process for the controlled hydrogenation of a ketosis or a ketosis-containing sugar mixture

摘要

A process for the hydrogenation of a ketose or a ketose-containing sugar mixture to produce a product mixture comprising at least two stereoisomeric sugar alcohols is disclosed. The process comprises the provision of a reaction mixture comprising said ketose or ketose-containing sugar mixture, the addition of a concentration of solid nickel-based catalyst to said reaction mixture, and conducting a hydrogenation reaction in said reaction mixture in the presence of hydrogen gas. With this process, it is possible to obtain a predefined ratio of cis-isomer to trans-isomer of the two stereoisomeric sugar alcohols. The ratio of cis-isomer to trans-isomer can be decreased by increasing the concentration of solid nickel-based catalyst, by decreasing the starting temperature of the heating step, and/or by decreasing the heating rate of the heating step.