秸秆循环水解、超高交联吸附树脂吸附/脱附绿色制备乙酰丙酸和糠醛调控机制研究

As novel green platform chemicals, levulinic acid (LA) and furfural (FUR) were widely used in petrochemical, medicine and pesticide etc. The hydrolysis was a main technology for conversion of straw to LV and FUR. However, there were some drawbacks in the prepared from straw including heavily polluted and difficult to purify and separate. Therefore, developed an environmentally friendly recycling hydrolysis technology to prepared LV and FUR was remarkable to promote the biological refining technology. Herein, the hyper-cross-linked polymeric adsorbent resin (HPAR) with high sorption capacity and selectivity for LA and FUR, controllable surface property and porous structure were synthesized and the structure-activity relationships of the surface property, backbone and pore size distribution of HPAR on LV and FUR absorption capacity were investigated, and then explored the influence of the by-products such as carboxylic acid etc. on the LA and FUR adsorb-desorbs of HPAR in the hydrolysis process, followed by investigating the effect of carboxylic acid and other by-products on the synergic hydrolysis mechanism of lignocellulose as well as the controlling mechanism between recycling hydrolysis of lignocellulose and adsorb-desorbs of LV and FUR by HPAR. Meanwhile, the adsorption kinetics, the adsorption thermodynamics and the adsorption equilibrium model was developed. At last, an integrated technology of green recycling hydrolysis of lignocellulose and adsorb-desorbs of LV and FUR by HPAR would be established in order to developed the methods for the cleaner production of LV and FUR from lignocellulose. The project has great great significance to promote the development of biological refining industry.

乙酰丙酸和糠醛是秸秆水解生产的重要平台化合物，广泛应用于树脂、塑料、医药、农药等行业。然而，秸秆直接水解制备乙酰丙酸和糠醛存在酸废水排放量大、产物提纯困难等问题。本项目拟设计并合成一种对秸秆水解液中乙酰丙酸和糠醛具有优异选择性吸附性能且孔结构和表面性质可控的超高交联吸附树脂（HPAR），探索HPAR的表面性质、骨架结构、孔径分布等性质与其对水解液中乙酰丙酸和糠醛吸附/脱附性能之间的构效关系，阐明水解副产物羧酸等对树脂吸附/脱附乙酰丙酸和糠醛性能的竞争性吸附影响规律及羧酸对秸秆的协同水解机制，并建立相应的吸附分离数学模型，阐明秸秆稀酸水解和HPAR吸附/脱附两个过程之间相互影响及耦合机制，建立秸秆稀酸循环水解、HPAR吸附/脱附制备LA和糠醛的绿色循环水解路线，实现木质纤维素直接水解制备乙酰丙酸和糠醛工艺酸碱废水的“零排放”，对促进生物炼制行业的发展具有重要意义。

秸秆经稀酸水解可生成重要的平台化合物乙酰丙酸和糠醛，它们化学性质活泼，可以广泛应用于树脂、塑料、医药、农药等行业。本项目针对秸秆直接水解制备乙酰丙酸和糠醛存在酸废水排放量大，产物提浓、提纯困难等问题，设计并合成了聚苯乙烯类、聚丙烯酸酯类、聚丙烯酰胺类三类超高交联吸附树脂（HPAR），探究了HPAR的表面性质、孔结构、孔径分布等性质与其吸附/脱附水解液中乙酰丙酸和糠醛性能之间的“构效关系”，筛选出了对秸秆水解液中乙酰丙酸和糠醛吸附选择性好、吸附容量高的聚丙烯酰胺类HPAR。开展了色谱柱研究，构建了科学合理的数学模型，为系统的优化和放大奠定了理论基础。在此基础上，通过研究水解过程中产生的羧酸（甲酸、乙酸）及其它副产物对HPAR吸附、脱附乙酰丙酸和糠醛性能的影响规律，阐明了秸秆稀酸水解和HPAR吸附/脱附两个过程之间相互影响及绿色制备乙酰丙酸和糠醛的调控机制，并建立了秸秆稀酸循环水解、HPAR吸附/脱附制备乙酰丙酸和糠醛的绿色循环水解路线。此外，拓展了以乙酰丙酸与糠醛为原料催化加氢制备γ-戊内酯、1,4-戊二醇等化学品的研究，取得了良好的研究进展，这将为秸秆资源制备生物基化学品提供全链条的技术支撑和理论指导，对促进生物炼制行业的发展具有重要意义。在项目执行期间，共发表论文17篇（其中SCI收录论文16篇），申请发明专利7件，获得授权2件，培养研究生5名。