Assessing the effect of K2CO3 and aqueous phase recycling on hydrothermal liquefaction of corn stover

The effects of reaction temperature (300-340 degrees C) and reaction time (30-90 min), catalyst loading (0-10% K2CO3), and aqueous phase recycling (up to 3 recycling rounds) on the hydrothermal liquefaction (HTL) of corn stover were investigated. The oil yield ranged from 0.28 to 14.54%daf. A high reaction temperature and a long reaction time have a synergistic effect on the oil production under non-catalytic HTL. The effect of K2CO3 loading on oil yield is dependent on the reaction temperature. The FTIR analysis of the solid residue showed that the peak characteristics of lignin and cellulose are still intact without or with different K2CO3 loading suggesting low lignin and cellulose degradation. The effect of the aqueous phase with the presence of K2CO3 showed an increased oil yield, energy recovery, and abundance in silanes and siloxanes after the 3rd round of recycling.