Patent ID: 8545704

Claim:
A method for recovering amine from amine-containing waste water, comprising: capturing amine from amine-containing waste water with cation exchange resins; eluting the amine captured in the cation exchange resin (S 10 ) to produce an eluate stream; sensing a pH value and a conductivity value of the eluate stream; diverting the eluate stream to an amine recovery tank ( 12 ) when the eluate stream has a pH value of 8-12 and a conductivity value of 0.01-4 μs/cm indicative of a high purity amine; diverting the eluate stream to a low purity amine storage tank ( 13 ) when the eluate has a pH value not equal to 8-12 and a conductivity not equal to 0.01-4 μs/cm indicative of a low purity amine; performing distillation of the low purity amine stream at a temperature of 150° C. or lower under a pressure of 100 mmHg or lower (S 30 ) to produce a gas stream; condensing the gas stream to produce a condensate stream; sensing a pH value and a conductivity value of the condensate stream; diverting the condensate stream to the amine recovery tank ( 12 ) when the condensate stream has a pH value of 8 or higher and a conductivity value of 10 μs/cm or higher indicative of a high purity amine; and diverting the condensate stream to a water emission area when the condensate stream has a pH value of 7 or lower and a conductivity value less than 10 μs/cm indicative of water.