Pretreatment Influence of an Imitative Deep Eutectic Solvent Composed of Biomass Light Oil and Choline Chloride on Boosting Selective Saccharification during Corn Stalk Pyrolysis

As a novel pretreatment method, a deepeutectic solvent (DES) can effectively deconstruct lignocellulose to promote its selective saccharification. In this research, biomass light oil (BL-oil) and choline chloride (ChCl) were employed to prepare a novel, low-cost imitative DES to boost pyrolytic saccharification of corn stalk (CS). The physical–chemical properties of original CS and pretreated samples were investigated. Furthermore, the influence of mass ratio of BL-oil and ChCl as well as pretreated temperature on pyrolytic product distribution was studied. The results showed that the imitative DES had a similar pretreated effect to commercial DESs, which can destroy the structure of CS to facilitate the degradation of hemicellulose and lignin. In addition, the imitative DES was more conducive to removal of alkali metals and alkaline earth metals. The yield of levoglucosan increased from 2.59 to 59.87 mg/g under the optimum imitative DES pretreated condition. The preparation and utilization of a biomass-derived imitative DES broadened the application of biomass pyrolysis oil and realized the “closed-loop” concept of biorefinery.