氨水还原剂在燃煤锅炉SCR脱硝中的应用

目前氨水作为脱硝还原剂用于燃煤锅炉SCR脱硝国内尚未普遍使用，尤其在大机组上的应用经验较少。通过对实际应用案例的分析，总结了运行经验，为氨水还原剂在大机组SCR的脱硝应用提供参考。     

尿素为还原剂燃煤烟气脱硝技术的研究与应用

尿素由于运输、储存安全性较高，作为还原剂进行脱硝备受关注。从工艺原理、系统组成和工程应用等方面，对尿素制氨选择性催化还原技术（SCR）、选择性非催化还原技术（SNCR）和尿素法三种脱硝方法进行了综述。分析了不同技术运用过程存在的问题，并提出解决措施。     

SCR氨区的运行维护

液氨是选择性催化还原脱硝法（ SCR）工艺首选的脱硝反应剂，它属于危险化学品。氨区的安全运行是SCR系统安全运行的基础保障。从氨区的运行、维护、人员防护和事故处理等方面阐述了SCR系统运行维护中需要注意的一些关键点。     

1000 MW机组SCR脱硝系统运行中的问题及措施

针对某电厂1000 MW机组SCR脱硝系统运行中出现的突出问题，分析原因并提出治理措施，经实践检验，通过优化燃烧调整、对氨喷射系统及导流板进行优化、更换液氨蒸发器、脱硝催化剂层增加声波吹灰器、空预器进行相应技改后，效果明显，脱硝系统及下游设备空预器运行正常，为同类机组脱硝系统的技改和运行提供了参考。     

再燃法烟气脱硝技术

综述了再燃法烟气脱硝技术及其主要影响因素。通过对几种脱硝技术的分析比较，认为再燃脱硝是一种很有前景的脱硝技术，其投资和运行费用界于低NO。燃烧器和选择性催化还原技术之间，有喷氨条件下的先进再燃脱硝效率接近于选择性催化还原技术。总结了国内外对先进再燃脱硝技术各种参数影响条件的研究结果，并论述了该技术的应用要点。     

燃煤电厂脱硝还原剂选择原则及用量计算

面向燃煤烟气氮氧化物控制过程，详细阐述了燃煤电厂脱硝技术还原剂选择原则，对不同还原剂方案进行综合比较。根据SCR、SNCR和SCR／SNCR联合工艺三种不同工艺，重点对还原剂用量计算方法进行了综述，为工程技术人员提供参考。     

烟气脱硝装置与电厂设备运行的相互影响

火电厂烟气脱硝装置中的二氧化硫、灰分、氨及催化剂中的各种重金属在高温烟气的作用下发生各种化学作用,生成的硫酸氢氨等产物对火电厂的各种设备均会产生不同影响.同时由于系统阻力及荷载的变化,也会对电厂其他相关设备产生影响,根据目前工程的运行经验,火电厂在增设脱硝装置后,均会对空气预热器、引风机、锅炉钢架等进行改造.通过综合分析烟气脱硝装置产生的影响原因及解决办法,为脱硝装置的设计提供参考.     

火电厂脱硝改造技术路线及方案研究

介绍了锅炉低氮燃烧技术及烟气脱硝技术的分类。通过技术经济分析的方法研究了火电厂脱硝改造的技术原则及应遵循的技术路线；并以锅炉低氮燃烧技术加SCR烟气脱硝技术组合改造为例进行了技术方案讨论，涉及锅炉部分的低氮燃烧改造、空预器改造以及SCR烟气脱硝部分的还原剂选择、催化剂选择、SCR入口参数等。     

600MW燃煤机组SCR脱硝工程设计特点

介绍了我国第一批烟气脱硝工程之一——山西阳城电厂600MW燃煤机组SCR工程的设计特点，包括反应器本体设计、催化剂选型设计和氨区设计等。结合实践经验，对脱硝系统设计提出了一些优化建议。     

燃煤电站SNCR脱硝系统喷射还原剂介质对锅炉效率的影响

以燃煤电厂1台600MW机组配套SNCR脱硝系统为例,分别介绍了采用尿素、液氨为SNCR脱硝还原剂时,各还原剂的喷入量对锅炉效率和燃煤成本的影响。结果发现,以设计煤种Qnet,ar=11766.7kJ/kg计,当浓度5%的尿素溶液喷入时,有1.67%的燃煤发热量被水蒸发所吸收,导致排烟损失增加0.6659%。假设其他损失不变,不计固体尿素的升温、分解热反应等的影响,尿素溶液的喷入对锅炉热效率的影响在0.6659%左右,燃煤成本约增加900多万元/a;在喷入氨空混合气情况下,约0.2%的燃煤发热量被混合气所吸收,导致排烟损失增加0.02%。假设其他损失都不变,不计分解热反应等的影响,混合气的喷入对锅炉的热效率的影响亦即在0.02%左右,燃煤成本约增加30万元/a。从节能的角度看,液氨为还原剂应作为优选。     

促脱剂协同传统吹脱法处理高氨氮工业废水

在中试吹脱装置上,通过投加低浓度促脱剂协同传统吹脱法处理高氨氮工业废水(氨氮质量浓度2 369～3 600 mg/L)。结果表明:在相同处理条件下,阴离子促脱剂的氨氮去除效果优于阳离子促脱剂,且促脱剂的碳数越高越有利于氨氮的去除;废水处理的最佳工艺条件为废水pH 12.0、废水温度50℃、吹脱时间5 h、促脱剂投加量25 mg/L、气液比600∶1;该条件下,以木质素磺酸钠为促脱剂协同吹脱法处理高氨氮废水,氨氮去除率可达99%以上,高于传统吹脱法20个百分点以上。     

