Opportunities for Low‐Cost Particulate Matter Sensors in Filter Emission Measurements

Commercial low‐cost sensors for particulate matter measurements are a fast growing market and find many applications in the particulate matter (PM) immission characterization in the environment. This application includes uncontrolled factors such as humidity, making the devices more prone to errors. These factors are controllable in closed emission control applications, turning these affordable sensors into potential monitoring devices for exhaust concentrations. Time‐resolved PM emissions of a surface filter were measured at various concentration levels. The suitability and limitations of a SDS011 PM2.5 low‐cost sensor were evaluated by comparing its PM readings to a welas® 2100 sensor by Palas®. Experimental setup and results are presented and further discussed in this paper.     

Investigations on the Possibilities of a MISiCFET Sensor System for OBD and Combustion Control Utilizing Different Catalytic Gate Materials

Different catalytic materials, like Pt and Ir, applied as gate contacts on metal insulator silicon carbide field effect transistors — MISiCFET—facilitate the manufacture of gas sensor devices with differences in selectivity, devices which due to the chemical stability and wide band gap of SiC are suitable for high temperature applications. The combination of such devices in a sensor system, utilizing multivariate analysis/modeling, have been tested and some promising results in respect of monitoring a few typical exhaust and flue gas constituents, in the future aiming at on board diagnostics (OBD) and combustion control, have been obtained.     

化工仓储库废气排放及处理技术研究

介绍了化工仓储废气排放的特点,减少废气排放的控制措施。对燃烧法、吸收法、吸附法、冷凝法、膜分离法等废气处理技术原理及适用性进行分析和对照;结合废气处理方式的选择因素及相关经验,提出选择方案。     

船舶尾气脱硫脱硝技术研究进展

远洋船舶燃烧低品质重油所释放的尾气中,NO_x与SO_x等有害成分比例高,严重威胁海洋的生态环境和沿海居民健康。本文介绍了现有国内外船舶尾气后处理技术的分类、原理及优缺点,综述了船舶尾气脱硫、脱硝和脱硫脱硝一体化处理技术的研究进展,认为现有的大部分船舶尾气后处理技术去除污染物成分单一,不能高效地实现船舶尾气污染物的减排,研究脱硫脱硝一体化处理技术是实现船舶尾气高效治理的发展方向,但是高效低能耗的一体化处理技术目前仍然处于探索与实验阶段。通过分析脱硫脱硝一体化技术面临的瓶颈问题,指出光催化技术和低温等离子体技术近年来虽得到了巨大的发展,但因成本高且安全问题难以保证尚无法在实船应用;改性海水法则凭借处理效率高、占用船舱面积小,成本较低等优势,未来在船舶尾气综合治理方面具有良好的发展前景。     

Reductant flow control for NOX removal from lean exhaust gases

This review article describes and discusses the literature on reducing agent control systems for NO_x emission reduction in the exhaust gas of full lean‐burn engines. The literature can be classified as feedback, feedforward, feedforward‐feedback, feedforward/feedforward‐feedback and periodical dosing control systems, which can be further classified as classical, override, co‐ordinated, constrained and split systems or a combination of those. As long as reproducible, fast and cheap NO_x sensors are not commercially available, the control system should be an inferential feedforward or feedforward‐feedback system supplied with constraints for environmental and economical reasons. For future applications an oxidation catalyst downstream of the deNO_x catalyst should be applied to convert any inevitable reductant slip, due to modelling errors, to harmless compounds.     

Modellierung und Simulation von Filtrations‐, Regenerations‐ und Umlagerungseffekten in Gasfiltersystemen am Beispiel eines Dieselruß‐Partikelfilters

The drastic tightening of regulations regarding emission limits of motor vehicles demands for an efficient exhaust gas treatment of diesel motor engines. One potential concept is an integrated diesel soot filter within the exhaust gas system. Basic requirement for a safe filter system operation is a fundamental comprehension of all involved individual processes. In this paper an experimentally validated CFD‐model describing the life cycle of a diesel root filter is presented. Its results can be used to fully exploit the potential of such filter systems and provide a basis for a variety of applications in the field of gas filtration.     

稀土在汽车排气催化净化中的应用

催化剂技术是治理汽车污染的重要措施之一，作为催化剂组分的稀土在其中起了重要的作用。本文讨论了稀土在汽车排气催化净化中的应用。其作用在于：提高了载体性能，储氧功能，提高催化剂的抗中毒性，提高催化剂热稳定性，作为助剂，应用在氧传感器中等。     

祥光铜业废水处理与烟气超低排放技术的发展历程

介绍了祥光铜业从建设初期至今废水处理与烟气超低排放技术的发展过程.通过对全厂水资源的统一调配,对生产废水循环利用和梯度利用,最终实现了生产废水的资源化和减量化.在烟气治理方面,遵循分而治之的思路,根据各工序产出的烟气性质不同,对烟气处理系统不断优化,采用布袋除尘、高温陶瓷膜除尘、湿法洗涤除尘、高浓度SO2制酸、钠碱法脱...     

