Influence of green solvent on levulinic acid production from lignocellulosic paper waste

Lignocellulosic wastes constitute a significant portion of the municipal solid waste, which should be valorised for the synthesis of value-added chemicals to achieve circular bioeconomy. This study evaluates the use of gamma-valerolactone (GVL) and acetone as green co-solvents to produce levulinic acid (LA) from lignocellulosic paper towel waste at different temperatures using dilute H2SO4. At the highest reaction temperature (200 degrees C), H2O-only system achieved similar to 15 Cmol% of LA at maximum. while GVL/H2O and acetone/H2O co-solvent systems enhanced the depolymerisation of paper towel waste and the subsequent conversion to LA, with the highest yield amounted to similar to 32 Cmol%. Acetone/H2O solvent system generated similar to 17 Cmol% LA at a lower temperature (180 degrees C), while higher temperature induced polymerisation of soluble sugars and intermediates, hindering further conversion to LA. In contrast, the availability of soluble sugars was higher in the GVL/H2O system, which favoured the production of LA at higher temperatures.