How would I go about making an ethyl ester from vegetable oil?

Question

I'm teaching myself how to make lotion and a lot of lotions contain esters like isopropyl myristate or isopropyl palmitate. I'd like to make an ethyl ester from a popular skin-care oil (olive, apricot kernel, or castor).

Since there's so much controversy about using isopropyl alcohol in skin-care, I'd like to avoid that if possible. It's very difficult to find any info on the process, and the closest I could get was how to make biodiesel. All of those use methanol though.

How would I go about making an ethyl ester from these oils?

Answer 1

The biodiesel process should work well, you will need just slightly more aggressive conditions (i.e. slightly more catalyst, slightly higher EtOH excess, and/or slightly longer time) to make ethyl esters instead of methyl esters, as ethanol is slightly less reactive than methanol.

For skin care, you will need higher purity than biodiesel processes usually provides. I would imagine that the cosmetics industry uses vacuum distillation to purify their esters. This would separate the ethyl esters from unreacted triacylglycerols, any base (or acid) catalyst left over from the reaction and soluble in the organic ester phase, organic-soluble glycerol, and organic-soluble impurities.