(560ha) Regeneration of Ptsoxzrti/SiO2 By Hydrogen Treatment. Part I. Spent Catalyst Characterization

PtSO4TiZr/SiO2 spent catalysts used for alkylation of isobutane with ethylene and propylene in presence of hydrogen were produced in a pilot plant and then extracted with CS2 and regenerated in hydrogen in a fluidized bed reactor at different operating conditions. Four spent, six extracted and four regenerated catalysts were obtained; spent catalyst were characterized, and alkylation activity measured was tested in a continuous stirred reactor. Solid were characterized by nitrogen adsorption, FTIR, XPS, Raman, TEM, TPO, TPR, CS2 extraction and chemical analyses to determine the characteristic of the coke. It was found that there are three different types of coke (hydrocarbons) present on spent catalysts produced during alkylation of isobutane by olefins in pilot plant; The characterization determined the average species present in these three types of cokes. The characteristic and reactivity of coke in presence of hydrogen depend of alkylation operating conditions and the number of passes through alkylation-regeneration process. The mechanism of coke formation in three active sites and the role of hydrogen is discuss based on solid characterization and DFT simulation.