Using Biodiesel

Biodiesel refers to a diesel-equivalent, processed fuel derived from biological sources (such as vegetable oils), which can be used in unmodified diesel-engine vehicles. It is thus distinguished from the straight vegetable oils (SVO) or waste vegetable oils (WVO) used as fuels in some diesel vehicles.
In this article's context, biodiesel refers to alkyl esters made from the transesterification of vegetable oils or animal fats. Biodiesel is biodegradable and non-toxic, and typically produces about 60% less net carbon dioxide emissions than petroleum-based diesel,[1] as it is itself produced from atmospheric carbon dioxide via photosynthesis in plants. Pure biodiesel is available at many gas stations in Germany.
Some vehicle manufacturers are positive about the use of biodiesel, citing lower engine wear as one of the benefits of this fuel. However, as biodiesel is a better solvent than standard diesel, it 'cleans' the engine, removing deposits in the fuel lines, and this may cause blockages in the fuel injectors. For this reason, car manufacturers recommend that the fuel filter is changed a few months after switching to biodiesel (this part is often replaced anyway in regular servicing). Most manufacturers release lists of the cars which will run on 100% biodiesel.
Other vehicle manufacturers remain cautious over use of biodiesel. In the UK many only maintain their engine warranties for use with maximum 5% biodiesel — blended in with 95% conventional diesel — although this position is generally considered to be overly cautious.[citation needed] Peugeot and Citroën are exceptions in that they have both recently announced that their HDI diesel engine can run on 30% biodiesel. Scania and Volkswagen are other exceptions, allowing most of their engines to operate on 100% biodiesel.
Biodiesel can also be used as a heating fuel in domestic and commercial boilers. Existing oil boilers may require conversion to run on biodiesel, but the conversion process is believed to be relatively simple.
Biodiesel can be distributed using today's infrastructure, and its use and production are increasing rapidly. Fuel stations are beginning to make biodiesel available to consumers, and a growing number of transport fleets use it as an additive in their fuel. Biodiesel is generally more expensive to purchase than petroleum diesel but this differential may diminish due to economies of scale, the rising cost of petroleum and government tax subsidies. In Germany, biodiesel is generally cheaper than normal diesel at gas stations that sell both products.

Description
Biodiesel is a light to dark yellow liquid. It is practically immiscible with water, has a high boiling point and low vapor pressure. Typical methyl ester biodiesel has a flash point of ~ 150 °C (300 °F), making it rather non-flammable. Biodiesel has a density of ~ 0.88 g/cm³, less than that of water. Biodiesel uncontaminated with starting material can be regarded as non-toxic.
Biodiesel has a viscosity similar to petrodiesel, the industry term for diesel produced from petroleum. It can be used as an additive in formulations of diesel to increase the lubricity of pure Ultra-Low Sulfur Diesel (ULSD) fuel, which is advantageous because it has virtually no sulfur content. Much of the world uses a system known as the "B" factor to state the amount of biodiesel in any fuel mix, in contrast to the "BA" or "E" system used for ethanol mixes. For example, fuel containing 20% biodiesel is labeled B20. Pure biodiesel is referred to as B100.
Biodiesel is a renewable fuel that can be manufactured from algae, vegetable oils, animal fats or recycled restaurant greases; it can be produced locally in most countries. It is safe, biodegradable and reduces air pollutants, such as particulates, carbon monoxide and hydrocarbons. Blends of 20 percent biodiesel with 80 percent petroleum diesel (B20) can generally be used in unmodified diesel engines. Biodiesel can also be used in its pure form (B100), but may require certain engine modifications to avoid maintenance and performance problems. The industry standard for the amount of time it takes to produce biodiesel used to be 4 hours, but a San Antonio based company is currently experimenting, and has claimed to produce biodiesel fuel in a fraction of what it formerly was, with a 1.4 minute contact time.

