{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T02:09:44Z","timestamp":1775182184283,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,2,8]],"date-time":"2023-02-08T00:00:00Z","timestamp":1675814400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["52006052"],"award-info":[{"award-number":["52006052"]}]},{"name":"National Natural Science Foundation of China","award":["52276109"],"award-info":[{"award-number":["52276109"]}]},{"name":"National Natural Science Foundation of China","award":["E2020202093"],"award-info":[{"award-number":["E2020202093"]}]},{"name":"National Natural Science Foundation of China","award":["B2020003025"],"award-info":[{"award-number":["B2020003025"]}]},{"name":"National Natural Science Foundation of China","award":["52006052"],"award-info":[{"award-number":["52006052"]}]},{"name":"National Natural Science Foundation of China","award":["52276109"],"award-info":[{"award-number":["52276109"]}]},{"name":"National Natural Science Foundation of China","award":["E2020202093"],"award-info":[{"award-number":["E2020202093"]}]},{"name":"National Natural Science Foundation of China","award":["B2020003025"],"award-info":[{"award-number":["B2020003025"]}]},{"name":"Natural Science Foundation of Hebei Province","award":["52006052"],"award-info":[{"award-number":["52006052"]}]},{"name":"Natural Science Foundation of Hebei Province","award":["52276109"],"award-info":[{"award-number":["52276109"]}]},{"name":"Natural Science Foundation of Hebei Province","award":["E2020202093"],"award-info":[{"award-number":["E2020202093"]}]},{"name":"Natural Science Foundation of Hebei Province","award":["B2020003025"],"award-info":[{"award-number":["B2020003025"]}]},{"name":"High Level Talents Funding Project of Hebei Province","award":["52006052"],"award-info":[{"award-number":["52006052"]}]},{"name":"High Level Talents Funding Project of Hebei Province","award":["52276109"],"award-info":[{"award-number":["52276109"]}]},{"name":"High Level Talents Funding Project of Hebei Province","award":["E2020202093"],"award-info":[{"award-number":["E2020202093"]}]},{"name":"High Level Talents Funding Project of Hebei Province","award":["B2020003025"],"award-info":[{"award-number":["B2020003025"]}]},{"name":"Heilongjiang Touyan Innovation Team Program","award":["52006052"],"award-info":[{"award-number":["52006052"]}]},{"name":"Heilongjiang Touyan Innovation Team Program","award":["52276109"],"award-info":[{"award-number":["52276109"]}]},{"name":"Heilongjiang Touyan Innovation Team Program","award":["E2020202093"],"award-info":[{"award-number":["E2020202093"]}]},{"name":"Heilongjiang Touyan Innovation Team Program","award":["B2020003025"],"award-info":[{"award-number":["B2020003025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The use of a coal-based energy structure generates a large amount of CO2 and NOx. The numerous emissions from these agents result in acid rain, photochemical smog, and haze. This environmental problem is considered one of the greatest challenges facing humankind in this century. Preheating combustion technology is considered an essential method for lowering the emissions of CO2 and NO. In this research, the char prepared from O2\/CO2 and O2\/H2O atmospheres was employed to reveal the effects of the addition of an oxidizing agent on the combustion characteristics of char. The structural features and combustion characteristics of preheated chars were determined by Raman, temperature-programmed desorption (TPD), and non-isothermal, thermo-gravimetric (TGA) experiments. According to the experimental results, the addition of oxidizing agents promoted the generation of smaller aromatic ring structures and oxygen-containing functional groups. The improvement in the surface physicochemical properties enhanced the reactivity of char and lowered its combustion activation energy. Furthermore, the combustion mechanisms of the char prepared from the O2\/CO2 and O2\/H2O atmospheres were investigated using the density functional theory (DFT). The simulation results illustrated that the combustion essence of char could be attributed to the migration of active atoms, the fracture of the benzene ring structure, and the reorganization of new systems. The addition of oxidizing agents weakened the conjugated components of the aromatic ring systems, promoting the successive decomposition of CO and NO. The results of this study can provide a theoretical basis for regulating the reaction atmosphere in the preheating process and promoting the development of clean combustion for high-rank coals.