Optimizing energy use in the integrated utilization of woody biomass: Process development and simulation

Abstract

A biorefinery process is developed for the fractionation of oil-tea camellia fruit shell wastes into three main products. A scale-up experiment was first carried out in this paper. Oil-tea camellia fruit shell wastes were first hydrolyzed in a C₆H₈O₇/H₂O system to remove the hemicellulose. The aqueous fraction comprises monosaccharides and oligosaccharides, achieving a hemicellulose removal efficiency of 79.7 %. Lignin was extracted from the residual solids using an ethanol/isopropanol solvent system with a purity of 87.81 %. The solid product obtained after lignin extraction can serve as a growing medium. Then given the energy-intensive nature of pretreatment, energy consumption of the process was assessed via process simulation software. The water evaporation utilities account for approximately 62 % of the overall energy consumption. When the pretreatment reaction is conducted at 130 °C with a raw material to water mass ratio of 1:3, energy consumption can be optimized to 0.2140 t/t. With the adoption of reaction liquid recycling, energy consumption can be further reduced to 0.1763 t/t. This paper outlined a pathway for the integrated utilization of lignocellulose, facilitating the feasibility of engineering calculations for biorefinery processes.