Vol 8, No 1 (2017) > Mechanical Engineering >

Modeling of the Crossing Point Temperature Phenomenon in the Low-temperature Oxidation of Coal

Muksin Saleh, Yuswan Muharram, Yulianto S. Nugroho


Abstract: In this study, modeling
of the crossing point temperature (CPT) phenomenon in the low-temperature
oxidation of coal was carried out using COMSOL Multiphysics®.
Low-temperature oxidation can lead to spontaneous combustion of coal
stockpiles. The CPT phenomenon was modeled with the kinetics data obtained from
a prior laboratory experimental study. The coupling of the heat-transfer
phenomenon through conduction and convection determined the thermal evolution
model. In this case, coal received the initial heat of the oven temperature increases.
As the coal temperature rose, the heat generated from oxidation was released
into the environment via conduction and convection. Meanwhile, oxidation
products and oxygen were transferred by convection and diffusion. The effects
of moisture and the humidity were not considered. The outcomes of modeling were
validated through comparison with the results of experimental tests, and the
modeling result agreed well with the experiment tests, with temperature
deviations of about 0.9%. The effects of airflow rate, oxygen concentration,
porosity, and the initial temperature on low-temperature coal oxidation were
also examined.
Keywords: Coal; Crossing point; Low-temperature oxidation; Modeling; Spontaneous combustion

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