Acidic gas removal using dry sorbent injection
View Patent ↗A system and method for desulfurization or acidic gas removal from a hot flue gas is provided that uses a dry sorbent injection technology with downstream sorbent reproduction based on a dual-alkali process. As such, lime and flue gas carbon dioxide are used in a process to produce the dry sorbent, sodium bicarbonate.
1. A dry flue gas desulfurization system comprising:
an injector operable to inject a sorbent into a duct through which plant flue gas flows to a particulate collection device for flue gas acid gas removal by the sorbent;
filters within the particulate collection device operable to collect spent sorbent from flue gas flowing therethrough;
an alkali reactor operable for reaction of spent sorbent, lime, water and air to produce sodium hydroxide and gypsum; and
a carbon dioxide absorber operable for reaction of sodium hydroxide with flue gas carbon dioxide to produce sorbent for injection.
2. The system of claim 1 , wherein the sorbent is sodium bicarbonate.
3. The system of claim 1 , wherein the filters are fabric or electrostatic.
4. The system of claim 1 , wherein the produced sodium hydroxide and gypsum are separated in a product separator.
5. The system of claim 1 , wherein the produced sodium hydroxide and gypsum are separated in a hydrocyclone.
6. The system of claim 1 , wherein the spent sorbent is reacted with sulfuric acid prior to reaction with lime.
7. The system of claim 1 , wherein flue gas acid gas removal includes desulfurization.
8. The system of claim 1 , wherein flue gas acid gas removal includes SO 2 , SO 3 , HCl and HF.
9. A method of dry flue gas desulfurization comprising:
injecting a sorbent into a duct through which plant flue gas flows to a particulate collection device for flue gas acid gas removal by the sorbent;
collecting with filters within the particulate collection device spent sorbent from flue gas flowing therethrough;
reacting spent sorbent, lime, water and air to produce sodium hydroxide and gypsum; and
reacting sodium hydroxide with flue gas carbon dioxide to produce sorbent for injection.
10. The method of claim 9 , wherein the sorbent is sodium bicarbonate.
11. The method of claim 9 , wherein the filters are fabric or electrostatic.
12. The method of claim 9 , wherein the produced sodium hydroxide and gypsum are separated in a product separator.
13. The method of claim 9 , wherein the produced sodium hydroxide and gypsum are separated in a hydrocyclone.
14. The method of claim 9 , wherein the spent sorbent is reacted with sulfuric acid prior to reaction with lime.
15. The method of claim 9 , wherein flue gas acid gas includes SO 2 , SO 3 , HCl and HF and removal includes desulfurization.