Physicochemical characterizations and desulfurization properties in coal combustion of three calcium and sodium industrial wastes
- Zhejiang University, Hangzhou (China). State Key Laboratory of Clean Energy Utilization
To recycle industrial wastes and reduce SO{sub 2} pollutant emission in coal combustion, the mineralogical compositions, porosity structures, surface morphologies, and desulfurization properties of three calcium and sodium industrial wastes were investigated via X-ray diffraction (XRD), porosimeter, scanning electron microscopy (SEM), and a fixed-bed reactor. (1) White lime mud (WLM) mainly composed of CaCO{sub 3} with Na{sub 2}O and K{sub 2}O impurities has smaller CaCO{sub 3} particles and a higher surface area than limestone. But calcined WLM has larger CaO particles and a lower surface area than limestone calcined at 1200{sup o}C for 300 s. (2) Calcium carbide residue (CCR) mainly composed of Ca(OH)2, has the highest surface area and smaller Ca(OH){sub 2} particles than the CaCO{sub 3} particles in WLM. Its surface area monotonously and dramatically decreases at 1200{sup o}C for 300 s, but the sintered CaO particles are still smaller than those in the limestone. (3) When brine sludge (BS), mainly composed of NaCl and CaCO{sub 3}, is heated at 1200{sup o}C for 300 s, the NaCl/CaO eutectic solvent facilitates the aggregation of some complex composites to form many larger particles. (4) WLM gives the highest desulfurization efficiency of 80.4% at 1000{sup o}C and 65.0% at 1100{sup o}C in coal combustion. Combined CCR and limestone give a synergistic desulfurization efficiency of 45.8% at 1200{sup o}C. BS with a molar ratio of Na/Ca at 1:15 effectively promotes the synergistic desulfurization efficiency of combined CCR and limestone to a peak of 54.9% at 1200{sup o}C. 23 refs., 10 figs., 3 tabs.
- OSTI ID:
- 21261537
- Journal Information:
- Energy and Fuels, Vol. 23, Issue 5; ISSN 0887-0624
- Country of Publication:
- United States
- Language:
- English
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