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分析了石灰-石膏法脱硫技术在回转窑烟气处理方面的应用。对不同烟气脱硫技术进行分析比较,认为石灰-石膏湿法脱硫工艺是当前最合适冶炼企业的低浓度SO2烟气脱硫工艺。并结合某湿法炼锌厂回转窑烟气脱硫工程,阐述了该工艺的基本原理和流程,以及该脱硫工程中主要设备的选型和投产后的处理效果。分析了工程实施后产生的环境效益和社会效益,表明该工艺具有技术成熟,运行可靠,成本相对低廉的特点。 相似文献
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湿法烟气脱硫技术是控制SO2污染的主要技术和手段,脱硫工艺和设备的选择直接关系到脱硫的效率和成本以及该工艺的推广应用。详细介绍了国内外各种湿法烟气脱硫技术及研究进展,对各种工艺的优缺点进行了综合比较,并指出今后烟气脱硫工艺的改进及开发研究方向。 相似文献
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简述了目前烟气脱硫技术的国内外研究现状,并对循环流化床烟气脱硫技术作了技术和经济分析,主要针对该技术的特点和存在的缺点以及有待解决的问题进行了分析,与其它脱硫技术的经济参数和指标进行了对比,得出该技术在我国有广泛应用前景. 相似文献
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随着环境问题的日益严峻及燃煤锅炉超低排放工作的实施,由燃煤引起的大气污染问题及脱硫和除尘设备协同脱除污染物的作用逐渐受到关注。由燃煤释放的SO2和颗粒物对人类健康及自然环境造成严重危害,因此对SO2和颗粒物的治理至关重要。笔者综述了湿法烟气脱硫技术如石灰石-石膏法、氨法等,半干法烟气脱硫技术如循环流化床烟气脱硫技术(CFB)、高倍率灰钙循环烟气脱硫(NGD)等以及干法烟气脱硫技术如电子射线辐射法脱硫技术、活性炭(活性焦、活性半焦)吸附脱硫技术等的发展历史、技术特点及适用范围,并对比分析了各脱硫技术对颗粒物排放特性的影响。结果表明,湿法烟气脱硫技术SO2脱除效率最高,尤其是石灰石-石膏法烟气脱硫技术,总效率可达99%以上。入口颗粒物浓度高于5 mg/m^3时,此技术能够协同脱除烟气中的颗粒物,除尘效率可达50%~80%,脱硫前后粒径分布都为典型的双峰分布,且脱硫后粒径峰值向小粒径偏移,硫酸盐成分增加;入口颗粒物质量浓度低于5 mg/m^3时,出口颗粒物浓度可能出现不降反增的现象,另外,由于其投资和运行成本高,多应用于大型燃煤机组和脱硫剂来源丰富的地区,同时湿法烟气脱硫产物还具有一定的经济效益;半干法和干法烟气脱硫技术SO2脱除效率在60%~90%,与湿法脱硫技术相比具有投资和运行成本低,占地面积小和节约水资源等优点,在中小型锅炉领域如燃煤工业锅炉具有较好的应用前景,但大量脱硫产物和脱硫剂随烟气进入除尘设备,浓度高达1 000 g/m^3以上,为除尘设备造成极大的运行压力,加大了投资和运行成本。目前半干法烟气脱硫技术及干法烟气脱硫技术对颗粒物排放特性的影响研究较少,还需在脱硫系统对颗粒物粒径、成分及形貌特性等方面的影响规律做进一步研究。 相似文献
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Recent laboratory research has indicated that coal fly ash derived from subbituminous and bituminous type coals is a sink for atmospheric mercury (Hg), however lignite-based ash was found to emit Hg to the air. Solids collected from systems with components that enhance Hg removal (i.e. activated carbon injection (ACI), flue gas desulfurization (FGD), and selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR)) may have higher Hg concentrations and therefore a higher potential for Hg release. For this study we investigated the potential for Hg release to the air and water from coal combustion products (CCPs) collected from coal-fired units with FGD equipment, SCR and SNCR equipment, and sorbent injection for Hg removal. In the laboratory study, most dry samples acted as sinks for atmospheric Hg in the dark at 25 °C. When exposed to light or increased temperature (45 °C), deposition of Hg to the fly ash substrates in most cases continued but decreased. Wet FGD samples emitted Hg. However, they became a sink for atmospheric Hg or exhibited low Hg emission rates when dried. Mercury flux in the dark at 25 °C was correlated with fly ash carbon content (LOI). Most liquid extracts derived using the synthetic precipitation leaching procedure (SPLP EPA method 1312) had very low Hg concentrations (<13 ng/l). 相似文献
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在石灰石/石膏湿法脱硫工程实际应用中,影响脱硫效率的因素很多,主要问题包括结垢堵塞、设备和管道的腐蚀等,正确处理这些问题是保证烟气脱硫(FGD)系统长期稳定可靠运行的关键。相应的技术措施需综合考虑技术上的可行性和经济上的合理性等诸多因素,设计、设备选型、营运等各个阶段各个因素之间互相影响。如何优化设计方案,降低投资和运行检修费用,需要综合加以考虑。提出的方案是根据已运行项目的工程实际结果得出的结论,具有一定的实用和参考价值。 相似文献
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Selene M. A. Guelli U. Souza Fabiane B. F. Santos Antonio Augusto Ulson de Souza Fernando Vidal Barrero 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(9):1208-1214
BACKGROUND: Wet FGD technologies account for around 87% of such systems worldwide, particularly those that use limestone as the absorbent. This technique is widely used in large thermal power stations. Limestone reactivity is one of the parameters that most influence the yield of the FGD process. With the aim of improving the design and operation of desulfurization units, many studies have been carried out to investigate the rate of limestone dissolution. RESULTS: In this study, experimental equipment was set up to evaluate the limestone reactivity. In addition, a model to simulate the dissolution of limestone particles was developed. The proposed model considers the particle size distribution and composition, along with the pH of the liquid matrix where dissolution occurs. The average relative error between the experimental and numerically calculated results is 5%, after 10 min of experiment. CONCLUSION: A model based on film theory predicts with precision limestone dissolution as a function of the particle size distribution, chemical and physical composition of the limestone, pH and the solution composition. Copyright © 2010 Society of Chemical Industry 相似文献