scholarly journals Investigation on Mercury Reemission from Limestone-Gypsum Wet Flue Gas Desulfurization Slurry

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Chuanmin Chen ◽  
Songtao Liu ◽  
Yang Gao ◽  
Yongchao Liu

Secondary atmospheric pollutions may result from wet flue gas desulfurization (WFGD) systems caused by the reduction of Hg2+to Hg0and lead to a damping of the cobenefit mercury removal efficiency by WFGD systems. The experiment on Hg0reemission from limestone-gypsum WFGD slurry was carried out by changing the operating conditions such as the pH, temperature, Cl−concentrations, and oxygen concentrations. The partitioning behavior of mercury in the solid and liquid byproducts was also discussed. The experimental results indicated that the Hg0reemission rate from WFGD slurry increased as the operational temperatures and pH values increased. The Hg0reemission rates decreased as the O2concentration of flue gas and Cl−concentration of WFGD slurry increased. The concentrations of O2in flue gas have an evident effect on the mercury retention in the solid byproducts. The temperature and Cl−concentration have a slight effect on the mercury partitioning in the byproducts. No evident relation was found between mercury retention in the solid byproducts and the pH. The present findings could be valuable for industrial application of characterizing and optimizing mercury control in wet FGD systems.

2012 ◽  
Vol 610-613 ◽  
pp. 1473-1477 ◽  
Author(s):  
Chuan Min Chen ◽  
Li Xing Jiang ◽  
Song Tao Liu ◽  
Yu Ze Jiang

Secondary atmospheric pollutions may result from wet flue gas desulfurization (WFGD) systems caused by the reduction of Hg2+to Hg0and lead to a damping of the co-benefit mercury removal efficiency by WFGD systems. The effects of the operating conditions, which included the pH, temperature, and oxygen concentrations, on Hg0re-emission inhibition efficiency by DTCR from WFGD liquors was carried out. The established data reflected an outstanding performance on the Hg0re-emission inhibition from the simulated WFGD liquors by adding DTCR. Our data suggested that a concentration of 0.0005% (v/v) was enough for Hg0re-emission inhibition in the simulated WFGD liquors. The results also indicated that the Hg0re-emission inhibition efficiency by adding DTCR decreased as the operational temperatures increased and the Hg0re-emission inhibition efficiency increased as pH values and the oxygen concentration in the flue gas increased. The present findings could be valuable for industrial application of DTCR as a precipitant for stabilizing dissolved Hg2+to prevent re-emission of Hg0in WFGD solutions.


2012 ◽  
Vol 610-613 ◽  
pp. 2033-2037 ◽  
Author(s):  
Yu Ze Jiang ◽  
Chuan Min Chen ◽  
Li Xing Jiang ◽  
Song Tao Liu ◽  
Bin Wang

Hg2+captured by wet flue gas desulfurization (WFGD) systems can easily be reduced by reducing substances such as S(IV) (SO32-or HSO3-) and results in emissions of elemental mercury (Hg0). The re-emission of Hg0would lead to a damping of the total mercury removal efficiency by WFGD systems. The effects of the operating conditions, which included the pH, temperature, Cl-concentrations and oxygen concentrations, on Hg0re-emission from WFGD liquors was carried out. The experimental results indicated that the Hg0re-emission rate from WFGD liquors increased as the operational temperatures and pH values increased. The Hg0re-emission rates decreased as the O2concentration of flue gas and Cl-concentration of WFGD liquors increased. So the Hg0re-emission from WFGD system can be reduced or slowed by decreasing the temperature and pH, or by using forced oxidation. The present findings could be valuable for industrial application of characterizing and optimizing mercury control in WFGD systems.


2012 ◽  
Vol 518-523 ◽  
pp. 2509-2513 ◽  
Author(s):  
Hai Long Liu ◽  
Yan Liu ◽  
Jin Gang Wang ◽  
Shao Feng Zhang

In this paper the desulfurization and denitration of simulation flue gas using calcium hypochlorite as absorbent was studied experimentally. Absorption experiments of the desulfurization and denitration in calcium hypochlorite solutions were carried out in a Porous Globular Gas Liquid Reactor (PGGLR) which was a new and innovative core design. Three experiments were conducted at NTP conditions. The mechanism of removal for SO2 and NOX was investigated. Under these experiment conditions, the removal efficiency of 100%, 67% for SO2 and NOX were achieved. The results can offer valuable references for industrial application.


