Continuous Hydrogenation of 2-Butyne-1,4-diol to 2-Butene- and Butane-1,4-diols

Abstract

Continuous catalytic hydrogenation of 2-butyne-1,4-diol (B3D) was carried out in a fixed-bed reactor over 1% Pt/CaCO3 catalyst to give 2-butene-1,4-diol (B2D) and butane-1,4-diol (B1D) without formation of any other side products. In case of continuous hydrogenation, higher selectivity (66%) to B2D could be obtained and the selectivity pattern was completely different from that found in case of batch slurry operation in which B1D selectivity was very much higher (83%) than the B2D selectivity (17%). Another interesting feature was that by varying the contact time, the selectivity to both B2D as well as B1D could be varied over a wide range which is an attractive option to obtain the desired products mix of B1D and B2D, depending on the fluctuation in the market demand. Further, a mathematical model for reactor performance was also developed on the basis of the kinetic data obtained previously in a batch slurry reactor. The predicted values of conversion, selectivity, and rate of hydrogenation were found to agree with the experimental data over a wide range of conditions.