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介绍了SAPO-34分子筛催化甲醇制烯烃反应时催化剂的积炭机理,催化剂物化性能、反应工艺条件对催化剂积炭行为的影响,积炭和烧炭动力学研究成果。总结显示,导致SAPO-34失活的积炭物种为蒽、菲、芘等稠环芳烃。适当降低分子筛酸密度、减小粒径,可减缓积炭失活速率。随着反应温度升高,催化剂积炭量呈指数规律增长,反应初始阶段的积碳生成速率很快,随后趋于平缓;增加剂醇比,催化剂上积炭量降低;增加原料中水含量,反应初期催化剂积炭量明显降低,但随着反应进行,水的效果逐渐减弱。积炭燃烧速率与氧气分压、催化剂积炭量成正比。对甲醇制烯烃反应过程中催化剂上的积炭问题进行系统分析,为确定催化剂改进方向,延长催化剂寿命、提高低碳烯烃选择性而合理控制反应和再生工艺条件提供依据。
The effect of catalyst coke deposition, catalyst physico-chemical properties and reaction conditions on the catalyst carbon deposition behavior, and the research results of carbon deposition and carbonization kinetics of SAPO-34 zeolite catalysts for methanol-to-olefin reaction are introduced. It is concluded that the coke species that inactivate SAPO-34 are anthracene, phenanthrene, pyrene and other polycyclic aromatic hydrocarbons. Properly reduce the molecular sieve acid density, reduce particle size, can slow down the rate of carbon deposition inactivation. With the increase of reaction temperature, the amount of coke deposition increases exponentially, and the rate of carbon deposition in the initial stage of the reaction is very fast, then tends to be gentle; the ratio of alcohol to catalyst decreases, the amount of coke deposited on the catalyst decreases, During the initial reaction, the coke deposition decreased obviously, but as the reaction proceeded, the effect of water gradually weakened. Coke combustion rate and partial pressure of oxygen, the catalyst is proportional to the amount of carbon deposition. The systematic analysis of the carbon deposition on the catalyst during the reaction of methanol to olefins was carried out to provide the basis for determining the direction of catalyst improvement, prolonging the life of the catalyst, increasing the selectivity of light olefins and rationally controlling the reaction and regeneration process conditions.