Microwave-Assisted Hydrothermal Carbonisation of Waste Biomass: The Effect of Process Conditions on Hydrochar Properties

Hydrochars are an alternative form of biochar produced by hydrothermal carbonisation (HTC), a potentially cheaper and greener method. In this paper, the effect multiple variables on hydrochar properties was investigated. Waste biomass converted to via microwave-assisted carbonisation. The were temperature, solution ratio (water-biomass ratio), time, particle size, pH acetone washing. measured yield, carbon, oxygen ash content, higher heating value (HHV), carbon energy recovery dye water adsorption. Feedstock significance investigated using apple, wheat, barley, oat pea straw. investigation into specific combination feedstock has not been done before. HTC increased content (~60%), HHV (~24 MJ/kg) adsorption reduced Thermal analysis suggested hydrochars suitable for sequestration. Decreasing most significant factor in increasing yield. Increasing temperature decreasing content. This affected HHV, with temperatures producing material, surpassing brown coal. at high ratio, times showed best Smaller size yield but Low lowered recovery, High Acetone decreased oxygen, Barley highest HHV. Apple All promise as solid fuels, soil additive precursor activated lacked pollutant adsorbents stability