Effects of 5-MeV electron accelerator irradiation on cycling separation of lignocellulose from Triarrhena lutarioriparia by formic acid

Abstract

The effect of 5-MeV electron accelerator irradiation of 400 kGy on the formic acid cycling separation of cellulose, lignin, and xylose from Triarrhena lutarioriparia (TL) were studied, and the enzymatic conversion rate and structural characteristics of TL cellulose were analyzed. For 400 kGy irradiated TL, the results revealed that the average purity of cellulose was 81.13% and the recovery of lignin and xylose were 28.68% and 10.16%, respectively, which were higher than those of the unirradiated sample. The recovery of cellulose, concentration of xylose, and purity of lignin increased with the increase in cycle times. The final concentration of xylose for pre- and post-irradiated TL were 31.35 mg/mL and 37.35 mg/mL, respectively, and the purity of lignin was more than 90%. Fourier transform infrared and X-ray diffraction results revealed that TL cellulose separated by formic acid were formylated and exhibited high crystallinity. The enzymatic conversion rate of TL cellulose was 54.30%–57.47% after hydrolysis for 120 h, this rate was considerably higher than that of TL. These results indicated that the formic acid recycling fractionation process could effectively separate TL lignocellulosic components, which could support its large-scale utilization.

Keywords

• electron beam irradiation
• formic acid
• cycling separation
• triarrhena lutarioriparia
• lignocellulose