Abstract
The conversion of methanol to olefins reaction has been tested over synthesized and commercial SAPO-11, where the supplied and synthesized materials inhibit different morphology, surface area, and acid sites density. The synthesized samples were synthesized with the hydrothermal method and the effect of static and rotational crystallization in a temperature range of 150 to 180 °C were investigated for prepared synthesis mixtures. All samples were characterized by PXRD, SEM, TGA, N2 physisorption, MP-AES, EDS, and CO-FTIR. The results obtained, indicated a systematic decrease in the measured diameter (µm) for the synthesized SAPO-11 aggregates. The trend was reported as a function of increased temperature under both static and rotational conditions. This screening also revealed that the most uniform SAPO-11 aggregates were obtained at high crystallization temperature. Elemental analysis showed the silicon content for the as-synthesized SAPO-11 was 10 times lower than the supplied SAPO-11. This finding was linked to the difference in catalytic activity observed between commercial SAPO-11 and synthesized SAPO-11 at 180 °C. Performance test revealed methanol to olefins conversion was feasible for both supplied and synthesized samples. The supplied SAPO-11 sample showed an initial higher methanol conversion towards hydrocarbon formation, whilst the in-house synthesized samples inhibited a similar behavior at lower conversion percentages. All tested samples obtained highest selectivities toward C5+ hydrocarbons. Nevertheless, synthesized samples proved to be more stable and selective towards the C2-C4 hydrocarbons compared to the commercial sample.