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氧化镁基催化剂及脱硝性能研究 总被引:1,自引:1,他引:1
为控制燃烧烟气中NOx的污染,对共混合方法制备的氧化镁基催化剂进行烟气直接催化分解法脱硝实验研究,分析模拟烟气脱硝塔内温度及床层高度及氧气浓度、NO浓度和空速对脱硝效率的影响.研究表明:氧化镁基催化剂可以采用直接催化分解法对烟气脱硝,脱硝率85%~95%,氧化镁基催化吸附剂组成为氧化镁、固化剂、添加剂;脱硝的床层高度4~5 cm,脱硝反应温度130~170℃,烟气空速2 500~3 000 h-1;研究推测出氧化镁基催化剂存在活性缺陷,并对脱硝机理进行了初步分析. 相似文献
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氧化镁烟气脱硫反应特性研究 总被引:7,自引:2,他引:5
利用实验室规模的鼓泡式反应装置,对比了碳酸钙、氧化镁和氧化镁/硫酸镁脱硫剂的反应活性,证实脱硫液中高浓度硫酸镁的存在是保证镁法脱硫效率高于钙法的重要因素,并考察了硫酸镁浓度、脱硫剂(氧化镁)浓度、烟气量、SO2浓度和吸收液温度等因素对脱硫效率的影响。结果表明,脱硫反应可以根据pH分为2个不同阶段;反应过程中脱硫效率随着硫酸镁浓度的增加而显著升高;烟气量增加将会导致脱硫效率有所下降;入口SO2浓度升高,脱硫效率下降;氧化镁浓度、温度对脱硫效率影响不显著。结合实验现象进行推断,氧化镁脱硫的反应过程受SO2在气液两相界面的传质扩散和其水解产物在液相的扩散控制。 相似文献
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针对无锡某废纸造纸企业产生的污水经厌氧-好氧-化学混凝处理后,出水在放流池产生结垢现状,对各段污水中主要离子浓度进行跟踪分析,并对结垢的组分、结垢原因、机理和防治结垢对策进行了探讨。结果表明:垢样的主要成分为CaCO3;污水中含有较高浓度的钙离子和碳酸氢根离子是导致结垢的主要原因,较高的水温、pH值、流速、流动状态、池壁的粗糙程度以及PAC的投加对结垢也有一定的影响;最佳防治对策为使用Ca(OH)2+PAM代替PAC+PAM混凝,保证COD达标排放同时,也解决了出水结垢问题。 相似文献
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石灰湿式洗涤法脱硫的应用研究 总被引:4,自引:0,他引:4
本文介绍了石灰湿式洗涤法脱硫的改进思路,通过采用三级串联喷淋,低液气比和投加防垢剂等办法,成功解决了设备管道结垢问题,实践表明,该法具有工艺简单,投资省,操作简便,运行费用低,脱硫率高待特点. 相似文献
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Dennis W. Weeter 《Journal of the Air & Waste Management Association (1995)》2013,63(7):751-753
Several designated hazardous wastes (metal plating waste, oil sludge, heavy metal processing sludge) were studied relative to potential detoxification using dry calcium based FGD sludges. The FGD waste was generated from a pilot scale system which utilized slurried lime, a spray drier, and a bag filter. Following detailed physical and chemical identification of the raw FGD and hazardous wastes, various mixtures were prepared and cured. In all cases, even with the organic sludge, a rigid structural material evolved due to the pozzolanic reactions occurring from the wetted dry FGD waste. Structural characteristics, physical character, and chemical leaching effects were evaluated. The solids were leached via both EPA-RCRA and ASTM proposed leaching procedures. In all cases, the hazardous constituents were retained and not leached. Finally, the feasibility of using dry FGD wastes as fixating materials is discussed. 相似文献
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J. David Mobley John C. S. Chang 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1249-1253
Extensive research has determined that adipic acid, when used as an additive to a limestone flue gas desulfurization (FGD) system, will improve the performance of the system. Both SO2 removal and limestone utilization can be greatly increased by the buffering effect of adipic acid. Successful testing in laboratory, bench, pilot, prototype, and full scale systems has demonstrated the benefits of this technology for new and retrofit applications. Although adipic acid does degrade in the scrubber, no significant operating problems or environmental impacts have been identified. Economic estimates have shown the adipic acid enhanced limestone FGD system to be economically attractive when compared to conventional FGD systems. In addition, further research is underway to decrease the cost of using additives in FGD systems. 相似文献
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中国电力工业烟气脱硫的现状及发展趋势 总被引:4,自引:0,他引:4
研究我国电力工业燃煤发电厂烟气脱硫的现状及其发展趋势 ,包括我国电力工业大气SO2 污染状况 ,烟气脱硫现状 ,烟气脱硫综合经济技术评价 ,烟气脱硫技术的选择和烟气脱硫的发展趋势。研究与开发有针对性和较强应用前景的烟气脱硫技术 ,发展具有独立自主知识产权的烟气脱硫技术 ,是我国电力工业烟气脱硫技术及设备国产化的必经之路 相似文献
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L. N. Davidson R. A Goffredi C. P. Wedig 《Journal of the Air & Waste Management Association (1995)》2013,63(6):685-690
