| Regenerative, alumina-supported, copper-based sorbent/catalysts provide a promising technique for simultaneous removal of SO2 and NO x from flue gas. These sorbents can remove over 90% of SO2 and 70+% of NOx while generating no wastes, reducing energy consumption, and producing valuable by-products. The lack of a cost-effective sorbent with low attrition rate and good reactivity has been the main hurdle to commercialization of this copper oxide process. Developing such a sorbent is the focus of this dissertation.; This work examines using sol-gel techniques rather than traditional processes to produce γ-alumina and copper coated 7-alumina granular sorbents. Important modifications to the established sol-gel synthesis process were made, which minimized generated wastes and reduced preparation time and sorbent cost.{09}A laboratory scale semi-continuous process providing a basis for large-scale synthesis was developed.; The effect of the copper content on the surface area and dispersion of the active species on sol-gel-derived sorbents coated by the one step and wet-impregnation methods was studied. The sol-gel-derived sorbents showed superior sulfation and regeneration properties than the existing commercial sorbents used in the copper oxide process in terms of sulfation capacity, fast regeneration, recovery of sorption capacity, and SO2 concentration in the regenerated effluent.; The optimum temperature for NO reduction by NH3 over sol-gel-derived CuO/γ-Al2O3 was found to be 350°C for both fresh and sulfated catalysts. This was also the optimum operating temperature for simultaneous removal of SO2 and NOx from simulated flue gas. At 350°C, the adsorption capacity of the sol-gel sorbent/catalyst was higher than UOP's sorbent, and very close to the capacity of ALCOA's sorbent, while the catalytic activity for NO reduction of the sol-gel-derived CuO/γ-Al 2O3 sorbent fell between the commercial sorbents.; The new mesoporous sol-gel-derived materials showed larger surface area, better mechanical strength, and more uniform dispersion of the copper species than existing commercially available sorbents. The superior mechanical properties, better cost effectiveness, and comparable efficiency for simultaneous removal of SO2 and NOx of the sol-gel-derived CuO/γ-Al 2O3 sorbents with respect to the commercial ones make them a good option for use in the copper oxide process for combined removal of SO2 and NOx from flue gas. |
