光气尾气处理最优材料——SN7501催化载体

光气是农药、染料、工程塑料等化学工业的重要原料之一,生产中排放的尾气因含有部分光气而污染大气,危害人民的身体健康。应用沈阳市耐酸材料厂制造的 SN7501催化载体对光气尾气进行催化水解法处理,取得良好的效果。诸如常州化工厂、大连染料厂、太原化工厂、上海染化二厂、北京双桥农药厂等均已应用数年,实践证明其效果优于任何其它处理方法。催化水解工艺及 SN7501催化载体经化工部科技局1979年9月鉴定通过,1982     

对我国LD31-92标准中关于光气尾气高空排放规定的探讨

在光气生产及使用过程中,由于受生产技术发展水平的限制,很难将尾气中所含的光气彻底清除,往往需要经烟囱高空排放,通过在大气中的扩散和稀释,降低光气在环境中的浓度,消除光气对环境的危害。我国劳动部于１９９２年３月４日发布了中华人民共和国劳动及劳动安全行业...     

柴油车尾气处理液应用展望

尾气处理液是柴油车尾气处理SCR技术中所必需的还原剂。本文通过分析柴油车尾气的排放情况及SCR技术应用发展趋势,着重介绍了柴油车尾气处理液的研究现状及应用情况,总结了尾气处理液应用中存在的问题并阐明了后续的发展方向。     

PAPI生产中光气尾气的分析

1.取样方法(1)针筒法适用于高浓度的样品,一般在尾气进入处理工段前用针筒法取样。在指定取样口处,插入100毫升的医用针筒,反复抽吸几次,置换针筒内的空气,然后慢慢地抽取光气尾气样品100毫升。随后,将此针筒插入气体吸收瓶的前导管的橡胶头     

催化氧化法处理氯甲烷废气

用催化氧化法处理氯甲烷废气,考察了各种因素对催化氧化处理效果的影响。实验结果表明：在反应温度为350℃、空速为4800h^-1、空气与氯甲烷废气的体积比为15的条件下,氯甲烷转化率和总烃转化率均大于99％,催化氧化过程中基本不产生光气;催化氧化反应后尾气中的HCl用NaOH溶液作吸收剂的吸收效果较好;γ—Al2O3为载体的催化剂活性基本稳定。     

硫酸生产尾气的回收

我国中、小型硫酸生产中 ,仍有一些厂家采用一转一吸工艺流程 ,二氧化硫的转化率约为 90 %～95%。含 SO2 的炉气虽经转化吸收 ,排放尾气中 SO2的含量仍在 0 .4 %～ 0 .5% (质量分数 )。一家年产 4 .5万 t的硫酸厂 ,排放尾气中的 SO2 可达 540 0 t,既浪费资源 ,又污染环境。尾气的回收势在必行。目前 ,SO2 回收方法中应用较多的为氨酸法 ,但由于此法选用的设备结构及操作条件不尽合理 ,使尾气很难达到国家排放标准。我们采用氨酸法对某硫酸厂尾气的回收工艺条件及设备进行合理选择 ,不仅使尾气达到国家排放标准 ,同时生产出合格的液体 SO…     

硫酸尾气中SO_2超标原因分析及改进措施

浙江巨化股份有限公司硫酸厂采用二段氨法处理硫酸尾气,在执行GB4282-84时SO2可以达到排放标准,在执行GB12697-1996时,SO2排放速率低于标准规定限值,但因受处理装置SO2吸收效率的限制,SO2排放浓度时有超标。为此,1999年该厂对影响硫酸尾气中SO2排放质量提高的因素进行了全面分析,找出了超标原因,并通过完善处理装置、优化工艺指标等措施,提高了处理装置的SO2吸收效率,做到了达标排放。1　处理装置概况1.1　尾气的产生该公司硫酸厂硫酸生产装置的生产能力为年产硫酸180kt,以硫铁矿为主要生产原料,分新老两个生产系统,新系统为水洗净化…     

