Abstract:

The effects of acid hydrotrope(p-toluenesulfonic acid(p-TsOH)) on the fractionation of bamboo residues, and the preparation of monosaccharides, lignin nanoparticles and furfural were investigated. The physicochemical structure variations of bamboo residues before and after the pretreatment were analyzed using scanning electron microscopy(SEM), X-ray diffraction(XRD) and infrared spectroscopy(FT-IR), and the lignin nanoparticles were analyzed by transmission electron microscopy(TEM). Under the conditions of p-TsOH mass fraction of 55%, temperature of 90 ℃ and pretreatment time of 120 min, the results showed that the removal rates of xylan and lignin were 82.72% and 82.16% respectively, while the retention rate of cellulose was as high as 87.3%.The glucose yield was 96.4% after 72 h enzymatic hydrolysis. After pretreatment, the spent liquor was diluted by slowly adding water to precipitate the lignin nanoparticles(with an average particle size of 69.33 nm). The liquid after lignin precipitation was concentrated by vacuum evaporation. Furfural was then prepared by subjecting the concentrated liquid to a reactor at 170℃ for 5 min, and the yield of furfural was 78.5%. The results of mass balance demonstrated that 1 000 g dried bamboo residues could produce 426.6 g of fermentable sugars(including 390.9 g glucose and 35.7 g xylose), 217.1 g lignin nanoparticles and 85.4 g furfural.

Key words: p-toluenesulfonic acid, bamboo residues, enzymatic hydrolysis, lignin nanoparticles, furfural