| 摘要 |
PURPOSE:To inexpensively recover formic acid as useful resources, by absorbing acidic gas in coke oven gas with waste water generated at the time of the purification of the coke oven gas to remove the same and separating a formic acid compound contained in the acidic gas absorbed solution. CONSTITUTION:The coke oven gas generated in a coke oven 1 is cooled by a primary cooler 2 and desulfurized in a desurfurization tower 3 while the absorbing solution used in removing acidic gas (H2S, HCN or CO2) in the coke oven gas is supplied to a deaidification tower 4 to separate the absorbed acidic gas. The used absorbing solution is guided to an ammonia still 5 where ammonia is separated to generate waste solution. Calcium formate is contained in this waste solution and separated by an ion exchange membrane electrodialytic apparatus 6. The absorbing solution, from which the formic acid compound was removed, is reduced in a load amount and can be stably treated in a biochemical water treatment apparatus 9. |
