Preparation of levulinic acid and 5-(chloromethyl)furfural directly from terrestrial and marine biomass in a batch reactor under conventional and microwave heating.

Lignocellulosic waste and seaweed represent second- and third-generation biomass resources, respectively, with significant potential as renewable feedstocks for the sustainable production of liquid fuels and value-added organic chemicals. In this study, the production of levulinic acid (LA) and 5-(chloromethyl)furfural (CMF), two important carbohydrate-derived platform chemicals, was investigated using selected lignocellulosic wastes and dried seaweed flakes (DSF) of E. spinosum. CMF was synthesized in a biphasic system comprising aqueous HCl (35%) and 1,2-dichloroethane, whereas LA was produced in 20% aqueous HCl under batch reaction conditions. The synthesis of both CMF and LA was examined under conventional heating and microwave irradiation (MWI). Furthermore, the effects of acid concentration, additives, reaction temperature, reaction time, catalyst loading, and biomass loading were systematically optimized to maximize product yields. Under the optimized conditions (20% aqueous HCl, 120 °C, 4 h), LA was obtained in 11 wt% yield, while MWI enabled an enhanced LA yield of 29 wt% from E. spinosum DSF within 30 min. CMF was produced in 13.5 wt% yield under optimized conditions (80 °C, 2 h). Selected terrestrial lignocellulosic wastes also furnished appreciable yields of CMF and LA under the optimized reaction conditions.