What is the differnce between inter esterification and trans esterification?

1 Answer
Apr 13, 2018

Here's what I get.



Transesterification is the exchange of an alkoxy group between an ester and an alcohol.

#"R"_1"CO"underbrace("-OR"_2)_color(red)("alkoxy") + "R"_3"O-H" ⇌ "R"_1"CO-"underbrace("OR"_3)_color(red)("alkoxy") + "R"_2"OH"#

The process usually involves catalysis by an acid, a base, or an enzyme.

Transesterification is the process that forms biodiesel fuel.


Used fats and oils are triglycerides: esters of glycerol and long-chain fatty acids.

They react with methanol in the presence of a catalyst to release the glycerol and form fatty acid methyl esters (FAME), which are the components of biodiesel.


Interesterification is the exchange of alkyl groups between two different esters,

#"R"_1"CO-OR"_2+ "R"_3"CO""-OR"_4 ⇌ "R"_1"CO-OR"_4 + "R"_2"CO-OR"_2"#

The process usually uses acid, base, or enzyme catalysis.

The biodiesel industry also uses the interesterification process.


The food industry uses interesterification to produce triglycerides with the desired properties (stability, melting point, etc.).


For example, a polyunsaturated triglyceride reacts with a saturated triglyceride to form a product with intermediate properties.