Papers by Keyword: SO₂

Abstract: The simultaneous desulfurization and denitrification performance from the N₂-SO₂-NO simulated flue gas using the urea solution as the reduction absorbent and piperazine as the additive was investigated. The influences of the concentration of urea solution and the concentration of piperazine solution on the simultaneous desulfurization and denitrification behavior were also discussed. The experimental results showed that the addition of piperazine in the urea solution could enhance the denitrification performance, which could result the desulfurization efficiency of 94.07% and the denitrification efficiency of 85.11%.

Abstract: Through an analysis about the atmospheric environment SO₂ space effect of China from 2000 to 2011, this article puts forward that the atmospheric pollution in China is influenced by per capital GDP and industrial structure to a large extent. Meanwhile, environmental efficiency factors which should restrict atmospheric environmental pollution have positive spillover effect to environmental pollution to surrounding area, which indicates that the environmental pollution treatment in China in current stage is only transition of the pollution in a disguised form. In some regions, industries are moved to less developed areas around in order to enhance their environmental compliance, so polluting industries cannot be moved out like those in developed regions and the environment is difficult to improve.

Abstract: The objective of this work was to study the effect of some operating condition on the simultaneous removal of NO and SO₂ from simulated flue gas in the lab-scale agitated bubbling reactor. The experimental results showed that NO removal efficiency increased with the increase in the molar ratio of O₃/NO, while removal efficiency of SO₂ decreased. When absorption liquid changed from distilled water to Na₂CO₃ solution, it is observed that removal efficiencies of NO and SO₂ increase with the increase in the concentration of Na₂CO₃ solution. At 0.08 mol/L of Na₂CO₃ solution, the removal efficiencies of SO₂ and NO are 100% and 93%, respectively

Abstract: Based on a detailed survey on the source and volume of SO₂ emission over Chengdu economic circle, the third-generation air quality model CMAQ is adopted for simulating the concentration of SO₂ in the air over Chengdu Economic Circle. The results show that the hourly average concentration, daily average concentration and annual average concentration of SO₂ in air exceed the limit of national standard, and the affected areas respectively account for 0.12%, 0.18% and 0.03% of the total area of the economic circle. Meanwhile, according to the result of calculation, the SO₂ emissions of thermal power plants, chemical industry, building materials plants and industrial area sources make the largest contribution to the SO₂ concentration in the air, with ratios of 36.15%, 18.67%, 11.81% and 8.34% respectively. thus,main measures to reduce emissions of SO₂ in Chengdu economic circle are proposed as follows: focusing on the control of the emissions of SO₂ from industrial enterprises, especially in the thermal power plants, chemical industry, building materials plants as well as industrial boilers; joint prevention and control measures should be implemented between the cities, so as to reduce the interaction caused dy emissions of SO₂. With the application of the above measures, the total SO₂ emissions can be reduced by 50% and the concentration of SO₂ in the air can meet with the Class II of national ambient air quality Standard.

Abstract: As an air pollutant, the emission and monitoring of SO₂ gas have been widely concerned. In the paper, the characteristics of domestic and imported portable SO₂ gas analyzers based on nondispersive infrared (NDIR) absorption technique have been tested. The performance of the analyzers has been discussed detailedly. The results reveal that domestic portable SO₂ gas analyzer can provide excellent performance like imported instrument. In additon, all the analyzers have been in comparison with the continuous emission monitoring system (CEMS) for monitoring the SO₂ emission of a power plant. The results demonstrate that domestic portable SO₂ gas analyzers can be used to evaluate and supervise CEMS operating situation. Based on the comparison results and domestic demand, we also give some suggestion for the future technique research and instrument development.

Abstract: There are large amount of ammonia in coking wastewater. It is a good recycling desulfurizer. Sintering flue gas has the characteristics, such as large amount of, low SO₂ concentration, great changes of operation load. Treating sintering flue gas with coking wastewater can attain the destination of treating waste with waste. This paper adopts a spray tower countercurrent device, and SO₂ concentration in the entrance and exit flue gas is on line detected by an automatic flue gas detection instrument. The paper studies on the change rule of SO₂ concentration in the process of treating sintering flue gas using coking wastewater, and the influence of SO₂ initial concentration in sintering flue gas to the desulfurization rate. The results show that after being treated the sintering flue gas can reach the emission standard for air pollutants of iron and steel industry.