The successful, reliable operation of a power plant flue gas desulfurization (FGD) system depends largely on a good program of maintenance. Identifying the FGD equipment that is most critical to an FGD system’s overall reliability or its ability to meet emission regulations plays an important role in determining the extent of a maintenance program for a particular site. FGD maintenance programs vary considerably, depending on site-specific requirements and the support of plant owners. Many owners are reluctant to spend money on FGD maintenance because an FGD system is a nonproductive part of a power plant; however, a good maintenance program can result in longer equipment life, improved equipment performance, increased system availability, better safety, and lower operating costs. This paper uses wet and dry lime FGD systems to illustrate the advantages of good maintenance and the consequences of poor maintenance. Examples of specific tasks for preventive, scheduled, planned, and emergency maintenance are described. Also, because of the importance of FGD maintenance personnel, a section on organization and training is included. 相似文献
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循环流化床烟气脱硫技术及其环境经济可行性探讨 总被引:1,自引:0,他引:1
简要介绍了循环流化床烟气脱硫技术的原理和国内外研发的现状,并与目前得到广泛应用和继续发展的其它3种烟气脱硫工艺进行比较,得出循环流化床烟气脱硫净化工艺具有投资相对较低、脱硫效率较高、运行可靠、操作维护方便等优点。再通过实例,从投资、技术、运行成本等方面论述其环境经济的可行性,得出循环流化床烟气脱硫技术符合江阴现阶段经济发展状况,能满足中、小型锅炉脱硫要求,是一种较为可行的大气污染控制技术。 相似文献
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Mercury emission and plant uptake of trace elements during early stage of soil amendment using flue gas desulfurization materials 总被引:2,自引:0,他引:2
Cheng CM Chang YN Sistani KR Wang YW Lu WC Lin CW Dong JH Hu CC Pan WP 《Journal of the Air & Waste Management Association (1995)》2012,62(2):139-150
A pilot-scale field study was carried out to investigate the distribution of Hg and other selected elements (i.e., As, B, and Se), i.e., emission to ambient air, uptake by surface vegetation, and/or rainfall infiltration, after flue gas desulfurization (FGD) material is applied to soil. Three FGD materials collected from two power plants were used. Our results show Hg released into the air and uptake in grass from all FGD material-treated soils were all higher (P < 0.1) than the amounts observed from untreated soil. Hg in the soil amended with the FGD material collected from a natural oxidation wet scrubber (i.e., SNO) was more readily released to air compared to the other two FGD materials collected from the synthetic gypsum dewatering vacuum belt (i.e., AFO-gypsum) and the waste water treatment plant (i.e., AFO-CPS) of a forced oxidation FGD system. No Hg was detected in the leachates collected during the only 3-hour, 1-inch rainfall event that occurred throughout the 4-week testing period. For every kilogram of FGD material applied to soil, AFO-CPS released the highest amount of Hg, B, and Se, followed by SNO, and AFO gypsum. Based on the same energy production rate, the land application of SNO FGD material from Plant S released higher amounts of Hg and B into ambient air and/or grass than the amounts released when AFO-gypsum from Plant A was used. Using FGD material with lower concentration levels of Hg and other elements of concern does not necessary post a lower environmental risk. In addition, this study demonstrates that considering only the amounts of trace elements uptake in surface vegetation may under estimate the overall release of the trace elements from FGD material-amended soils. It also shows, under the same soil amendment conditions, the mobility of trace elements varies when FGD materials produced from different processes are used. 相似文献
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Maria Gårding Gunnar Svedberg 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1275-1280
