| abstract |
The present invention relates to a process for preparing 1,2-propanediol by hydrogenation of glycerol by means of hydrogen gas, wherein glycerol is reacted with hydrogen in at least “i” fluidically interconnected reactors R 1 to R i each having a hydrogenation catalyst to form 1,2-propanediol, wherein the process comprises sequential steps from reactors R 1 through R n , wherein n as used hereinafter is an integer in the range from 2 to i. The process includes introducing hydrogen gas and a glycerol phase into the first reactor R 1 and a first 1,2-propanediol containing phase and a first hydrogen phase are formed in the reactor, and introducing sequentially the 1,2-propanediol containing phase formed in the preceding reactor and hydrogen into each of the subsequent reactors wherein the glycerol phase containing at least 60% by weight, based on the total weight of the glycerol phase of glycerol. |