Microwave pretreatment effects on switchgrass and miscanthus solubilization in subcritical water and hydrolysate utilization for hydrogen production

Higher temperature microwave processing reduced the biomass recalcitrance resulting in microwave treated materials having 7-10% higher solubility in subcritical water than untreated materials. However, gasification of pretreated biomass hydrolysates produced less gaseous products compared to untreated biomass for both switchgrass and miscanthus. Miscanthus biomass was more vulnerable to destruction by microwave treatment and recalcitrance of this biomass was achieved at lower temperature compared to switchgrass. Miscanthus biomass that was not microwave treated produced the highest gas yield. Microwave pretreatment caused significant increases in the formation of ungasified solid carbon residue in the APR process.