Kinetics of hydrogenation of dimethyl 1,4‐cyclohexanedicarboxylate to 1,4‐cyclohexanedimethanol

Abstract

AbstractThe kinetics of dimethyl 1,4‐cyclohexanedicarboxylate (DMCD) hydrogenation, via the half‐hydrogenated product methyl 4‐(hydroxymethyl) cyclohexanecarboxylate (MHMCC), to 1,4‐cyclohexanedimethanol (CHDM) in gas phase was established over CuMnAl catalyst. The intrinsic kinetic experiments were carried out on a fixed‐bed reactor under a wide range of reaction conditions with temperature varied from 493 to 523 K, pressure varied from 4 to 6 MPa, and weight hourly space velocity of DMCD varied from 0.948 to 3.792 h−1. Eight rival possible two‐site LHHW models were proposed to simulate the experimental results. The model involving dissociative adsorption of esters and surface reaction as the rate‐determining step was found to fit the experimental data best. The rather large activation energy values (138.4 and 121.4 kJ·mol−1) of two reactions (DMCD to MHMCC and MHMCC to CHDM) suggest that the reactions are both temperature sensitive. The coefficients of determination (R2) for DMCD conversion and CHDM selectivity were 0.989 and 0.983 respectively. Statistical and thermodynamic test further verified the reliability of the results.