STUDIES ON A NEW CATALYTIC-SYSTEM FOR HET EROGENEOUS CARBONYLATION OFMETHANOL TO METHYL FORMATE

By using zeolite-supported alkali methoxide liquid-film catalysts, suc h as KOCH3- PEG/NaZSM-5 (or NaY), the heterogeneous catalytic carbonyl ation of methanol to methyl formate was realized in a fixed-bed contin uous flow reactor. Under the reaction conditions of 353 K, 1.0 MPa, fe edgas composition of CO/CH3OH = 6.48 (molar ratio) and GHSV = 11 160 h (-1), the STY of MF reached up to 1 900 mg/(h.g cat.), with selectivit y to MF at 100%. The experimental results indicated that methoxide ani on CH3O- was crucial catalytically active species. The role of the add itive polyethylene glycol(PEG) in generating a liquid film environment , in which the carbonylation reaction would take place, is important, especially in the case of supports with large pore-diameter as SiO2. H owever, in the case of some support materials with abundant micropore structure such as ZSM-5 or Y-type zeolite, it is probable to design an d select appropriate reaction conditions(mainly, temperature and parti al pressure of methanol in feedstream) to generate directly liquid-fil m of methanol by means of the ''capillary condensation effect'', as a consequence, addition of PEG may be cut down, or even, avoided.