Self‐Healing and Shape‐Memory Superconducting Devices

Intelligent materials possess the function of self‐judgment and self‐optimization while sensing external stimuli such as stress, temperature, moisture, pH, electric or magnetic fields, or light. Besides, they often require self‐healing—the ability to repair damage spontaneously—or shape‐memory—the ability to return from a deformed state to their original shape induced by an external stimulus. Introducing such intelligence into superconducting (SC) devices is highly desirable to meet the critical requirement of maintenance‐free performance. Here, self‐healing and shape‐memory functions are realized in liquid metal based SC devices using smart packaging polymers. Without deteriorating their superconductivity, the SC devices can repair themselves by simply raising the temperature, without any other treatment. Beyond the specific functions achieved here, this work sheds new light on future SC devices with advanced functions such as self‐diagnosis, self‐adjusting, and sensing.     

Diesel particulate emission control

This paper reviews the emission control of particulates from diesel exhaust gases. The efficiency and exhaust emissions of diesel engines will be compared with those of otto engines (petrol engines). The formation of particulates (or “soot”), one of the main nuisances of diesel exhaust gases, will be briefly outlined. The effects of various emission components on human health and the environment will be described, and subsequently the emission standards for particulates and for NO_x, which have been introduced worldwide, will be summarized. Possible measures for reducing exhaust emissions of particulates and NO_x will be discussed, such as the use of alternative fuels, modifications to the engine and the use of aftertreatment devices. It will be made clear that aftertreatment devices may become necessary as diesel emission standards become more stringent, in spite of important progress in the other fields of reducing exhaust emissions. Selective catalytic reduction via hydrocarbons, ammonia or urea, a possible aftertreatment method for NO_x emission control, will be discussed briefly. Filters for collecting particulates from diesel exhaust gases will be examined in more detail and aftertreatment control systems for particulate removal will be reviewed. These can be divided into (i) non-catalytic filter based systems which use burners and electric heaters to burn the soot once it has been collected on the filter; (ii) catalytic filter-based systems which consist of filters with a catalyst coating, or filters used in combination with catalytically active precursor compounds added to the diesel fuel; and (iii) catalytic non-filter-based systems in which gaseous hydrocarbons, carbon monoxide and part of the hydrocarbon fraction of the particulates are oxidized in the exhaust gases. Finally, recent trends in diesel particulate emission control will be discussed, indicating the growing importance of the catalytic solutions: the fast introduction of non-filter-based catalysts for diesel engines and the possible application of filters in combination with catalytically active precursor compounds added to diesel fuel.     

Current Tasks and Challenges for Exhaust Aftertreatment Research. A Viewpoint from the Automotive Industry

Automotive emission control through modern engine design and active exhaust gas aftertreatment has reached a very high technological level. This led to a considerable decrease of exhaust emissions from automobiles in the last years, despite continuous increase of vehicle numbers and kilometres travelled. Nevertheless, a number of challenges for scientists and engineers remain, to develop further improved catalyst materials and exhaust aftertreatment systems. The paper describes the state of the art of exhaust aftertreatment and the major technological paths that will be followed in further development. It concentrates mainly on aftertreatment systems to achieve near zero emissions for vehicles in especially emissions sensitive regions and on exhaust aftertreatment technologies for lean burn engines, with a special emphasis on nitrogen oxides and particulates. These engines and therefore these aftertreatment systems will be mandatory to fulfil the requirements on CO₂ reduction.     

催化燃烧技术处理石油化工企业含VOCs废气的工艺研究

石油化工企业工艺装置尾气及污水处理场逸散的废气均含有VOCs,其排放给区域空气质量和人体健康带来严重威胁。针对工艺尾气和污水处理场废气的特点,研究了催化燃烧工艺在处理这两类废气时工艺流程及控制方案。对工艺尾气采用碱洗—催化燃烧组合工艺,对污水处理场废气采用脱硫—均化—催化燃烧组合工艺。研究表明,针对上述两种废气,合理选择催化燃烧组合工艺及控制方案,能够有效处理废气中的VOCs组分,且处理后的气体烃类浓度均可达到国家有关标准。     

动力波ZnO脱硫技术在铅锌冶炼尾气脱硫中的应用

介绍了动力波氧化锌脱硫技术在铅锌冶炼行业制酸尾气脱硫中的应用情况.该脱硫装置采用铅冶炼烟化炉产生的氧化锌浆液作为脱硫剂,使排放气体SO2质量浓度从2 g/m^3降至200 mg/m^3以内,确保制酸尾气达标排放.脱硫产生的硫酸锌用作炼锌原料不产生二次污染.针对运行中存在的问题,技术人员通过不断技术改造,优化工艺参数,基本予以解决,确保了装置平稳运行.     

