Recycling of sodium hydroxide and production of gypsum from dry flue gas desulfurization

摘要

The present invention is directed towards a system that makes high quality gypsum from a dry flue gas desulfurization process which utilizes a low temperature regeneration of the carbon adsorbent in the flue gas process. The high quality gypsum is easily filterable with large crystal size and has high purity with few contaminants, such as calcium sulfite and heavy metals. This invention is also directed towards a system that regenerates the carbon used in dry flue gas desulfurization at a temperature below 120 DEG C. and the recycling of sodium hydroxide to form a sodium sulfite reducing solution for carbon adsorbent regeneration.