Biodiesel production is a process of synthesizing biodiesel, it is a liquid fuel source highly compatible with petroleum based diesel fuel. Synthesis is method which is used by manufacturer, in which reaction of a glyceride containing plant with short chain alcohol like methanol or ethanol in a step called as transesterification.
The reaction which occur during this process is below,
Animal and plant fats and oil are made up of triglycerides. There are esters of free fatty acids with tryholic alcohol, glycerol. Here the alcohol is deprotonated with a base to make it stronger nucleophile. Generally in esterfication ethanol or methanol is used.
From reaction one can easily find out there us no other input than the triglyceride and alcohol.
This reaction occurs very slowly or may not occur. Acid or base are used to make the reaction more quickly, also can used heat. It is very much important to not that acid or base should not be consumed by esterification reaction. Base catalyzed technique is used for most economical process which requires low temperatures and pressures. It produces more than 98% conversions yield.
If you are using waste vegetable oil, it should be filtered and remove dirt, charred food and other non oil material often food.
Water used to be removed from process because its presence causes the triglycerides to hydorlyze which gives to salts of the fatty acids. It is accomplished by heating the filtered oil approximately 120C. At this temperature any suspended water get boil off. When water gets boils, it used to spitters, so to prevent injury to container, there should be sufficiently large container, they should be closed but not sealed. In laboratory to remove water, they used drying agent like magnesium sulfate.
Neutralization of Fatty acids:
Titration of cleaned oil with standard solution of base which used to make for determines the concentration of free fatty acids (RCOOH) which is present in waste vegetable oil. Base quantity is measure which is required to neutralize the acid.
The measured quantity of base used to added slowly to the alcohol. It is then stirred until till it get dissolves. Three full equal size triglyceride are made by adding sufficient alcohol. Excess alcohol is added to complete the reaction.
The solution of sodium hydroxide is being added to a warm solution of waste oil, then the mixture is heated to process transesterification.
After completion of reaction glycerol get sink. Emulsion used to occur when ethanol being used. It is being broken by standing, centrifugation, also by addition of low boiling, decanting, distilling. Then the top layer mixture of biodiesel and alcohol is decanted, where the excess of alcohol is distilled off or it is used to extracted through water. Biodiesel should be dried by distillation. It can also be done with the help of drying agent.
Benefits of Process
It is continuous process
It's FAME=98.59 before washing process
It's FAME=99.85 after washing process
It reduces space requirement
It is very low in process inventory
It require minimum manpower
Oils and fats can be produced
Reactors from 1GPM up to 500GPM are available
This process is successful for even poor quality of crude oil.