Removal of HCl in Flue Gases by Calcined Limestone at High Temperatures

Abstract

Experimental study of dry HCl removal from simulated combustion flue gases using calcined limestone (CaO) is reported. The study was conducted in a unique fixed-bed reactor coupled with an online Fourier transform infrared (FTIR) spectrometer to investigate the effects of the presence of SO 2 , CO 2 and O 2 on the chlorination reactivity of calcined limestone. The dechlorination efficiency, defined by the effluent HCl concentration, would be used to describe the HCl absorption history to gain a better understanding of the chlorination behavior. The experimental results indicated that the HCl uptake capacity remains less affected under various gas atmospheres at 650 °C although the chlorination is found to be faster when CO 2 is present. At temperatures of 750 or 850 °C, the presence of SO 2 or O 2 significantly decreases the reactivity of the calcined limestone toward HCl. The concurrent sulfation of chlorides, such as CaCl 2 •H 2 O and/or CaClOH, causes the subsequent rerelease of HCl to the gas phase, thus reducing the attainable extent of the chlorination reaction. The presence of O 2 impedes the conversion of calcined limestone to chlorides, presumably through some type of reaction involving the dechlorination of the sorbent particles.

Porous metal electrodes enable efficient electrolysis of carbon capture solutions

“…If the recovered CO 2 is to be electrolytically converted into chemicals or fuels of economic value (e.g., CO; eqn (2); Fig. 1), [2][3][4][5][6][7] the CO 2 will then need to be purified [8][9][10][11] and pressurized 12 prior to entering the electrolyser (Fig. 1).…”

A Review of Hot Gas Cleaning Techniques for Hydrogen Chloride Removal from Biomass-Derived Syngas

“…Lin et al [92] investigated the removal of dry HCl using calcined limestone, in a fixed-bed reactor, taking into account the effect of the presence of SO2, CO, and CO2 on the chlorination reactivity of calcined limestone. The study demonstrated that the adsorption of HCl is less affected under various gas atmospheres at 650 °C and the chlorination is faster when CO2 is present.…”

Field Study on the Emission Characteristics of Micro/Trace Pollutants and Their Correlations from Medical Waste Incineration

“…Figure S1 shows the stable temperatures at six online temperature-monitoring points during the test, which can well ensure the representation of our sampling results. High-sulfur-content coal was mixed with medical waste before combustion, which can benefit the stable combustion of medical waste and reduce the formation of NO x and PCDD/Fs. , Meanwhile, calcium oxide (CaO) was also added to the medical waste with a feeding rate of 40 kg/h, which can remove HCl in flue gas Table also shows the hourly emission concentration of conventional pollutants, and all of them can meet the national standard .…”

“…39,40 Meanwhile, calcium oxide (CaO) was also added to the medical waste with a feeding rate of 40 kg/h, which can remove HCl in flue gas. 41 Table 1 also shows the hourly emission concentration of conventional pollutants, and all of them can meet the national standard. 42 The detailed emission information on conventional pollutants is graphed in Figure S2.…”