Oxy-steam combustion: The effect of coal rank and steam concentration on combustion characteristics

Escudero, Ana I. (Universidad de Zaragoza) ; Aznar, María ; Díez, Luis I. (Universidad de Zaragoza)

Resumen: This paper addresses the experimental investigation of coal combustion characteristics (ignition, burnout and NO formation) under oxy-steam combustion conditions. Two coals are selected in order to compare the effect of the rank: bituminous and sub-bituminous ones. The experiments have been conducted in an electrically-heated entrained flow reactor for a set of O2/N2, O2/CO2 and O2/H2O/CO2 atmospheres, with O2 concentrations up to 35% and H2O concentrations up to 40%. Regarding ignition, 10% H2O reduces ignition temperature (max. 16–19 K) but the trend is reversed when supplying additional steam to 25% and 40%. This behaviour is similar for both coals, with slight larger variations in the case of the low rank coal. Burnout degree of the sub-bituminous coal is barely affected by the steam concentration since all observed conversions are very high. Larger increments (up to 6.1 percentage points) are obtained for the bituminous coal, with a maximum burnout degree for the 25/35% H2O/O2 atmosphere. A very different effect of steam on NO formation is found depending on the coal rank. Significant reduction rates are observed for the bituminous coal in comparison to the dry O2/CO2 atmospheres, with a maximum diminution of 24% when 40% H2O replaces CO2. On the contrary, the higher volatile content in the sub-bituminous coal leads to NO increments up to 9%. For all the combustion characteristics studied, the increase of O2 concentrations attenuates the effects caused by the steam addition.

Idioma: Inglés

DOI: 10.1016/j.fuel.2020.119218

Año: 2021

Publicado en: Fuel 285 (2021), 119218 [9 pp.]
ISSN: 0016-2361

Factor impacto JCR: 8.035 (2021)

Categ. JCR: ENGINEERING, CHEMICAL rank: 19 / 143 = 0.133 (2021) - Q1 - T1
Categ. JCR: ENERGY & FUELS rank: 29 / 119 = 0.244 (2021) - Q1 - T1

Factor impacto CITESCORE: 11.2 - Chemical Engineering (Q1) - Energy (Q1)

Factor impacto SCIMAGO: 1.514 - Energy Engineering and Power Technology (Q1) - Organic Chemistry (Q1) - Chemical Engineering (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MICIU/ENE2015-67448
Financiación: info:eu-repo/grantAgreement/ES/MICIU/RTI2018-094488-B-C21
Financiación: info:eu-repo/grantAgreement/ES/MICIU/RTI2018-094488-B-C22
Financiación: info:eu-repo/grantAgreement/ES/MINECO/BES-2016-078573

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Máquinas y Motores Térmi. (Dpto. Ingeniería Mecánica)