Separation of cellulose from Triarrhena lutarioriparia by irradiation-assisted formic acid and characterization of its enzymatic hydrolysis

Abstract

In this study, Triarrhena lutarioriparia was irradiated by a 5 MeV electron accelerator. The effects of temperature, formic acid concentration, and absorbed dose on the separation efficiency of cellulose from Triarrhena lutarioriparia were investigated, and the separation conditions of cellulose from Triarrhena lutarioriparia were optimized by an orthogonal test. Results showed that the optimal parameters were an absorbed dose of 200 kGy, mass fraction of formic acid of 88%, oil bath temperature of 110 ℃, and reaction time of 2 h. Under these conditions, the purity of cellulose was 73.26%, and the extraction rate of cellulose was 92.99%. Under the conditions of a solid—liquid ratio of 1∶10, cellulase dosage of 15 FPU/g, enzymatic hydrolysis temperature of 50 ℃, and rotation speed of 130 r/min, an enzymatic hydrolysis reaction of Triarrhena lutarioriparia cellulose, derived from the irradiation-assisted formic acid treatment, was conducted. After 96 h, the cellulose conversion rate reached 28.43%, which was 2.43 times higher than that of the untreated raw material. Fourier transform infrared spectroscopy and X-ray diffraction showed that the structure of the separated cellulose components was intact, and the crystallinity increased significantly after treatment.

Keywords

• electron beam irradiation
• formic acid method
• triarrhena lutarioriparia cellulose
• enzymatic hydrolysis
• structural analysis