Study On Catalytic Hydrogenolysis Of Glycerol To Propanediol

With the bloom of bio-diesel industry, amount of glycerol influxes to the market, therefore, re-use of glycerol has become topical interest in the scientific community, and hydrogenolysis of glycerol to propanediol is the focus. It achieves good utilization of glycerol, improves the economic and cyclical of bio-diesel industry.In this paper, six factors including Cu / Cr ratio, pH, aging temperature and time, calcination temperature and time, were studied in the preparation of copper-chromium catalysts, The effect of these factors on the reaction of copper-chromium catalysts was investigated by XRD, FT-IR, TG-DTA, BET. The results showed that the domain active elements of copper-chromium catalysts were CuCr₂O₄ and CuO. Catalytic activity of copper-chromium catalysts was the best under the preparation condition of Cu / Cr ratio 0.5, pH from 5 to 5.5, aging temperature from 40 to 50℃, aging and calcination time from 3 to 4 hours, calcination temperature 300℃. The yield of propanediol was more than 36%.The studies of reaction parameters drawed that the reaction was optimized in the condition of temperature from 200 to 210℃, hydrogen pressure from 2 to 2.5 MPa, amount of catalyst from 8 % to 10 % after 24 hours. We also got that the highest selectivity of propanediol, 70.96%, was obtained when the water content of glycerol was 10%.The copper-chromium catalysts was modified by doped third metal elements. The results indicated that the effect of copper-chromium catalysts was enhanced when doped metal Mn or Ba by improving the selectivity of propanediol. The best catalytic activity was achived when the mount of MnO is 3 % under the premise of Cu / Cr ratio of 0.5 or the mount of BaO 8 % to 12 %, Cu / Cr ratio of 0.25.