环境空气氮氧化物自动监测仪器的维修方法

分析了环境空气氮氧化物(NOx)自动监测仪故障产生的原因,并提出了判断和处理故障的维修方法.     

超细煤粉在氧化条件下NOx的释放特性实验研究

采用DTG(热重/差热分析仪)和GC-MS(气相色谱质谱联用仪)对鹤岗煤超细化煤粉进行燃烧试验,分析了粒径、氧气浓度、升温速率对NO_x释放的影响.结果表明,不同粒径的鹤岗煤在氧气浓度为20％的燃烧条件下,NO_x的析出均为单峰曲线;粒径对煤粉燃烧NO_x释放有重要影响,超细化煤粉可以减少NO_x的排放;在5、10、20 ℃/min升温条件下,随升温速率的增大NO和NO₂的析出量也增加,并且NO的最大析出速率对应的温度随着升温速率的提高也提高;随着燃烧气氛氧气浓度的增高,NO_x的析出量相应增加,并且NO_x的最大析出速率对应温度相应降低.     

焦炉加热过程中热力型氮氧化物的生成及影响因素研究

以武钢焦化公司6 m、7 m、7.63 m 3种炉型焦炉为对象,研究了焦炉加热过程中热力型氮氧化物的生成规律和影响因素。结果表明,焦炉氮氧化物排放量与炉型、空气过剩系数以及立火道温度有着直接的关系。7 m、7.63 m焦炉的氮氧化物排放量平均值均在210 ppm以下,6 m焦炉氮氧化物排放量平均值在400 ppm以上。6 m焦炉废气中NOx排放量明显高于7 m和7.63 m焦炉,这是由于7 m和7.63 m焦炉采用了分段加热方式,可以有效控制在焦炉加热过程中热力型NOx的生成,有利于减少最终烟气中NOx的浓度。     

适用循环流化床锅炉的脱硝技术

循环流化床锅炉由于NOx 排放浓度低在我国应用十分广泛，但如果不采取任何环保措施已不能满足目前的环保要求。简要分析了NOx的产生机理，通过几种脱硝技术的对比，指出循环流化床采用低氮燃烧＋SNCR脱硝技术是较好的选择。     

烟气联合脱硫脱硝一体化吸收／催化剂

燃烧等带来的SO2、NOx是酸雨的主要来源，开发能联合控制SO2与NOx污染的技术具有广阔的前景。回顾了金属氧化物烟气联合脱硫、脱硝技术的发展史，对目前国内外的研究现状进行了总结，指出了其存在的问题及其发展前景。     

好氧反硝化去除低浓度NO_x的动力学模型研究

在好氧条件下,对利用生物滴滤塔（bio-trickling filter,BTF）反硝化净化废气中NOx的过程进行了理论模型探讨,并用实验结果进行了验证。在分析NOx在BTF内传质以及生物降解过程的基础上,建立了NOx在气相和生物膜相的质量守恒方程,结合Fick定律和好氧条件下的Monod微生物反应动力学方程,最终得到了NOx在BTF中＂吸附-微生物降解＂过程的动力学方程。模型计算值与实验结果表明,BTF中好氧反硝化过程为一级反应过程,利用该模型可以较好地模拟进口浓度、停留时间等因素对出口浓度的影响,对实际应用具有指导意义。     

在监测过程中探讨氮氧化物的产生与抑制

通过在环境监测中发现的问题,对抑制NOx的产生提出了具体办法.     

双回路热解炉垃圾焚烧NOx排放特性研究

本文利用双回路立式热解焚烧炉对某地区的垃圾进行试验研究,通过调节过量空气系数,一、二次风机的风量等参数,研究双回路热解炉垃圾焚烧NOx排放特性.结果表明：焚烧炉的二燃室温度能够达到850℃,烟气停留时间超过2秒,燃烧灰的热灼减率小于3％.随着引风机风量系数的增加,烟气中NOx的含量先增加后减少;二燃室的温度先升高后降低.     

The Concepts of Energy,Environment, and Cost for Process Design

Abstract

The process industries (specifically, energy and chemicals) are characterized by a variety of reactors and reactions to bring about successful process operations. The design of energy-related and chemical processes and their evolution is a complex process that determines the competitiveness of these industries, as well as their environmental impact. Thus, we have developed an Enviro-Energy Concept designed to facilitate sustainable industrial development. The Complete Onion Model represents a complete methodology for chemical process design and illustrates all of the requirements to achieve the best possible design within the accepted environmental standards. Currently, NOx emissions from industrial processes continue to receive maximum attention, therefore the issue problem of NOx emissions from industrial sources such as power stations and nitric acid plants is considered. The Selective Catalytic Reduction (SCR) is one of the most promising and effective commercial technologies. It is considered the Best Available Control Technology (BACT) for NOx reduction. The solution of NOx Emissions problem is either through modifying the chemical process design and/or installing an end-of-pipe technology. The degree of integration between the process design and the installed technology plays a critical role in the capital cost evaluation. Therefore, integrating process units and then optimizing the design has a vital effect on the total cost. Both the environmental regulations and the cost evaluation are the boundary constraints of the optimum solution.     

Surface-exchange of NOx and NH3 above a winter wheat field in the Yangtze Delta, China

Introduction N itrogen oxides (N O x=N O N O 2) in the troposphere are m ainly derived from fuel com bustion, soil-biogenic em issions, biom ass burning, and lightning (Finlayson-Pitts et al., 1986; H am eed and D ignon, 1988; Levy et al., 1989; Logan, 1…