Reducing methane formation in methanol to olefins reaction on metal impregnated SAPO-34 molecular sieve

摘要

SAPO-34 silicoaluminophosphate molecular sieve produces large amounts of methane at elevated temperatures in the methanol to olefins (MTO)process.This significantly reduces the lower olefins selectivity-a key factor in determining the commercial viability of this catalyst.Impregnation of the SAPO-34 molecular sieve with metal ions such as K,Cs,Pt,Ag and Ce was found to reduce the amount of methane significantly at hgiehr temperatures thereby increasing the lower olefins selectivity.This observed effect is less apparent at lower temperatures where the amount of methane formed is generally low.