Synthesis of MTO Catalyst for Enhancement of Light Olefins Selectivity; Study the Effect of Crystallization time, Agitation and Template ratio

The silicoaluminophosphate (SAPO)-34 as the catalyst of methanol conversion to low olefins; ethylene and propylene, was synthesized using the hydrothermal method. Tetraethyl ammonium hydroxide (TEAOH) was employed as the organic template of the synthesis process at two different levels. The effect of some operational conditions such as time of synthesis and presence or absence of agitation during crystallizationhave been studied on the property of the prepared catalyst. The instrumental techniques such as BET, XRD and FT-IR were employed to characterize the synthesized samples. The catalytic performance of the samples was tested in MTO reaction and the activity of the catalyst and selectivity toward ethylene and propylene production against CO, CO2 and parafins were examined. The results revealed that crystallization accompanied by agitation during 24 hr at 200C with higher molar ratio of TEAOH could achieve to a catalyst with higher stability and higher selectivity of light olefins in MTO reaction.

Keywords:

SAPO-34 , Synthesis , MTO reaction , catalyst performance , low olefins selectivity