Dry processes for controlling sulfur dioxide emissions by injecting sodium based sorbents in the ductwork ahead of a bag filter are effective and more simple alternatives to conventional FGD processes. This paper presents a fundamental kinetic model of the dry injection process. Experimental data from pilot scale tests are reported. The model is shown to be applicable to the dry injection process. However, further experimental work is recommended to get a better understanding of the reaction mechanisms. 相似文献
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Differential partitioning and speciation of Hg in wet FGD facilities of two Spanish PCC power plants
R. Ochoa-GonzálezP. Córdoba M. Díaz-Somoano O. FontM.A. López-Antón C. LeivaM.R. Martínez-Tarazona X. QuerolC. Fernández Pereira A. TomásP. Gómez P. Mesado 《Chemosphere》2011,85(4):565-570
This paper evaluates the speciation and partitioning of mercury in two Spanish pulverised coal combustion power plants (PP1 and PP2), equipped with wet limestone-based flue gas desulphurisation facilities (FGD) operating with forced oxidation and re-circulation of FGD water streams. These plants are fed with coal (PP1) and coal/pet-coke blends (PP2) with different mercury contents. The behaviour, partitioning and speciation of Hg were found to be similar during the combustion processes but different in the FGD systems of the two power plants. A high proportion (86-88%) of Hg escaped the electrostatic precipitator in gaseous form, Hg2+ being the predominant mercury species (68-86%) to enter the FGD. At this point, a relatively high total Hg retention (72% and 65%) was achieved in the PP1 and PP2 (2007) FGD facilities respectively. However, during the second sampling campaign for PP2 (2008), the mercury removal achieved by the FGD was much lower (26%). Lab-scale tests point to liquid/gas ratio as the main parameter affecting oxidised mercury capture in the scrubber. The partitioning of the gaseous mercury reaching the FGD system in the wastes and by-products differed. In the low mercury input power plant (PP1) most of the mercury (67%) was associated with the FGD gypsum. Moreover in PP2 a significant proportion of the gaseous mercury reaching the FGD system remained in the aqueous phase (45%) in the 2007 sampling campaign while most of it escaped in 2008 (74%). This may be attributed to the scrubber operating conditions and the different composition and chemistry of the scrubber solution probably due to the use of an additive. 相似文献
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Flue gas desulfurization by-products additions to acid soil: alfalfa productivity and environmental quality 总被引:2,自引:0,他引:2
Flue gas desulfurization (FGD) by-products are created when coal is burned and SO2 is removed from the flue gases. These FGD by-products are often alkaline and contain many plant nutrients. Land application of FGD by-products is encouraged but little information is available related to plant responses and environmental impacts concerning such use. Agricultural lime (ag-lime) and several new types of FGD by-products which contain either vermiculite or perlite were applied at 0, 0.5, 1.0, and 2.0 times the soil's lime requirement (LR) rate to an acidic soil (Wooster silt loam). The highest FGD by-products application rate was equivalent to 75.2 Mg ha(-1). Growth of alfalfa (Medicago sativa L.) was significantly increased compared to the untreated control in the second year after treatment with yields for the 1 x LR rate of FGD approximately 7-8 times greater compared to the untreated control and 30% greater than for the commercial ag-lime. Concentrations of Mo in alfalfa were significantly increased by FGD by-products application, compared to the untreated control, while compared to the ag-lime treatment, concentrations of B increased and Ba decreased. No soil contamination problems were observed, even at the 2xLR rate, indicating these materials can be safely applied to agricultural soils. 相似文献