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Wang Y, Su W, Chen J, Xing Y, Zhang H, Qian D. A review of hydrogen chloride removal from calcium- and sodium-based sorbents. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27322-5. [PMID: 37213019 DOI: 10.1007/s11356-023-27322-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/25/2023] [Indexed: 05/23/2023]
Abstract
With the steady progress of ultra-low emissions in various industries, the management of unconventional pollutants is gradually attracting attention. A such unconventional pollutant that negatively affects many different processes and pieces of equipment is hydrogen chloride (HCl). Although it has strong advantages and potential in the treatment of industrial waste gas and synthesis gas, the process technology of removing HCl by calcium- and sodium-based alkaline powder has not yet been thoroughly studied. The impact of reaction factors on the dechlorination of calcium- and sodium-based sorbents is reviewed, including temperature, particle size, and water form. The most recent developments in sodium- and calcium-based sorbents for capturing hydrogen chloride were presented, and the dechlorination capabilities of various sorbents were contrasted. In the low-temperature range, sodium-based sorbents had a stronger dechlorination impact than calcium-based sorbents. Surface chemical reactions and product layer diffusion between solid sorbents and gases are crucial mechanisms. Meanwhile, the effect of the competitive behavior of SO2 and CO2 with HCl on the dechlorination performance has been taken into account. The mechanism and necessity of selective hydrogen chloride removal are also provided and discussed, and future research directions are pointed out to provide the theoretical basis and technical reference for future industrial practical applications.
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Affiliation(s)
- Yan Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
| | - Wei Su
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
- Key Laboratory of Knowledge Automation for Industrial Processes, Ministry of Education, Beijing, 100083, People's Republic of China
| | - Jing Chen
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
| | - Hongshuo Zhang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
| | - Dayi Qian
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China.
- Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China.
- Key Laboratory of Pollutant Chemistry and Environmental Treatment, School of Chemistry and Environmental Science, Yili Normal University, Yining, China.
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Gas cyclone-liquid jet absorption separator used for treatment of tail gas containing HCl in titanium dioxide industry. Chin J Chem Eng 2022. [DOI: 10.1016/j.cjche.2021.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Usmani A, Watthaisong P, Grisdanurak N, Suthirakun S. Insight into the effect of alkali treatment on enhancing adsorptivity of activated carbon for HCl removal in H2 feedstock. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-022-02111-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AbstractThe removal of contaminated HCl gas in the petrochemical plants is essential to prevent corrosion problems, catalysts poisoning, and downstream contamination. Alkali-treated activated carbon (AC) was proposed as an effective adsorbent for HCl removal. Understanding the underlying mechanism of HCl adsorption on modified AC is key to design promising strategies for removal of HCl and other chlorinated hydrocarbon gases in the H2 feedstock. Here, a combined experimental and computational approach was used to study the role of alkali treatment on the adsorption behavior of HCl on the AC surfaces. We find that an interplay between alkali ions and oxygen-containing functional groups on the AC surface plays a crucial role in stabilizing the adsorbed HCl. The origin of such stable adsorbed configurations can be attributed to the dissociative adsorption of HCl leading to a formation of low energy species such as water, OH– and Cl– anions. These anions are electrostatically stabilized by the alkali ions resulting in a strong adsorption of −3.61 eV and −3.69 eV for Na+ and K+, respectively. Close investigation on charge analysis reveals that the epoxy functional group facilitates adsorbent-surface charge transfer where O and Cl atoms gain more charges of 0.37 e and 0.58 e which is in good correlation with the improved adsorption strength. The calculated results are consistence with the experimental observations that the Langmuir adsorptivity has been enhanced upon alkali modification. The maximum adsorption capacity of AC has been improved approximately by 4 times from 78.9 to 188.9 mg/g upon treatment.
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