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[Display omitted] • A field-scale demonstration setup was used to investigate particle growth and removal. • Particle size in actual flue gas was analyzed. • 80.05% particle removal efficiency could be achieved by heat exchanger. • The strategy of temperature management to control the pollutants was obtained. Flue gas generated from coal combustion is the primary source of air pollution. Temperature is an essential parameter for the treatment process of flue gas pollutants. In this study, a field-scale demonstration setup was used to investigate the effect of temperature on particle growth and removal by using actual flue gas. The ionic migration in heat exchanger was also studied, and a temperature management method was established. Results showed that the temperature had a substantial influence on particle growth and removal, the outlet particle median diameter increased from 0.116 µm to 0.155 µm, and the outlet particle mass concentration decreased from 7.05 mg/Nm3 to 4.49 mg/Nm3 when the flue gas temperature difference was 2.9–4.6 K. Changing the boiler load from 100% to 65% led to the increase in the particle removal efficiency from 78.06% to 80.33%. This increment was mainly related to the changes in temperature. In addition, when the temperature difference increased from 2.9 K to 4.6 K, the concentration of the ions in the sample significantly increased, and the removal amount of mercury was enhanced by 2.57 times. The pollutant in the flue gas was effectively removed by the temperature management installation between the wet flue gas desulfurization and wet electrostatic precipitator. [ABSTRACT FROM AUTHOR]

Wet flue gas desulfurization systems (WFGD) are the most popular method to remove the SO 2 from the flue gas in China's power plants. Most WFGD systems contain an oxidation subsystem, which is one of the most important subsystems. In this paper, a hybrid modeling and operating optimization method of oxidation process of WFGD system is proposed, verified and applied on the WFGD system of a typical 1000 MW unit. The influence of important parameters such as the diameter of droplets or bubbles, the liquid-gas ratio or the gas-gas ratio (the ratio of between oxidized air flow rate and flue gas flow rate) and the height of the natural oxidation zone or the slurry level on natural oxidation rate and forced oxidation rate are further explored. The application results show that the above method can significantly reduce the operating energy consumption of the oxidation fan by more than 25 %. Furthermore, field tests are also carried out on the WFGD systems of 130 t/h and 220 t/h circulating fluidized bed (CFB) units. The energy consumption can be reduced by 30.6 % and 37.5 %, respectively. The results will be helpful to reduce the auxiliary power consumption and additional CO 2 emission of WFGD. [Display omitted] • Hybrid modeling method for oxidation process of WFGD system. • Influence of important parameters on natural oxidation rate and forced oxidation rate. • Operating optimization strategy of oxidation process with or without VFD. • Application on typical 1000 MW unit and two circulating fluidized bed (CFB) units. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-stage circulation integrated SO 2 and CO 2 capture, coupled with NH 3 recovery. • Over 99.5% SO 2 and 70% CO 2 was captured with desorption duty of 2.48 GJ/t CO 2. • Adaptable strategies balanced efficiency and economy amid complex conditions. Amidst growing environmental concerns stemming from fossil fuel combustion, which releases a considerable amount of pollutants and greenhouse gas. In an effort to mitigate the costs of existing combustion flue gas desulfurization and CO 2 capture systems, a new multi-stage circulation (MSC) process for integrating capture of CO 2 and SO 2 using ammonia-based absorbents was proposed. Different functional zones were interconnected using ammonia (NH 3) and potassium carbonate (K 2 CO 3) blended solution as the absorbent, enabling efficient SO 2 capture in the 1st stage, CO 2 enrichment in the 2nd stage, CO 2 capture enhancement in the 3rd stage and recovery of escaped NH 3 in the 4th stage. Experimental results demonstrated the effectiveness of NH 3 /K 2 CO 3 solution in enhancing CO 2 capture efficiency. The overall CO 2 capture efficiency varied between 95.4 % and 84.1 % at inlet CO 2 concentrations ranging from 5 % to 30 %. Under typical combustion flue gas conditions of 622 ppm SO 2 and 15 vol% CO 2 , the process exhibited a SO 2 removal efficiency exceeding 99.5 %, with CO 2 capture efficiency surpassing 70 %. Furthermore, the CO 2 desorption duty was determined to be 2.48 GJ/t CO 2. 13C NMR results confirmed that simultaneous absorption of CO 2 and SO 2 led to the accumulation of SO 2 in the liquid phase, reducing the CO 2 loading in rich solvent. To address these challenges, coupled optimization strategies was proposed, ensuring high capture efficiency and low CO 2 desorption duty under the complex and variable conditions of flue gas parameters, SO 2 concentration, and CO 2 concentration. [ABSTRACT FROM AUTHOR]