Modelling of homogeneously catalyzed hemicelluloses hydrolysis in a laminar-flow reactor

Abstract

Hydrolysis of hemicelluloses with acid catalysts yield different sugar monomers and oligomers, depending on the substrate as well as the process design. The hydrolysis kinetics are typically rather slow, which leads to requirements of long residence times, i.e. slow flow rates, in order to achieve adequate conversion. Hydrolysis experiments of two different polysaccharides – o-acetylgalactoglucomannan (GGM) and inulin - were conducted in an isothermal tubular continuous reactor in laboratory scale, working in the laminar flow regime. A dynamic mass balance-based reactor model was developed, including convection and molecular diffusion in axial and radial directions, as well as the self-accelerating kinetics of the reaction. The model gave a very satisfactory description of the experimental data. The behavior of the laminar flow reactor in the hemicellulose hydrolysis was further illustrated by numerical simulations.