FDCA Production from Glucose

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

Furans production. The glucose content of the feed is first enzymatically isomerized to fructose, and the effluent is passed through ion-exchange resins to separate unreacted glucose from the fructose. The former is recycled to the isomerization reactor and the latter is sent to the furans conversion reactor. There, crystallized fructose is solubilized with a 95 wt.% methanol aqueous solution and sulfuric acid. The reaction is conducted at 50 bars and 200ºC. Fructose is dehydrated to hydroxyl methyl furan (HMF) and, due to the excess of methanol, most HMF is converted to MMF, which is more stable than HMF.

MMF purification. The reactor effluent is then sent to a distillation system to recover the solvent and separate the MMF from other impurities. Methanol and water are recovered and returned to the furans conversion area, while methyl levulinate is recovered as a byproduct. Also, a heavies stream is recovered to be used as boiler fuel, and finally, purified MMF is recovered and directed to the FDCA production area.

FDCA production. Purified MMF 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, and purified FDCA is recovered from the solid materials. The liquid effluent is a waste stream.