泡沫陶瓷纳米催化剂体系的构筑及其催化部分氧化生物质焦油制氢机理研究

The problem of tars in the process of pyrolysis and gasification has become a bottleneck and affected its industrial applications. However, the low tars removal efficiency and carbon deposition on catalyst in the purification of gasification produce gas are currently the major problems that restrict its practical application. Traditional catalysis method can improve the decomposition of tars and enhance the removal efficiency, however, its low removal efficiency, low desistance to carbon deposition and low H2 production are the key technical barrier, and this disadvantage limited the development of tars removal in gasification and pyrolysis. In the project, Nanocatalysts based modified foam ceramic are utilized for tars catalytic decomposing for hydrogen production. The intrinsic mechanism of catalyst structural characteristics and surface properties affect the reaction activity and H2 selectivity was clarified. Partial oxidization approach will be introduced in area of in situ reactivation of catalysts. It can provide catalysts long-time activity with tars high cracking capability. Therefore, it is reasonable to expect that the nanocatalysts based foam ceramic combined with partial oxidization approach can carry out good performance in both tars decomposition and hydrogen production. The results are significant for the design and preparation of modified foam ceramic nanocatalysts, partial catalytic oxidation control method, hydrogen selection and coking resistance and their application in the themochemical treatment.

气化热解过程存在的焦油问题是影响其产业化应用的瓶颈，如何提高焦油的高效去除及催化剂易积碳等问题是其面临的主要科学问题。传统催化法虽然能够有效分解焦油组分，但是因其存在转化率较低以及催化剂抗积炭性差、易失活、氢产率低等问题，限制了其在气化热解领域的应用。本研究提出构建以改性泡沫陶瓷为载体的纳米催化材料，阐明催化剂结构特性与表面性质影响反应活性和H2选择性的内在机制；以部分氧化的方法实现对焦油组分的催化产氢以及催化剂的原位再生，在确保焦油有效分解转化的前提下，能够充分保证催化剂对焦油的长效催化。拟开展的研究工作对开发改性泡沫陶瓷纳米催化剂的制备，研究纳米催化剂的氢选择性与抗积炭性能，深入了解部分氧化控制策略和焦油转化与产氢机制，并探索其在气化热解领域的应用途径具有指导意义。

气化热解过程存在的焦油问题是影响其产业化应用的瓶颈，如何提高焦油的高效去除及催化剂易积碳等问题是其面临的主要科学问题。传统催化法虽然能够有效分解焦油组分，但是因其存在转化率较低以及催化剂抗积炭性差、易失活、氢产率低等问题，限制了其在气化热解领域的应用。本项目主要围绕构建改性泡沫陶瓷为载体的纳米催化材料开展生物质焦油的催化产氢研究。在实现对泡沫陶瓷的改性基础上，利用浸渍法、溶胶法、共沉淀法等催化剂制备方法，成果制备了纳米催化剂。在煅烧温度为700 ℃，催化剂负载量为3.50±0.2%时，生物质焦油催化氢产量在95.87-97.74 g H2/kg tar之间，制得的泡沫陶瓷催化剂对焦油催化重整反应具有较高的活性和稳定性。研究了生物质焦油部分氧化催化产氢性能，获得焦油转化氢气的最佳工艺参数，揭示了焦油催化产氢机理。在反应温度为500-900 ℃，S/C比为0-4时，ER为0时，氢产量在28.29-105.28 g H2/kg tar之间。但随着空气当量的增加，氢产量不断下降。经过氧化再生过程中催化剂仍保持较高的活性。对生物质焦油和重整油的分析表明，催化剂活性组分镍促进了链烃化合物和苯环支链上C-C键、C-O键断裂以及杂环类化合物发生开环反应。研究了焦油模拟物的催化产氢性能，对比研究了不同质量空速比的焦油模拟物的催化产氢的影响，焦油催化氢转化率达到92.5%，生物质焦油催化产氢转化效果非常显著。本项目的研究，对发展新型纳米催化材料的制备技术，焦油类物质的高效去除与催化转化，以及生物质的热化学转化与有机固体废物的热解气化方面具有重要的应用前景。