Patent ID: 6896858
Filing Date: 2005-05-24
Classification: B01D,B01J,C01F,C10K

Abstract:
1. A gas refining method for adsorbing a reducing gas obtained by pressure gasification of coal or oil, said method comprising the steps of: providing a reducing gas stream comprising sulfur-containing compounds obtained by gasification of a coal or oil; introducing the reducing gas stream into an adsorbing and removing zone; contacting the reducing gas stream with an adsorbent contained within the adsorbing and removing zone; adsorbing the sulfur-containing compounds onto the adsorbent in said zone; introducing a first oxygen-containing gas stream into the adsorbing and removing zone; contacting the first oxygen-containing gas stream with the adsorbent having sulfur compounds absorbed thereon to form a regeneration gas containing sulfur dioxide; bringing the regeneration gas, a second oxygen-containing gas stream, and a calcium-containing liquid slurry stream into gas-liquid contact in a second zone to effect absorption of sulfur dioxide by said liquid slurry and precipitation of a gypsum compound selected from the group consisting of α-gypsum hemihydrate and gypsum dihydrate from said liquid slurry; and varying the temperature of the calcium-containing liquid slurry stream in said second zone between a first predetermined temperature range which causes selective precipitation of α-gypsum hemihydrate and a second predetermined temperature range which causes selective precipitation of gypsum dihydrate.