面向木质纤维素水解液脱毒的新型渗透汽化膜的制备及传质机理研究

Recent years, pervaporation ushers in the new opportunities and new requirements, followed with the demand of biomass energy in the world. In the proposed project, a novel dual-way grafting modified hybrid membrane is designed to develop a cost-effective, thermal and chemical stable pervaporation membrane. In order to have both high selectivity and flux, an ultrathin mixed matrix membrane will be fabricated as the functional layer for organic separation, which is filled with modified zeolitic imidazolate frameworks ZIF-71. A dual-way grafting modified will be applied to enhance the affinity between ZIF-71and polydimethylsiloxane. Due to the stable chemical bonding between inorganic particles and polymer in the membrane, the stability of inorganic particles in the hybrid membrane will be enhanced. The separation of inhibitors will be studied, the synergistic mechanism of multicomponents on membrane permeability and selectivity will be revealed, and the mass transfer model of the hybrid membrane will be constructed to direct the screening of membrane materials and detoxification of lignocellulose hydrolyzate. The prepared hybrid membrane will be applied to the removal of the inhibitor in lignocellulose hydrolysis, and effective bioconversion of the lignocellulose will be achieved. The success of this project will be a significant progress in the research of pervaporation and will probably lead to massive application of hybrid membranes in the utilization of lignocellulose.

随着近年来世界各国对生物质能源的需求，渗透汽化技术迎来了新的机遇，同时也对膜的性能提出了新的要求。本项目提出双向接枝改性杂化膜的新概念，旨在开发一种经济、高效、稳定的有机-无机杂化膜。本课题拟采用类沸石咪唑骨架材料ZIF-71填充的聚二甲基硅氧烷作为分离层；为了克服传统杂化膜相容性差的问题，本课题将对ZIF-71和聚二甲基硅氧烷进行有机胺双向接枝改性，通过化学连接作用，增强无机颗粒与高聚物的作用力，以有效提高无机颗粒在杂化膜中的稳定性。通过探索杂化膜对抑制物的分离过程，揭示多元组分对膜渗透性和选择性的协同作用机制，构建传质模型，指导膜材料的筛选和脱毒过程。拟将制备的杂化膜应用于木质纤维素水解液抑制物的去除，实现木质纤维素的高效生物转化。本项目通过对材料的独创性设计，有助于推动渗透汽化疏水膜的广泛应用，并为渗透汽化疏水膜的研发开辟一个新的方向，具有重要的学术意义。

改善传统复合膜制备过程中有机无机界面相容性差是提高性能渗透汽化膜性能的关键，也是实现木质纤维素水解液脱毒预处理的重要保证。本项目通过对ZIF-71和聚二甲基硅氧烷进行有机胺双向接枝改性，增强了无机颗粒与高聚物的作用力，有效的提高了无机颗粒ZIF-71在杂化膜中的稳定性。通过双向接枝改性后，ZIF-71的添加量可提高到50%，通量和分离因子分别为PDMS膜的8.225倍和6.459倍。对渗透汽化复合膜传质机理和脱除木质纤维素水解液抑制物的研究，渗透汽化处理21 h能够完全脱除糠醛和89.05%的乙酸，渗透处理后的木质纤维素水解液用于生产乙醇，乙醇浓度、产率和木质纤维素转化率都得到提高，实现了木质纤维素的高效生物转化。本项目通过对材料的独创性设计，有助于推动渗透汽化疏水膜的广泛应用，并为渗透汽化疏水膜的研发开辟一个新的方向，具有重要的学术意义。