Biodiesel is one type of biofuel. Biodiesel is alkyl esters of compounds produced through a process of alcoholysis of triglycerides with methanol or ethanol with the aid of an alkaline catalyst to alkyl esters and glycerol; or esterified fatty acids (free) with methanol or ethanol with the aid of a base catalyst alkyl ester compounds and water.
Biodiesel produced crude trans-esterification process oil (or esterified fatty acids) are usually still contains the remnants of catalyst, methanol, and glycerol (or water). To purify, the crude biodiesel can be washed with water, so that the impurity-impurity is dissolved in and carried away by the next phase of the washing water is separated.
The first portion of water used for washing is recommended that a small amount of acid or base to neutralize the remnants of the catalyst. Biodiesel that has been washed and then dried under vacuum to produce a clear (sign-free water) and drip flame 100C (methanol-free sign.)
Through the precise combinations of reaction conditions and methods of water removal, and perhaps also with a gradual implementation of the reaction, complete conversion of fatty acids into esters metilnya can be completed within 1 to several hours. The process of trans-esterification and esterification can be combined to process raw materials containing free fatty acids such as moderate to high CPO low grade, as well as PFAD.
As a raw material of biodiesel can be used include castor oil, palm oil, coconut oil, etc.. Biodiesel has a carbon chain between 12 and 20 and contain oxygen. The presence of oxygen in biodiesel with petroleum diesel to distinguish the main components consisting only of hydrocarbons. So the composition of biodiesel and petroleum diesel are very different. Biodiesel made from vegetable fatty acid methyl esters, while petroleum diesel is a hydrocarbon.
However, biodiesel has chemical and physical properties similar to petroleum diesel that can be used directly for diesel engines or blended with petroleum diesel. Mixing 20% biodiesel into petroleum diesel fuel products without changing the physical properties significantly. This product in the United States known as Diesel B-20 that is widely used to fuel buses.
The energy generated by biodiesel is relatively no different from petroleum diesel (128,000 vs. 130,000 BTU BTU), so that the engine torque and horsepower produced is also similar. Although the calorie content of biodiesel is similar to petroleum diesel, but because biodiesel contains oxygen, then the flash pointnya higher so that is not flammable. Biodiesel also does not produce harmful vapor at room temperature, then biodiesel safer than petroleum diesel in storage and use.
In addition, biodiesel contains no sulfur and benzene compounds are carcinogenic, so that biodiesel is a fuel that is cleaner and easier to handle compared to petroleum diesel.
The use of biodiesel can also reduce emissions of carbon monoxide, total hydrocarbons, particulate matter, and sulfur dioxide. Emissions of nitrous oxide can also be reduced by the addition of catalytic converters. Another advantage in terms of the environment is the level of toxicity that is 10 times lower than the table salt and its biodegradability same level of glucose, making it very suitable for use in activities in the waters to fuel boat / motor. Biodiesel does not add to the greenhouse effect as well as petroleum diesel because of the resulting carbon into the carbon cycle.
For the use of biodiesel essentially no need modification on diesel engines, biodiesel and even has a cleansing effect on the fuel tank, injectors and hoses.