Systems for selective removal of contaminants from a composition and methods of regenerating the same

A system for producing a refined oil product comprising:

• a production reactor for producing a crude oil product mixture, the reactor comprising a lipid reservoir, and an alcohol reservoir;
• and
• an organic acid removal reactor in fluid communication with the production reactor, the organic acid removal reactor comprising a housing defining an interior volume, the housing configured to receive the crude oil product mixture from the production reactor, metal oxide media disposed within the interior volume of the removal reactor housing, the metal oxide media comprising a metal oxide selected from the group consisting of zirconia, alumina, hafnia, and titania;
• the system configured to periodically regenerate the metal oxide media of the organic acid removal reactor by contacting the metal oxide media with a fatty acid alkyl ester composition at a temperature of greater than about 100 degrees Celsius.