Process and reactor for the preparation of hydroxymethylfurfural by transformation of a hexose, useful as an organic synthetic intermediate

摘要

Continuous preparation of hydroxymethylfurfural(HMF) by thermal transformation of an aqueous sugar solution comprising a hexose and/or an oside precursor such as saccharose. - The process is carried out in a multi-contact reactor maintained at the reaction temperature. The sugar solution is introduced in the upper part and an extraction solvent, of low water miscibility, in the lower part to dissolve the HMF and extract it from the reaction medium. In the upper part of the reactor, above the inlet for the sugar solution, an organic fraction is removed from which the HMF is extracted, and in the lower part (below the inlet for extraction solvent) an aqueous phase is removed. The reactor is designed to have internal surface elements adapted so as not to create any mechanical and/or chemical and/or electrostatic interaction with humines formed. A specific phase of humines accumulation is created in the reaction medium by a density gradient which is removed at this level. - Independent claims are also included for the reactor and the installation of the process.