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Biodiesel is a domestic, clean burning renewable fuel for diesel engines. Made from agricultural co-products (natural vegetable oils and fats) such as soybean oil and greases.
About
Biodiesel is a domestic, clean burning renewable fuel for diesel engines. Made from agricultural co-products (natural vegetable oils and fats) such as soybean oil and greases, it is an advanced biofuel made through a chemical process which converts oils and fats of natural origin into fatty acid methyl esters (FAME). To be called biodiesel, it must meet the strict quality specifications of ASTM D 6751. Biodiesel is intended to be used as a replacement for petroleum diesel fuel, or can be blended with petroleum diesel fuel in any proportion. Biodiesel does not require modifications to a diesel engine to be used and has reduced exhaust emissions as well as lower toxicity compared to petroleum diesel fuel. It is safer to handle compared to petroleum diesel fuel because the flash point (the point at which fuel ignites) for biodiesel in its pure form is a minimum of 94 degrees versus about 52 degrees Celsius for regular No. 2 diesel and biodiesel is biodegradable. Biodiesel is a product made from vegetable oil or animal fat that can be used as a replacement for diesel fuel in diesel powered vehicles. The process is a chemical reaction involving alcohol, such as methanol or ethanol, into which is added a catalyst, such as sodium or potassium hydroxide. This mixture is blended into the vegetable oil causing a chemical reaction, called transesterification, which separates the vegetable oil into two components. One component is a heavier liquid called glycerol (also called glycerine). Glycerol has many food and industrial uses, such as cosmetics, toothpaste, pharmaceuticals, foodstuffs, plastics, explosives, and cellulose processing to name a few. However, the material obtained from biodiesel production requires purification before it could be used for these purposes. Biodiesel is a cleaner burning alternative to petroleum-based diesel fuel. Just like petroleum-based diesel fuel, biodiesel operates in the compression ignition (diesel) engines. The successful introduction and commercialization of biodiesel in many countries around the world has been accompanied by the development of standards to ensure high product quality and user confidence. Some biodiesel standards are ASTM D6751 (ASTM = American Society for Testing and Materials) and the European standard EN 14214 and Requirements SANS 1935, Edition 2, and dated 19/12/2011 is the South African Standard for biodiesel (South African Bureau of Standards, 2006). The biodiesel is characterized by determining its physical and fuel properties including density, viscosity, iodine value, acid value, cloud point, pure point, gross heat of combustion and volatility. In general, biodiesel compares well to petroleum-based diesel. Air pollution is one of the most serious environmental problems all over the world. The combustion of petroleum-based diesel fuel is a major source of GHG emissions. Apart from these emissions, petroleum-based diesel fuel is also major source of other air contaminants including carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx), particulate matter (PM), and volatile organic compounds (VOCs). Biodiesel, a fuel that can be made from renewable biological sources, such as vegetable oils, animal fats and waste cooking oils, may have the potential to reduce the reliance on imported oil and reduce air pollutant emissions from diesel engines. Using biodiesel in a conventional diesel engine substantially reduces emissions of HCs, CO, PM, sulfates, polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons. Biodiesel has the highest energy balance ratio of any liquid fuel. It has been reported that the growth of energy crops for biodiesel production produces a positive energy balance of 2.5–3.2 as output of energy from the use of biodiesel exceeds that of the energy input for manufacturing the fuel. The Sheehan et al. study left out many of the fossil energy inputs to achieve an energy balance of 3.2. Most fossil fuels have a negative energy balance meaning it takes more units of energy to recover, transport and process the fuel than it returns in units of fuel energy. Every unit of fossil fuel energy used to extract and refine crude oil into petroleum diesel yields only 0.83 units of energy – a negative energy balance.
Key Benefits
Advantages of Biodiesel • It costs less than regular diesel • It contains no or little sulphur • It has a higher Cetane rating that improves the efficiency of compression ignition • NO engine modifications are necessary to use biodiesel on any diesel engine • It is non-flammable, non-hazardous, non-toxic & environmentally friendly • It has a flash point greater than 120°C while fossil diesel is approx. 70°C • Users can switch between biodiesel and regular diesel as they wish • It has superior cleaning properties over all other regular diesel • It provides much better engine lubrication than regular diesel • It produces 75% less exhaust smoke emissions • It produces 80% less carbon dioxide emissions • It is made from new or used cooking oil • It extends engine life by up to 200% • It mixes very well with regular diesel • It is safe to store and handle • It is a renewable fuel • It is a “green” fuel
Applications
Biodiesel can be substituted directly for or blended in varying proportions with regular diesel fuel or heating oils, requiring no changes to existing infrastructure, engines, or equipment. (Biodiesel blends are concentrations of biodiesel between 2% and 99%, denoted B2–B99, with the number following the ―B‖ indicating the percentage of biodiesel in a litter of fuel). Biodiesel‘s performance advantages over regular diesel fuel include a higher cetane index and greater lubricity (especially compared to low-sulphur diesel). Biodiesel also has a higher flashpoint than regular diesel fuel, making it less combustible and therefore safer to store, use, and transport.