Single step preparation of cetoses, preferably fructose, from sugar solutions

摘要

Process for the continuous preparation of a cetose solution, preferably cetohexose, from a sugar solution containing at least one aldose, preferably one or more aldohexose compounds, comprises: (a) adding the sugar solution continuously to at least one vertical multi-contact reactor (1) containing one or more tectosilicate or argile suitable as a heterogeneous isomerisation catalyst, which is continuously circulated inside the reactor; and (b) circulating at least one microporous solid, compatible with the isomerisation reaction conditions, from the top of the reactor downwards for carrying out selective adsorption to either adsorb aldose compounds from the sugar solution or adsorb cetose compounds from the isomerisation product. Also claimed is the apparatus for carrying out the process comprising a continuously operating vertical multi-contact reactor (1), preferably a pulsing column, used along with devices (12, 13) for maintaining two different temperatures in at least two different reactor zones (14, 15).