{"title":"挥发性二次炭对纤维素基水硬质合金燃烧行为的影响","authors":"","doi":"10.1016/j.combustflame.2024.113703","DOIUrl":null,"url":null,"abstract":"<div><p>Hydrothermal carbonization (HTC) can transform a wide range of biomass into renewable biofuels. Hydrochar, the solid fuel resulting from HTC, has a similar energy density to low-rank coals. Despite an extensive body of literature detailing the thermogravimetric analysis (TGA) of hydrochar under slow pyrolysis and oxidation, there remains a limited understanding of hydrochar's behavior in realistic combustion settings. In this work, we integrate combustion experiments and TGA to understand the combustion characteristics of a model hydrochar fuel. Cellulose-based hydrochars produced at different temperatures along with solvent-extracted chars are tested in a Hencken burner across varying temperatures and oxygen concentrations in the oxidizer gas. Simultaneous CH* chemiluminescence, particle image velocimetry, and two-color pyrometry are used to measure ignition delay time and identify homogeneous/heterogeneous ignition mechanisms and combustion phases. Incorporating TGA with combustion results shows that the ignition mode and combustion processes are strong functions of surrounding gas temperature and oxygen mole fraction. The level of carbonization of the hydrochar dictates the ignition delay time and combustion modes. Further, the presence of a tar-like secondary char on the as-carbonized hydrochars leads to more rapid ignition due to high volatility.</p></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":5.8000,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Role of volatile secondary char on the combustion behavior of cellulose-based hydrochars\",\"authors\":\"\",\"doi\":\"10.1016/j.combustflame.2024.113703\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Hydrothermal carbonization (HTC) can transform a wide range of biomass into renewable biofuels. Hydrochar, the solid fuel resulting from HTC, has a similar energy density to low-rank coals. Despite an extensive body of literature detailing the thermogravimetric analysis (TGA) of hydrochar under slow pyrolysis and oxidation, there remains a limited understanding of hydrochar's behavior in realistic combustion settings. In this work, we integrate combustion experiments and TGA to understand the combustion characteristics of a model hydrochar fuel. Cellulose-based hydrochars produced at different temperatures along with solvent-extracted chars are tested in a Hencken burner across varying temperatures and oxygen concentrations in the oxidizer gas. Simultaneous CH* chemiluminescence, particle image velocimetry, and two-color pyrometry are used to measure ignition delay time and identify homogeneous/heterogeneous ignition mechanisms and combustion phases. Incorporating TGA with combustion results shows that the ignition mode and combustion processes are strong functions of surrounding gas temperature and oxygen mole fraction. The level of carbonization of the hydrochar dictates the ignition delay time and combustion modes. Further, the presence of a tar-like secondary char on the as-carbonized hydrochars leads to more rapid ignition due to high volatility.</p></div>\",\"PeriodicalId\":280,\"journal\":{\"name\":\"Combustion and Flame\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.8000,\"publicationDate\":\"2024-09-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Combustion and Flame\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0010218024004127\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENERGY & FUELS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Combustion and Flame","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0010218024004127","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
Role of volatile secondary char on the combustion behavior of cellulose-based hydrochars
Hydrothermal carbonization (HTC) can transform a wide range of biomass into renewable biofuels. Hydrochar, the solid fuel resulting from HTC, has a similar energy density to low-rank coals. Despite an extensive body of literature detailing the thermogravimetric analysis (TGA) of hydrochar under slow pyrolysis and oxidation, there remains a limited understanding of hydrochar's behavior in realistic combustion settings. In this work, we integrate combustion experiments and TGA to understand the combustion characteristics of a model hydrochar fuel. Cellulose-based hydrochars produced at different temperatures along with solvent-extracted chars are tested in a Hencken burner across varying temperatures and oxygen concentrations in the oxidizer gas. Simultaneous CH* chemiluminescence, particle image velocimetry, and two-color pyrometry are used to measure ignition delay time and identify homogeneous/heterogeneous ignition mechanisms and combustion phases. Incorporating TGA with combustion results shows that the ignition mode and combustion processes are strong functions of surrounding gas temperature and oxygen mole fraction. The level of carbonization of the hydrochar dictates the ignition delay time and combustion modes. Further, the presence of a tar-like secondary char on the as-carbonized hydrochars leads to more rapid ignition due to high volatility.
期刊介绍:
The mission of the journal is to publish high quality work from experimental, theoretical, and computational investigations on the fundamentals of combustion phenomena and closely allied matters. While submissions in all pertinent areas are welcomed, past and recent focus of the journal has been on:
Development and validation of reaction kinetics, reduction of reaction mechanisms and modeling of combustion systems, including:
Conventional, alternative and surrogate fuels;
Pollutants;
Particulate and aerosol formation and abatement;
Heterogeneous processes.
Experimental, theoretical, and computational studies of laminar and turbulent combustion phenomena, including:
Premixed and non-premixed flames;
Ignition and extinction phenomena;
Flame propagation;
Flame structure;
Instabilities and swirl;
Flame spread;
Multi-phase reactants.
Advances in diagnostic and computational methods in combustion, including:
Measurement and simulation of scalar and vector properties;
Novel techniques;
State-of-the art applications.
Fundamental investigations of combustion technologies and systems, including:
Internal combustion engines;
Gas turbines;
Small- and large-scale stationary combustion and power generation;
Catalytic combustion;
Combustion synthesis;
Combustion under extreme conditions;
New concepts.