US 7,544,338 B2
Mercury removal system and mercury removal process
Shintaro Honjo, Hiroshima-ken (Japan); Kenichi Okada, Hiroshima-ken (Japan); Susumu Okino, Hiroshima-ken (Japan); Yasuhiro Takeuchi, Hiroshima-ken (Japan); Satoru Sugita, Hiroshima-ken (Japan); and Yoshio Nakayama, Hiroshima-ken (Japan)
Assigned to Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)
Filed on Dec. 12, 2006, as Appl. No. 11/609,867.
Claims priority of application No. 2005-367344 (JP), filed on Dec. 21, 2005.
Prior Publication US 2007/0202020 A1, Aug. 30, 2007
Int. Cl. B01D 53/50 (2006.01); B01D 53/56 (2006.01); B01D 53/64 (2006.01); B01D 53/74 (2006.01); B01D 53/78 (2006.01); G05D 7/00 (2006.01)
U.S. Cl. 423—210  [423/239.1; 423/242.1; 423/243.08; 423/DIG. 5; 422/168; 422/169; 422/170; 422/171; 422/180; 422/105; 422/108; 422/111] 11 Claims
OG exemplary drawing
 
1. A process for removing mercury from a mercury-containing exhaust gas containing nitrogen oxides, sulfur oxides and mercury, which comprises:
feeding a mercury chlorinating agent to a flue exhaust gas containing nitrogen oxide, sulfur oxide and mercury;
carrying out reductive denitration in the presence of a solid catalyst; and
desulfurizing in wet process with an alkaline absorbing solution,
wherein the step of feeding a mercury chlorinating agent further comprises a step of:
gasifying a non-gaseous agent for mercury chlorination which is in the non-gaseous form at normal temperature and normal pressure prior to the feed into the flue;
measuring the concentration of the gaseous agent for mercury chlorination upstream of a desulfurization unit in the flue;
calculating an initial concentration of the gaseous agent for mercury chlorination to be fed by a mercury chlorinating agent feed unit based on the measured concentration of the gaseous agent for mercury chlorination; and
controlling an amount of the non-gaseous agent for mercury chlorination to be fed into the flue based on the calculated initial concentration.