Deepak Pudasainee

Emission Characteristics of PM and PM2.5 from Bituminous Coal Combustion Power Plants

Particles emitted from three coal-fired power plants burning bituminous and sub-bituminous coals were examined for PM and size fractions PM¤2.5 and PM2.5. The ratio of PM2.5/PM was ranged from 10 to 62%, and PM emission increased with the amount of coal feed, which was 7.23~15.66 kg/h. The emission range of PM2.5 from three power plants was 1.24~4.48 kg/h (dry), which was function of the mixed rate of viscous sub-bituminous coal in feed. Of course such effect should be examined by further tests in details. Based on the consumed coal and thermal load, the emission factors averaged were shown as 59.03 g-PM/ton-coal, 14.79 g-PM2.5/ton-coal and 22.51 g-PM/MWh, 5.54 g-PM2.5/MWh, respectively.

Bromination of petroleum coke for elemental mercury capture

Activated carbon injection has been proven to be an effective control technology of mercury emission from coal-fired power plants. Petroleum coke is a waste by-product of petroleum refining with large quantities readily available around the world. Due to its high inherent sulfur content, petroleum coke is an attractive raw material for developing mercury capture sorbent, converting a waste material to a value-added product of important environmental applications. In this study, petroleum coke was brominated by chemical-mechanical bromination. The brominated petroleum coke was characterized for thermal stability, mercury capture capacity, and potential mercury and bromine leaching hazards. Bromine loaded on the petroleum coke was found to be stable up to 200°C. Even after treating the brominated petroleum coke for 30min at 600°C, 1/3 bromine remained on the solid. The sorbent from bromination of sulfur-containing petroleum coke was shown to be a promising alternative to commercial brominated activated carbon for capture of elemental mercury from coal combustion flue gases.

A Comparative Study on Lignite Coal Drying by Different Methods

ABSTRACT Abundance of low-rank coal (LRC) and increasing demand for energy provides motivation for upgrading LRC in terms of their high moisture content. Canadian lignite coal (425–1000 µm) was dried at different temperatures using different methods, namely hydrothermal treatment (HT), vacuum drying and hot air drying. These processes resulted in significant reduction (up to 9.65%) in moisture from as-received lignite coal (34%), especially at higher temperatures (300 and 325°C) using HT for 30 minutes. Vacuum drying (70°C) over the period of 7 hours and hot air drying (70°C) for 110 minutes liberated almost the same amount of moisture from the raw coal. Several investigations were conducted on these samples and chars derived from these in conditions similar to a boiler to understand the impact of drying methods. Char samples were prepared by pyrolyzing at 1200°C under inert atmosphere (N2) in a drop tube furnace (DTF). The morphological changes of these char samples were investigated by scanning electron microscopy analysis to see the physiochemical changes that occurred during different treatment processes. Raw and treated coal samples were also analyzed by several analytical techniques including Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA). The present paper also describes the effectiveness of the different processes for upgrading the LRC and how it transforms LRC to a value-added coal that is easily transportable and environmental friendly source of energy.