Densification of a fermented lignocellulosic biomass rich in cellulolytic enzymes

Abstract

This study was conducted to compare the performance of two densiflcation processes, namely pelletization and granulation, on quality parameters (enzyme activity and density) of a beta-glucanase-rich biomass, processing time/material throughput, and power consumption. The pellet mill heating condition (dry heating and steam conditioning settings) had more effect on the product quality parameters than the storage temperature (ranging from -18-C to 45-C) of biomass during pelletization. In pelletization, the factor of heating source (dry and steam heating) was more effective than the factor of biomass initial temperature (ranged from -18-C to 45-C) on the quality parameters. In no-heat or dry-heat (temperatures of up to 55-C) and low-flow steam conditioning, enzyme activities of over 90% were obtained. However, at the high-flow steam conditioning, a lower material throughput, higher power consumption, and a complete loss of enzyme activity was obtained. In granulation, the factor of moisture content (MC) was more important than binder inclusion, material residence, and extrusion direction in affecting product quality parameters. Compared to pelletization, granulation would be a preferable process resulting in a uniform and small-sized densified product. However, it has higher energy consumption and less efficiency in terms of product densiflcation.