A kinetic study of acid catalysed hydrolysis of sugar cane bagasse to levulinic acid

Abstract

There is a significant research effort worldwide to identify attractive chemical conversion routes for lignocellulosic biomass to organic (bulk-)chemicals. This study has focussed on the acid-catalysed hydrolysis of sugar cane bagasse for the production of levulinic acid (LA), a platform chemical used for the synthesis of a variety of materials for applications such as fuel additives and polymer and resin precursors. The objectives of this study were to develop a broadly applicable kinetic model for the acid-catalysed hydrolysis of sugar cane bagasse to LA and to determine the optimum reaction conditions for its production. Systematic kinetic experiments were carried out by varying the reaction temperature between 150 and 200°C, and the sulphuric acid concentration between 0.11 and 0.55M. The highest LA yield was obtained at 150°C and 0.55M H2SO4 at 63mol%, which equates to the production of 194kg of LA from 1 dry tonne of sugar cane bagasse. The kinetic model developed was in good agreement with the experimental data and also with the previous kinetic models developed for cellulose and sugar cane bagasse. Our kinetic model, though developed for the sugar cane bagasse, can be applied over a wide range of hydrolysis reaction conditions for lignocellulosic biomass. Based on the optimisation study carried out using our kinetic model, an empirical equation is proposed to predict the LA yield at a particular temperature and acid concentration.