微波膨化促蔗渣半纤维素高效分离机制与过程调控

结构致密及细胞壁屏阻效应是限制半纤维素高效分离的瓶颈所在，对薄壁细胞和纤维细胞差异化微波膨化破壁处理是实现半纤维素高效分离并掌控其性能的重要依据。通过对微波膨化处理前后纤维细胞微观孔隙结构变化、半纤维素在细胞壁微区分布的差异性和半纤维素理化性质等的研究，厘清纤维细胞壁微观结构与半纤维素溶出的关联规律；阐明微波膨化作用下细胞壁亚层中半纤维素的迁移和聚集行为，为破解纤维细胞壁的传质扩散屏阻效应提供参考。依据 Fick 扩散定律和 Arrhenius方程，测定和计算微波膨化提取过程中蔗渣半纤维素的扩散系数和活化能，建立半纤维素溶出过程的传质动力学方程和动力学模型，系统地阐述微波膨化提取过程中半纤维素的传质扩散动力学行为和溶出机制，进而实现半纤维素溶出过程的精细化调控。课题的开展可为从源头上解决半纤维素低质、低效的提取问题提供理论依据，也对提升农副产品附加值，推动区域经济发展方面具有重要意义。

The difficulty in utilization of hemicelluloses mainly rises from their intricate structure and shielding of the cell wall. The relationship between cell wall micropore structure and hemicellulose dissolution will be made clear by studying pore structure, crystallinity and physicochemical properties of hemicellulose in the process of microwave expansion. The key factors of microwave expansion promoting hemicellulose dissolution will be identified in order to establish the differential separation process of the microwave/water─microwave/ammonium carbonate expansion two-stage bagasse hemicellulose. While the promotion of microwave expansion on the migration of hemicellulose would be studied and then the key measures to break the barrier effect of cell wall diffusion will be proposed and evaluated. According to the Fick's first law of diffusion and the Arrhenius equation, the diffusion coefficient and activation energy of hemicelluloses in the process of microwave extraction will be measured and calculated, and then the hemicelluloses mass transfer kinetics equation and dynamic model of the process will be constructed. The strict regulation of microwave extraction of hemicelluloses will be made clear by the systematic study on the kinetic behavior of mass transfer diffusion and dissolution mechanism. The research could provide a theoretical basis for solving the problem of low quality and low-efficiency extraction of hemicelluloses from the origin. The results would increase the added value of the main agricultural and sideline products and promote the development of regional economic development.