Absorption behavior of chlorine and sulfur by Ca(OH)2 under simulated conditions with a fluidized bed combustor

Abstract

This study was carried out to investigate the absorption reaction of chlorine and sulfur with Ca(OH) 2 under simulated conditions related to the co-combustion of refuse-derived fuel and sewage sludge in the fluidized bed combustor, such as high temperature, moisture and a mixing of samples. The combustion experiments were carried out in an electrical furnace with PVC and sulfur powders as the waste samples. High-purity slaked lime powder was used to capture the chlorine and sulfur. The experimental results showed that the removal efficiencies of both chlorine and sulfur were over 90% when the mole ratios of Ca on Cl and S were over 2.5. Furthermore, simultaneous absorption was helpful in improving the removal efficiency of chlorine and sulfur. The presence of chlorine markedly increased the removal efficiency of sulfur. The removal efficiency of chlorine was the highest at 700°C in both independent and simultaneous absorption. The removal efficiency of sulfur increased as the temperature increased, but the removal efficiency of chlorine sharply decreased from 95 to 83% when the moisture content in gases increased from 0 to 20 vol%. These results were confirmed by the combustion test of granular CaCl 2 .

Simultaneous HCl/SO2 Capture by Calcined Limestone from Hot Gases

“…So far, a large volume of published research has been devoted to the fundamental investigation of either sulfation or chlorination; however, very few reports have discussed the simultaneous control of SO 2 and HCl at high temperatures, suggesting that this area has still not been completely explored. Even so, some reports conclude that the SO 2 retention efficiency is markedly promoted in the presence of HCl, while the concurrent chlorination reaction is suppressed. − The reason for this phenomenon is not yet clear, indicating the need for further experimental evidence and analysis. To analyze how they affect each other is important and necessary to understand the competitive mechanism between sulfation and chlorination of calcined limestone.…”

Se Capture by a CaO-ZnO Composite Sorbent during the Combustion of Se-Rich Stone Coal

“…One effective means of capturing Se during the process of stone coal combustion involves the application of a highly active sorbent material. Many solid sorbents have been used to trap Se during coal combustion, or gasification processes, including calcium-based materials, − activated carbon, , fly ash − and metals. − The calcium-based materials have shown good capabilities for SO 2 removal from flue gases in high or medium temperature ranges − and have also exhibited enormous potential for the retention of Se in flue gases produced during coal combustion. Gullett and Raghunathan produced the first study of different kinds of calcium-based materials, including hydrated lime, limestone, kaolinite, and bauxite, investigating the removal of Se in the presence of various metallic air toxins produced by upper-furnace injection .…”

Chloride Resistance of Concrete with Marine Blended Cement Using Corrosion Resistant Mineral Admixture

“…High performance admixtures have recently gained recognition as one of most practical methods for minimizing the chloride permeability of concrete structures [2,3]. In this study, the chloride resistance of MBC (marine blended cement) that includes a corrosion resistant mineral admixture in TBC concrete was evaluated using an accelerated corrosion test of reinforcement in concrete [4].…”