One-step MIBK synthesis from 2-propanol: Catalyst and reaction condition optimization

G. TORRES; C.R. APESTEGUÍA; J.I. DI COSIMO

APPLIED CATALYSIS A-GENERAL

Elsevier

Año: 2007 vol. 317 p. 161 - 170

0926-860X

A gas-phase process for methyl isobutyl ketone (MIBK) synthesis from 2-propanol in one-pot is studied as an alternative to the conventional technology for producing MIBK from acetone (DMK). Bifunctional copper/acid–base catalysts able to operate at mild temperatures and atmospheric pressurewere prepared and characterized by measuring the acid and base properties aswell as the metal dispersion. It was found thata Cu-Mg-Al mixed oxide catalyst gives high MIBK yields. In this catalyst, the metal fraction in loadings of 2–6 wt% promotes the ydrodehydrogenation steps at high rates whereas the surface acid–base sites of moderate acid and base properties favor the aldol condensation reaction. The effect of different operational conditions such as reaction temperature and reactant partial pressure was also investigated. The MIBKformation rate was enhanced by increasing 2-propanol partial pressure in a wide range, consistently with a positive 2-propanol reaction order in the overall kinetics whereas the presence of hydrogen in the reactant mixture inhibited MIBK synthesis due to a negative order with respect to H2. An increase of the reaction temperature and the use of inert atmosphere improved the MIBK yield. By operation at 533 K in N2 the Cu-Mg-Al catalyst with 6.4 wt% Cu, yields 27% MIBK in comparison to the 30% typically obtained in current commercial liquid-phase high-pressure processes from DMK.