Patent ID: 6946571
Filing Date: 2005-09-20
Classification: C07C

Abstract:
1. A method of removing at least a portion of water from moist, solid adipic acid that is obtained from solid-liquid separation of an adipic acid solution, the moist, solid adipic acid comprising adipic acid and water to produce a hot, dry adipic acid, said method comprising: contacting the moist, solid adipic acid with a gas that does not react with adipic acid or water, in a succession of stages beginning with a first stage and terminating with a final stage, in which the moist, solid adipic acid is dried in the first stage by contacting the moist, solid adipic acid with the gas at a temperature in the range of 70 to 110 degrees C. to produce a partially-dried solid adipic acid, and, in at least one stage after the first stage, contacting the partially-dried solid adipic acid with the gas at a temperature in the range of 100 to 150 degrees C., the temperature in the first stage being lower than the temperature of any of said stages subsequent to said first stage.