Effect of cobalt-60 gamma-ray irradiation on separation of components from corncob by formic acid

Corncob was irradiated to different absorbed doses (200, 400, 800 kGy) to study the effect of ⁶⁰Co γ-ray irradiation on separation of cellulose, lignin, and xylan from corncob by formic acid. The cellulose and lignin obtained were subjected to purity measurement and Fourier transform infrared (FT-IR) spectroscopy analysis. The results showed that the energy consumption in crushing corncob decreased, while the degradation degree of cellulose and xylan increased, with increasing absorbed doses. Compared with the control group (0 kGy), corncob cellulose and xylan decreased by 27.68% and 42.19% after irradiation at 800 kGy. With the increase of absorbed doses (200, 400, 800 kGy), the extraction rate of lignin had no significant change, and the extraction rate of corncob cellulose decreased, while that of xylose increased by 14.45%, 41.10%, and 58.63%, respectively; the purity of cellulose increased by 5.77%, 14.53%, and 18.51%, and that of lignin increased by 7.50%, 16.11%, and 18.79%, respectively. The results of FT-IR spectroscopy analysis showed that the cellulose crystallinity and the content of hydroxyl in lignin declined with the absorbed dose increased. It can be concluded that irradiation combined with formic acid treatment can effectively separate cellulose, lignin, and xylan from corncobs and provide technical support for efficient utilization of all components of corncob. (authors)