Catalytic Hydrogenation Of Sugars

In a number of comparative hydrogenation experiments with sucrose as a raw material it is demonstrated that high yields (up to 75%) of distillable polyalcohols (mainly glycerol and 1,2-propanediol) can be obtained at moderate temperatures (200-250°) with copper chromite catalysts activated with beryllium oxide. Nickel catalysts are active even at still lower temperatures, especially in the presence of Ca(OH)2; thus 70% of distillable polyalcohols were obtained by hydrogenating sucrose in methanol in the presence of 3·5 wt.-% of Ca(OH)2 and 15% of a nickel-onkieselguhr catalyst during 105 min. at 195°. The product distribution analysis according to Weber allowed an easy comparison of the experimental results, particularly in regard to the selectivity of the applied catalysts.