水稻秸秆好氧发酵行为及其生物机械制浆性能探讨

Aerobic Fermentation Behavior and Bio-mechanical Pulping Performance of Rice Straw

对农业秸秆进行好氧发酵耦合机械解离可获取高性能纤维制纸浆模塑、纸和纸板产品,为秸秆离田高值化利用提供一条新途径。本研究采用复合菌剂(2株土芽孢杆菌(Geobacillus sp)、1株副土芽孢杆菌(Parageobacillus sp)和4株栖热菌(Thermus sp))对水稻秸秆进行堆垛发酵30 d后再进行机械解离,考察其生物机械浆的性能。研究结果显示:发酵过程呈现显著的阶段性:升温1天、高温发酵阶段10天,第12天进入降温腐熟阶段,其中高温发酵段最高温度达60.0~66.2℃。好氧发酵至第8天时,固体物料得率为71.22%,与未发酵处理的纤维物料相比,发酵8天物料解离后纤维保水值达到1.95,增加18.56%,平均纤维长度为0.639 mm,增加2.73%,浆料抗张指数(8.51 N·m/g)、撕裂指数(9.2 mN·m^(2)/g)和耐破指数(0.72 kPa·m^(2)/g)分别增加15.15%、9.52%和10.77%。水稻秸秆升温和高温发酵阶段主要物质损失来自半纤维素和纤维素,木质素降解较为缓慢,其中半纤维素和纤维素的快速降解为堆体快速升温和高温提供了主要的碳源和热量。综合考虑发酵得率及纤维浆料的强度性能,水稻秸秆的发酵时间宜控制在8天以内。

The high-performance fiber for pulp molding,paper and paperboard products could be obtained by aerobic fermentation coupling with mechanical dissociation from agricultural straw,which would provide a new way for the high-value utilization of straw from the field.In this study,the properties of bio-mechanical pulp of rice straw were investigated by mechanical dissociation after 30 days of stacking and fermentation with composited microbials(2 Geobacillus sp,1 Parageobacillus sp and 4 Thermos sp).The results showed that the fermentation exhibited staged processes:1 day of warming,10 days of high temperature fermentation stage,and 12 days of cooling and decomposition,where the highest temperature of the fermentation reached 60.0-66.2 ℃.After 8 days of aerobic fermentation,the yield of fermented materials was 71.22%.Compared with the non-fermented fiber material,the water retention value(1.95) of the fiber after 8 days fermentation increased by 18.56%,the average fiber length(0.639 mm) increased by 2.73%,and the tensile index(8.51 N·m/g),tear index(9.2 mN·m^(2)/g) and break resistance index(0.72 kPa·m^(2)/g) increased by 15.15%,9.52% and 10.77%,respectively.The mass losses of straw material in the heating and the high-temperature fermentation stage mainly caused by hemicellulose and cellulose,and the degradation of lignin was relatively low.The rapid degradation of hemicellulose and cellulose provided the main carbon source and heat for the rapid heating and high temperature of the compost pile.Considering the fermentation yield and strength properties of pulp fiber,the fermentation time of the straw should be controlled within 8 days.