Hydrogenation of diethyl maleate in a fixed-bed catalytic reactor: kinetics, reactor modelling and pilot plant studies

Hydrogenation of diethyl maleate using copper chromite catalyst was investigated in a fixed-bed reactor with the aim of kinetic modelling and reactor performance studies. The effect of contact time (W/F), hydrogen pressure (1-5 MPa), and feed composition on the global rate of hydrogenation and selectivity was studied. The main products formed were gamma-butyrolactone (GBL), tetrahydrofuran (THF), diethyl succinate (DES) and 1,4 butanediol (BDO), but the selectivity of THF was higher in comparison to GEL and BDO in most cases. The results at d(P) < 600 mu m were found to be in kinetic regime and both intraparticle and external mass transfer resistances were negligible, but for d(P) > 3 mm, intraparticle diffusion effects were found to be important. Based on the integral reactor data, the rate equations have been proposed for various reaction steps assuming single site L-H-type mechanism. Hydrogenation experiments were also carried out on a pilot plant scale (1.5 kg catalyst capacity) and the reactor performance was found to agree reasonably well with the predictions of a theoretical model. (C) 1999 Elsevier Science Ltd. All rights reserved.