柱撑蒙脱石层间环境对煤直接液化影响与评价研究

Development of low-cost and high active new catalyst is one of the key issues for direct coal liquefaction process.The proposed multi-metal ion pillared catalyst will be made from China's large reserves, wide occurrence and cheap montmorillonite as raw materials by the purification, pretreatment and pillared processing of Fe / M (Cr, Co, Ni) composite multi-hydroxyl ions between montmorillonite silicon-oxygen tetrahedron and aluminum oxygen octahedral layers, which has a wealth of layered nanostructure and high specific surface area and catalytic activity. However, the structure and catalytic properties of pillared montmorillonite are affected by raw montmorillonite, pillared ion species and occurrence forms and montmorillonite interlayer environment, the constraints of its structure and catalytic activity is still unresolved theoretical problem. This project will investigate the influence mechanism of layer charge of montmorillonite, composite pillared ions composition and forms on structure and properties of pillared catalyst.Combined with the performance evaluation and characterization results of catalyst in coal liquefaction, it will be put forward the structure formation model, preparation mechanism and catalytic activity variation of multi-hydroxyl ions pillared montmorillonite, establishing the catalytic performance regulation theory of composite ions pillared montmorillonite, forming technical achievements with independent intellectual property rights, in order to improve the core competitiveness of China's coal liquefaction technology.

研制低成本、综合活性高的新型催化剂是目前煤直接液化工艺所面临的关键问题之一。本项目提出研究的聚合多金属离子柱撑催化剂,使用我国储量大、赋存广、廉价蒙脱土为原料，经提纯、预处理、Fe/M(Cr、Co、Ni)等复合多羟基离子柱撑在蒙脱石硅氧四面体和铝氧八面体层域间制备而成，具有丰富的层状纳米结构和高比表面积及催化活性。然而，由于柱撑蒙脱石的结构及催化性能受制于蒙脱土原料性能、柱撑离子种类及蒙脱石层间柱环境、赋存形式等，其结构和催化活性的制约因素仍是目前尚未解决的重要理论问题。本课题将系统研究蒙脱石的层面电荷、复合柱撑离子组合及其形态对柱撑催化剂结构和性能的影响机制，结合催化剂在煤液化试验中的性能评价及测试表征，提出聚合多离子柱撑蒙脱石结构形成的理论模型、制备机理和催化活性变化规律，建立起复合离子柱撑蒙脱石催化性能调控理论，形成具有自主知识产权的技术成果，提高我国煤液化技术核心竞争力。

研制低成本、催化活性高的新型催化剂一直是煤直接液化工艺所面临的关键问题之一。本项目使用我国储量大、赋存广、廉价蒙脱土为原料，进行了Fe/M（Cr、Co、Ni）复合双金属离子柱撑蒙脱石矿物的制备工艺研究，成功制备出Fe/Cr、Fe/Ni及Fe/Co三种柱撑蒙脱石。利用现代测试技术，对柱撑蒙脱石样品进行了表征分析，表明具有丰富的层状纳米结构和高比表面积及催化活性。通过褐煤液化试验，详细考察了制备的三种柱撑蒙脱石对褐煤直接液化的催化活性及对液化产物分布的影响，并分析评价了柱撑蒙脱石层间环境对煤加氢液化、催化剂热稳定性的影响，获得了提高柱撑蒙脱石催化活性、热稳定性的工艺方法。研究结果表明：在Fe/Cr柱撑蒙脱石催化剂制备过程中，引入硅溶胶有助于增大柱撑蒙脱石的层间距，提高Fe/Cr柱撑蒙脱石催化剂在煤液化过程中的热稳定性；采用十六烷基三甲基溴化铵（CTAB）对蒙脱石进行预撑处理，有利于促进Fe/Ni复合羟基离子柱化剂对蒙脱石的柱撑，并能提高柱撑蒙脱石层间距及其热稳定性，提高Fe/Ni柱撑蒙脱石的催化活性；硅烷在提高Fe/Co柱撑蒙脱石层间距、表面酸性和热稳定性方面亦起着重要作用。这些研究结果对建立多金属离子柱撑蒙脱石催化活性调控理论、形成具有自主知识产权的技术成果具有重要意义，有望开发出能实际应用于煤直接液化的新型柱撑蒙脱石催化剂及催化技术，提高我国煤液化工艺的核心竞争力。