Grinding of a high volatile bituminous coal was performed in three comminution devices: Raymond Mill, Rolls Crusher and Ball Mill. The pulverised samples were sieved to obtain four particle size fractions and temperature-programmed combustion (TPC) was used for the evaluation of their combustion behaviour. In addition, three coals of different hardness and rank were mixed in various proportions...

Coal gasification with carbon dioxide is a process for generating clean gaseous fuels and relieving greenhouse effect. Zhundong coal has high alkali and alkali earth metals (AAEMs) content, medium volatile and low ash in nature. Isothermal CO2 gasification of char derived from Zhundong coal (R-char) and char from acid washing R-char (AR-char) are performed in thermo-gravimetric analyzer (TGA). ...

There is a large range of time and length scales of turbulent fluctuations in an entrained flow coal gasifier. To figure out the turbulent effects on coal gasification processes and the controlling mechanisms of different regions in an entrained flow coal gasifier, the characteristic time and length scales for all major processes are estimated.On the basis of the comparisonbetween the length/ti...

This laboratory study uses a novel furnace to resolve nitrogen evolution during the three stages of pulverized coal combustion. primary devolatilization, secondary pyrolysis, and com­ bustion The behavior of six coals depicts continuous rank variations, as well as suppressed nitrogen evolution {i'om low volatility coals. During primary de volatilization of any coal, ar­ omatic compounds in tar ...

To clarify the effects of volatile-char interaction on the redistribution of fuel-N to N2 during devolatilization and the reduction of NO through gas-solid reactions during combustion, two types of experiments were performed on a novel reactor. The separate combustion of volatile and char and the combustion of entrained pulverized coal, and the formation of NO was examined between 800 and 1100 ...

Oxygen-enhanced and oxygen-fired pulverized coal combustion is actively being investigated to achieve emission reductions and reductions in flue gas cleanup costs, as well as for coal-bed methane and enhanced oil recovery applications. To fully understand the results of pilot scale tests and to accurately predict scale-up performance through CFD modeling, accurate rate expressions are needed to...

Knowledge of surface properties is essential for understanding the reaction mechanisms involved in several coal conversion processes. However, due to the complexity and heterogeneity of coal this is rather difficult and the use of known model compounds could be a valuable tool. Single model compounds have been widely used, but they give a quite simplified picture. In this work a mixture of mode...

This study develops a computational framework for ranking Bangladeshi coals for industrial use based on fuzzy set theory. The ranking process considers coal quality parameters (known as selection or ranking criteria) such as sulphur content (ultimate analysis), fixed carbon, volatile matter, moisture content, and ash content (proximate analysis) and calorific value. The selection criteria are f...

High-temperature processes, such as coal and oil combustion in electric power stations and industrial plants, roasting and smelting of ores in non-ferrous metal smelters, melting operations in ferrous foundries, refuse incineration, and kiln operations in cement plants, emit several pollutants, especially those being easily volatile. Among the volatile pollutants are As, Cd, Pb and Hg. In this ...