Absorptive separation for resource utilization by selective SO2 removal from flue gas is a potential method applicable in practice. A flue gas desulfurization process for SO2 utilization by selective absorption in a l...Absorptive separation for resource utilization by selective SO2 removal from flue gas is a potential method applicable in practice. A flue gas desulfurization process for SO2 utilization by selective absorption in a lab-scale absorption tower at atmospheric pressure using N-formylmorpholine (NFM) as the absorbent is developed to capture and concentrate the SO2 from flue gas, in which the CO2 content is several orders higher than that of SO2. The investigation of the effects of different operating conditions on the SO2 removal efficiency shows that the SO2 removal efficiency can be obviously enhanced by increasing NFM concentration, or decreasing the absorption temperature, the superficial gas velocity, the gas-liquid ratio, or the SO2 concentration in absorption solution. Under the optimum operating conditions (covering a temperature of 40 °C, a superficial gas velocity of <0.0165 m/s, a gas-liquid ratio of 200—250, a SO2 concentration in lean NFM solution of 0—10 mg/L, and a NFM concentration of 3 mol/L), the SO2 removal rate reaches over 99.5% while the absorption of CO2 is negligible. Similarly, the SO2 removal rate is as high as 99.5% obtained in consecutive absorption-desorption cycles. Desorption experiment results indicate that the absorption of sulfur dioxide is completely reversible and the release of SO2 from NFM is very easy and rapid at 104 °C. The absorption simulation result for desulfurization of flue gas vented from the industrial catalytic cracking regenerator shows that 98.0% of SO2 can be absorbed in the absorber and most of them are released in the desorber. The experimental and simulated results show that the desulfurization ability and regenerability of NFM solution is encouraging for the development of FGD process to capture the SO2 from flue gas.展开更多
Land application of anaerobic digestion(AD)effluent as a fertilizer is desirable for nutrient recycling,but often supplies excess phosphorus(P),which contributes to surface water eutrophication.Reducing the P content ...Land application of anaerobic digestion(AD)effluent as a fertilizer is desirable for nutrient recycling,but often supplies excess phosphorus(P),which contributes to surface water eutrophication.Reducing the P content in AD effluent filtrate using calcium(Ca)treatment prior to land application is a potential strategy for improving effluent disposal and meeting the discharge standard.This study took flue gas desulphurization(FGD)gypsum,a by-product of coal-fired power plants,as a low-cost Ca source,and combined with traditional phosphorus removal agents to achieve high phosphorus removal efficiency with less chemical cost.As the results showed,FGD gypsum dosages of 20 mmol/L Ca(3.44 g/L)and 40 mmol/L Ca(6.89 g/L)removed up to 97.1%of soluble P(initially 102.8 mg/L)within 60-90 minutes.Combining FGD gypsum treatment with traditional chemical treatments using calcium hydroxide[Ca(OH)2]or ferric chloride(FeCl3)could achieve>99%P removal with reduced chemical costs.This study demonstrated that FGD gypsum is an efficient calcium-based precipitant for phosphorus removal,offering a cost-effective and sustainable approach to enhance wastewater treatment practices and meet discharge standards in wastewater management.展开更多
