Biodiesel is a typical "green energy", which has the characteristics of good environmental protection performance, good engine starting performance, good fuel performance, wide source of raw materials, renewable and so on. In recent years, many studies have confirmed that after burning biodiesel, whether it is a small or light diesel engine, a large or heavy diesel engine or a tractor, hydrocarbons, particulate matter, CO and polycyclic aromatic hydrocarbons are reduced by 55%~60%, 20%~50%, 45% and 75%~85% respectively. Biodiesel refers to fatty acid methyl ester or ethyl ester formed by transesterification of vegetable oil (such as rapeseed oil, soybean oil, peanut oil, corn oil, cottonseed oil, etc.). ), animal oil (such as fish oil, lard, butter, sheep oil, etc. ), gutter oil or microbial oil is added with methanol or ethanol. Vegetable oils and animal fats of fatty glycerides (triglycerides) with certain structural symbols are usually used as raw materials for biodiesel.
Fuel characteristics
The fuel performance of biodiesel is close to that of petroleum-based diesel, and it has incomparable performance.
(1) has good ignition performance. Cetane number is a quality index to measure the fuel performance of compression ignition engine. The cetane number of biodiesel is higher than 45 (that of petrochemical diesel is 45), and its ignition performance is better than that of petrochemical diesel.
(2) The combustion is more complete. The oxygen content of biodiesel is higher than that of petrochemical diesel, reaching 1 1%. The oxygen required in the combustion process is less than that of petrochemical diesel oil, and the combustion is more complete than that of petrochemical diesel oil. [ 1]
(3) wide applicability. Biodiesel can not only be used as an alternative fuel for buses, trucks and other diesel engines, but also be used as an alternative fuel for off-road diesel engines such as marine transportation, hydropower equipment, geological mining equipment and oil-fired power plants.
(4) protect power equipment. The kinematic viscosity of biodiesel is slightly higher than that of diesel, and it is easier to form an oil film on the inner wall of the cylinder without affecting the fuel atomization, thus improving the lubricity of moving parts and reducing the wear of parts.
(5) Good universality. Without replacing the diesel engine, it can be directly added for use, and at the same time, there is no need to add special refueling equipment, storage and transportation equipment and technical training of personnel (usually other alternative fuels may need to be modified before they can be used).
(6) Safe and reliable. The flash point of biodiesel is higher than that of petrochemical diesel, which is beneficial to safe storage, transportation and use.
(7) Saving energy and reducing consumption. Biodiesel itself is a kind of fuel. Mixing it with petrochemical diesel in a certain proportion can reduce fuel consumption and improve power performance.
(8) Strong climate adaptability. Biodiesel is widely used because it contains no paraffin and has good fluidity at low temperature.
(9) Many functions. Biodiesel can be used as both fuel oil and additive to promote combustion effect, which has dual functions.
(10) has excellent environmental protection characteristics. The low sulfur content in biodiesel makes the emission of SO2 and sulfide lower, which can be reduced by about 30% (using catalyst can be reduced by 70%). Biodiesel does not contain aromatic hydrocarbons that will pollute the environment, so the waste gas produced has low harm to human body.