Kinetic modelling of the hydrothermal carbonisation of the macromolecular components in lignocellulosic biomass

Abstract

Hydrothermal carbonisation (HTC) can play a significant role in the valorisation of lignocellulosic biomass to increase the share of renewable sources in the energy system. However, due to the complexity and the variety of biomass, literature lacks HTC kinetic models with predictive capabilities for specific classes of biomass.This study developed and tested three comprehensive kinetic models for the hydrothermal carbonisation of the macromolecular components in lignocellulosic biomass: cellulose, hemicellulose and lignin. The kinetic models were developed to accurately predict the carbon concentrations in the hydrochar, gas and liquid residuals. The estimated kinetic parameters were presented for each reaction and compared to those reported in the literature. The model validations were carried out by processing a total of 106 experimental data points in a wide range of operating conditions. The kinetic models were able to accurately predict the carbon content in all the HTC product phases.