Analysis of conversion and operation strategies for enzymatic hydrolysis of lignocellulosic biomass in a series of CSTRs with distributed feeding

Abstract

Design considerations for enzymatic hydrolysis of lignocellulosic biomass in two and three continuous stirred tank reactors (CSTRs) in series with distributed feeding of substrate and enzyme, followed by a series of CSTRs, are discussed. A previously developed, fitted, and validated kinetic model is extended to accommodate distributed feeding and used along with the micromixing limiting situations of macrofluid and microfluid to describe the reaction system. The capabilities of the reaction system proposed are explored for a range of cumulative substrate concentration from 5 to 20% w/w (dry basis). Continuous distributed feeding does not show advantages in terms of cellulose conversion when compared with the operation where an equivalent mass of substrate is added at the first reactor of the series, but the potential to increase substrate concentration beyond the concentrations that can be handled in conventional CSTRs, and therefore, the volumetric productivity of reactors, is evident.