Mixed-Template Synthesis of Nanostructured CoAPSO-34 Catalyst Using TEA-DEA-MOR for Methanol to Light Olefins Conversion

Over the recent decades the conversion of methanol to light olefins (MTO) has drawn a remarkable attention due to the industrial interest as it reduces the dependency on petroleum naphtha to produce the highly desired ethene and propene derived products. The silicoaluminophosphate SAPO-34 was reported to be the most promising catalyst giving maximum light olefins selectivity. Applying mixed templates compared to those prepared with single template resulted in enhancement of catalyst life time and simultaneously causing the reduction in catalyst preparation costs. Current research was focused on the synthesis of nanostructured CoAPSO-34 catalysts with various mixtures of templates excluding expensive TEAOH template. Three sets of mixed templates are taken in to account for CoAPSO-34 synthesis, being TEA/DEA, TEA/morpholine and DEA/morpholine with constant composition of 50%:50%. The catalysts were prepared via hydrothermal method and characterized with XRD, FESEM and FTIR techniques. The nanostructured catalyst synthesized with DEA/morpholine mixture exhibits the highest crystallinity evidenced by the XRD analysis. The FESEM results indicated that the nature of the template determines the morphology of nanostructured CoAPSO-34 catalyst due to different rate of crystal growth. The methanol to light olefins reaction were carried out using constant feed ratio and gas hourly space velocity (GHSV) at different reaction temperatures to identify the influence of reaction temperature. The stability test was conducted maintaining at constant temperature, molar feed ratio and GHSV to distinguish the effect of time on stream performance

Keywords:

Methanol , Olefins , MTO , CoAPSO-34 , Mixed Template