造纸污泥基于热醇解酸催化液化的资源化及反应机制研究

Paper sludge is a major solid waste arising from wastewater treatment process of pulping and papermaking operations, and its reasonable dispose concerns sustained and sound development of the paper industry. Currently, landfills and burning remain the principal treatment approaches of paper sludge, which not only waste resources but also pollute environment. Carbohydrate, lignin and inorganic chemicals are the main constituents of paper sludge, which have potential utilization values. Thus, it is of significance to explore the reasonable resource comprehensive utilization pathway of paper sludge in the light of its chemical properties. In this project, two typical paper sludge including primary sludge and deinking sludge are selected as the study subjects to carry out the research of their resource utilization based on biorefinery using the acid-catalyzed liquefaction in high-temperature alcohols. Firstly, chemical reactivity and liquefaction mechanism in the conversion of paper sludge and its key component (i.e., celllose, hemicellulose and lignin) at various temperature and alcohol medium will be explored. Then, we will be focus on building catalytic regulation pathway for strengthening alcoholysis of organic matter in paper sludge into key high-value chemicals. On this basis, separation from the resulting product mixture and the recycling of inorganic mineral will be investigated. The research of this project will establish the academic and technological bases for the resource comprehensive utilization of paper sludge, in which the organic substances are converted into high-value chemicals and the inorganic chemicals can be recycled.

造纸污泥是制浆造纸工业废水处理过程中的大宗固体废弃物，其合理处理事关造纸工业持续健康发展。当前造纸污泥处理途径仍以填埋和焚烧为主，不仅造成资源浪费也污染环境。造纸污泥成分主要包含有碳水化合物、木质素和无机化学品等，均具潜在开发利用价值，因此根据其特性探索合理途径进行资源化利用将具多重现实意义。本项目拟选用制浆造纸工业中两种具代表性的造纸污泥（一次污泥和脱墨污泥）作为研究对象，开展其基于热醇解酸催化液化生物炼制的资源化利用研究，揭示造纸污泥及其主要有机组分（纤维素、半纤维素和木质素）在不同高温醇体系中的化学反应性及醇解液化机制；着重构建能强化造纸污泥中有机物醇解液化成主高值化学品的催化调控途径；进而探索基于此途径的产物组分分离与无机物资源化。预期研究成果可为造纸污泥中有机物转化成高值化学品和无机化学品回收的资源化综合利用奠定理论和新技术基础。

造纸污泥是制浆造纸工业废水处理过程中的大宗固体废弃物，其合理处理事关造纸工业持续健康发展。造纸污泥富含碳水化合物等有机质，探索其关键组分的资源化高效利用具有重要意义。本项目以卫生纸厂造纸污泥作为研究对象，开展了其基于热醇解酸催化液化生物炼制的资源化利用研究，并对其主要有机组分（纤维素、半纤维素和木质素）的醇解反应性及资源化利用进行了系统探索。研究表明：造纸污泥中纤维素组分在特定B酸协同L酸作用下可有效醇解选择性合成新能源化学品乙酰丙酸酯和5-乙氧甲基糠醛，收率分别可达65%和50%左右；半纤维素组分衍生物木糖和糠醛在构建的多功能催化剂作用下可整合脱水、转化加氢和醇解反应直接一锅选择性合成乙酰丙酸酯和γ-戊内酯，收率分别可达53%和86%左右；通过对比催化剂物化特性、不同底物及中间产物的反应性、溶剂的介入影响、产物组分与生成动力学情况，对以上反应过程机理进行了合理解析；基于上述热醇解酸催化液化过程，反应产物、溶剂和催化剂经固液分离、蒸馏、萃取等手段可实现有效分离与回收；造纸污泥中有机组分（如纤维素、木质素）也可用于构建新型碳基固体酸催化剂用于生物质催化转化中，有效提升了其资源化利用渠道。研究成果在国际重要学术期刊发表SIC收录论文8篇、申请受理中国发明专利5项，可为造纸污泥的资源化综合利用以及其关键组分的高值利用提供重要基础支撑，也为相关生物质资源的开发利用提供有益理论参考和技术借鉴。