Mild hydrogenation of bio-oil and its derived phenolic monomers over Pt–Ni bimetal-based catalysts
Mild hydrogenation of bio-oil and its derived phenolic monomers over Pt–Ni bimetal-based catalysts
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DOI：
10.1016/j.apenergy.2020.115154
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发表时间：
2020-10
期刊：
影响因子：
11.2
通讯作者：
Xing Zhang;Kaige Wang;Jun-hao Chen;Lingjun Zhu;Shurong Wang
中科院分区：
文献类型：
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作者：
Xing Zhang;Kaige Wang;Jun-hao Chen;Lingjun Zhu;Shurong Wang
已知生物油中酚类化合物的温和预氢化可有效减轻裂化催化剂表面上发生的严重焦化。本研究研究了酚类单体（即，苯酚、邻苯二酚和愈创木酚）在不同Ni/Pt比下在Pt-Ni/SiO2上的催化活性。结果表明，在Pt-Ni/SiO2催化剂上，芳环优先加氢，而Caryl-OR键有轻微的氢解。所制备的Pt-Ni/SiO2催化剂不仅使Pt和Ni物种在SiO2上具有良好的分散性，而且促进了H2的自发解离和生成的H原子在Pt-Ni/SiO2上的容易扩散，从而有助于其显著的催化性能。优化后的3 Pt 6 Ni/SiO2催化剂不仅实现了66%-99%的高苯酚转化率和80%的高液体产物收率，而且显著抑制了产物导致气体形成的副反应。此外，在24小时内稳定的苯酚转化率约为80%，表明3 Pt 6 Ni/SiO2具有优异的上级稳定性。随后，对加氢生物油的催化裂化进行了研究。结果表明，温和加氢有利于低碳烯烃中间体的形成和芳构化，从而增加单环芳烃的生成。生物油馏分的油相产率为38.6%，完全包含烃，其中82.2%是单环芳烃。因此，本研究提供了一个有前途的方法，转化生物油中的酚类化合物的高度加氢产物，这是准备为后续的催化裂化。
Mild prehydrogenation of phenolics in bio-oil is known to effectively alleviate the severe coking that occurs on the surface of the cracking catalysts. This study investigated the hydrogenation of phenolic monomers (i.e., phenol, catechol, and guaiacol) over Pt–Ni/SiO2at different Ni/Pt ratios. The results show that the hydrogenation of aromatic rings preferentially occurred over the Pt–Ni/SiO2catalyst, with a slight hydrogenolysis of the Caryl–OR bond. The prepared Pt–Ni/SiO2catalysts not only offered a good dispersion of the Pt and Ni species on SiO2, but also promoted spontaneous dissociation of H2and facile diffusion of the resulting H atoms on Pt–Ni/SiO2, thereby contributing to its remarkable catalytic performance. The optimized 3Pt6Ni/SiO2catalyst not only achieved a high phenolic conversion of 66%−99% and a high liquid product yield of 80%, but also significantly inhibited the side reaction of the products leading to gas formation. Furthermore, a stable phenolic conversion of ~80% within 24 h indicates the superior stability of 3Pt6Ni/SiO2. Subsequently, catalytic cracking of the hydrotreated bio-oil was investigated. The results indicate that mild hydrogenation benefits the formation and aromatization of light olefin intermediates, leading to increased formation of monocyclic aromatic hydrocarbons. The oil phase yield of the bio-oil fraction was 38.6%, comprising entirely hydrocarbons, of which 82.2% were monocyclic aromatic hydrocarbons. Hence, this study provides a promising approach for converting the phenolics in bio-oil into highly hydrogenated products, which are ready for the subsequent catalytic cracking.