Repetskyi I. Selective deactivating the outer surface of zeolite catalysts of isobutane with butenes alkylation

Thesis is devoted to developing of solid catalyst as potential substitute of high concentrated sulfur and fluoric acids in the isobutane with butenes alkylation processes. The main problem arising when trying such a substitution is achieving as much as possible solid catalyst work duration up to regeneration. In the work this problem has been dissolved by selective deactivating the external surface of zeolite crystals which are used as the solid alkylation catalysts. First by isomorphic aluminum by silicon substitution in the zeolite of X type, using (NH4)2SiF6 or SiCl4 as silicon-containing agents and n-tetradecane and sodium chloride as agents for blocking zeolite inner volume, the catalysts of deactivated external surface and saved high inner pore activity as well as optimal acid strength of active centers have been synthesized. Selective deactivation of external surface, lowering the formation of external surface coke essentially, ensure unimpeded access of reagents to inner pore active centers during the long time, what resulting in increasing catalyst work up to regeneration from 23 to 175 hours: today that is highest index for solid alkylation catalysts. The mechanisms of isobutane with butenes alkylation as well as of isoparaffine molecules Н/D-exchange, explaining from the non-contradictory positions newest experimental results, were proposed. Alkylation process as such is treated as proceeding two parallel competitive reactions: through isobutane protonation to expedient products without the coke formation as well as through the butenes protonation doing not exclude the coke formation. Predominance of corresponding reaction depends on catalyst nature und conditions of process realization. From the reaction mechanism, which does not need contacting the olefin molecules with the catalyst active sites, issues good outlook for solid catalyst alkylation technology. Sphere of use is oil chemistry.