Activated carbon samples were developed from coal samples obtained from a coal mine, rat （Zonguldak, Turkey） and anthracite （Siberia, Russia）, applying pyrolysis in a temperature range of 600-900 ℃ under N2 flow,...Activated carbon samples were developed from coal samples obtained from a coal mine, rat （Zonguldak, Turkey） and anthracite （Siberia, Russia）, applying pyrolysis in a temperature range of 600-900 ℃ under N2 flow, and activation using chemical agents such as KOH, NH4Cl, ZnCl2 at 650 ℃. Nitrogen adsorption at low temperature （77 K） was used to characterize the activated carbon samples, and their pore structure properties including pore volume, pore diameter and pore size distribution were determined by means of the t-plots and DFT methods. The surface area values were higher for rat coal samples than for anthracite one, and for the rat coal samples treated with KOH ＋ NH4Cl ＋ ZnCl2 at 650 °C [Rat650（2）] there are highest surface area and total pore volume, 315.6 m2·g^-1 and 0.156 ml·g^-1, respectively. The highest value of the hydrogen sorption capacity was found as 0.71% （by mass） for the rat coal sample obtained by KOH ＋ ZnCl2 treatment at 650 °C [Rat650（1）].展开更多
A 30 kW bench-scale rig of pulverized anthracite combustion preheated by a circulating fluidized bed （CFB） was developed. The CFB riser has a diameter of 90 mm and a height of 1,500 mm. The down-fired combustion cha...A 30 kW bench-scale rig of pulverized anthracite combustion preheated by a circulating fluidized bed （CFB） was developed. The CFB riser has a diameter of 90 mm and a height of 1,500 mm. The down-fired combustion chamber （DFCC） has a diameter of 260 mm and a height of 3,000 mm. Combustion experiments were carded out using pulverized anthracite with 6.74% volatile content. This low volatile coal is difficult to ignite and burn out. Therefore, it requires longer burnout time and higher combustion temperature, which results in larger NOx emis- sions. In the current study, important factors that influence the combustion characteristics and NOx emissions were investigated such as excess air ratio, air ratio in the reducing zone, and fuel residence time in the reducing zone. Pulverized anthracite can be quickly preheated up to 800~C in CFB when the primary air is 24% of theo- retical air for combustion, and the temperature profile is uniform in DFCC. The combustion efficiency is 94.2%, which is competitive with other anthracite combustion technologies. When the excess air ratio ranges from 1.26 to 1.67, the coal-N conversion ratio is less than 32% and the NOx emission concentration is less than 371 mg/m^3 （@6% O2）. When the air ratio in the reducing zone is 0.12, the NOx concentration is 221 mg/m^3 （@6% O2）, and the coal-N conversion ratio is 21%, which is much lower than that of other boilers.展开更多
基金provided by the project DPT2002K120640 funded by State Planning Organization (DPT), Turkey
文摘Activated carbon samples were developed from coal samples obtained from a coal mine, rat （Zonguldak, Turkey） and anthracite （Siberia, Russia）, applying pyrolysis in a temperature range of 600-900 ℃ under N2 flow, and activation using chemical agents such as KOH, NH4Cl, ZnCl2 at 650 ℃. Nitrogen adsorption at low temperature （77 K） was used to characterize the activated carbon samples, and their pore structure properties including pore volume, pore diameter and pore size distribution were determined by means of the t-plots and DFT methods. The surface area values were higher for rat coal samples than for anthracite one, and for the rat coal samples treated with KOH ＋ NH4Cl ＋ ZnCl2 at 650 °C [Rat650（2）] there are highest surface area and total pore volume, 315.6 m2·g^-1 and 0.156 ml·g^-1, respectively. The highest value of the hydrogen sorption capacity was found as 0.71% （by mass） for the rat coal sample obtained by KOH ＋ ZnCl2 treatment at 650 °C [Rat650（1）].
基金supported by the National Natural Science Foundation of China(51006103)
文摘A 30 kW bench-scale rig of pulverized anthracite combustion preheated by a circulating fluidized bed （CFB） was developed. The CFB riser has a diameter of 90 mm and a height of 1,500 mm. The down-fired combustion chamber （DFCC） has a diameter of 260 mm and a height of 3,000 mm. Combustion experiments were carded out using pulverized anthracite with 6.74% volatile content. This low volatile coal is difficult to ignite and burn out. Therefore, it requires longer burnout time and higher combustion temperature, which results in larger NOx emis- sions. In the current study, important factors that influence the combustion characteristics and NOx emissions were investigated such as excess air ratio, air ratio in the reducing zone, and fuel residence time in the reducing zone. Pulverized anthracite can be quickly preheated up to 800~C in CFB when the primary air is 24% of theo- retical air for combustion, and the temperature profile is uniform in DFCC. The combustion efficiency is 94.2%, which is competitive with other anthracite combustion technologies. When the excess air ratio ranges from 1.26 to 1.67, the coal-N conversion ratio is less than 32% and the NOx emission concentration is less than 371 mg/m^3 （@6% O2）. When the air ratio in the reducing zone is 0.12, the NOx concentration is 221 mg/m^3 （@6% O2）, and the coal-N conversion ratio is 21%, which is much lower than that of other boilers.