Application of the SOLVTM Process: A Total Systems Approach to Environmental Remediation

Commodore Solution Technologies, Inc. has developed an innovative total systems approach to environmental remediation that utilizes a patented chemistry called Solvated Electron Technology (SET^TM). Solvated electron solutions are some of the most powerful reducing agents know. Formed by dissolving alkali and alkaline-earth metals in anhydrous liquid ammonia to produce a solution of metal cations and free electrons, solvated electron solutions are capable of providing reductants of great activity and uniqueness. They provide a highly useful mechanism for the reductive destruction of many organic molecules and are extremely effective in the dehalogenation of halogenated organic compounds. Commodore has received a nation-wide EPA operating permit for the nonthermal destruction of PCBs using this process. The SoLV^TM process is a total solution approach that incorporates SET^TM with pre-and post-treatments, when necessary, for environmental cleanup. It is applicable to a broad range of substrates including liquids, solids, soils, and job materials. This article presents results from several pilot, field, and commercial validation studies utilizing the SoLV^TM process.     

选择性非催化还原法烟气脱硝工业试验

以氨水作为还原剂，在日产5kt的新型干法水泥生产线分解炉上进行选择性非催化还原脱硝工艺的工业性试验研究。在氨水质量分数为13.0%、喷入点温度为894℃、n（NH₃）∶n（NO_x）为1.2、雾化压力为0.35MPa的条件下，NO_x去除率最高，为72.8%，剩余NO_x质量浓度为196mg/m³，剩余NH₃质量浓度小于0.9mg/m³，远低于《水泥工业大气污染物排放标准》征求意见稿中限定的NO_x和NH₃质量浓度。     

磷石膏制硫酸钾的新工艺

介绍了由磷石膏制硫酸钾的新工艺：磷石膏与碳酸氯铵在5－30℃下反应,得硫酸铵溶液,该溶液与氯化钾在30℃左右反应,并添加一种有机溶剂,得硫酸钾。低温反应的优点是所得物料便于固液分离,节省加热蒸汽,减少氨挥发。添加某种有机溶剂降低了硫酸钾在体系中的溶解度,使硫酸钾收率提高到90％。此外,采用多釜串联连续反应装置,既提高了设备的生产强度,又使工艺操作条件及产品质量得到稳定。     

锑污染土壤固化-稳定化的影响因素

通过比较不同稳定剂、固化剂、土壤pH条件下土壤中重金属锑的修复效果,研究了锑的固化-稳定化影响因素并探讨了相关稳定化机理.实验结果表明:铁基稳定剂的效果明显优于磷酸二氢钾和腐殖酸钠,而零价铁的稳定化效果更优于硫酸铁和硫酸亚铁,较适宜的稳定剂投加量为5％(w);水泥做固化剂对锑的稳定化效果优于氧化钙,最佳投加量为5％(w...     

An assessment of bioreactor landfill costs and benefits

Because effective operation of bioreactor landfills involves careful operation and construction of infrastructure beyond that necessary in traditional landfills, upfront capital and operating costs are greater than those associated with traditional landfills. Prior to investing in bioreactor landfills, landfill owners must be convinced that larger short-term expenses (e.g., liquid and/or air injection infrastructure) will be balanced by future economic benefits (e.g., extension of landfill life, reduced leachate treatment costs, etc.). The purpose of this paper is to describe an economic model developed to evaluate the impact of various operational (anaerobic, aerobic, or hybrid) and construction (retrofit and as-built) bioreactor landfill strategies on project economics. Model results indicate retrofit bioreactor landfills are more expensive than traditional landfills, while both the as-built and aerobic bioreactor landfills are less costly. Simulation results indicate the parameters that influence bioreactor economics most significantly are airspace recovery, gas recovery and subsequent use to generate electricity, and savings resulting from reduced leachate treatment costs.     

Selecting state-of-the-art incinerators for complex aqueous wastes

The Rocky Mountain Arsenal (RMA) in Adams County, Colorado has been identified as a priority site on the Superfund National Priority List. The Program Manager's Office of RMA announced in early 1990 its intention to implement installation of a state-of-the-art incineration plant to treat the most complex and controversial waste stream on the site. Established in 1942, RMA served as an Army manufacturing center for chemical agents such as mustard gas, white phosphorus, napalm, and GB nerve agent. Parts of the site were also leased to Shell Oil Company, which manufactured pesticides and other agricultural chemicals at this location between 1952 and 1982. To support these activities, the Army operated a ninety-three-acre surface impoundment called Basin F for collection and evaporation of chemical wastewaters. As a result of the wide variety of wastes received and concentrated at Basin F and early treatment attempts, its contents became one of the most unusual chemical cocktails known to man. By the time a formal interim response action for remediation was initiated in 1985, the composition of the Basin consisted of a multi-phase fluid and sludge, including super-saturated levels of inorganic salts; 30 percent or more organics such as pesticides, military agent by-products, degradation products, and solvents; high levels of ammonia compounds and bound nitrogen; and percent levels of copper, arsenic, and other metals. Selection of a remedial alternative involved twelve years of characterizationstudies and eleven years of treatability testing programs encompassing the universe of containment; encapsulation; stabilization; component separation; and thermal, electrical, chemical, and biological degradation technologies. The program resulted in the selection of a state-of-the-art down-fired liquid incinerator for destruction of aqueous organic contaminants in metallic salt matrices. The treatability demonstration, and the technical justification for selection of the T-Thermal submerged quench incinerator for this application, is the subject of this article.