<\/jats:p>","DOI":"10.3390\/molecules28041638","type":"journal-article","created":{"date-parts":[[2023,2,9]],"date-time":"2023-02-09T01:37:07Z","timestamp":1675906627000},"page":"1638","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Experimental and DFT Research on the Effects of O2\/CO2 and O2\/H2O Pretreatments on the Combustion Characteristics of Char"],"prefix":"10.3390","volume":"28","author":[{"given":"Lei","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9332-1839","authenticated-orcid":false,"given":"Jie","family":"Xu","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rui","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhuozhi","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xingyi","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mengfan","family":"Yuan","sequence":"additional","affiliation":[{"name":"School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiangquan","family":"Wu","sequence":"additional","affiliation":[{"name":"School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7878","DOI":"10.1021\/acs.energyfuels.8b01237","article-title":"Industrial Experiments on Anthracite Combustion and NOx Emissions with Respect to Swirling Secondary Air for a 300 MWe Deep-Air-Staged Down-Fired Utility Boiler","volume":"32","author":"Wang","year":"2018","journal-title":"Energy Fuels"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"122212","DOI":"10.1016\/j.fuel.2021.122212","article-title":"SO2 and NO emissions during combustion of high-alkali coal over a wide temperature range: Effect of Na species and contents","volume":"309","author":"Tang","year":"2022","journal-title":"Fuel"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1551","DOI":"10.1016\/j.apenergy.2019.01.080","article-title":"Experimental characterization of anthracite combustion and NOx emission for a 300-MWe down-fired boiler with a novel combustion system: Influence of primary and vent air distributions","volume":"238","author":"Wang","year":"2019","journal-title":"Appl. Energy"},{"key":"ref_4","unstructured":"Ministry of Ecology and Environment of the People\u2019s Republic of China (2020, February 27). Comprehensive Implementations of Ultra-Low Emissions and Energy Saving Schemes for Coal-Fired Power Plants, Available online: http:\/\/english.mee.gov.cn\/."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"116589","DOI":"10.1016\/j.energy.2019.116589","article-title":"Adaptive selective catalytic reduction model development using typical operating data in coal-fired power plants","volume":"192","author":"Lv","year":"2020","journal-title":"Energy"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1134\/S004060152106001X","article-title":"Development of SNCR Technology and Prospects of Its Application","volume":"68","author":"Anichkov","year":"2021","journal-title":"Therm. Eng."},{"key":"ref_7","unstructured":"Carlos, E.R., and Wang, X. (2019). Advances in Ultra-Low Emission Control Technologies for Coal-Fired Power Plants, Woodhead Publishing Series in Energy."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2534","DOI":"10.1002\/apj.2534","article-title":"NOx emissions of pulverized coal combustion in high-temperature flue gas","volume":"15","author":"Zhu","year":"2020","journal-title":"Asia-Pac. J. Chem. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1186","DOI":"10.1016\/j.fuproc.2008.05.008","article-title":"Pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed","volume":"89","author":"Lu","year":"2008","journal-title":"Fuel Process. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"120538","DOI":"10.1016\/j.fuel.2021.120538","article-title":"Experimental study on NOx emissions of pulverized coal combustion preheated by a 2 MW novel self-sustained preheating combustor","volume":"294","author":"Ouyang","year":"2021","journal-title":"Fuel"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106725","DOI":"10.1016\/j.fuproc.2021.106725","article-title":"Experimental investigation on the evolution characteristics of anthracite-N and semi-coke reactivity under various O2\/H2O pre-oxidation atmospheres","volume":"216","author":"Wang","year":"2021","journal-title":"Fuel Process. