APPARATUS AND METHOD FOR RECOVERING OF CARBOXYLIC ACID AND REMOVING OF WATER FROM REACTOR EMISSION IN THE OXIDATION PROCESS OF AROMATIC COMPOUND BY USING ENERGY CONTRIBUTING COMBINED DISTILLATION

摘要

PURPOSE: An apparatus recovering a carboxylic acid is provided to reduce energy use for recovering the carboxylic acid by using two or more dehydration columns. CONSTITUTION: An apparatus recovering a carboxylic acid comprises as follows: a first and second dehydration column(21a,21b); a first dehydration column condenser(23a) installed in the upper downstream of the first dehydration column; a first dehydration column condensate drum transfer pump(28), and a vacuum pump(29) each of which is installed in the upper downstream of the first dehydration column; a first dehydration column reboiler(22a) and a second dehydration condenser(23b) which condenses discharged material from the first dehydration column and the second dehydration column; and a second dehydration column cooler and a second dehydration condensate drum(24) which are selectively installed; and a second dehydration reboiler(22b) installed in the second dehydration column. [Reference numerals] (A2.B2) Liquid stream with low concentration of acetic acid(concentration of acetic acid 40-70%); (C2) Gaseous stream with high concentration of acetic acid(concentration of acetic acid 70-88wt%); (D2) Collecting acetic acid(concentration:88-95wt%; (E2) Aqueous stream; (F2) Vent gas; (G2) Reflux azeotropic agent; (I2) Oil stream; (J2) Organic materials removed from water; (K2) Discharge water(concentration of acetic acid 0.01-0.05 wt%); (L2) Organic materials removed from the azeotropic agent; (M2) Azeotropic agent to be collected; (N2) Collecting aromatic compounds; (O2) Acetic acid collected in the lower part of a first dehydration column; (P2) Acetic acid discharged from the lower part of the first dehydration column; (Q2) Upper gas(vapor) of the first dehydration column; (R2) Reflux of the first dehydration column; (S2) Upper discharge liquid form the first dehydration column transferred to a second dehydration column; (T2) Upper gas(vapor) of the second dehydration column; (U2) Condensed liquid of the second dehydration column; (V2) Condensed liquid drum vent gas of the first dehydration gas