Advanced exhaust gas aftertreatment systems for gasoline and diesel fuelled vehicles

In this article, the main reasons for the intensive development work being done on automotive emission control catalysts are discussed and the most important features of these technologies are described. Special attention is paid to the development of improved three-way catalysts for gasoline engines, that have to fulfil the more stringent future emission standards. Diesel fuelled vehicles and lean burn gasoline engines show completely different exhaust gas emission characteristics, which lead to dissimilar demands for the aftertreatment systems.     

燃煤电厂逃逸氨迁移转化特性研究进展

我国燃煤电厂实施超低排放改造后,逃逸氨超标现象日渐凸显。过大的逃逸氨给烟气处理设施的正常运行和大气环境带来消极影响,逃逸氨的控制与排放已成为今后燃煤电厂大气污染防治方面的工作重点之一。本文分析了燃煤电厂逃逸氨的产生来源,综述了逃逸氨的排放特性,包括逃逸氨在各环保设施中的排放浓度和主要形态。分析了逃逸氨在脱硝及其下游烟气处理设施中的迁移转化,以及影响各烟气处理设施对逃逸氨捕集效率的因素。最后基于污染物排放因子研究现状,展望了未来燃煤电厂逃逸氨控制的研究方向有：推进燃煤电厂逃逸氨监测和排放标准的制定与落实,优化工艺条件促进现有烟气处理系统对逃逸氨的协同脱除作用,跟踪含氨副产物如粉煤灰、脱硫废水和石膏等在后续处理过程中的氨再释放情况。     

绿色智能焦化技术在唐钢美锦公司的应用

针对传统焦化企业能源利用效率低、环境污染严重、产业链短、产品附加值低等共性难题,本文指出唐钢美锦焦化公司研究开发和使用了一系列焦化新工艺新技术,采用的新工艺主要有宽炭化室多段加热的7m大容积焦炉、高温高压干熄焦的高效发电工艺、废水综合处理的高效回用工艺、焦化全流程除尘工艺、固体废弃物回收利用工艺、高效节能的焦炉煤气制取液化天然气工艺等,采用的新技术主要有焦炉煤气高效净化技术、粉尘和有毒有害气体控制及逸散气体负压回收综合技术、粗苯萃取精制精馏优化技术和智能焦化技术等。唐钢美锦焦化公司通过这些新工艺、新技术的使用,实现了炼焦全流程工艺整体优化,解决了焦化企业绿色转型过程中的难题,为焦化行业摆脱高能耗高排放,实现降本增效和环境友好拓宽了思路,对焦化行业绿色转型发展起到了引领和示范作用。     

含氨尾气综合回收治理

随着环保要求的不断提高,如何回收化工生产过程中的生产尾气以及无组织排放气体,已经成为众多化工生产企业的难点之一,本套装置利用现场局排抽风系统,将回收的含氨尾气和无组织排放气体通过填料塔洗涤回收,达到回收、治理尾气的目的,具有广泛的借鉴作用.     

Critical considerations on the use of a bi‐directional probe in heat release measurements

In various medium to large scale fire test equipment, such as the ISO room corner (RC) test and more recently the single burning item (SBI) test, the mass flow measurement of the combustion gases plays a key role in the determination of the heat release rate and smoke production rate. To date a bi‐directional low‐velocity pressure probe has been used to calculate this flow based on a differential pressure measurement on the axis of the exhaust duct. The objectives of this paper were to evaluate this bi‐directional probe—and the modified SBI version—when used for measuring flows in exhaust ducts. Recommendations are given on the future use of pressure probes measuring exhaust gas mass flows. Copyright © 2005 John Wiley & Sons, Ltd.     

Reinigung von lösemittelhaltiger Prozessabluft in Biorieselbettreaktoren

In numerous industrial processes, solvent-containing exhaust gas is generated and has to be purified to comply with the emission limits prescribed by law. However, conventional exhaust gas purification technologies, such as thermal post-combustion, require high temperatures of 1200 °C and often fossil fuels. As a significantly more sustainable alternative, biotrickling filters enable biodegradation at 20 °C. The pollutants are converted into harmless substances by bacteria in a biofilm on lava stones.     

烟气换热工艺在耐火材料隧道窑环保治理中的应用

耐火材料在生产过程中会产生颗粒物、二氧化硫、氮氧化物等大气污染物,为实现烟气达标排放,需要进行治理。隧道窑的排烟温度一般较低,不能直接满足深度治理设施正常运行的温度要求,通过烟气换热治理工艺以较低的能耗提升隧道窑的排烟温度,在同样达标排放的条件下,该工艺操作简便,运行成本低,并充分利用烟气热量实现烟气消白。该工艺在耐火材料企业实际应用后取得良好的效果,在基准含氧量18%(φ)的条件下,颗粒物、二氧化硫、氮氧化物排放浓度分别达到10、35、50 mg·m-3以内,每吨产品增加成本约20元,在企业的承受范围之内。