Abstract: To find out the characteristics and relationships of air pollutants and greenhouse gases emissions in China is of important practical significance for the state, to make relative policies on cooperative control of atmospheric pollutants and greenhouse gases. The panel data (1995 to 2010) of 30 provinces (municipalities and autonomous regions) in Chinese mainland is selected, to apply Mathematical Statistics and Data Envelopment Analysis method to research on the emission characteristics and efficiency of the major atmospheric pollutant (SO₂) and the main greenhouse gas (CO₂). The results shows: Chinese regional and industrial SO₂ and CO₂ emission levels have significant differences, the total emissions of the eastern and central region are higher than the western region, however, the emission intensity of the western region is much higher than the eastern region, especially, the SO₂ and CO₂ emission intensity of Ningxia region are both the highest in the country. The calculation results of relative efficiency with DEA show that the efficiency ranking of the three regions is: Eastern>Central>Western. 7 provinces as Shanghai, Jiangsu, Fujian, Guangdong, Hainan, Qinghai and Tianjin are at the production frontier,the relative efficiency is 1, 3 provinces with the lowest efficiency are all in western region as Yunnan, Shanxi and Inner Mongolia, which is basically consistent with the regional characteristics of emission intensity. Finally, the implications of SO₂ and CO₂ emissions characteristics for the control of atmospheric pollutants and greenhouse gases emission reduction will be analyzed.

Abstract: This work is dedicated to the development of an on-line monitoring system of SF6 decomposition in electrical devices (SF₆DcpMS) in order to evaluate the health condition of the devices in real time. The feature decomposition, SO₂, and SF₆ purity are continuously monitored. Considering the oxidation-reduction reactions of SO₂ electrochemical sensor during detection, the methodology of utilizing the air in the electrical device is proposed based on the tests of serving devices. And it is proved via tests that electrochemical sensors can be applied into SF₆DcpMS. Besides, infrared detector is employed to detect SF₆ purity. Sampling method of SF₆ in electrical devices is described. There are three keys in the sampling device design for the on-line monitoring system: -- Sensor working environment: The rating pressure is one atmospheric pressure for sensor working. Therefore, a gas chamber is constructed, in which the suitable environment for sensor is completed via a pressure regulator and a pressure sensor. At the same time, an appropriate control method is scheduled. Gas in the chamber is continuously replaced with that in the electrical device to ensure detection accuracy within an acceptable range. -- SO₂ adsorption feature: The monitoring accuracy is seriously influenced by the adsorption feature of SO₂. As we known, flowing gas can decrease SO₂ adsorption feature. So, a micro bump is designed in the gas chamber, which can ensure the gas flowing at the speed of 200ml/min. -- Sample gas back into electrical devices: In order to avoid the gas cause harm to humans, the gas leakage is not allowed in the on-line monitoring system, and the sample gas must be sent back to the electrical device after detection is accomplished. Sample gas back into electrical devices is realized via a bump and a check valve with adjustable cracking pressure. The first SF₆DcpMS in China has been successfully put into service in Zunyi substation, and its performance has been proved out.

Abstract: With the rapid development in industrialization and urbanization, various air pollutants are emitted into atmospheric environment. NO, SO₂, Hg⁰ are the most important pollutant in the flue gas. The application of non-thermal plasma (NTP) technology in the removal of NO, SO₂, Hg⁰ was reviewed respectively. Environmental applications have mainly involved plus corona discharge (PCD) and dielectric barrier discharge (DBD) system. In the future, the application of plasma technology in the flue gas could be focused on multiple pollutants synergistic mechanism.

Abstract: In this paper, the desulphurization of coals prepared briquettes using lime based products (calcium hydroxide and calcium carbonate) and sodium hydroxide as desulphurizing agents (DSA) was investigated in a vertically integrated experimental furnace. Meanwhile, the effect of sodium hydroxide on the denitrification was also studied. The results indicated that calcium carbonate as a DSA is more efficient for SO₂ removal during the char combustion, whereas hydrated lime and NaOH are efficient in both char and volatile combustion. For most of the coals, the desulfurization efficiencies in case of lime hydrated reaches over 80 %, whereas desulfurization efficiencies is below 70% when calcium carbonate is used as DSA. It was also found that NaOH can be used as denitrifying agent as well as desulphurizing agent, and the maximum denitrifying efficiencies by using NaOH denitrifying agents for coal A and coal B are 59% and 54%, respectively.