Kinetics investigation on the combustion of biochar in O2/CO2 atmosphere
Oxy‐biomass combustion produces negative CO2 emissions. This study investigated the combustion kinetics of biochar in O2/CO2 atmosphere using a thermo‐gravimetric analyzer. The effects of atmosphere, O2 concentration, and fuel type were considered in this investigation. Results show that the reactio...
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Published in | Environmental progress & sustainable energy Vol. 34; no. 3; pp. 923 - 932 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Blackwell Publishing Ltd
01.05.2015
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Subjects | |
Online Access | Get full text |
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Summary: | Oxy‐biomass combustion produces negative CO2 emissions. This study investigated the combustion kinetics of biochar in O2/CO2 atmosphere using a thermo‐gravimetric analyzer. The effects of atmosphere, O2 concentration, and fuel type were considered in this investigation. Results show that the reaction order of biochar combustion ranges from 0.5 to 1. Furthermore, the kinetic compensation effect can be observed between the apparent activation energy E and the frequency factor A. This relation is given by lnA = 0.181E − 14.618. Compared with O2/N2 atmosphere, O2/CO2 atmosphere delays biochar ignition and reduces activation energy. The ignition temperature of straw char is significantly lower than that of wood and coal char. The apparent activation energy of char combustion follows the inequality wood char > straw char > coal char. This result indicates that biochar combustion is more sensitive to temperature than coal char combustion. The reactivity of char combustion improves with increasing O2 concentration, but biochar has a lower degree of improvement than coal char. The change from air combustion to oxy‐fuel combustion and the increase in O2 concentration exert minimal effects on biochar combustion than on coal char combustion. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 923–932, 2015 |
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Bibliography: | istex:5B8E0FA904594CD750AB0536A286F98F1F581971 ArticleID:EP12063 ark:/67375/WNG-CSSC9KD5-J National Natural Science Foundation of China - No. 51306142 and 51376147 |
ISSN: | 1944-7442 1944-7450 |
DOI: | 10.1002/ep.12063 |