| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and apparatus for purifying a coke oven gas whereby the desulfurization efficiency can be enhanced by increasing the ammonia concentration in an absorption liquid of a desulfurization tower by using a high-concentration ammonia vapor containing no impurity. SOLUTION: This method comprises a desulfurization step having a desulfurization tower 1 using an aqueous ammonia water as an absorption liquid and a desulfurization absorption-liquid regeneration tower 2 and a deammoniation step having an ammonia absorption tower 3 using an aqueous ammonium dihydrogenphosphate solution as an absorption liquid, an ammonia stripper 4, and an ammonia distillation tower 5. A bottom liquid flowing out of the bottom of the ammonia distillation tower is indirectly heated with a bottom liquid flowing out of the bottom of the ammonia stripper to evaporate ammonia, and the resultant ammonia vapor is supplied to the desulfurization absorption-liquid regeneration tower and/or the desulfurization tower.
|
