EXCEEDING EQUILIBRIUM CONVERSION WITH A CATALYTIC MEMBRANE REACTOR FOR THE DEHYDROGENATION OF METHYLCYCLOHEXANE

A catalytic membrane reactor containing a tubular palladium-silver (Pd -Ag) membrane sealed in the centre to separate in situ the hydrogen pr oduced, was used to exceed equilibrium limitations in the dehydrogenat ion of methylcyclohexane. A sulphided, monometallic, noble metal catal yst produced higher than equilibrium yields of toluene and hydrogen fr om methylcyclohexane at economically viable throughputs. Experiments i n the membrane reactor in the temperature range of 573-673 K, pressure range of 0.5-2.0 MPa and liquid hourly space velocity range of 2-12 v olume feed/h/reactor volume showed conversions up to 4 times higher th an equilibrium values after 300 h onstream and repeated temperature cy cling. Exceeding equilibrium was due to the selective permeation of on e of the reaction products, i.e. hydrogen, through the membrane. React or axial temperature profiles for the reaction with and without a memb rane showed that the total amount of catalyst is more efficiently util ized in the membrane reactor.