| 摘要 |
The present invention produces acetic acid while effectively inhibiting the concentration of hydrogen iodide in an evaporation tower (second evaporation tower) which purifies crude acetic acid by re-evaporation. An acetic acid production method comprises: an acetic acid collection step in which a volatile component, comprising at least acetic acid, methyl acetate, methyl iodide, water and hydrogen iodide, is supplied to a first evaporation tower, a first low-boiling-point component is separated, and a first liquid fluid containing mainly acetic acid is collected; and an acetic acid purification step in which the first liquid fluid is supplied to a second evaporation tower, a second low-boiling-point component is separated, and a second liquid fluid containing acetic acid is collected. In the acetic acid production method, an alkali component is added to the first liquid fluid by the following method (1) and/or (2), and a fluid to be treated containing the alkali component and the first liquid fluid is evaporated in the second evaporation tower. (1) The alkali component is added to or mixed with the first liquid fluid before being supplied to the second evaporation tower. (2) The alkali component is added to or mixed with the first liquid fluid in the second evaporation tower from the same height or above the height at which the first liquid fluid is supplied. |