石灰石-石膏湿法烟气脱硫(wet flue gas desulfurization,WFGD)工艺具有吸收剂来源广、成本低、脱硫效率高等优点,成为应用最广泛的烟气脱硫工艺。湿法脱硫过程中,燃煤烟气在喷淋浆液的洗涤作用下不仅能高效脱除SO2而且可以协同去除细...石灰石-石膏湿法烟气脱硫(wet flue gas desulfurization,WFGD)工艺具有吸收剂来源广、成本低、脱硫效率高等优点,成为应用最广泛的烟气脱硫工艺。湿法脱硫过程中,燃煤烟气在喷淋浆液的洗涤作用下不仅能高效脱除SO2而且可以协同去除细颗粒物,但同时存在石灰浆液夹带导致出口颗粒物浓度增加的问题。本文首先综述了湿法脱硫的应用现状,对比了湿法脱硫系统前后细颗粒物物性变化,然后概述了应用于湿法脱硫协同去除细颗粒物的新方法,包括脱硫塔内部结构调整以及促进细颗粒物凝聚长大,同时分析了湿法脱硫工艺中采用荷电细水雾吸附细颗粒物并增益脱除SO2的可行性,以期为燃煤电厂细颗粒物排放控制提供借鉴。最后指出未来湿法脱硫技术不仅要实现高脱硫效率,而且能有效脱除未被静电除尘器脱除的细颗粒物,湿法脱硫技术的发展趋势是多种技术耦合实现多污染物的协同脱除。展开更多
为了促进污染物协同控制和超低排放的实现,简化烟气脱硫除尘工艺,为选择性催化还原法(selective catalytic reduction,SCR)脱硝创造适宜的烟气条件,利用烟气干法脱硫除尘一体化装置,研究了碳酸氢钠干法脱硫的温度、钠硫比(stoichiometri...为了促进污染物协同控制和超低排放的实现,简化烟气脱硫除尘工艺,为选择性催化还原法(selective catalytic reduction,SCR)脱硝创造适宜的烟气条件,利用烟气干法脱硫除尘一体化装置,研究了碳酸氢钠干法脱硫的温度、钠硫比(stoichiometric ratio of sodium bicarbonate to sulfur,NSR)、入口SO2质量浓度、Na HCO3粒径和粉尘质量浓度等因素对脱硫效率的影响,对装置的脱硫性能做出评价,最佳脱硫效率达到95%以上.实验结果表明:温度、NSR为主要影响因素,在130~200℃温度范围内,脱硫效率随温度的升高呈先下降后保持稳定的趋势;随着NSR的增大,效率呈先增加后保持稳定的规律;入口SO2的质量浓度为1000~2000 mg/m3,脱硫效率随入口质量浓度的增大而有所增加;粒径较小的NaHCO3颗粒脱硫效率更好;烟气中的粉尘在一定程度上能够促进脱硫反应的进行.展开更多
基金supported by National Natural Science Foundation of China (Major Program: 61590923)International (Regional) Cooperation and Exchange Project(No. 61720106008)+2 种基金National Natural Science Foundation of China (No. 61873093)National Science Fund for Distinguished Young Scholars (61725301)the Fundamental Research Funds for the Central Universities
文摘Absorptive separation for resource utilization by selective SO2 removal from flue gas is a potential method applicable in practice. A flue gas desulfurization process for SO2 utilization by selective absorption in a lab-scale absorption tower at atmospheric pressure using N-formylmorpholine (NFM) as the absorbent is developed to capture and concentrate the SO2 from flue gas, in which the CO2 content is several orders higher than that of SO2. The investigation of the effects of different operating conditions on the SO2 removal efficiency shows that the SO2 removal efficiency can be obviously enhanced by increasing NFM concentration, or decreasing the absorption temperature, the superficial gas velocity, the gas-liquid ratio, or the SO2 concentration in absorption solution. Under the optimum operating conditions (covering a temperature of 40 °C, a superficial gas velocity of <0.0165 m/s, a gas-liquid ratio of 200—250, a SO2 concentration in lean NFM solution of 0—10 mg/L, and a NFM concentration of 3 mol/L), the SO2 removal rate reaches over 99.5% while the absorption of CO2 is negligible. Similarly, the SO2 removal rate is as high as 99.5% obtained in consecutive absorption-desorption cycles. Desorption experiment results indicate that the absorption of sulfur dioxide is completely reversible and the release of SO2 from NFM is very easy and rapid at 104 °C. The absorption simulation result for desulfurization of flue gas vented from the industrial catalytic cracking regenerator shows that 98.0% of SO2 can be absorbed in the absorber and most of them are released in the desorber. The experimental and simulated results show that the desulfurization ability and regenerability of NFM solution is encouraging for the development of FGD process to capture the SO2 from flue gas.
