Modeling and scale-up of hydrothermal pretreatment in compressible lignocellulosic biomass fixed-beds with changing properties

High-pressure flow-through pretreatment with pressurized liquid hot water (LHW, 170 to 230 °C, 40 to 50 bar) is a promising approach for valorization of lignocellulosic biomass like wheat straw. In the present work, a comprehensive and highly dynamic fixed-bed model was developed and validated experimentally in two available LHW fixed-bed units at 3 and 40 L scale (5.2 and 2.6 L/D). It considers a significant porosity change due to chemical reactions and its effects on pressure drop and irreversible bed compression. The model was analyzed regarding parameter sensitivity, operation modes, optimization as well as scale-up and fixed-bed stabilization.