Highly Selective Hydrodecarbonylation of Oleic Acid into n‐Heptadecane over a Supported Nickel/Zinc Oxide–Alumina Catalyst
Highly Selective Hydrodecarbonylation of Oleic Acid into n‐Heptadecane over a Supported Nickel/Zinc Oxide–Alumina Catalyst
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DOI：
10.1002/cctc.201500418
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发表时间：
2015-09
期刊：
影响因子：
4.5
通讯作者：
Guangci Li;Feng Zhang;Lei Chen;Chuanhui Zhang;He Huang;Xuebing Li
中科院分区：
文献类型：
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作者：
Guangci Li;Feng Zhang;Lei Chen;Chuanhui Zhang;He Huang;Xuebing Li
通过加氢处理生产具有甘油三酯或其衍生物的第二代生物柴油被认为是制造运输燃料的有前途的方法。本研究制备了一系列负载于碱性复合氧化物（MO-Al 2 O3，M=Mg，Ca，Ni，Cu，Zn）上的Ni基催化剂，用于H2存在下油酸的催化脱氧反应。Ni/ZnO-Al 2 O3具有最高的脱氧活性和烷烃选择性，这取决于其适度的碱性。对反应条件（包括反应时间、反应温度、H2压力和Ni负载量）的研究表明，正十七烷是主要产物，并且其含量随着反应温度而增加。在油酸催化脱氧反应中，反应温度比氢气压力更重要。此外，根据硬脂酸、十八醇和硬脂酸十八酯在不同反应时间和反应速率下的产物分布，提出了油酸转化的总体反应路径，其中油酸中的氧原子主要以CO的形式通过氢化-脱氢-脱羰反应途径脱除。如果使用甘油三油酸酯代替油酸，则Ni/ZnO-Al 2 O3表现出高的加氢脱羰活性和对正十七烷的选择性。
The production of second‐generation biodiesel with triglycerides or their derivatives through hydroprocessing is considered as a promising approach to make transportation fuels. In this study, a series of Ni‐based catalysts supported on basic composite oxides (MO‐Al2O3, M=Mg, Ca, Ni, Cu, Zn) were prepared for the catalytic deoxygenation of oleic acid in the presence of H2. Ni/ZnO‐Al2O3 exhibited the highest deoxygenation activity and alkane selectivity, which depended on its moderate basicity. Investigations of the reaction conditions, which include reaction time, reaction temperature, H2 pressure, and Ni loading, suggested that n‐heptadecane was the predominant product and its content increased with reaction temperature. The reaction temperature was more important than H2 pressure in the catalytic deoxygenation of oleic acid. Additionally, the overall reaction pathways for the conversion of oleic acid were proposed based on the product distribution for different durations and reaction rates of stearic acid, 1‐octadecanol, and stearyl stearate, in which the oxygen atoms in the oleic acid were mainly removed in the form of CO through a hydrogenation–dehydrogenation–decarbonylation reaction route. If glycerol trioleate was used instead of oleic acid, Ni/ZnO‐Al2O3 exhibited a high hydrodecarbonylation activity and selectivity to n‐heptadecane.