Isobutane/Butene Alkylation On HPA/MCM-41 Catalyst

The alkylation of isobutane with butene produces a gasoline with a high octane number. Liquid-phase processes with concentrated sulfuric acid or hydrogenuoride as catalysts are currently being used. Replacement of the liquid catalysts by a solid acid is an important target of modern research.The solid acid catalysts which consist of heteropoly acid supported on a mesoporous melecular sieve MCM-41 have been prepared by hydrothemal methods. The structure, HPA dispersive state and acidity have been investigated by XRD, IR, TG-DTA. The results show that HPA/MCM-41 catalysts have a high acidity. HPA can exist on MCM-41 surface and retain the Keggin unit even at HPA loadings as high as 40%. The catalyst which has 40% HPA loadings is applied to the alkylation of isobutane and butene. The acidity of the catalyst depends on the temperature under nitrogen which results in the loss of crystalline water. The optimerized temperature of activation is about 250℃. Supercritical conditions clearly prolong the catalyst's life. But the selectivity of the catalyst is unsatisfactory. Product olefins are massive in the liquid. The results of in-situ FT-IR point out that why the product distribution on this catalyst.