Simultaneous production of furfural and levulinic acid from pine sawdust via acid-catalysed mechanical depolymerization and microwave irradiation

Abstract In this work pine sawdust was converted into levulinic acid (LA) and furfural. Sawdust was first pre-treated with sulfuric acid-catalysed mechanical depolymerization. The conversion reactions were then performed with microwave heating at 180 °C. To enhance the furfural yield and the efficient separation of furfural and LA, a biphasic water-toluene reaction system was used. The effect of an additional catalyst, AlCl 3 , on the yield of LA and furfural was also studied. According to the results the pre-treatment method enhanced the yields of LA. In addition, due to the microwave heating the reaction times were short. Additional AlCl 3 catalyst enhanced the LA yield, however excellent furfural yields were achieved even without it. Best LA yield (38%) was achieved with 6 h of milling combined with 30 min of microwave heating while the best furfural yield (85%) was achieved with 4 h of milling and 20 min of microwave heating.