硫酸尾气中SO2超标原因分析及改进措施

浙江巨化股份有限公司硫酸厂采用二段氨法处理硫酸尾气,在执行GB4282－84时SO2可以达到排放标准,在执行GB12697－1996时,SO2排放速率低于标准规定限值,但因受处理装置SO2吸收效率的限制,SO2排放浓度时有超标。为此,1999年该厂对影响硫酸尾气中SO2排放质量提高的因素进行了全面分析,找出了超标原因,并通过完善处理装置、优化工艺指标等措施,提高了处理装置的SO2吸收效率,做到了达标排放。     

机动车尾气排放控制及试验方法综述

叙述了机动车尾气排放现状.根据欧洲排放新法规实行欧3标准,提出一些应对措施.介绍了机动车尾气排放试验方法Ⅰ型试验--常规排气排放试验;Ⅳ型试验--蒸发排放试验;Ⅵ型试验--低温排气排放试验.介绍了OBD试验的技术要求和测试设备,并引述了国家环保局和石化部门控制机动车尾气排放污染的做法.     

炉排炉焚烧垃圾过程中主要污染物的控制

概述了二恶英、重金属、酸性气体、灰渣等垃圾焚烧的主要污染物,以二段式（往复）焚烧炉为例,介绍了炉排炉焚烧处理工艺和污染控制设备。提出通过控制垃圾焚烧条件、尾气处理以及吸附等方法,可以有效控制二恶英类污染物的排放;重金属的控制可以用除尘器或使用相应的吸附剂处理;采用较为成熟的烟气处理技术,可以控制处理酸性气体;灰渣可采用固化稳定化或酸提取法处置。     

Gas production, composition and emission at a modern disposal site receiving waste with a low-organic content

AV Miljø is a modern waste disposal site receiving non-combustible waste with a low-organic content. The objective of the current project was to determine the gas generation, composition, emission, and oxidation in top covers on selected waste cells as well as the total methane (CH₄) emission from the disposal site. The investigations focused particularly on three waste disposal cells containing shredder waste (cell 1.5.1), mixed industrial waste (cell 2.2.2), and mixed combustible waste (cell 1.3). Laboratory waste incubation experiments as well as gas modeling showed that significant gas generation was occurring in all three cells. Field analysis showed that the gas generated in the cell with mixed combustible waste consisted of mainly CH₄ (70%) and carbon dioxide (CO₂) (29%) whereas the gas generated within the shredder waste, primarily consisted of CH₄ (27%) and nitrogen (N₂) (71%), containing no CO₂. The results indicated that the gas composition in the shredder waste was governed by chemical reactions as well as microbial reactions. CH₄ mass balances from three individual waste cells showed that a significant part (between 15% and 67%) of the CH₄ generated in cell 1.3 and 2.2.2 was emitted through leachate collection wells, as a result of the relatively impermeable covers in place at these two cells preventing vertical migration of the gas. At cell 1.5.1, which is un-covered, the CH₄ emission through the leachate system was low due to the high gas permeability of the shredder waste. Instead the gas was emitted through the waste resulting in some hotspot observations on the shredder surface with higher emission rates. The remaining gas that was not emitted through surfaces or the leachate collection system could potentially be oxidized as the measured oxidation capacity exceeded the potential emission rate. The whole CH₄ emission from the disposal site was found to be 820 ± 202 kg CH₄ d⁻¹. The total emission rate through the leachate collection system at AV Miljø was found to be 211 kg CH₄ d⁻¹. This showed that approximately ¼ of the emitted gas was emitted through the leachate collections system making the leachate collection system an important source controlling the overall gas migration from the site. The emission pathway for the remaining part of the gas was more uncertain, but emission from open cells where waste is being disposed of or being excavated for incineration, or from horizontal leachate drainage pipes placed in permeable gravel layers in the bottom of empty cells was likely.     