基金supported by the Shaanxi Province Science Foundation for Youths(Grant No.2023-JC-QN-0202)the Technology Innovation Center for Land Engineering and Human Settlements(Grant No.201912131-D2)+1 种基金the Shaanxi Province Key Research and Development Projects(Grant No.2022ZDLNY02-07)the“Young Talent Starting Fund”,and“Human Environment Improvements and Resources Utilization in Rural Areas”Research Projects of Xi’an Jiaotong University(Grant No.202012435).
文摘Land application of anaerobic digestion(AD)effluent as a fertilizer is desirable for nutrient recycling,but often supplies excess phosphorus(P),which contributes to surface water eutrophication.Reducing the P content in AD effluent filtrate using calcium(Ca)treatment prior to land application is a potential strategy for improving effluent disposal and meeting the discharge standard.This study took flue gas desulphurization(FGD)gypsum,a by-product of coal-fired power plants,as a low-cost Ca source,and combined with traditional phosphorus removal agents to achieve high phosphorus removal efficiency with less chemical cost.As the results showed,FGD gypsum dosages of 20 mmol/L Ca(3.44 g/L)and 40 mmol/L Ca(6.89 g/L)removed up to 97.1%of soluble P(initially 102.8 mg/L)within 60-90 minutes.Combining FGD gypsum treatment with traditional chemical treatments using calcium hydroxide[Ca(OH)2]or ferric chloride(FeCl3)could achieve>99%P removal with reduced chemical costs.This study demonstrated that FGD gypsum is an efficient calcium-based precipitant for phosphorus removal,offering a cost-effective and sustainable approach to enhance wastewater treatment practices and meet discharge standards in wastewater management.
文摘石灰石-石膏湿法烟气脱硫(wet flue gas desulfurization,WFGD)工艺具有吸收剂来源广、成本低、脱硫效率高等优点,成为应用最广泛的烟气脱硫工艺。湿法脱硫过程中,燃煤烟气在喷淋浆液的洗涤作用下不仅能高效脱除SO2而且可以协同去除细颗粒物,但同时存在石灰浆液夹带导致出口颗粒物浓度增加的问题。本文首先综述了湿法脱硫的应用现状,对比了湿法脱硫系统前后细颗粒物物性变化,然后概述了应用于湿法脱硫协同去除细颗粒物的新方法,包括脱硫塔内部结构调整以及促进细颗粒物凝聚长大,同时分析了湿法脱硫工艺中采用荷电细水雾吸附细颗粒物并增益脱除SO2的可行性,以期为燃煤电厂细颗粒物排放控制提供借鉴。最后指出未来湿法脱硫技术不仅要实现高脱硫效率,而且能有效脱除未被静电除尘器脱除的细颗粒物,湿法脱硫技术的发展趋势是多种技术耦合实现多污染物的协同脱除。
文摘为了促进污染物协同控制和超低排放的实现,简化烟气脱硫除尘工艺,为选择性催化还原法(selective catalytic reduction,SCR)脱硝创造适宜的烟气条件,利用烟气干法脱硫除尘一体化装置,研究了碳酸氢钠干法脱硫的温度、钠硫比(stoichiometric ratio of sodium bicarbonate to sulfur,NSR)、入口SO2质量浓度、Na HCO3粒径和粉尘质量浓度等因素对脱硫效率的影响,对装置的脱硫性能做出评价,最佳脱硫效率达到95%以上.实验结果表明:温度、NSR为主要影响因素,在130~200℃温度范围内,脱硫效率随温度的升高呈先下降后保持稳定的趋势;随着NSR的增大,效率呈先增加后保持稳定的规律;入口SO2的质量浓度为1000~2000 mg/m3,脱硫效率随入口质量浓度的增大而有所增加;粒径较小的NaHCO3颗粒脱硫效率更好;烟气中的粉尘在一定程度上能够促进脱硫反应的进行.
