The process GBI uses is called transesterification.
TRANSESTERIFICATION
We add methanol (an alcohol) and potassium hydroxide, or caustic potash (a catalyst) to the tallow and cooking oil (feedstock).
These chemicals react with the feedstock to produce a new compound – Fatty Acid Methyl Ester (FAME), otherwise known as biofuel.
TRANSESTERIFICATION
We add methanol (an alcohol) and potassium hydroxide, or caustic potash (a catalyst) to the tallow and cooking oil (feedstock).
These chemicals react with the feedstock to produce a new compound – Fatty Acid Methyl Ester (FAME), otherwise known as biofuel.
Biofuel Production Process
Biodiesel is the product you get when a vegetable oil or animal fat is chemically reacted with an alcohol (methanol) and a catalyst (KOH) to produce a new compound that is known as a fatty acid methyl ester (Biodiesel or FAME). This process is called transesterification.
All vegetable oils and animal fats consist primarily of triglyceride molecules as shown schematically below. R1, R2, and R3 represent the hydrocarbon chain of the fatty acid elements of the triglyceride. Note that there is a three-carbon chain called the glycerol backbone that runs along the left side of the molecule. Extending away from this backbone are the three long fatty acid chains. In their free form, free fatty acids ( FFA), have the configuration shown below.
The process that will be used in the proposed plant is called transesterification and involves the splitting of the fatty acids away from the glycerol backbone to give glycerol and biodiesel, a fertiliser. The chemical reaction with methanol and a catalyst is shown schematically below.
FINAL STAGES
The biodiesel then undergoes a series of washing steps before finally being distilled to produce biodiesel which meets the European standard and a distillate by product which can be used to fuel the steam boiler in the process.
The glycerol phase also goes through a refining process where it is separated from the catalyst (KOH) to give crude glycerol (80%) and a potassium based fertiliser.