Biomass waste valorization assisted by microwaves: a feasible approach for the co-production of value-added products

The use of microwave-assisted acid hydrolysis (MAAH) for the co-production of furfural, furfuryl alcohol, and formic acid from several lignocellulosic-based waste materials was investigated. The MAAH experiments were carried out in a microwave system based on the single reaction chamber (SRC) technology. Experimental conditions were selected using grass as a model of lignocellulosic waste, by evaluating the feedstock amount (10 to 700 mg), temperature (120 to 240 degrees C), time (1 to 40 min), and H2SO4 concentration (10 mL solution, 1 to 9%). One-pot conversion of grass, sugarcane straw, rice husk and wood waste into furfural (37-42%), furfuryl alcohol (10-26%), formic acid (10-15%), and glucose (0.6-8.1 %) was achieved even without a specific step for lignin removal. Higher biomass amount (0.5 L load, grass as model) was performed using a microwave SRC reactor. MAAH showed to be efficient for processing of several types of biomass waste, and the co-production of several interesting industrial products.