Hydrogenation of 2-butyne-1,4-diol in supercritical carbon dioxide promoted by stainless steel reactor wall

Hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol promoted by stainless steel reactor wall has been investigated in supercritical carbon dioxide (scCO2) as well as in conventional organic solvents in the absence of catalysts at 50 °C. scCO2 was found to be an effective medium at pressures higher than supercritical region (7.3 MPa). The influence of phase behavior, pressure and reaction time has been discussed. The first step hydrogenation of butynediol (CC) to butenediol (CC) is slower but the second-step hydrogenation of butenediol (CC) to butanediol (CC) is faster in scCO2 compared with the case of ethanol.