FDCA Production from Raw Sugar

The process under analysis comprises three major sections: (1) Fructose Obataining; (2) Fructose Dehydration; and (3) FDCA Production and Purification.

Fructose Obtaining. Raw sugar is diluted with a hot water stream, forming a sucrose solution that is fed to ion exchangers, yielding a solution comprising glucose and fructose, which is sent to the Glucose Isomerization reactor. In this reactor, glucose is enzymatically isomerized to fructose. The reactor effluent is routed to an evaporator to remove excess water, and then to a chromatographic separator, a set of ion exchange resins that separates fructose, directed to a crystallizer, from glucose, which is recycled to the reactor.

Fructose Dehydration. Fructose slurry form the crystallizer is dissolved in an ionic liquid and fed to the Dehydration Reactor, a heated column where it is converted to HMF. Methyl isobutyl ketone (MIBK) is fed into the reactor in counter-current mode, continuously extracting formed HMF from the reaction phase. The extractant phase is sent to HMF Separation, where MIBK is recovered to the reactor and HMF is purified, while the ionic liquid phase is routed to a column to separate water from fructose, which is recycled to the reactor.

FDCA Production and Purification. Purified HMF is mixed with acetic acid solvent and catalyst in the oxidation reactor to be converted to FDCA. This stream is filtered to recover crude FDCA. The acetic-acid-rich liquid is purified using two distillation columns. Catalyst is also recovered, but it must be reactivated before being recycled to the process. Crude FDCA is mixed with water and hydrogen in a hydrogenation reactor, where impurities are removed. The effluent from the reactor is crystallized, centrifugated and dried, and finally purified FDCA is recovered sent to storage.