Hydrogenation process for improving yield of hydrogenated bisphenol-A-based epoxy resin

A hydrogenation process for improving yield of hydrogenated bisphenol-A-based epoxy resin, comprising steps of:

• a) providing a column-shaped hydrogenation reactor required to have a height/diameter ratio ranging between 0.4 and 3 for hydrogenating a liquid reactant placed therein and further comprise a heat exchange plate or a cooling coil for timely removing heat generated in the course of hydrogenation reaction and a gas-distributing agitator internally equipped in the reactor and comprising a hollow shaft thereof and blades at a terminal of the hollow shaft for introducing and exhausting hydrogen gas to the liquid reactant and simultaneously stirring the liquid reactant if started;
• b) introducing a liquid reactant containing bisphenol-A-based epoxy resin prepared in a solvent into the hydrogenation reactor;
• c) adding a hydrogenation catalyst selected one from ruthenium, palladium, platinum, rhodium or nickel in an amount ranging between 0.5 and 5 wt % by weight of the bisphenol-A-based epoxy resin into the liquid reactant of step b);
• d) introducing hydrogen gas having a pressure ranging between 360 and 735 lb/in2 into the hydrogenation reactor
• e) activating the gas-distributing agitator rotated in a predetermined rotation rate to have the hydrogen gas drawn into the hollow shaft of the gas-distributing agitator through gas inlets formed on the hollow shaft and located above a liquid surface of the liquid reactant, and further have the drawn hydrogen gas exhausted out through gas outlets formed on the hollow shaft and immersed in the liquid reactant, thereby the rotating blades of the gas-distributing agitator evenly distributing the exhausted hydrogen gas over the liquid reactant;
• f) performing hydrogenation reaction at a reaction temperature ranging between 80 and 90° C. for a reaction time ranging between 1 and 18 hours;
• and
• g) at completion of the hydrogenation reaction, cooling the liquid reactant to the room temperature, filtering out the catalyst and removing the solvent to obtain hydrogenated bisphenol-A-based epoxy resins with a yield ranging between 99.0 and 99.9%.