等离子体脱硫脱硝研究

文中综述了等离子体脱硫脱硝的重要成果,总结了国内外应用等离子体技术脱硫脱硝的反应机理,特性及其发展,最后对该技术的前景作一展望。     

烟气脱硫脱硝技术浅析

简要叙述火电、钢铁行业脱硫脱硝现状，结合“十二五”环保、节能减排规划对火电、钢铁行业中的烟气脱硫脱硝技术进行简要分析。     

大型火电厂锅炉脱硫脱硝及烟气除尘方案研究

新的《火电厂大气污染物排放》（GB13223-2011）已经实施,新的排放标准对电厂烟尘、SO2、NOx、汞及其化合物的要求更加严格。分析论证了大型燃煤电厂的烟气处理技术路线,为大型燃煤机组烟气深度净化提出了完整解决方案。     

转底炉烟气脱硫脱硝技术路线的选择

随着国家对大气环境保护的越发重视，钢铁行业超低排放的不断深入，转底炉项目污染物排放限值的要求也将进一步收紧。结合转底炉生产情况，分析其燃料特性和烟气污染物的生成机理，阐述了转底炉烟气处理的必要性、难点以及推动超低排放的合理化建议。基于对传统的烟气污染物控制技术进行综述，介绍了湿法脱硫、半干法脱硫、干法脱硫、选择性催化还原法和选择性非催化还原法等主流的烟气脱硫脱硝技术，从技术、投资和运行等多方面进行了对比探讨，为转底炉烟气脱硫脱硝新形势下超低排放技术路线的选择提供了一定的借鉴。转底炉烟气处置技术路线首选为“低氮燃烧器+SNCR+余热锅炉+SDS干法脱硫+布袋除尘器”,次选为“低氮燃烧器+余热锅炉+SDS干法脱硫+布袋除尘器+SCR”技术路线。     

撬装式注汽锅炉烟气脱硫脱硝装置的开发

为减少移动式注气锅炉烟气中二氧化硫及氮氧化物的排放,以11.5 t/h燃油注气锅炉为研究对象,通过撬装式脱硫脱硝装置的开发及现场试验,对注气锅炉烟气SO₂和NO_x的排放及现场环境因素等问题进行了研究。研究表明,采用氢氧化钠和双氧水作为吸收剂的脱硫脱硝装置能明显降低烟气中的SO₂和NO_x的浓度,其中SO₂脱除效率高于95%,NO_x脱除效率在65%以上;通过余热利用可有效降低系统的运行费用。撬装模式的开发,可有效解决设备移动性差、占地面积大、浆液补给困难等影响注气锅炉运行的问题。     

基于氨法的烧结烟气脱硫脱硝技术研究与探讨

氨水溶液能有效去除废气中的SO₂,但对NO_x的去除受到一定的限制。本文研究了添加不同氧化剂的氨水对填料塔中SO₂和NO_x同时吸收的情况。结果表明,环保型氧化剂H2O2在能保证SO₂的高脱除率情况下,也能较好地提升氨水对NO_x的脱除率。同时,从填料塔的液气比、反应温度、溶液pH值等角度对氨水脱硫脱硝条件进行了优化,并找出了最优实验条件。最后,探讨了在氨法脱硫的基础上引入等离子体预氧化实现脱硫脱硝一体化的技术可行性。     

低温等离子体-催化协同脱硝技术中若干问题探讨

等离子体-催化吸附协同脱硝是一种新型NOx脱除技术。文中论述了该技术中若干问题，包括电源形式、反应器型式、催化剂选择、添加剂以及温度的影响等，分析了它们对脱硝的影响，并指出了该技术的发展方向。     

燃煤电厂烟气脱硫脱硝一体化技术发展趋势

火电厂燃煤中排放的硫化物及氮氧化物是造成大气污染的主要成分之一,经济且有效地控制燃煤电厂排放的SO2与NOx对中国这样一个以煤炭为主要资源的国家显得尤为重要。分析了中国现今的脱硫脱硝技术并着重介绍了几种燃煤电厂烟气脱硫脱硝一体化技术,分析它们的特点及存在的问题。指出具有应用前景的脱硫脱硝技术并给出建议。     

我国燃煤火电厂烟气脱硫脱硝技术发展现状

火电厂燃煤过程排放的污染物是我国大气污染的主要来源之一.基于对我国火电厂烟气脱硫脱硝技术的大量调研,回顾了"十五"以来我国燃煤火电厂烟气脱硫脱硝技术的发展历程.着重介绍了石灰石-石膏法、烟气循环流化床、海水脱硫、氨法等脱硫技术,并简要介绍了每种技术的应用现状;对炉内氮氧化物控制技术及SCR、SNCR等烟气脱硝技术的发展进行了概括.在此基础上,总结了目前脱硫脱硝行业的主要问题和开发重点.     

