Brown bin waste can be used for the production of butanol and butyric acid by employing fermentation techniques. This study focuses on heterogeneous solid acid catalyst obtained from solid residues derived from a fermentation process and applied for the efficient conversion of butyric acid to butyl butyrate. The solid acid catalysts were produced by sulfonation of char obtained from the slow pyrolysis of brown bin waste digestate at various temperatures (400, 500 and 600 A degrees C). The catalysts possessing the highest surface area and acid density were shown to have the highest catalytic activity and thus performed better giving competitive results to Amberlyst 15 and H2SO4 (96 % yield), after 24 h reaction. Increasing the catalyst loading was found to positively affect the yields of butyl butyrate, especially at early reaction time. Realistic kinetic parameters were formulated for the optimum char based solid acid catalyst using two power law models.