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3985","DOI":"10.1021\/acs.energyfuels.5b00791","article-title":"Experimental Study on Nitrogen Transformation in Combustion of Pulverized Semi-coke Preheated in a Circulating Fluidized Bed","volume":"29","author":"Yao","year":"2015","journal-title":"Energy Fuels"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7724","DOI":"10.1021\/ef402146w","article-title":"An Experimental Study on NOx Emissions in Combustion of Pulverized Coal Preheated in a Circulating Fluidized Bed","volume":"27","author":"Zhu","year":"2013","journal-title":"Energy Fuels"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"120758","DOI":"10.1016\/j.fuel.2021.120758","article-title":"The effects of particle size on flameless combustion characteristics and NOx emissions of semi-coke with coal preheating technology","volume":"297","author":"Ding","year":"2021","journal-title":"Fuel"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"10956","DOI":"10.1021\/acs.energyfuels.8b02000","article-title":"Low NOx emissions from pulverized coal MILD combustion in O2 and CO2 preheated by a circulating fluidized bed","volume":"32","author":"Zhu","year":"2018","journal-title":"Energy Fuels"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1016\/j.fuel.2019.04.153","article-title":"NO emissions under pulverized char combustion in O2\/CO2\/H2O preheated by a circulating fluidized bed","volume":"252","author":"Zhu","year":"2019","journal-title":"Fuel"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7554","DOI":"10.1021\/acs.energyfuels.0c00845","article-title":"Effect of CO2 and H2O on Char Properties. Part 2: In Situ and Ex Situ Char in Oxy-Steam Combustion","volume":"34","author":"Li","year":"2020","journal-title":"Energy Fuels"},{"key":"ref_18","first-page":"129","article-title":"A quantum chemistry study of CO and NO desorption from oxidation of nitrogen-containing char by oxygen","volume":"36","author":"Zhang","year":"2011","journal-title":"J. China Coal Soc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"25594","DOI":"10.1021\/acsomega.1c03673","article-title":"Quantum Chemical Calculation of the Effects of H2O on Oxygen Functional Groups during Coal Spontaneous Combustion","volume":"6","author":"Huo","year":"2021","journal-title":"ACS Omega"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"624","DOI":"10.1016\/j.psep.2020.11.041","article-title":"Quantum chemical calculation of reaction characteristics of hydroxyl at different positions during coal spontaneous combustion","volume":"148","author":"Zhu","year":"2021","journal-title":"Process Saf. Environ. Prot."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1061","DOI":"10.1016\/j.fuel.2018.11.100","article-title":"A surface activation function method to determine the intrinsic reactivity of coal char oxyfuel conversion","volume":"239","author":"Liu","year":"2019","journal-title":"Fuel"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.apenergy.2016.08.121","article-title":"Effects of steam and CO2 on the characteristics of chars during devolatilization in oxy-steam combustion process","volume":"182","author":"Xu","year":"2016","journal-title":"Appl. Energy"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/S0016-2361(01)00127-2","article-title":"Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal. Part, I. Volatilisation of Na and Cl from a set of NaCl-loaded samples","volume":"81","author":"Quyn","year":"2002","journal-title":"Fuel"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/j.wasman.2018.01.002","article-title":"Combustion behaviors and kinetics of sewage sludge blended with pulverized coal: With and without catalysts","volume":"74","author":"Wang","year":"2018","journal-title":"Waste Manag."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"659","DOI":"10.1016\/j.fuel.2016.06.109","article-title":"Effects of demineralization on the structure and combustion properties of Shengli lignite","volume":"183","author":"Song","year":"2016","journal-title":"Fuel"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1038\/201068a0","article-title":"Kinetic Parameters from Thermogravimetric Data","volume":"201","author":"Coats","year":"1964","journal-title":"Nature"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1016\/j.carbon.2020.05.055","article-title":"Microstructural analysis of nitrogen-doped char by Raman spectroscopy: Raman shift analysis from first principles","volume":"167","author":"Ayiania","year":"2020","journal-title":"Carbon"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1700","DOI":"10.1016\/j.fuel.2006.03.008","article-title":"FT-Raman spectroscopic study of the evolution of char structure during the pyrolysis of a Victorian brown