In order to reduce fire hazards caused by spontaneous combustion in longwall gob areas, a computational fluid dynamics (CFD) study is being conducted by National Institute for Occupational Safety and Health (NIOSH) to simulate the spontaneous heating of coal in longwall gob areas. A CFD model was first developed to model the spontaneous heating process in a two longwall panel district using a b...

A thermal power station is a power plant in which the prime mover is steam driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this is known as a Rankine cycle. The greatest variation in the design of thermal power stations is due ...

In this study, a circulating fluidized bed of 125 mm diameter and 1800 mm height was used to find the combustion characteristics of olive cake (OC) produced in Turkey. Olive cake alone and olive cake+lignite coal mixtures were burned separately. Various olive cake/lignite coal ratios were tried. A suitable feeding mechanism of olive cake to the bed was developed. On-line concentrations of O2, S...

Oxy-fuel combustion is one of the energy utilization technologies for CO2 capture which is ready for commercial demonstration. System steady-state simulation is an effective tool to help us understand the thermodynamic properties and adjust operation conditions of oxy-fuel combustion system. Moreover, dynamic simulation is essential for understanding the dynamic characteristics of the system, w...

Spherical and hollow fly ash particles having density < 1g/cm are known as cenospheres. Their concentration in coal combustion ash is typically << 1%; as a consequence, their value is relatively high (~$0.70/kg). However, cenospheres are really particles containing gas bubbles independent of their density. Hence, cenosphere densities can vary between 0.6 g/cm to near or greater than 2.0 g/cm. T...

Chemical-Looping Combustion (CLC) is an emerging technology for CO2 capture because separation of this gas from the other flue gas components is inherently to the process and thus no energy is expended for the separation. For its use with coal as fuel in power plants, a process integrated by coal gasification and CLC would have important advantages for CO2 capture. This paper presents the combu...

In the current stage over 85% of world energy demand is supplied by fossil fuels. Coal-fired plants discharged roughly 40% of the total CO2 are the main contributors in CO2 emissions (Kim & Kim, 2004; Yang et al., 2008). Environmental issues caused by exhaust green house gases (GHG) and toxics have become global problems. Through the past studies of five decades, increased GHG levels in atmosph...

Three species of biomass origin (straw pellets, olive cake and wood pellets) and two coals from different countries (Coal Polish and Coal Colombian) have been studied to understand the fate of their ash forming matter during the combustion process and to investigate the influence of co-firing biomass with coal. Three different approaches to investigate the ash behaviour were employed: (1) chemi...

Spontaneous combustion of coal is an important problem in mining and storage, in terms of both safety and economics. This is because coal reacts with oxygen in the air and an exothermic reaction occurs, even in ambient conditions. The heat of the reaction accumulates and the reaction becomes progressively faster and thermal runaway may take place to the point of ignition. A detailed computer mo...