| 摘要 |
PROBLEM TO BE SOLVED: To carry out a dehydration reaction in liquid phase in high efficiency using formaldehyde, a carboxylic acid, etc., as the raw materials by using an acid-type zeolite ZSM-5 catalyst having high activity and selectivity and produced exclusively from inorganic materials by hydrothermal synthesis. SOLUTION: Dehydration reaction using one or more compounds selected from formaldehyde, carboxylic acid and alcohol is carried out in the presence of an acid-type zeolite ZSM-5 catalyst in a liquid phase at <=200 deg.C. A zeolite ZSM-5 produced exclusively from inorganic materials by hydrothermal synthesis is used as the catalyst. The catalyst can be produced by preparing a ZSM-5- forming composition of a silica source, an alumina source, an alkali metal, water and an inorganic acid such as sulfuric acid, converting the composition to zeolite ZSM-5 e.g. by the hydrothermal synthesis under autogenous pressure at 120-200 deg.C and exchanging the ion to convert the cation of ZSM-5 to proton. The dehydration reaction is preferably a reaction to synthesize methylal from formaldehyde and methanol. |
