Inner Relationship between CO, NO, and Hg in a 6 kW_th Circulating Fluidized Bed Combustor under an O₂/CO₂ Atmosphere

Abstract

Combustion experiments of semianthracite coal were conducted on a 6 kWth oxy-fuel circulating fluidized bed combustor. The inner relationship between CO, NO, and Hg in the combustor under an O2/CO2 atmosphere was explored. The results demonstrate that all temperatures are lower under a 21% O2/79% CO2 atmosphere than those under an air atmosphere. In oxy-coal combustion, the increasing oxygen concentration can increase CO emission. NO emission in oxy-coal is much lower than that in air combustion as a result of coal particle combustion generating less oxygen status under a 21% O2/79% CO2 atmosphere. The percentage of mercury oxidation is higher under air–coal combustion than that under 21% O2/79% CO2–coal combustion, because the specific heat of CO2 is higher in 21% O2/79% CO2 than that in air. The increase of the oxygen concentration under oxy-coal combustion leads to the total reducing atmosphere decrease, which is suitable for the mercury oxidation. These results are very significant for selection of operating conditions for an oxy-coal circulating fluidized bed.

Three-Dimensional Eulerian–Eulerian Simulation of Coal Combustion under Air Atmosphere in a Circulating Fluidized Bed Combustor

“…The circulating fluidized bed (CFB), as a chemical reactor, has attained great attention due to its unique advantages of high fuel flexibility, excellent heat transfer, and low pollutant emission. Nowadays, it is still under rapid development and has been experimentally studied in the chemical, energy, and environmental industries for applications − such as fluid catalytic cracking (FCC), fuel combustion and gasification, as well as pollutant emission reduction. Besides, with the increasing concerns about global warming, it is also a promising method for CO 2 capture when combined with the O 2 /CO 2 combustion technology. − …”

Synergistic effect between H2O and SO2 on mercury removal by activated carbon in O2/CO2 conditions

“…Three different H 2 O concentrations (8%, 15%, 23%) were selected, and the SO 2 concentration was 1000 ppm. The H 2 O concentrations and SO 2 concentration were set according to our previous results conducted in 6 and 50 kW th circulating fluidized beds …”

Prediction of Synergic Effects of H2O, SO2, and HCl on Mercury and Arsenic Transformation under Oxy-Fuel Combustion Conditions

“…This paper designed two kinds of baseline atmospheres (air-coal combustion and oxy-coal combustion atmosphere) combined with our previous results from 6 kW th , and 50 kW th Figure S1 shows the schematic diagram of 50 kW th oxy-CFB with warm flue gas recycling designed by our group from Southeast University .…”