Field and Laboratory Simulation Study of Hot Spots in Stockpiled Bituminous Coal

Abstract

Large coal piles (50–150 000 tons) undergo weathering processes during long-term storage in open air. Chemisorption of atmospheric oxygen, formation of surface oxides, and partial oxidative decomposition of the coal macromolecule matrix result in the release of organic and inorganic gases [e.g., methane (CH4), ethylene (C2H4), ethane (C2H6), carbon dioxide (CO2), carbon monoxide (CO), and hydrogen (H2)]. Some of these processes are exothermic, and when the rate of heat dissipation in the pile is lower than that of its formation, a significant increase in the temperature can be measured. These places are termed “hot spots”, which, in extreme cases, can result in fire eruptions. The maximal temperature measured in the hot spots was 330 °C. Monitoring of hot spots at the Israel Electric Company (IEC) bituminous coal storage sites has been conducted. A unique monitoring unit that can penetrate up to 8 m into the coal pile to sample gases and also measure the temperature was used.

Inhibiting effect of CO2 on the oxidative combustion thermodynamics of coal

“… 1 However, spontaneous combustion of coal is commonplace in many coal-producing countries, resulting in not only safety problems and resource waste 2–4 but also ecological damage and environmental pollution. 5,36 Therefore, understanding the characteristics of coal spontaneous combustion and developing preventative technology is crucial. 6 Conventional techniques adopted to prevent and control coal spontaneous combustion are irrigation with water and loess mud.…”

Heterocyclic Addition Reactions during Low Temperature Autoxidation

“…Coal weathering is undesirable, not only due to the risk of autoignition, but also due to the loss of the calorific value of the coal. 2,3 Our interest has been on the impact that autoxidation has on processes related to the oilsands industry. In the oilsands industry the weathering of exposed oilsands deposits is linked to reduced bitumen recovery.…”

Insight into the intrinsic reaction of brown coal oxidation at low temperature: Differential scanning calorimetry study

“…The second stage, from 91.5°C to 149.0°C, is denoted as the accelerated oxidation stage. In this stage, the oxygenated complexes undergo a thermal decomposition that contributes to the emission of carbon oxides [24] and their decomposition rate is greater than their formation rate. This may be the main reason why the exothermic intensity is weaker than that in the first stage.…”