Advantage:
(1) The performance of biodiesel is very similar to that of petroleum diesel. As the fuel of diesel engine, there is no need to modify the engine and the storage of biodiesel is the same as that of petroleum diesel.
(2) Biodiesel used as automobile fuel can reduce emissions of carbon dioxide (CO2) by 80%, sulfur oxides by 100%, unburned hydrocarbons by more than 90%, aromatic hydrocarbons by 75-90% and carcinogens by 90%.
(3) The carbon dioxide produced by biodiesel combustion is much lower than that absorbed by plants during the whole growth process, which is conducive to alleviating the greenhouse effect.
(4) Biodiesel contains 11 w% oxygen and no sulfur, and has excellent lubricity. It has no effect on fuel consumption, fuel ignition, output power and engine torque.
(5) Biodiesel is also renewable because the raw material is animal and vegetable oils.
（6）Biodiesel is environmentally friendly, does not contain benzene or other carcinogenic polycyclic aromatic hydrocarbons, and has low volatile organic compounds (VOCs).
（7）Biodiesel has high safety, its flash point is very high, about 70 C higher than petroleum diesel, so it need not be considered as flammable.
（8）Biodiesel is easy to biodegrade. Its biodegradability is four times faster than petroleum diesel. After 28 days, biodiesel can degrade 85-88% in water. It has the same degradation rate as glucose. Accidents will not bring harm to land or water.
（9）The toxicity of biodiesel is very low. Acute oral toxicity lethal dose > 17.4 g/kg body weight is one tenth of the toxicity of salt; relatively safe, it must be fuel but not drink!
（10）The irritation to human skin is low. The irritation of undiluted biodiesel to human skin is less than that of 4% soap water.
Disadvantages:
The calorific value of biodiesel is slightly lower than that of petroleum diesel.
(2) Biodiesel has high solubility, which can remove the carbon deposit of the engine, protect the engine and prolong the service life of the engine.
(3) When biodiesel is used as automobile fuel, the emission of NOx is slightly higher than that of petroleum diesel.
(4) Raw materials have a great influence on the properties of biodiesel. If the content of saturated fatty acids in raw materials is high, such as palmitic acid or stearic acid, the low temperature fluidity of biodiesel may be poor; if the content of polyunsaturated fatty acids, such as linoleic acid or linolenic acid, is high, the oxidation stability of biodiesel may be poor, which needs to be solved by adding corresponding additives.