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Thermogravimetric characteristics of char obtained at high heat rate
Características termogravimétricas de carbonizados obtenidos a altas velocidades de calentamiento
DOI:
https://doi.org/10.15446/ing.investig.v29n2.15157Keywords:
thermogravimetry, char, high heat rate (en)termogravimetría, carbonizado, altas velocidades de calentamiento (es)
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Coal reactivity during combustion is determined by the thermogravimetric characteristics of char. The thermogravimetric characteristics of chars obtained in a droptube furnace were studied in this work. Chars from the devolatilisation of three bituminous coals were obtained at three times (100, 150 and 300 ms), three temperatures (900, 1,000 and 1,100ºC) and at high heat rate (104 K/s). The chars were burned using non-isothermal thermogravimetry (heated to 900ºC) and isothermal thermogravimetry at 700ºC, 800ºC and 900ºC to obtain their combustion profiles. Characteristic temperatures (ignition, peak and final temperatures) were determined by non-isothermal thermogravimetry; it was found that chars from La Yolanda coal gave the highest figures for the characteristic temperatures. Isothermal thermogravimetry revealed that the combustion rate for the three coals decreased with increased devolatilisation time and combustion temperature.
La reactividad de un carbón en los procesos de combustión la determinan las características termogravimétricas de sus carbonizados. En este trabajo se estudiaron las características termogravimétricas de carbonizados obtenidos en un reactor tubular de caída. Los carbonizados proceden de la desvolatilización de tres carbones bituminosos, se prepararon a tres tiempos (100, 150 y 300 ms), tres temperaturas (900, 1.000 y 1.100 ºC) de desvolatilización y a altas velocidades de calentamiento (104K/s). Estos carbonizados se quemaron para obtener los perfiles de combustión por termogravimetría no isotérmica (calentando hasta 900 ºC) y por termogravimetría isotérmica a temperaturas de quemado 700, 800 y 900 ºC. Por termogravimetría no isotérmica se determinaron las temperaturas características (temperaturas de ignición, pico y final). Se encontró que los carbonizados del carbón La Yolanda presentan los mayores valores de las temperaturas características. Por termogravimetría isotérmica se encontró que la velocidad de quemado de los carbonizados de los tres carbones disminuye con el aumento del tiempo de desvolatilización y de la temperatura de quemado.
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