Pretreatment with alkyl trimethylammonium bromide-based deep eutectic solvent cetyltrimethyl ammonium bromide/lactic acid/Al3 + benign system for the efficient production of furfural

Abstract

Furfural, which can be derived from renewable biomass, is a natural precursor for producing of drugs, biofuels, biochemicals, and polymers. This research synthesized a ternary deep eutectic solvent (DES) for the efficient conversion of rapeseed straw into furfural. The DES was firstly synthesized by mixing surfactant cetyltrimethylammonium bromide (CTAB), lactic acid (LAC) and metal chloride (AlCl 3 ), which exhibited 29.3 mN/m of surface tension and 1293.8 cp of viscosity. The CTAB/LAC/Al 3+ -water reaction system was used to transform rapeseed straw for producing furfural through a two-step reaction method, with a furfural yield reaching 71.6 %. The structure characterization alteration of rapeseed straw before and after CTAB/LAC/Al 3+ action was explored by using SEM, CLSM, BET, FT-IR and other methods. The interaction between the biomass model and solvents in the CTAB/LAC/Al 3+ -water reaction system was revealed through molecular dynamics simulation. By combining the CTAB/LAC/Al 3+ properties, chemical component changes of biomass, biomass surface and structure alterations, and molecular dynamics analysis, the catalysis mechanism for treatment and transformation of rapeseed straw into furfural was interpreted. This work involving the application of ternary DES CTAB/LAC/Al 3+ -water benign system to transformation of waste biomass provided an efficient way for production of furfural. • Acidic ternary DESs could be used to sustainably catalyze RS to synthesize FAL. • CTAB/LCA/Al 3+ eliminated considerable amounts of hemicellulose and lignin. • The furfural yield reached up to 71.6 % via a sustainable and efficient approach. • CLSM revealed the destructive effect of CTAB/LAC/Al³ ⁺ on RS cell wall and lignin. • Interaction between biomass model and CTAB/LCA/Al 3+ was revealed.

Topics & Concepts