Year-end Sale % OFF 
Abstract
To achieve the efficient utilization of low-concentration mine gas, reduce resource waste and alleviate environmental pollution, the high-temperature oxidation of low-concentration gas at a concentration range of 1.00% to 1.50%, which is directly discharged into the atmosphere during coal mine production, was carried out to recover heat for reuse. The gas oxidation equipment was improved for the heating process and the safety of low-concentration gas oxidation under a high-temperature environment was evaluated. The experimental results showed that the reactor could provide a 1000 °C high-temperature oxidation environment for gas oxidation after installing high-temperature resistant ceramics. The pressure variation curves of the reactor with air and different concentrations of gas were similar. Due to the thermal expansion, the air pressure slightly increased and then returned to normal pressure. In contrast, the low-concentration gas exhibited a stable pressure response in the high-temperature environment of 1000 °C. The outlet pressure was significantly greater than the inlet pressure, and the pressure difference between the inlet and outlet exhibited a trend to increase with the gas concentration. The minimum pressure difference was 4 kPa (air) and the maximum was 11 kPa (1.50% gas). The explosion limit varied with the temperature and the blend of oxidation products. The ratio of measured gas pressure to air pressure after oxidation was below the explosion criterion, indicating that the measured concentration of gas is still safe after the shift of the explosion limit, which provides a safe concentration range for the efficient use of low-concentration gas in the future.
Highlights
Coal mines emit a large amount of low-concentration gas every year
The residual heat after gas oxidation from a gas concentration of 0.4% or more has economic value [3] and the utilized concentration is generally controlled at 1.2% [4]
The gas system was in an oxygen-depleted state near the upper flammable limit with the generation of CO during the production process
Summary
Coal mines emit a large amount of low-concentration gas every year. unstable gas source conditions and low long-term utilization rates lead to a waste of energy and high greenhouse gas emissions [1]. Low-concentration gas emits heat at high-temperatures, which provides energy for gas oxidation and affords the remaining heat for utilization [2]. The reaction temperature and pressure affect the explosion limit. The maximum explosive pressure increased and the density of the flammable mixture increased [13]. The higher the initial pressure or temperature, the higher the upper flammable limit [14]. The gas system was in an oxygen-depleted state near the upper flammable limit with the generation of CO during the production process. The lower limit of the flammability of the gas at high pressure was slightly reduced. When the gas concentration was above 3 MPa, the upper limit of flammability was significantly increased. This work provides a theoretical basis for the efficient use of low-concentration gas
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
