Recovery of levoglucosan from liquid pyrolysis products of lignocellulosic biomass and using in bioethanol production

In this study, fixed bed pyrolysis of the MDF dust, which is an industrial lignocellulosic waste, obtained during furniture production and evaluation of levoglucosan existing in the liquid pyrolysis product for bioethanol production were investigated. It was obtained a liquid product that has levoglucosan content in 66,5 g/kg of concentration in the mass yield of 40 % by heating the material produced with diluted phosphoric acid pre-treatment of MDF dust at 400 °C of pyrolysis temperature in the fixed bed system. It was determined that 92,5 % of levoglucosan could be extracted to aqueous phase by using 0.25 of water: bio-oil ratio. The conversion of levoglucosan which is existing in aqueous solution to glucose was realized in the excess of 86 % by an acidic hydrolysis procedure applied in 0,54 M of H2SO4 concentration at 120 °C of temperature for 90 min. Obtained hydrolysate solution was subjected to a detoxification treatment by adding solid Ca(OH)2 in the concentration of 40 g/L to remove inhibitory substances. In addition, detoxified solution by Ca(OH)2 precipitation were subjected to advanced detoxification procedures by using of various combinations of methyl isobutyl ketone (MIBK) extraction, ethyl acetate (EA) extraction and activated carbon adsorption. The fermentation experiments were made for the solutions detoxified by using various detoxification routes with Saccharomyces cerevisiae NRRL Y-12632 strain. Maximum bioethanol production yield was obtained as 0,47 g ethanol/g glucose by using the solution prepared by successive treatments in series of Ca(OH)2 detoxification-MIBK extraction-activated carbon adsorption.