Coal spontaneous combustion is one of the most severe and constant hazards in coal industry. Understanding mechanisms basis for effective hazard control coal-producing process. This paper investigated two types oxidized samples from re-mining faces an underground mine. Proximate analysis, elemental surface temperature-programmed experiments, differential scanning calorimetry analysis were condu...

Emission samples were obtained from two medium-sized power plants, one fired with oil and the other with pulverized coal. Particles obtained by a miniscale plume stack gas sampler (MIPSGAS), simulating the dilution process in the plume, were subjected to detailed physical, chemical and biological characterization. Studies by scanning electron microscopy and by Coulter counter demonstrated that ...

The R70 self-heating test has been used as one of the major laboratory methods for testing the intrinsic properties of coal that influences its propensity for spontaneous combustion. The R70 test is conducted in an artificially created adiabatic environment so that only and all the heat generated by the coal sample is used to prompt the oxidation process and to increase the temperature of the s...

The combustion of coal in power plants generates solids (e-g., fly ash, bottom ash) and flue gas (e.g., SOX, C02). New Clean Air Act mandated reduction of SOX emissions from coal burning power plants. As a result, a variety of Clean Coal Technologies (CCT) are implemented to comply with these amendments. However, most of the CCT processes transfer environmentally sensitive elements (e.g., As, C...

The influence of fluidized bed combustion (FBC) temperature and coal rank on polycyclic aromatic hydrocarbon (PAH) emissions was assessed. A low-rank coal and a high-rank coal were burnt in a fluidized bed reactor (FBR) on a laboratory scale. An outlet gas sample was passed through a capture system provided with three traps: nylon titer, Teflon filter and XAD-2 resin. The PAH captured were anal...

Industries using conventional fossil fuels have an interest in better understanding the mechanism of particulate formation during combustion since such is responsible for emission of undesired inorganic elements that directly impact the atmospheric pollution level. Fine and ultrafine particulates have tendency to escape the flue gas cleaning devices to the atmosphere. They also preferentially c...

The results of a theoretical study of the formation and growth of the submicron flyash aerosol around a single burning coal particle are presented. The vaporization of ash and subsequent aerosol formation near the coal particle are studied because the local combustion environment influences these proewes strongly. A mathematical model is developed that describes the transport of ash vapor and a...

Recently, the worldwide supply of rare earth element (REE) resources will be severely restricted. On the other hand, coal fly ash particles emitted from coal-fired electric power plants contain relatively high concentrations of REEs. The contents of REEs in coal fly ash are regularly several hundreds of ppmw. In order to extract and recover REEs from coal fly ash particles, as a first step, we ...

Fly ashes and gypsum are one of the main wastes produced in coal-fired power stations which may be sent to landfills for their disposal. In this work, leaching and speciation of mercury in fly ashes and gypsum from a modern co-combustion power plant equipped with a selective catalytic reduction (SCR) unit in the Netherlands were studied. The mercury leachable contents were checked against diffe...

Practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully c...