coal","volume":"85","author":"Li","year":"2006","journal-title":"Fuel"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"111923","DOI":"10.1016\/j.combustflame.2021.111923","article-title":"Mechanisms of the N2O formation and decomposition over coal char surface","volume":"238","author":"Zhang","year":"2022","journal-title":"Combust. Flame"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.combustflame.2020.06.032","article-title":"Updated effect of carbon monoxide on the interaction between NO and char bound nitrogen: A combined thermodynamic and kinetic study","volume":"220","author":"Zhang","year":"2020","journal-title":"Combust. Flame"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"116286","DOI":"10.1016\/j.energy.2019.116286","article-title":"Theoretical study on the reduction reactions from solid char(N): The effect of the nearby group and the high-spin state","volume":"189","author":"Zhang","year":"2019","journal-title":"Energy"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"125730","DOI":"10.1016\/j.fuel.2022.125730","article-title":"Application of experiments and density function theory on the formation mechanism of NH3 during O2\/Ar and O2\/H2O combustion process of demineralized coals","volume":"331","author":"Zhang","year":"2023","journal-title":"Fuel"},{"key":"ref_33","unstructured":"Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman, J.R., Scalmani, G., Barone, V., Mennucci, B., and Petersson, G.A. (2009). Gaussian 09 (Revision C.01), Gaussian, Inc."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1002\/jcc.22885","article-title":"Multiwfn: A multifunctional wavefunction analyzer","volume":"33","author":"Lu","year":"2011","journal-title":"J. Comput. Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1016\/j.egyr.2020.10.038","article-title":"Analysis of reaction kinetics for torrefaction of pelletized agricultural biomass with dry flue gas","volume":"6","author":"Onsree","year":"2020","journal-title":"Energy Rep."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"122477","DOI":"10.1016\/j.fuel.2021.122477","article-title":"Analysis of functionality distribution and microstructural characteristics of upgraded rice husk after undergoing non-oxidative and oxidative torrefaction","volume":"310","author":"Zhang","year":"2022","journal-title":"Fuel"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.fuel.2013.07.066","article-title":"Inhibiting and other effects of hydrogen during gasification: Further insights from FT-Raman spectroscopy","volume":"116","author":"Tay","year":"2014","journal-title":"Fuel"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3171","DOI":"10.1021\/ef700353n","article-title":"Comparison of Chars Obtained under Oxy-Fuel and Conventional Pulverized Coal Combustion Atmospheres","volume":"21","author":"Angeles","year":"2007","journal-title":"Energy Fuels"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1016\/j.enconman.2010.07.028","article-title":"Characteristic of coal combustion in oxygen\/carbon dioxide atmosphere and nitric oxide release during this process","volume":"52","author":"Niu","year":"2011","journal-title":"Energy Convers. Manag."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1267","DOI":"10.1021\/acs.energyfuels.8b03987","article-title":"Pyrolysis Characteristics and Kinetics of Coal\u2013Biomass Blends during Co-Pyrolysis","volume":"33","author":"Chen","year":"2019","journal-title":"Energy Fuels"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1755","DOI":"10.1016\/S0016-2361(99)00124-6","article-title":"The predictions of coal\/char combustion rate using an artificial neural network approach","volume":"78","author":"Zhu","year":"1999","journal-title":"Fuel"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"125080","DOI":"10.1016\/j.fuel.2022.125080","article-title":"Experimental and density functional theory investigation of the NO reduction mechanism by semichars preheated in Ar and CO2\/Ar atmospheres","volume":"326","author":"Zhang","year":"2022","journal-title":"Fuel"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/28\/4\/1638\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:28:28Z","timestamp":1760120908000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/28\/4\/1638"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,8]]},"references-count":42,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["molecules28041638"],"URL":"https:\/\/doi.org\/10.3390\/molecules28041638","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,2,8]]}}}