New fabrication of mixed oxygen carrier for CLC: Sludge and scale from a power plant

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• 作者：Kyeongsook Kim ; Seugran Yang ; Jeom-In Baek ; Chong Kul Ryu ; Mihwa Choi ; Yinsheng He ; Keesam Shin ; Gaeho Lee
• 关键词：Chemical-looping combustion (CLC) ; Oxygen carrier (OC) ; Iron oxide ; Sludge ; Scale
• 刊名：Fuel
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：111
• 期：Complete
• 页码：496-504
• 全文大小：2370 K

文摘

After successful operation of a 200 kW gas circulating combustion system for over 100 h with NiO/Al₂O₃ oxygen carrier (OC) particles, we are ready to scale-up the process up to a 1-10 MW system. To supply large quantity of OC particles for the scaled-up system at a lower cost, iron oxides are considered as a cheaper source material of OC. Mixed NiO/Fe₂O₃/Al₂O₃ OC particles were fabricated with commercial iron oxide reagents by a spray-dryer and tested for oxygen transfer capacity (OTC) and physical/chemical properties to investigate the feasibility of mass production. While looking for cheap iron oxides from wastes or industrial products, considerable amounts of scale and sludge were found from power plants. The main component of the sludge and scale collected from power plants was more than 95 % of iron oxides and the residue was also oxides, such as MnO, SiO₂, Cr₂O₃ and CaO, which can be an active material or a binder for OC. The particle size of the sludge and scale is also suitable for the OC fabrication, eliminating the need of pre-treatment. Four different OC particles were fabricated by a spray-dryer, calcined at 1100, 1200 and 1300 ¡ãC, and their physical/chemical properties were measured. It was found that mixed NiO/Fe₂O₃/Al₂O₃ oxide carriers are good candidates for a 1-10 MW class circulation combustion of fluidized bed. The contribution of this research is that the sludge and scale collected from power plants can be used to capture CO₂ emitted from power plants.