Hydrothermal liquefaction of biogenic municipal solid waste under reduced H₂ atmosphere in biorefinery format

Municipal solid waste (MSW), an inexorable by-product of anthropogenic activities composes of nearly 50% of the organic (biogenic) fraction. Hydrothermal liquefaction (HTL) was studied to facilitate thermal depolymerization of organic fraction of MSW to biocrude at sub-critical region of water (200 °C; 100 bar pressure) employing H₂ induced reducing conditions. Food, vegetable, and composite wastes were evaluated as feedstocks to produce HTL derivatives in the form of liquor (biocrude and aqueous phase), biochar and bio-gas. The biocrude (HTL_OF) showed middle oil as major fraction along with C₆-C₂₂ compounds. Composite waste resulted in relatively higher yield of biocrude fraction. The aqueous phase (HTL_AF) documented the presence of reducing sugars, sotolon and furfurals as major fraction. Biochar (HTL_BC) composition showed maximum carbon fraction followed by hydrogen and oxygen. H₂ induced reduced condition facilitated conversion of the biogenic MSW at relatively lower input conditions to various biobased fractions cohesively addressing the basic biorefinery requirement.