Single-Stage Pulping of Sugarcane Bagasse with Peracetic Acid

Abstract

Sugarcane bagasse was delignified by a single-stage peracetic acid (PAA) pulping process. It was found that temperature, pulping time, PAA loading, and liquor ratio all had very significant effects on pulp yield, kappa number (KN), degree of delignification, and holocellulose degradation. The optimum condition for single-stage PAA pulping was as follows: temperature of 75°C, PAA loading of 50%, liquor ratio of 4:1, and pulping time of 2 h. Under this condition, pulp with 53.7% yield, 11.3 kappa number, 51.12% ISO brightness, and 900 degree of polymerization were obtained. Compared with a kraft process, single-stage PAA pulping could obtain higher pulp yield and brightness, lower kappa number, and less degradation of carbohydrates. However, more chemicals were consumed in PAA pulping and the degree of polymerization of the pulp as well as some mechanical properties were a little lower than that of kraft pulp. Fourier transform infrared (FTIR) analysis indicated that PAA pulp had a lower lateral order index (LOI) and higher infrared crystallization index than kraft pulp. X-ray diffraction (XRD) analysis showed that the two pulps had similar pulp crystallinity index, and kraft pulp had a larger average crystallite size than PAA pulp.