Method and apparatus for denitration and desulfurization of FCC tail gas and dedusting from FCC tail gas by ammonia-based method

摘要

The present invention discloses an apparatus and a method for denitration and desulfurization of and dust removal from an FCC tail gas by an ammonia-based process. The apparatus comprises a first-stage waste heat recovery system, a denitration system, a dust removal and desulfurization system, a tail gas exhaust system, and an ammonium sulfate post-processing system. The dust removal and desulfurization system comprises a dedusting tower and an absorption tower disposed separately. The top and the bottom of the absorption tower are connected respectively to the tail gas exhaust system and the ammonium sulfate post-processing system. The absorption tower comprises sequentially, from bottom to top, an oxidation section, an absorption section, and a fine particulate control section. The method for denitration and desulfurization of and dust removal from an FCC tail gas by an ammonia-based process is implemented with the apparatus. The method of the present invention has the advantages of no waste water discharge, no secondary pollution, synergistic control of various pollutants, recovery of sulfur dioxide by resourcelization to obtain the finished product ammonium sulfate, reduced investment and operation cost, and long-term stable operation.