2012 ◽  
Vol 518-523 ◽  
pp. 2576-2579 ◽  
Author(s):  
Zhong Gen Li ◽  
Xin Bin Feng ◽  
Guang Hui Li ◽  
Run Sheng Yin ◽  
Ben Yu

Mercury distribution and stable isotope composition in solid samples of two coal-fired power plants in Guizhou province were determined. Results shown electrostatic precipitator (ESP) has mercury removal efficiency between 29.53% to 58.41%, and wet flue gas desulfurization (WFGD) between 12.29% to 58.60%, mercury removal efficiency of ESP and WFGD mainly depends on the coal properties. Most mercury (70% to 88%) in coal was captured by the combination of ESP+WFGD. Mercury in fly ash and gypsum were much heavier in isotope composition compared to the coal, hints mercury escaped into atmosphere was enriched in lighter mercury isotopes.


2013 ◽  
Vol 448-453 ◽  
pp. 608-612
Author(s):  
Li Bao Yin ◽  
Qi Sheng Xu ◽  
Jiang Jun Hu ◽  
Yang Heng Xiong ◽  
Si Wei Chen

The influences on the performance of wet flue gas desulfurization system in mercury removing after adding mercury removal additive were studied. As a consequence, the mercury removal efficiency can be improved by this kind of additive, that the efficiency of elemental mercury and total mercury is raised along with the amount of additive is increased. And so can the desulfuration efficiency. The oxidation of calcium sulfite in desulfurization is promoted by the mercury removal additive, increase the reduce speed of calcium sulfite concentration.


2019 ◽  
Vol 9 (15) ◽  
pp. 3085
Author(s):  
Kyle McGaughy ◽  
Jay P. Wilhelm ◽  
M. Toufiq Reza

Ion selective electrodes (ISE) were evaluated for use in a flue gas desulfurization (FGD) wastewater monitoring system. Calcium, chloride, nitrate, and nitrite ISE’s were calibrated in a broad range of concentrations that were designed to model an actual FGD wastewater sample that was obtained from an industrial partner. Ideal Nernst, Modified Nernst, and a multiparameter regression analysis was performed for each electrode and evaluated on general fit and sensitivity at anticipated operating conditions. The Ideal Nernst equation, even with correction for ionic strength, was not able to properly model actual electrode performance. The multiparameter regression was able to model the electrode performance with relative errors of 10–25% when ionic strengths were below 0.1 M. Through the evaluation of real-time sensor usage at real conditions, a methodology of washing and sampling rate is suggested to minimize error in the readings.


2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Ghulam Moeen Uddin ◽  
Syed Muhammad Arafat ◽  
Waqar Muhammad Ashraf ◽  
Muhammad Asim ◽  
Muhammad Mahmood Aslam Bhutta ◽  
...  

Abstract The emissions from coal power plants have serious implication on the environment protection, and there is an increasing effort around the globe to control these emissions by the flue gas cleaning technologies. This research was carried out on the limestone forced oxidation (LSFO) flue gas desulfurization (FGD) system installed at the 2*660 MW supercritical coal-fired power plant. Nine input variables of the FGD system: pH, inlet sulfur dioxide (SO2), inlet temperature, inlet nitrogen oxide (NOx), inlet O2, oxidation air, absorber slurry density, inlet humidity, and inlet dust were used for the development of effective neural network process models for a comprehensive emission analysis constituting outlet SO2, outlet Hg, outlet NOx, and outlet dust emissions from the LSFO FGD system. Monte Carlo experiments were conducted on the artificial neural network process models to investigate the relationships between the input control variables and output variables. Accordingly, optimum operating ranges of all input control variables were recommended. Operating the LSFO FGD system under optimum conditions, nearly 35% and 24% reduction in SO2 emissions are possible at inlet SO2 values of 1500 mg/m3 and 1800 mg/m3, respectively, as compared to general operating conditions. Similarly, nearly 42% and 28% reduction in Hg emissions are possible at inlet SO2 values of 1500 mg/m3 and 1800 mg/m3, respectively, as compared to general operating conditions. The findings are useful for minimizing the emissions from coal power plants and the development of optimum operating strategies for the LSFO FGD system.


2013 ◽  
Vol 800 ◽  
pp. 132-138 ◽  
Author(s):  
Li Li ◽  
Si Wei Pan ◽  
Jiang Jun Hu ◽  
Ji Fu Kuang ◽  
Min Qi ◽  
...  

Mercury in the flue gas in coal-fired power plant as the research object using halogen compound as the modified material, the fly ash was modified by chemical immersion method,Study on adsorption agent, the adsorption temperature, modified material and loading on mercury adsorption of flue gas in coal-fired power plants. Experiments showed that, iodine adsorption properties of modified fly ash was the most significant, with the increase of the sorbent dosage, Hg removal efficiency increased, fly ash adsorption amount of change was not obvious, between 80-140°C temperature range, fly ash on mercury existed mainly physical adsorption, the mercury removal efficiency decreased with the increase of temperature, chemical adsorption occurred at 160°C, mercury removal efficiency increased.


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