Gas stream multi-pollutants control systems and methods
In some embodiments, the invention provides systems and methods for removing carbon dioxide and/or additional components of waste gas streams, comprising contacting the waste gas stream with an aqueous solution, removing carbon dioxide and/or additional components from the waste gas stream, and containing the carbon dioxide and/or additional components, in one form or another, in a composition. In some embodiments, the composition is a precipitation material comprising carbonates, bicarbonates, or carbonates and bicarbonates. In some embodiments, the composition further comprises carbonate and/or bicarbonate co-products resulting from co-processing SOx, NOx, particulate matter, and/or certain metals. Additional waste streams such as liquid, solid, or multiphasic waste streams may be processed as well.
1. A method of treating an industrial waste gas, comprising
contacting an industrial waste gas comprising carbon dioxide and at least one other component selected from the group consisting of NOx, SOx, mercury, organic, particulate matter, and a combination thereof with an alkali to form a solution wherein the solution comprises sodium carbonate, sodium bicarbonate, or a combination thereof;
treating the solution with divalent cations to form a precipitation material comprising metastable carbonate selected from the group consisting of vaterite, aragonite, and a combination thereof and the at least one other component wherein the at least one other component is precipitated, trapped, adsorbed, or a combination thereof; and
combining the precipitation material with water to convert the metastable carbonate into stable carbonate.
2. The method of claim 1 , wherein the gas is pre-treated prior to contacting to remove particulate matter.
3. The method of claim 1 , wherein the gas is not pre-treated prior to contacting.
4. The method of claim 3 , wherein the gas comprises at least one other component, and wherein the at least one other component exits the gas and enters the liquid.
5. The method of claim 4 , wherein the at least one other component is a non-carbon dioxide acid gas.
6. The method of claim 4 , wherein the at least one other component is particulate matter.
7. The method of claim 1 , wherein the solution is a substantially clear solution.
8. The method of claim 1 , wherein the precipitation material is a slurry comprising solids and a supernatant.
9. The method of claim 8 , further comprising separating the solids from the supernatant.
10. The method of claim 9 , further comprising subjecting the solids to a carbon dioxide release protocol consisting essentially of grinding the solid such that particles of ground solid are less than 1 cm in the narrowest dimension if the particles are not already less than 1 cm in the narrowest dimension and immersing the solid in a solution having a pH between pH 4.8 and pH 5.2 and a temperature between 60 and 80° C. for 48 hours, producing no more than 5 grams carbon dioxide per 100 grams solid.
11. The method of claim 9 , further comprising subjecting the solids to a leaching process consisting essentially of
preparing 2×1 L of an extraction fluid consisting essentially of an aqueous solution of acetic acid, wherein each 1 L of the extraction fluid consists essentially of 5.7 mL acetic acid in deionized water;
grinding the solid such that particles of ground solid are less than 1 cm in the narrowest dimension if the particles are not already less than 1 cm in the narrowest dimension;
placing 100 g of the ground solid into an extraction vessel with 2 L of the extraction fluid to produce an extraction composition;
rotating the extraction vessel in an end-over-end fashion for 18±2 hours at room temperature;
filtering the extraction composition through borosilicate glass fiber with a pore size of 0.6 μm to 0.8 μm to produce a leachate; and
adjusting pH of the leachate with 1N nitric acid to a pH of pH 2 or less than pH 2,
producing a leachate comprising less than 0.2 mg/L of mercury.
12. The method of claim 11 , wherein the leaching process produces a leachate further comprising less than 5.0 mg/L arsenic, 100 mg/L barium, 1.0 mg/L cadmium, 5.0 mg/L chromium, 5.0 mg/L lead, 1.0 mg/L selenium, 5.0 mg/L silver, or a combination of the foregoing.
13. The method of claim 1 , wherein the industrial waste gas is a gas produced by power plant, chemical processing plant, mechanical processing plant, refinery, cement plant, or steel plant.
14. The method of claim 1 , wherein the alkali is sodium hydroxide.
15. The method of claim 1 , wherein the precipitation material is dried after the separation.
16. The method of claim 1 , wherein the at least one other component is mercury.
17. The method of claim 1 , wherein the at least one other component is NOx and SOx.
18. The method of claim 1 , wherein the precipitation material is dried after the formation to make supplementary cementitious material, cement, aggregate, mortar, concrete, pozzolan, or a combination thereof.
19. The method of claim 1 , wherein the at least one other component in the precipitation material is sulfate, sulfite, or a combination thereof.
20. A composition produced by the method of claim 1 .