Kinetics of pressurized oxy-combustion of coal chars
| Autor: | Piotr Babiński, Grzegorz Łabojko, Michalina Kotyczka-Morańska, Marek Ściążko |
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| Rok vydání: | 2019 |
| Předmět: |
Order of reaction
Materials science business.industry Diffusion Analytical chemistry 02 engineering and technology Activation energy 021001 nanoscience & nanotechnology Condensed Matter Physics Combustion 01 natural sciences Isothermal process 010406 physical chemistry 0104 chemical sciences Limiting oxygen concentration Coal Char Physical and Theoretical Chemistry 0210 nano-technology business Instrumentation |
| Zdroj: | Thermochimica Acta. 682:178417 |
| ISSN: | 0040-6031 |
| Popis: | A kinetic study of oxy-combustion of chars received from two Polish coals, namely lignite and hard subbituminous was conducted. The kinetics of char oxy-combustion was examined in the TA Instruments TG-HP150 s pressurized thermogravimetric analyzer at 0.1, 0.5 and 1 MPa of absolute pressure. The experiments were carried out at isothermal conditions and at wide range of temperature (773–1273 K). Mixture of gas containing 20% and 30% of O2 in CO2 was used as an oxidant. Additionally at temperature 873 K the experiments were performed using 5%, 10% and 40% of O2 in CO2. A kinetic model of pressurized oxy-combustion of coal char was presented. Kinetic parameters such as activation energy, pre-exponential factor and reaction order in respect of oxygen concentration were computed. Influence of temperature, pressure and O2 concentration were discussed. The results show a significant shift of the oxycombustion reaction from kinetically controlled regime to diffusion – controlled regime with increasing temperature and pressure. The method of selecting the proper reaction model was presented based on the integral and differential approach of experimental data analysis. |
| Databáze: | OpenAIRE |
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