Process for preparing dimethyl ether from crude methanol

摘要

The present invention relates to a process for preparing dimethyl ether from crude methanol. More particularly, this invention relates to an improved process for preparing dimethyl ether useful as a fresh fuel as well as a raw material in chemical industry with no generation of hydrocarbon as a by-product and no deactivation of a catalyst, performed in such a manner that the dehydration is carried out using as raw material crude methanol that contains water in the presence of the zeolite catalyst represented by the following formula (I), wherein hydrogen cations (H<+>) of hydrophobic zeolite in said zeolite catalyst are partially replaced with certain metal ions or ammonium ions:wherein H represents a hydrogen cation; M represents one or more cations selected from the group consisting of metal ions of IA Group, IIA Group, IB Group and IIB Group in Periodic Table and ammonium ions; n represents oxidation number of substituted cation (M); x represents mole % ranging from 10 to 90 based on the amount of hydrogen cations; and Z represehts a hydrophobic zeolite having the SiO2/Al2 O3 ratio of 20-200.