초록 ▼

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 hi

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.degree. C. and the recycling of sodium hydroxide to form a sodium sulfite reducing solution for carbon adsorbent regeneration.

대표청구항 ▼

[ What is claimed:] [1.] A process for making gypsum from flue gas containing sulfur dioxide, the process comprising:removing sulfur dioxide from the flue gas by adsorption on a dry activated carbon;contacting the sulfur dioxide containing carbon With an aqueous solution of sodium sulfite and sodium

[ What is claimed:] [1.] A process for making gypsum from flue gas containing sulfur dioxide, the process comprising:removing sulfur dioxide from the flue gas by adsorption on a dry activated carbon;contacting the sulfur dioxide containing carbon With an aqueous solution of sodium sulfite and sodium hydroxide at a temperature below 120.degree. C. and a pH above 7.0 to produce an aqueous solution of sodium sulfate;admixing the solution of sodium sulfate with calcium hydroxide to form a slurry comprising water, gypsum, and sodium hydroxide, and recovering gypsum from the slurry by filtration;separating activated carbon from the aqueous solution; anddrying the activated carbon after the step of removing sulfur dioxide from the flue gas by adsorption, wherein the step of drying comprises drying the activated carbon by at least one of hot air or nitrogen;the method further comprises placing dry activated carbon in an adsorber vessel after the step of drying the activated carbon by at least one of hot air or nitrogen, wherein the dry activated carbon in the adsorber vessel is capable of use in the step of removing sulfur dioxide from the flue gas by adsorption on a dry activated carbon.