Carboxylic acids production using residual glycerol as a substrate in anaerobic fermentation: A kinetic modeling study

Abstract

This work aimed to analyze the carboxylic acids (CA) production using residual glycerol (RG) from biodiesel as a substrate in the anaerobic fermentation and perform a kinetic study of this bioprocess. RG appeared to be a readily biodegradable carbon source to the acidogenic microorganisms. A yield of 0.62 mg acids mg CODA−1 was achieved, corresponding to 0.82 mg CODCA mgCODA−1. Caproic acid, a medium-chain CA, was produced even without external supplementation of electron donors. There was variation between the best fit models to describe the CA kinetics production. Most of the acids produced were better explained by exponential models, emphasizing the Cone and Fitzhugh models. Therefore, RG is a potential agro-industrial waste for CA production from a resource recovery perspective.