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Study On Aromatization Of FCC Gasoline For Clean Oil Production

Posted on:2009-04-25Degree:MasterType:Thesis
Country:ChinaCandidate:Z F WangFull Text:PDF
GTID:2121360272987199Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
Olefin is an important component for increasing the octane number of gasoline for a long time in China. However, lower olefins content in gasoline must lead to lower octane number of gasoline, which can not meet the new standard of vehicle gasoline. Aromatization of FCC gasoline was studied in this article. Olefins content in gasoline can be reduced greatly and the octane number of gasoline can be increased at the same time. Thus, the clean gasoline fuel will be produced.Based on the study on the aromatization performance of ZSM-5, USY and matrix, ZSM-5 was selected. Effects of Zn-modification and the transference in solid phase on the aromatization performance of ZSM-5 were studied emphatically. The results showed that Zn-modified ZSM-5 can reduce olefins content in gasoline and increase the octane number of gasoline. When ZSM-5 was modified with zinc nitrate, Zn transference in solid phase occurred during calcination. The transference of Zn was unhappened when ZSM-5 was modified with zinc oxide. The effect of content of ZSM-5 and the ratio of Si/Al on gasoline properties were studied. The results showed that high content of ZSM-5 was good for reducing olefins content in gasoline and increasing the octane number of gasoline. Low ratio of Si/Al had good aromatization function. Combined with the binding agent with good abrasion index and the appropriate matrix, An additive of aromatization was developed.As we all know, high hydrogen transfer activity is good for olefins conversion in gasoline and ZSM-5 can promote the aromatization. Based on the synergetic effect of hydrogen transfer and aromatization, high hydrogen transfer activity can promote the aromatization of olefins over ZSM-5 and prohibit formation of low carbon olefins, which results the loss of octane number of gasoline. Based on above viewpoints, we choose olefin reduction B-component catalyst and utilize assembly technology of catalyst to compound two catalytic compoents having different properties in order to develope new catalyst for aromatization reaction of FCC gasoline. The hydrogen transfer reaction is assured, the aromatization of low-C olefin in gasoline is enhanced, and the hydrogen transfer, shape-selective cracking, and aromatization are organically combined together. The evaluation results of the aromatization of FCC gasoline in small fixed fluidized bed show that after the modification of aromatization, the olefin content in gasoline is decreased from 41.02 v% to 16.34v%, which decreases by 24.68%, and the aromatic hydrocarbon content is increased by 12.98%. The octane value of the gasoline is increased obviously, and the RON is increased by 3 units.The reactivities of the catalysts in aromatization of FCC gasoline were investigated, and the influences of reaction airspeed, reaction temperature, ratio of catalyst to gasoline, reaction time, reactor type, gasoline fraction cutting temperature, etc., on the properties of secondary modification product of FCC gasoline were observed.
Keywords/Search Tags:catalytic cracking gasoline, clean oil, olefin, aromatization, octane number, zeolite ZSM-5
PDF Full Text Request
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