烟气脱硫技术及脱硫脱硝除尘与环保策略

随着我国社会经济的不断发展,对能源的需求也在逐渐增加,煤炭、石油等能源都是日常生活中必不可少的能源,这些能源在使用的过程中会对环境造成一定的污染,因此,要做好环境保护工作。基于此,本文对烟气脱硫技术及脱硫脱硝除尘与环保策略进行了分析,希望可以为我国环境保护工作提供一定的帮助。     

Chemical reactor network modeling of a microwave plasma thermal decomposition of H2S into hydrogen and sulfur

The conventional treatment method for H₂S is the Claus process, which produces sulfur and water. This results in a loss of the valuable potential product hydrogen. H₂S treatment would be more economically valuable if both hydrogen and sulfur products could be recovered. Based on standard heats of formation analysis, the theoretical energy required to produce hydrogen from H₂S dissociation is only 20.6 kJ/mol of H₂ as compared to 63.2 kJ/mol of H₂ from steam methane reforming and 285.8 kJ/mol of H₂ from water electrolysis. Among the many thermal decomposition methods that have been explored in the literature, Micro-wave plasma dissociation of H₂S prevails as the method of choice to attain the best conversion and energy efficiency. Chemical kinetics simulations using an ideal flow reactor network have been carried out on the CHEMKIN-PRO software package and they support these findings. The reactor network simulates the thermal plasma behavior in the plasma torch, the plasma reactor, and the sulfur condenser. Two chemical kinetics mechanisms have been used and the results show an almost complete conversion of H₂S into hydrogen and sulfur in the plasma reactor at an optimum temperature of about 2400 K at atmospheric pressure. While the most challenging task of the process is found to be the plasma cooling rate at the sulfur condenser where very fast quenching is required to conserve the hydrogen product from converting back to H₂S.     

HYSYS流程模拟技术在丁辛醇装置用能优化方面的应用

分析了大庆石化公司丁辛醇装置工艺流程中用能优化的潜力,即可增没换热器,实现温度较低的精EPA与温度较高的粗EPA的换热,充分利用内部循环热能,同时可节约冷却水和加热蒸汽用餐。介绍了利用HYSYS流程模拟技术．通过采用定义虚拟组分来计算增设换热器换热面积的计算方法。根据模拟计算结果,采用换热面积为35m^2的新增换热器,每年节约1．3MPa蒸汽1×10^4t、冷却水28×10^4t。     

Energy efficient simultaneous oxidative conversion and thermal cracking of ethane to ethylene using supported BaO/La2O3 catalyst in the presence of limited O2

An energy efficient conversion of ethane to ethylene involving simultaneous oxidative conversion (which is exothermic) and thermal cracking (which is endothermic) reactions of ethane in the presence of steam (steam/C₂H₆ mol RATIO=1.0) and limited O₂ (C₂H₆/O₂ mol ratio 4.0) over a BaO-promoted La₂O₃ supported on low surface area macroporous silica-alumina commercial catalyst carrier has been thoroughly investigated. Influence of various process parameters such as temperature (700–850°C), C₂H₆/O₂ feed ratio (4.0–8.0) and space velocity (50,000–200,000 cm³ g⁻¹ h⁻¹) on the conversion, product selectivity and net heat of reactions in the process has also been studied. At all the process conditions, there was no coke deposition on the catalyst. High selectivity ( 85%) for C₂₊ olefins (at 50–60% conversion) can be obtained in the process at a low contact time (<10 ms), particularly for the higher C₂H₆/O₂ ratios ( 6.0) and temperatures ( 800°C). The process exothermicity is decreased appreciably with increasing the temperature and/ or the C₂H₆/O₂ ratio. The net heat of reaction in the process can be controlled by manipulating the C₂H₆/O₂ ratio and reaction temperature. Also, because of simultaneously occurring endothermic and exothermic reactions, the process is highly energy efficient and non-hazardous.     

Design and evaluation of hydrogen electricity reconversion pathways in national energy systems using spatially and temporally resolved energy system optimization

For this study, a spatially and temporally resolved optimization model was used to investigate and economically evaluate pathways for using surplus electricity to cover positive residual loads by means of different technologies to reconvert hydrogen into electricity. The associated technology pathways consist of electrolyzers, salt caverns, hydrogen pipelines, power cables, and various technologies for reconversion into electricity. The investigations were conducted based on an energy scenario for 2050 in which surplus electricity from northern Germany is available to cover the electricity grid load in the federal state of North Rhine-Westphalia (NRW).A key finding of the pathway analysis is that NRW's electricity demand can be covered entirely by renewable energy sources in this scenario, which involves CO₂ savings of 44.4 million tons of CO₂/a in comparison to the positive residual load being covered from a conventional power plant fleet. The pathway involving CCGT (combined cycle gas turbines) as hydrogen reconversion option was identified as being the most cost effective (total investment: € 43.1 billion, electricity generation costs of reconversion: € 176/MWh).Large-scale hydrogen storage and reconversion as well as the use of the hydrogen infrastructure built for this purpose can make a meaningful contribution to the expansion of the electricity grid. However, for reasons of efficiency, substituting the electricity grid expansion entirely with hydrogen reconversion systems does not make sense from an economic standpoint. Furthermore, the hydrogen reconversion pathways evaluated, including large-scale storage, significantly contribute to the security of the energy supply and to secured power generation capacities.     

The production and application of hydrogen in steel industry

Due to the increasingly serious environmental issues and continuous depletion of fossil resources, the steel industry is facing unprecedented pressure to reduce CO₂ emissions and achieve the sustainable energy development. Hydrogen is considered as the most promising clean energy in the 21st century due to the diverse sources, high calorific value, good thermal conductivity and high reaction rate, making hydrogen have great potential to apply in the steel industry. In this review, different hydrogen production technologies which have potential to provide hydrogen or hydrogen-rich gas for the great demand of steel plants are described. The applications of hydrogen in the blast furnace (BF) production process, direct reduction iron (DRI) process and smelting reduction iron process are summarized. Furthermore, the functions of hydrogen or hydrogen-rich gas as fuels are also discussed. In addition, some suggestions and outlooks are provided for future development of steel industry in China.