不同条件下苯与丙烯烷基化反应的催化剂失活研究

对不同条件下苯与丙烯烷基化反应Hβ催化剂的寿命、失活催化剂的积炭量和积炭性质进行了研究。在5.7MPa下，随反应温度变化，反应介质在反应过程中所经历的相态变化不同，导致催化剂的寿命、失活催化剂的积炭量和积炭的性质也存在着较大差异。300℃时，反应介质处于接近于体系临界点的超临界相或高压液相状态，催化剂寿命最长，积炭量大。失活催化剂积炭的元素分析及TPO-MS表征结果发现，积炭的碳氢比与反应温度有关，温度越高，碳氢比越高；而积炭的脱炭温度与反应时间（催化剂寿命）相关，催化剂寿命越长，相应的脱炭温度也越高。

Deactivation of catalyst in benzene alkylation with propene under different reaction conditions

The deactivation of catalyst in benzene alkylation with propene over H β zeolites under different conditions was investigated. The amounts and properties of coke deposited on the spent catalysts under various reaction conditions were determined. With the change of reaction temperature from 270℃to 320℃at 5.7MPa, the reacting mixture may either lie in a phase of liquid (L) or supercritical fluid (SCF), or endure a phase variance from SCF to L, which results in different catalyst lifetimes, coke amounts and coke properties. SCF with the liquid like densities and enhanced transport properties is able to extract coke precursors in situ, thereby to prolong the catalyst life. Under the condition of 300℃and 5.7MPa, the reacting mixture was in a state of SCF or L near its critical point during the entire reaction process, and therefore the catalyst exhibits the longest life time and slowest coke deposition rate. The C/H mol ratio of the spent catalyst is related to the reaction temperature, while the burning up temperature of coke deposited in the spent catalyst increases with the prolonging of the catalyst lifetime.