Historical background
Transesterification of a vegetable oil was conducted as early as 1853 by scientists E. Duffy and J. Patrick, many years before the first diesel engine became functional. Rudolf Diesel's prime model, a single 10 ft (3 m) iron cylinder with a flywheel at its base, ran on its own power for the first time in Augsburg, Germany, on August 10, 1893. In remembrance of this event, August 10 has been declared "International Biodiesel Day". Diesel later demonstrated his engine and received the Grand Prix (highest prize) at the World Fair in Paris, France in 1900.
This engine stood as an example of Diesel's vision because it was powered by peanut oil — a biofuel, though not biodiesel, since it was not transesterified. He believed that the utilization of biomass fuel was the real future of his engine. In a 1912 speech Diesel said, "the use of vegetable oils for engine fuels may seem insignificant today but such oils may become, in the course of time, as important as petroleum and the coal-tar products of the present time."[4].
During the 1920s, diesel engine manufacturers altered their engines to utilize the lower viscosity of petrodiesel (a fossil fuel), rather than vegetable oil (a biomass fuel). The petroleum industries were able to make inroads in fuel markets because their fuel was much cheaper to produce than the biomass alternatives. The result, for many years, was a near elimination of the biomass fuel production infrastructure. Only recently have environmental impact concerns and a decreasing cost differential made biomass fuels such as biodiesel a growing alternative.
In 1977, Brazilian scientist Expedito Parente produced biodiesel through the use of transesterification and ethanol. This process, the first patented in the world, is classified as Biodiesel by international norms, conferring a "standardized identity and quality. No other proposed biofuel has been validated by the motor industry".[5] Currently, Parente's company Tecbio is working with Boeing and NASA to certify bioquerosene, another product produced and patented by the Brazilian scientist.[6]
Research into the use of transesterified sunflower oil, and refining it to diesel fuel standards, was initiated in South Africa in 1979. By 1983 the process for producing fuel-quality, engine-tested biodiesel was completed and published internationally.[7] An Austrian company, Gaskoks, obtained the technology from the South African Agricultural Engineers; the company erected the first biodiesel pilot plant in November 1987, and the first industrial-scale plant in April 1989 (with a capacity of 30,000 tons of rapeseed per annum).
Throughout the 1990s, plants were opened in many European countries, including the Czech Republic, Germany and Sweden. France launched local production of biodiesel fuel (referred to as diester) from rapeseed oil, which is mixed into regular diesel fuel at a level of 5%, and into the diesel fuel used by some captive fleets (e.g. public transportation) at a level of 30%. Renault, Peugeot and other manufacturers have certified truck engines for use with up to that level of partial biodiesel; experiments with 50% biodiesel are underway. During the same period, nations in other parts of the world also saw local production of biodiesel starting up: by 1998 the Austrian Biofuels Institute had identified 21 countries with commercial biodiesel projects. 100% Biodiesel is now available at many normal service stations across Europe.
In September of 2005 Minnesota became the first U.S. state to mandate that all diesel fuel sold in the state contain part biodiesel, requiring a content of at least 2% biodiesel.[8]

Technical standards

Biodiesel sample
The common international standard for biodiesel is EN 14214.
There are additional national specifications. ASTM D 6751 is the most common standard referenced in the United States and Canada. In Germany, the requirements for biodiesel are fixed in the DIN EN 14214 standard and in the UK the requirements for biodiesel is fixed in the BS EN 14214 standard, although these last two standards are essentially the same as EN 14214 and are just prefixed with the respective national standards institution codes.There are standards for three different varieties of biodiesel, which are made of different oils:
RME (rapeseed methyl ester, according to DIN E 51606)
PME (vegetable methyl ester, purely vegetable products, according to DIN E 51606)
FME (fat methyl ester, vegetable and animal products, according to DIN V 51606)
The standards ensure that the following important factors in the fuel production process are satisfied:
Complete reaction.
Removal of glycerin.
Removal of catalyst.
Removal of alcohol.
Absence of free fatty acids.
Low sulfur content.
Basic industrial tests to determine whether the products conform to the standards typically include gas chromatography, a test that verifies only the more important of the variables above. More complete tests are more expensive. Fuel meeting the quality standards is very non-toxic, with a toxicity rating (LD50) of greater than 50 mL/kg.

From wikipedia