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 investi gated 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 selec tivity 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 an d both intraparticle and external mass transfer resistances were negligible , but for d(P) > 3 mm, intraparticle diffusion effects were found to be imp ortant. Based on the integral reactor data, the rate equations have been pr oposed 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 reaso nably well with the predictions of a theoretical model. (C) 1999 Elsevier S cience Ltd. All rights reserved.