Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide To investigate the weight-change characteristics of coal under varying gas environments, a programmed temperature weight loss experiment is performed on bituminous coal (long-flame coal) under dry air, pure O 2, and pure N 2 conditions. The study analyzed and compared the temperature evolution patterns, weight loss behaviors, gas product properties, kinetic models of coal–oxygen composite reactions, and activation energies ( E a ) across the three environments. The experimental results indicate that the coal sample in an O 2 environment exhibits the highest heating rate, which is significantly greater than those in air and N 2 environments. The weight loss rate of coal samples in the air environment is consistently higher than that in the O 2 environment. In the N 2 environment, pyrolysis led to a gradual increase in the weight loss rate, which became predominant after the coal temperature exceeded 90 °C. The time required for coal samples to achieve the maximum weight loss rate is the shortest in the O 2 environment. Within the same time frame, the weight loss rates of coal samples in air and the O 2 environments are significantly higher than those in the N 2 environment. The concentration of carbon monoxide gas generated from coal combustion in a pure O 2 environment shows a marked increase after 150 °C, reaching concentrations 3–4 times higher than those observed in an ambient air environment. Meanwhile, in the N 2 atmosphere, a minor quantity of carbon–oxygen gases is released from the coal sample as a result of functional group pyrolysis during thermal treatment. The kinetic model describing the O 2 consumption reaction of coal samples in an air environment can be represented by the Avrami–Erofee complex multidimensional homogeneous nucleation model with n = 4. During the low-temperature stage (40–140 °C), the E a required for CO 2 generation is significantly lower than that for CO generation. Consequently, the coal sample exhibits a greater tendency to produce CO 2 in this temperature range. The research elucidates the dual inhibitory and promoting effects of O 2 concentration on coal oxidation-induced weight loss, as well as the pyrolysis characteristics in a N 2 atmosphere. These findings offer valuable theoretical insights for the precise prevention and control of the spontaneous combustion (SC) of residual coal in goaf areas.
Source: ACS Omega
Authors: Xian Wu, Haojie Zhang, Ronghao Xu, Ziwen Dong
Language: English
Subfield: Ocean Engineering
Field: Engineering
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $1,935
Award: G6362438119
OpenAlex ID: W4414199504