Study On Saccharification Of Biomass Promoted By Integrated Wood Rot Fungi/DES Pretreatment And Thermal Conversion Of Residue

As a rich and renewable resource,lignocellulose is expected to replace the commonly used fossil raw materials for biomass energy and various chemicals.Therefore,using a variety of technical strategies to improve the efficient utilization and conversion efficiency of lignocellulosic components has become a research hotspot and focus in recent years.Based on our previous research,this paper furthermore proposes a tandem pretreatment process of wood rot fungi Deep Eutectic Solvents(DES)to further improve the enzymatic saccharification efficiency of lignocellulose.At the same time,the lignin residue is converted into high value-added bio-oil and biochar by fixed-bed pyrolysis.Below are key research findings.The effects of different wood rot fungi/ DES coupling pretreatment on the saccharification efficiency of bamboo and masson pine were clarified.Established two kinds of pretreatment techniques of white rot fungus(P.vitreus)/Choline Chloride-Lactic acid(ChCl-Lac)coupled pretreatment of bamboo and brown rot fungus(L.cremeiporu)/ ChCl-Lac coupling pretreatment of Pinus massoniana,which significantly improved the efficiency of biomass hydrolysis and saccharification was proposed.And successfully converted lignin residue into bio-oil and biochar.P.vitreus/ ChCl-Lac-100°C coupling pretreatment of bamboo,cellulase enzymatic saccharification efficiency reached 332.20 mg / g matrix,L.cremeiporu / ChCl-Lac-100 °C coupling pretreatment of masson pine,cellulase enzymatic saccharification efficiency reached 517.00 mg/g matrix,which was increased by 202.14% and 165.13% compared with the untreated bamboo and masson pine materials,indicating that the wood rot fungus/ ChCl-Lac coupling pretreatment technology can significantly increase the efficiency of enzymatic saccharification.At the same time,the enzymatic residue and the lignin residue dissolved in ChCl-Lac were subjected to thermal cracking conversion research,and the highest yield of biochar was 25%,and the yield of bio-oil was 60%.In addition,the effects of fungal pretreatment and ChCl-Lac pretreatment onstructure and morphology were investigated by Component determination,Fourier transform infrared(FT-IR),Field emission scanning electron microscopy(FESEM)and Py-GC/MS characterization techniques.It was found that the lignin component decreased after pretreatment of P.vitreus,and the absorption peak intensity of lignin decreased in FT-IR,the oxidation product of C?-OH increased in Py-GC/MS and pyrolysis oil,indicating the P.vitreus degraded part of the lignin and oxidized the lignin-C?;After the pretreatment of masson pine with L.cremeiporu,the hemicellulose and cellulose components decreased,the absorption peak intensity of lignin in FT-IR increased,and the stretching vibration of-OH group increased,and in Py-GC/MS and pyrolysis oil analysis revealed bisphenol products,indicating that the L.cremeiporu demethylated the lignin component during the pretreatment process.FESEM observation showed that after treatment with ChCl-Lac at 100 °C and 120 °C,the structure of lignocellulose became loose and dense and had obvious tear damage.Under the combined action of biodegradation and chemical reaction,the coupling pretreatment technology effectively improved the accessibility of cellulase to the substrate and improved its enzymatic hydrolysis.In summary,the proposed biomass wood rot fungus and ChCl-Lac coupling pretreatment technology,combined with cellulase hydrolysis and fixed bed thermal cracking technology,can significantly improve the efficient conversion and utilization efficiency of lignocellulose components.This provides technical support for the full utilization of a variety of biomass resources,and has a good application prospect.