Patent ID: 7164044

Claim:
A process for producing a trialkanolamine having an APHA of not more than 40, comprising: producing a mixed alkanolamine by (1) a reaction of an alkylene oxide with liquid ammonia in the presence of a zeolite catalyst or (2) a reaction of an alkylene oxide with liquid ammonia in the presence of a zeolite catalyst and a reaction of an alkylene oxide with aqueous ammonia; removing unreacted ammonia, water, a monoalkanolamine, and a dialkanolamine from the mixed alkanolamine to obtain a mixture deprived of low-boiling substances; removing a high-boiling substance, which has a boiling point higher than that of the trialkanolamine, by subjecting the mixture deprived of the low-boiling substances to vacuum distillation to obtain a distillate; and redistilling the distillate obtained by the vacuum distillation using a distillation column without a filler to obtain the trialkanolamine.