纳米镍和镍钴催化剂及其生物油改性机理研究

The project applied the preparation technology of nano materials to the preparation of catalyst and aimed at researching the morphology and structure of the nanocrystalline Ni and Ni-Co catalyst. The main components of bio-iol which produced from the common agricultural waste in northeast of China was analyzed, and the model of bio-oil was used in the single factor catalysis experiment to find out the law of different factors. In order to obtain high quality catalyst, the deposit morphology, microstructure, acid center, active component valence, dispersity and other properties were analyzed. The catalysis product was analyzed which not only helped analyzing the reaction mechanism, but also revealed the effect of the catalyst morphology on its catalysis performance. The relationship between catalyst structure and properties could be obtained from the macro and micro aspects. The lifetime of catalysts was tested in the catalysis experiment. The char deposition and catalyst inactivation were analyzed by characterization methods. To optimizing the experimental process, the nano catalyst technology was applied in modification of bio-oil. The mechanism was analysis to improve the comprehensive performance of nanocrystalline catalyst and provided the theory on the further developing and application of the upgrading biomass fuel.

研究。对东北地区常见农业废弃物热解液体产物生物油的主要成分进行分析，利用生物油模拟物进行单因素催化实验，明确各影响因素之间的影响规律。对催化剂表面沉积形态、显微结构、酸性中心数量、活性组分价态、分散度等特性进行表征；通过检测反应后产物分析催化剂作用机理，揭示催化剂结构形貌对其性能影响，从宏观和微观两个方面阐述结构和性能之间关系。通过催化实验考察催化剂的使用寿命，通过表征分析手段对催化剂积炭、失活原因进行分析。优化实验工艺，将纳米催化剂应用于热解生物油改性。分析机理以提高纳米催化剂的综合性能，为生物油改性液体燃料的开发和利用提供理论依据。

生物质热解后所得液体产物热解焦油，能量密度较高且富含高附加值有机物，但又因成分复杂、粘度大且腐蚀性强等因素需改性后才能利用。本项目对东北地区常见的农业废弃物松子壳、稻壳、水稻秸秆及玉米秸秆热解焦油成分进行分析，并制备Ni/HZSM-5、Ni-Co/HZSM-5、块体纳米Ni和纳米Ni-Co催化剂对四种热解焦油进行催化改性试验，通过分析催化剂结构形貌和负载量等对产物成分和性质的影响，揭示不同催化剂作用机理。研究发现Ni-Co/HZSM-5比Ni/HZSM-5催化焦油过程中更能促进烃类和酚类发生烷基化反，应生成大量的具有较高热值的烷基酚，但烃类物质含量略低。Co元素的加入不但提高了Ni的分散性，氧化物和金属单质之间的转换起到了调节催化剂B酸量和L酸含量的作用，有效提高催化剂性能。块体纳米Ni和纳米Ni-Co催化剂性能主要取决于它的粒径大小，粒径越小活性位点越多，催化性能越好。纳米颗粒表面氢原子的强相互作用使得催化剂对芳烃的环氢化反应有着更强的活性和选择性，并且对得到烃类和酮类转化的选择性更高。Ni-Co/HZSM-5和块体纳米Ni-Co催化剂催化后焦油粘度降低至360-410 mPa•s之间，pH值在3.5-4.5之间，热值达到33.45~34.67 MJ•kg-1。研究结果为生物油改性液体燃料的开发和利用提供理论依据。