Application of pulsed electric energy for lignocellulosic biorefinery

Abstract

The biorefinery concept of conversion of lignocellulosic biomass is the hottest topic in the modern literature. Various physical, chemical, and biological techniques are tested in order to improve the efficiency of methods and their economic value. Recent applications of pulsed electric energy (PEE), both pulsed electric fields (PEF) and high voltage electrical discharges (HVED), in lignocellulosic biorefinery have demonstrated their high potential. The lignocellulosic biomass mainly consists of cellulose, hemicellulose, and lignin and contains small quantities of pectin, proteins, nonstructural sugars, chlorophylls, and ash. The existing schemes of lignocellulosic biomass biorefinery include thermo-chemical, physical, chemical, and biological (fermentation, digestion, and microbial processing) techniques. However, these techniques require a long processing time, large amounts of chemicals, solvents, and they are energy consuming. The PEF and HVED techniques can be effectively used for assistance of hydrolysis and fermentation, for production of biogas, and extraction of high added-chemicals and bioactive compounds. The range of tested biomass is rather limited so far and existing examples include wood and crop biomasses (sawdust, chips, barks, silage, and switch grass), sludges, and wastes. The recent findings evidenced the great potential of electroporation-assisted techniques for efficient utilization of agro-industrial waste, forestry wastes, and semisolid biological sludges. This chapter analyzes up-to-date information available on the PEE-assisted lignocellulosic biorefinery including the utilization of forest and agro-industrial residues, waste, and semisolid sludges.