{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T11:18:53Z","timestamp":1787570333370,"version":"build-2736575974"},"reference-count":35,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T00:00:00Z","timestamp":1787529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007129","name":"Shandong Provincial Natural Science Foundation","doi-asserted-by":"publisher","award":["ZR2025QC2174Z"],"award-info":[{"award-number":["ZR2025QC2174Z"]}],"id":[{"id":"10.13039\/501100007129","id-type":"DOI","asserted-by":"publisher"}]},{"name":"CHN Energy Investment Group","award":["GDDL-24-20"],"award-info":[{"award-number":["GDDL-24-20"]}]},{"award":["GDDL-24-20"],"award-info":[{"award-number":["GDDL-24-20"]}],"id":[{"id":"https:\/\/ror.org\/01z6fgx85","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This study aims to investigate the feasibility of ethanol-digested calcium oxide (CaO-E) as a novel dechlorination sorbent for the efficient removal of hydrogen chloride (HCl) from coal-fired flue gas and further evaluate its influence on mercury speciation and transformation in flue gas, thereby addressing the low efficiency and limited multi-pollutant control capability of conventional dry dechlorination technologies. Based on a laboratory-scale injection reaction system, ethanol-digested calcium-based sorbents were injected into simulated coal-fired flue gas to systematically examine the effects of key factors, including Ca\/Cl molar ratio, SO2, and fly ash, on dechlorination efficiency. Density functional theory (DFT) calculations were further employed to elucidate the reaction mechanisms. Meanwhile, mercury-laden flue gas was introduced to investigate the removal characteristics of elemental mercury (Hg0) and oxidized mercury (Hg2+) by CaO-E. The experimental results demonstrated that ethanol-digested CaO exhibited significantly superior performance compared with untreated samples, and the formation of a porous calcium hydroxide structure was identified as the key factor responsible for its high dechlorination efficiency. When the Ca\/Cl molar ratio reached 4.0, the dechlorination efficiency could be stably maintained above 80%. SO2 showed a pronounced inhibitory effect on the dechlorination process, whereas fly ash exhibited a slight promoting effect. Mercury removal experiments revealed that CaO-E had limited removal capability toward Hg0 but effectively reduced the concentration of Hg2+. Specifically, when the Ca\/Cl molar ratios were 3 and 5, the Hg2+ concentrations decreased to 1.4 and 0.6 \u03bcg\/m3, respectively. This behavior can be attributed to the fact that Hg2+ mainly exists in chlorinated forms such as HgCl2, which possess strong polarity and can be readily adsorbed by the alkaline active sites on the CaO-E surface. In addition, as the dechlorination process proceeded, chlorine-containing species in the flue gas were gradually consumed, suppressing the oxidation conversion of Hg0 to Hg2+ and thereby further reducing the Hg2+ concentration. Theoretical calculations indicated that both HCl and SO2 could undergo chemisorption on calcium active sites, while HCl possessed a lower reaction energy barrier and therefore dominated the competitive adsorption process, exhibiting preferential reactivity. Overall, ethanol-digested calcium oxide not only demonstrates excellent HCl removal performance, but also shows the capability to regulate mercury speciation in flue gas to a certain extent, providing both theoretical insights and technical support for the synergistic control of multiple pollutants in coal-fired flue gas.<\/jats:p>","DOI":"10.3390\/ma19173588","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T10:07:53Z","timestamp":1787566073000},"page":"3588","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Characteristics of Flue Gas Dechlorination by Ethanol-Digested Calcium Oxide and Its Effect on Mercury Speciation and Concentration"],"prefix":"10.3390","volume":"19","author":[{"given":"Shuzhou","family":"Wei","sequence":"first","affiliation":[{"name":"GD Power Development Co., Ltd., Beijing 100025, China"},{"name":"Beijing Guodian Electric Power Co., Ltd., Beijing 100101, China"},{"name":"National Energy Coal-Based CCUS Technology R&D Center, Beijing 100101, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongzheng","family":"Gu","sequence":"additional","affiliation":[{"name":"GD Power Development Co., Ltd., Beijing 100025, China"},{"name":"Beijing Guodian Electric Power Co., Ltd., Beijing 100101, China"},{"name":"National Energy Coal-Based CCUS Technology R&D Center, Beijing 100101, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianshan","family":"Li","sequence":"additional","affiliation":[{"name":"CHN Sanhe Power Generation Co., Ltd., Sanhe 065201, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chengzhe","family":"Shen","sequence":"additional","affiliation":[{"name":"CHN Sanhe Power Generation Co., Ltd., Sanhe 065201, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xintong","family":"Wen","sequence":"additional","affiliation":[{"name":"CHN Sanhe Power Generation Co., Ltd., Sanhe 065201, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hailong","family":"Liu","sequence":"additional","affiliation":[{"name":"CHN Sanhe Power Generation Co., Ltd., Sanhe 065201, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tao","family":"Yang","sequence":"additional","affiliation":[{"name":"CHN Sanhe Power Generation Co., Ltd., Sanhe 065201, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunxia","family":"Shao","sequence":"additional","affiliation":[{"name":"Guoneng (Shandong) Energy and Environment Co., Ltd., Jinan 250013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2912-001X","authenticated-orcid":false,"given":"Xiaoshuo","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Information and Electronic Engineering, Shandong Technology and Business University, Yantai 264005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1021\/acs.iecr.8b03092","article-title":"Adsorption of HCl on Calcined Ca and Zn Hydrotalcite-like Compounds (HTLs) at Medium-High Temperature in Flue Gas","volume":"58","author":"Cao","year":"2019","journal-title":"Ind. 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A"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/17\/3588\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T10:19:40Z","timestamp":1787566780000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/17\/3588"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,24]]},"references-count":35,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["ma19173588"],"URL":"https:\/\/doi.org\/10.3390\/ma19173588","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,24]]}}}