibited.  As a result, corn-alcohol stills, which many farmers used to make low cost ethanol fuel with, were banned.  Prohibition taxes were introduced for industrial alcohol usage, also causing a significant reduction in the use of ethanol as a fuel. In the early 1920s there was much concern about the demise of oil supplies.  "High quality oil" was becoming scarce and lower grade oil was being brought onto the market.  The use of low quality oil in cars resulted in engine knock.  Geological experts also believed that there would only be 20 to 30 years of oil stocks left in the United States.  As a result there was a great deal of work done investigating the useability of low quality oil in automobile engines.  Eventually GM selected tetra-ethyl lead (TEL) as an anti-knock gasoline additive.  We know this today as "leaded gasoline".  This solution was the most profitable alternative but GM would lead the public to believe that it was the only alternative.  Certainly there was pressure put on GM research to come up with a patentable solution.  There were certainly other viable additives including ethyl alcohol but was not patentable. This leads up to the second significant event which occurred in 1924 / 1925 timeframe.  17 workers died and many other workers were exposed to lead poisoning at two separate TEL manufacturing facilities.  Charles F. Kettering[1] and Thomas Midgley Jr.[2] subsequently told the government that no alternatives existed. "So far as science knows at the present time, tetraethyl lead is the only material available which can bring about these [antiknock] results, which are of vital importance to the continued economic use by the general public of all automotive equipment, and unless a grave and inescapable hazard exists in the manufacture of tetraethyl lead, its abandonment cannot be justified."  - Thomas Midgley Jr.  1925. In this era, farmers were hurting as a result of prohibition and desperately needed new markets to sell grain products in.  It was certainly plausible for the farm industry to produce enough ethanol to replace TEL as the anti-knock additive of choice. The Public Health Service, after investigating the accidents allowed leaded gasoline to remain on the market.   It is safe to say that in this particular instance the Public Health Service did not do their job.  Since 1926, the production and distribution of TEL has cost the health and lives of many workers.  The United States banned TEL in 1986, not because of health concerns, but because of it's adverse effect on exhaust catalysts.  Meanwhile, other countries such as the UK curtailed the use of alkyl leads due to the adverse health effects of lead emissions, especially on children.  Today the United States is a world leader in the production of ethanol with over 7 billion gallons of ethanol-blended  gasoline produced.  This represents approximately 12% of fuel sales including E85 (85% ethanol 15% gasoline) and E10 (10% ethanol 90% gasoline). [1] Charles F. Kettering headed up General Motors research division starting in 1919. [2] Thomas Midgley Jr. was Kettering's chief fuel researcher.  He developed both the tetra-ethyl lead (TEL) additive to gasoline and chlorofluorocarbons (CFCs).  One historian declared that Midgley "had more impact on the atmosphere than any other single organism in Earth history."

Internal Combustion Engine

History

The term internal combustion engine (ICE) refers to an engine where expansion of gases, produced by the combustion, apply force to a movable component of the engine.  The combustion of fuel occurs in a chamber with an oxidiser, typically air.  An exothermic reaction occurs that produces a gas at high pressure and temperature. The increasing hot gases will immediately put pressure on solid engine parts causing them to move.  Pistons, rotors or the engine itself then begins moving, causing the entire automobile to be propelled.

The first internal combustion engine was designed by the Dutch scientist Christian Huygens in 1678;  it was to have been fueled with gunpowder, but it was never built.  About 1860 a French inventor, Etienne Lenoir (1822-1900), built the first practical internal combustion engine; it burned illuminating gas.  In 1866 two German engineers, Eugen Langen (1833-1895) and Nikolaus August Otto (1832-1891), developed a more efficient gas engine, and in 1876 Otto built a four cycle engine, a prototype of the so-called Otto-cycle engines used in most modern automobiles and airplanes.

Operation 

The typical internal combustion engine uses a four-stroke cycle or Otto cycle. The cycle involves four phases namely:  induction, compression, power and exhaust.  These phases combine to generate an exothermic chemical process causing vehicle propulsion. During induction, oxygen or other oxidizers are introduced into the cylinder to act with the fuel.  Compression occurs as the gases start a response that continuously increase temperature and pressure within the cylinder.

When enough pressure is applied on the corresponding engine parts, the engine begins to gain power through movement coming from direct force application. The aftermath of the entire compression process will lead to exhaustion of by products like carbon monoxide, carbon dioxide and nitrogen wastes. These gases are freely emitted into the atmosphere. The combustion process is started through engine ignition using the spark ignition method or the compression ignition system.

Gasoline

Electric/gasoline systems use a combination of lead-acid battery plus an induction coil to create a high-voltage electrical spark.  The spark ignites the mix of air and fuel within the cylinder.  Gasoline engines get an air and gasoline mixture to be compressed to less than 185 psi.   The spark plug ignites the mixture during compression within the cylinder.  The battery is recharged during operation through an alternator or generator driven by the engine itself.  

As for diesel engines, these require only heat and pressure produced by the engine during the compression process for ignition. Diesel compression is approximately three times higher compared to a gasoline engine. Diesel engines use air only. Some diesel fuel is sprayed into the cylinder with the use of a fuel injector just before peak compression to start ignition immediately.  Homogeneous charge compression ignition (HCCI) engines also require only heat and pressure but take in fuel as well as air.  The compression process for diesel and HCCI engines is less robust for cold starts.

The Polluting Effects

Combustion products or the hot gases ignited and burnt inside the engine will have higher amounts of energy compared to the compressed fuel and air mixture. After available energy are used up to drive the engine pistons, remaining combustion products will be vented or exhausted through a valve or the exhaust outlet to bring back the piston in its original state also called top dead center (TDC).  Any heat which is not used up will become a waste product due to be removed from the engine via a liquid or air cooling system.

Air pollution emissions then result from incomplete combustion of carbonaceous fuel.  Examples of engine by products are carbon monoxide, soot, nitrogen wastes, sulfur and uncombusted hydrocarbons. These also result if the products did not operate near the stoichiometric ratio required for effective combustion.  The fuel would not have burnt very well due to factors like cool cylinder walls or lack of air. 

Both gasoline and diesel engines emit harmful gases that can be dangerous to humans as well as the environment. The greenhouse gases are trapped within the atmosphere leading to global warming.