Steam explosion of wood particles from fibreboard and particle board with indirect control by enzymatic hydrolysis

Abstract

Pretreatment of particles obtained from lignocellulosic materials by steam explosion with indirect control by enzymatic hydrolysis has been studied. The dendromass pretreatment model has been applied for recycled fibreboard and particle board based on softwood. Their structure and chemical composition partly predetermine these lignocellulosic materials consisting of a mixture of spruce and fir particles also for bioethanol production. Optimum steam explosion temperature of 205 °C was determined based on the concentration of total monosaccharides — glucose, xylose and arabinose, among all experimentally prepared hydrolysates. This corresponds to basic conditions for fine disintegration of biomass to lignocellulosic structure with good holocellulose accessibility. Particles obtained from fibreboard and particle board primarily consisting of softwood without steam explosion pretreatment provide relatively low cellulose accessibility for commercial enzymes activity while monosaccharides concentration is partly reduced because of torrefaction at high temperatures. The concentration of monosaccharides in hydrolysates was determined for original sample and each steam explosion temperature. Based on the steam explosion conditions, the effect of severity factors was investigated to find optimum pretreatment conditions to increase accessibility of softwood cellulose and hemicelluloses. The identified optimum severity factor RO = 4.09 matches the optimum steam explosion temperature of 205 °C and the residence time of 10 minutes.

New approaches in pretreatment methods of beech particles in enzymatic hydrolysis – effect of impregnation time and reactor selection

“…According to scientific papers (Demčák et al 2017;2019;Ibrahim et al 2020) it can be assumed that chemical structure of dendromass such as beech wood particles is mainly composed from cellulose, hemicelluloses and also lignin. The mentioned monosaccharides were formed just from holocellulosecellulose and hemicelluloses during enzymatic hydrolysis of pretreated waterimpregnated beech particles.…”

“…In essence, it is an optimization of the composition of input lignocellulosic raw materials. In addition, information obtained during enzymatic hydrolysis process and also from the material composition optimization can be potentially used in enzymology and in the wood processing industry (Pažitný 2019). The composition of different lignocellulosic materials may vary considerably between each other type (Jørgensen et al 2007;Joshi et al 2011;Bertero et al 2012;Hazuchová et al 2017;Kucharska et al 2018;Pažitný et al 2020b) and the chemical composition of individual wood species is variable also.…”