New Approach to the Combined Removal of NOx and SO2 for Circulating Fluidized Beds
Abstract
1. Introduction
2. Experimental Section
2.1. Fuel Characteristics
2.2. Test Platform
2.3. Measurements
2.4. Experimental Conditions
3. Results and Discussion
3.1. Effects of the Amount of Sorbent Addition in Post-Combustion Chamber on NOx and SO2 Emissions
3.1.1. Temperature Distribution at Different Amounts of Sorbent Addition
3.1.2. NOx and SO2 Emissions at Different Amounts of Sorbent Addition
3.2. Effects of Post-Combustion Air Arrangement on NOx and SO2 Emissions
3.2.1. Temperature Distribution at Different Post-Combustion Air Arrangements
3.2.2. NOx and SO2 Emissions at Different Post-Combustion Air Arrangements
3.3. NOx and SO2 Emissions: New Combined Removal Approach vs. Conventional Combined Removal Approach
3.3.1. Temperature Distribution in the CFB Furnace and Post-Combustion Chamber
3.3.2. NOx and SO2 Emissions Under Both Combined Removal Methods
4. Conclusions
- (a)
- Adding sorbent to the post-combustion chamber can reduce SO2 emissions, but further increasing the amount of sorbent will not significantly improve the desulfurization effect. Furthermore, the addition of sorbent in the post-combustion chamber will lead to an increase in NOx emissions, but the extent of the increase is not significant.
- (b)
- The injection position of the post-combustion air will affect the emissions of NOx and SO2 in the flue gas. When a three-stage distribution of post-combustion air is adopted, the further back the third nozzle is distributed, the lower the temperature in the post-combustion chamber, which is beneficial for controlling NOx and SO2 emissions.
- (c)
- Compared with the conventional combined removal method, the NOx emissions were significantly reduced under the new combined removal method. Through secondary desulfurization in the furnace and post-combustion chamber, oxygen-deficient combustion in the furnace can achieve the combined removal of NOx and SO2.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Item | Proximate Analysis (wt%, ad) | Ultimate Analysis (wt%, ad) | Low Heating Value (MJ/kg) | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Moisture | Ash | Volatile Matter | Fixed Carbon | Carbon | Hydrogen | Nitrogen | Oxygen | Sulfur | ||
Shenmu coal | 11.80 | 9.82 | 39.01 | 47.80 | 62.94 | 3.88 | 0.98 | 10.18 | 0.40 | 24.52 |
Composition | CaO | MgO | SiO2 | Fe2O3 | Al2O3 | K2O | SrO | TiO2 | P2O5 | Cl | SO3 | CuO |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Content (wt, %) | 52.79 | 3.13 | 1.21 | 0.71 | 0.41 | 0.09 | 0.07 | 0.07 | 0.02 | 0.01 | 0.01 | 0.01 |
Composition | CaO | MgO | Fe2O3 | SiO2 | Al2O3 | SO3 | K2O | MnO | Cl | P2O5 | ZnO |
---|---|---|---|---|---|---|---|---|---|---|---|
Content (wt% %) | 74.10 | 0.96 | 0.39 | 0.38 | 0.19 | 0.06 | 0.04 | 0.03 | 0.02 | 0.01 | 0.01 |
Case | T (°C) | FCa/S | PCa/S | Nozzles | λ | λCFB | Primary Air (m3/h) | Post-Combustion Air (m3/h) | Other Air(m3/h) | Feeding Coal (kg/h) |
---|---|---|---|---|---|---|---|---|---|---|
1-1 | 950 | 1.25 | 0 | 1/4/5 | 1.15 | 0.9 | 29.4 | 9.78 | 6 | 6.24 |
1-2 | 950 | 1.25 | 1.25 | 1/4/5 | 1.15 | 0.9 | 29.4 | 9.78 | 6 | 6.24 |
1-3 | 950 | 1.25 | 1.5–2 | 1/4/5 | 1.15 | 0.9 | 29.4 | 9.78 | 6 | 6.24 |
2-1 | 900 | 1.25 | 1.25 | 1/4/5 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-2 | 900 | 1.25 | 1.25 | 2/4/5 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-3 | 900 | 1.25 | 1.25 | 3/4/5 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-4 | 900 | 1.25 | 1.25 | 4/5/6 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-5 | 900 | 1.25 | 1.25 | 1/2/3 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-6 | 900 | 1.25 | 1.25 | 1/2/4 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-7 | 900 | 1.25 | 1.25 | 1/2/5 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
2-8 | 900 | 1.25 | 1.25 | 1/2/6 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
3-1 | 900 | 2.5 | 1~1.5 | 1/2/5 | 1.15 | 0.9 | 27 | 9.12 | 6 | 5.94 |
3-2 | 900 | 2.5 | 0 | 1/2/5 | 1.15 | 1.15 | 27 | 0 | 6 | 5.94 |
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Wang, C.; Lyu, Q. New Approach to the Combined Removal of NOx and SO2 for Circulating Fluidized Beds. ChemEngineering 2025, 9, 67. https://doi.org/10.3390/chemengineering9040067
Wang C, Lyu Q. New Approach to the Combined Removal of NOx and SO2 for Circulating Fluidized Beds. ChemEngineering. 2025; 9(4):67. https://doi.org/10.3390/chemengineering9040067
Chicago/Turabian StyleWang, Chao, and Qinggang Lyu. 2025. "New Approach to the Combined Removal of NOx and SO2 for Circulating Fluidized Beds" ChemEngineering 9, no. 4: 67. https://doi.org/10.3390/chemengineering9040067
APA StyleWang, C., & Lyu, Q. (2025). New Approach to the Combined Removal of NOx and SO2 for Circulating Fluidized Beds. ChemEngineering, 9(4), 67. https://doi.org/10.3390/chemengineering9040067