Hydrogenation of D-mannose to D-mannite using the catalyzer Ru/MN 100

This work is devoted to the process of hydrogenation of D-mannose to D-mannitol, which is valuable raw material for food, chemical and pharmaceutical industries. Experimental data on catalytic hydrogenation of D-mannose to D-mannitol, i. e. the dependence of the substrate conversion on temperature (varied from 393 up to 493 K), partial hydrogen pressure (varied from 20 atm up to 80 atm) and concentration of D-mannose (varied from 0.1 mol/L up to 0.6 mol/L), are presented in this work. The dependence of selectivity of the catalytic hydrogenation process on the substrate conversion is also shown. Hydrogenation of D-mannose was carried out in batch reactor. Ruthenium on hypercrosslinked polystyrene (HPS) with metal content of 3% (wt.) was used as a catalyst for the hydrogenation process. The catalyst was obtained by the impregnation of HPS of MN 100 type with water soluble ruthenium salt in solvent mixture: tetrahydrofuran-methanol-water in a ratio of 4:1:1. Before the experiment, the catalyst was reduced in hydrogen flow at atmospheric pressure and temperature of 573 K. Analysis of the samples of reaction mixture was carried out by high performance liquid chromatography using the liquid chromatograph “Chromatec - Crystal HPLC 2014”. Based on the experimental data, the possibility of the use of Ru/MN 100 catalyst for the efficient hydrogenation of D-mannose was shown. The choice of “optimal” conditions of catalytic hydrogenation of D-mannose to D-mannitol based on high process selectivity at almost complete conversion (99%) of the substrate was carried out. The literature data are presented for comparison of catalytic system, ruthenium supported on TiO2 modified with nickel oxide, with the Ru/MN 100. The comparison showed the advantage of the use of Ru/MN 100 for the hydrogenation of D-mannose.