Conversion of methanol to olefins over SAPO-34/SiO2 catalyst

SAPO-34 molecular sieves were synthesized by hydrothermal method and were characterized by means of SEM and XRD. The reactions of methanol to light olefins (MTO) on obtained molecular sieve catalyst were investigated. The effects of binder, silica sources, partial pressure of methanol and particle diameter of catalyst on performance of the catalyst in MTO were studied. There are induction periods in selectivities to light olefins at beginning of MTO. When silica sol is used as binder not only induction periods in selectivities shorten, but also selectivities themselves to light olefins increase by 1%-2%, compared with Al2O3 as binder or without any binder. Performance of catalyst is excellent when the partial pressure of methanol is less than 19 kPa, particle diameter of the catalyst is in range of 0.25-0.38 mm, and silica sol and tetraethyl orthosilicate (TEOS) are used as binder and as silica source correspondingly.