Bio-Adipic Acid Production from Glucose (Chemical Catalytic Process)

The process under analysis comprises two major sections: (1) Glucaric Acid Synthesis; and (2) Adipic Acid Synthesis.

Glucaric Acid Synthesis. A glucose solution is mixed with process water and heated before being fed to the oxidation reactor. Oxygen is supplied to the reaction by feeding compressed air to the bottom of the reactor. The overhead from the reactor is fed to a knock-out drum, a liquid stream is recycled to the reactor and most of the recovered gaseous stream is recycled to the air compressor. The reactor’s bottoms product is cooled and filtered, glucaric acid is recovered as a solid and fed to rotary driers to remove water.

Adipic Acid Synthesis. Glucaric acid solids are dissolved in acetic acid and heated before being fed to the hydrodeoxygenation reactor. Glucaric acid reacts with hydrogen at high pressure yielding adipic acid and water. The reactor’s overhead stream, a hydrogen-rich stream, is partially condensed to remove light by-products that are burned as fuel, the gaseous stream is recycled to the hydrogen compressors. The reactor’s product stream is expanded in a turbo generator, producing electricity. Its low-pressure output is directed to a knock-out drum in which a hydrogen-rich gaseous phase is recovered and recycled to the hydrogen compressor and a liquid phase, composed mostly of acetic acid, water and adipic acid, is directed to a crystallizer. The output from this crude crystallizer is then filtered and fed to a rotary drier to recover crude adipic acid. The mother liquor from the filter and acetic acid evaporated from the drier are mixed and fed to an extractive distillation system to remove the water content from the acetic acid so that it can be recycled to the hydrodeoxygenation feed mixer. Crude adipic acid must still be dissolved in water and then subjected to further crystallization, filtering and drying to reach fiber grade purity.