秸秆微波膨化中极性溶剂与木质纤维素相互作用机理研究

Despite it is prohibited by government, burning straw still occurs from time to time in vast rural areas of our country, which is not only a waste of resources but also serious pollution. It even causes haze and airport outage. Thus dealing with straw cleanly and efficiently is imminent. Crop straw is almost made up of lignocellulose. Its elements are all significant industrial chemicals. The chemical separation method makes great pollution, while the physical method is unable to process continually. They are all difficult to achieve large-scale industrial operation. Therefore, in this project, we first propose that separating lignocellulose elements with microwave puffing. Since the straw is hard to be puffed, we introduce the polar solvent into the process. With the efficiency and selectively heating characteristics of microwave, it makes the polar solvent which has been associated to the elements of the lignocellulose vaporized rapidly. It will make microwave straw puffing realized. Then the interaction forces between the various elements of the lignocellulose will be destroyed, and it will make the elements separated quickly and efficiently. Therefore, this project focuses on the fundamental research of the interaction between the polar solvent and lignocellulose. Molecular simulation, measurement and characterization of the effective permittivity will be used in the study to guide the preparation of the polar solvent to meet the requirements of the microwave puffing. Combined with multiphysics simulation and experimental verification, it will figure out the optimum conditions for microwave straw puffing. With the research of this project, it will provide a scientific basis and theoretical support for crop straw treatment cleanly, environmentally friendly and efficiently. It has a great significance to achieve our national policy of energy saving and emission reduction.

我国农村地区秸秆焚烧屡禁不止，这不仅浪费资源还严重污染环境，引起雾霾甚至机场停运。因此对秸秆清洁高效的处理迫在眉睫。农作物秸秆几乎全由木质纤维素构成，其分离产物是重要的化工原料。现有化学分离法污染大，而物理分离法很难进行连续处理，都难以实现大规模工业生产。因此本项目首次提出利用微波热处理极性溶剂与木质纤维素的混合体系，借助微波高效性、选择性加热的特点，使得已经缔合到木质纤维素各组分中的极性溶剂被迅速汽化，实现秸秆的微波膨化，破坏木质素纤维素各组分间的作用力，使其快速高效分离。为此项目将围绕极性溶剂与木质纤维素相互作用展开基础研究，采用分子模拟、等效介电常数测量与表征为研究手段，制备能满足上述微波膨化要求的极性溶剂，结合多物理场仿真计算与实验验证，得出微波膨化秸秆的最佳条件。这将为清洁、环保、高效地实现农作物秸秆处理提供科学依据和理论支持，对实现我国节能减排的战略目标具有重大意义。

我国农村地区秸秆焚烧屡禁不止，这不仅浪费资源还严重污染环境，引起雾霾甚至机场停运。因此对秸秆清洁高效的处理迫在眉睫。农作物秸秆几乎全由木质纤维素构成，其分离产物是重要的化工原料。现有化学分离法污染大，而物理分离法很难进行连续处理，都难以实现大规模工业生产。本项目利用微波热处理极性溶剂与木质纤维素的混合体系，借助微波高效性、选择性加热的特点，使得已经缔合到木质纤维素各组分中的极性溶剂被迅速汽化，实现秸秆的微波膨化，破坏木质素纤维素各组分间的作用力，使其快速高效分离。项目首先围绕极性溶剂与木质纤维素相互作用展开了基础研究，采用分子模拟、等效介电常数测量与表征为研究手段，发现微波对分子间氢键及分子团簇结构的影响，导致了有机溶剂与木质纤维素混合体系表现出显著的介电特异现象。进一步地，项目探索了木粉微波膨化的最佳条件。这将为清洁、环保、高效地实现农作物秸秆处理提供科学依据和理论支持。