等离子体联合技术处理挥发性有机化合物废气的研究进展

挥发性有机化合物（VOCs）废气污染面广、气量大、浓度低,含VOCs废气的排放将会受到越来越严格的控制,需要不断研究开发新的VOCs废气处理技术。等离子体联合技术具有多功能作用的效果,对污染物的降解率、能量利用率及对污染物的选择性均高于单一的等离子体技术。综述了等离子体与吸附剂、催化剂、铁电性物质联合处理VOCs废气技术的研究进展,展望了该技术的发展方向。     

Release and fate of fluorocarbons in a shredder residue landfill cell: 2. Field investigations

The shredder residues from automobiles, home appliances and other metal containing products are often disposed in landfills, as recycling technologies for these materials are not common in many countries. Shredder waste contains rigid and soft foams from cushions and insulation panels blown with fluorocarbons. The objective of this study was to determine the gas composition, attenuation, and emission of fluorocarbons in a monofill shredder residue landfill cell by field investigation. Landfill gas generated within the shredder waste primarily consisted of CH₄ (27%) and N₂ (71%), without CO₂, indicating that the gas composition was governed by chemical reactions in combination with anaerobic microbial reactions. The gas generated also contained different fluorocarbons (up to 27 μg L^?1). The presence of HCFC-21 and HCFC-31 indicated that anaerobic degradation of CFC-11 occurred in the landfill cell, as neither of these compounds has been produced for industrial applications. This study demonstrates that a landfill cell containing shredder waste has a potential for attenuating CFC-11 released from polyurethane (PUR) insulation foam in the cell via aerobic and anaerobic biodegradation processes. In deeper, anaerobic zones of the cell, reductive dechlorination of CFCs to HCFCs was evident, while in the shallow, oxic zones, there was a high potential for biooxidation of both methane and lesser chlorinated fluorocarbons. These findings correlated well with both laboratory results (presented in a companion paper) and surface emission measurements that, with the exception from a few hot spots, indicated that surface emissions were negative or below detection.     

In-situ emission characteristics of odorous gases from two food waste processing plants

Odorous gas emission is the main environmental concern of food waste treatment. Two typical food waste processing plants, one for animal feed production by hydrothermal hydrolysis + aerobic fermentation (Plant A), and the other for biogas production by anaerobic digestion (Plant B), were selected to conduct in situ monitoring of fugitive odorous gas emission for five consecutive days, and the emission characteristics of NH₃ and total volatile organic compounds (TVOC) were compared in this paper. The results showed that the two processes had different emission characteristics of odorous gases. Closed-operated hydrothermal hydrolysis had positive effects on overall fugitive odor control in plant A. Meanwhile, more fugitive odor gases may be released into the environment during the pretreatment with high-temperature and seemingly-open facilities in plant B. The emission strength of odor gases at night was generally lower than that in the day since more fresh food waste was received in the day and the higher temperature and lower air pressure in the day were favorable to gas emission. In general, the process of hydrothermal hydrolysis + aerobic fermentation was more advantageous in controlling odor than the process of anaerobic digestion.     

WSH-2型催化剂在环氧丙烷/苯乙烯装置废气处理中的工业应用

介绍了WSH-2型催化剂在环氧丙烷（PO）/苯乙烯（SM）装置废气处理中的应用。工业化装置的运行结果表明,在废气处理量86 000 Nm³/h、设定反应器进口温度250~300 ℃、设定进口非甲烷总烃（NMHC）质量浓度1 000~2 200 mg/m³的条件下,无论单系列还是双系列运转,采用WSH-2型催化剂均可对废气进行有效处理。处理后气体中的NMHC、苯、甲苯、乙醛、SM等的含量均符合GB 16297—1996《大气污染物综合排放标准》和GB 14554—1993《恶臭污染物排放标准》中的相关规定。NMHC去除率达到92.9%以上,装置运行稳定。按照目前的废气排放工况推算,预计催化剂的使用寿命可达5 a。     

Sustainable waste management in Africa through CDM projects

Only few Clean Development Mechanism (CDM) projects (traditionally focussed on landfill gas combustion) have been registered in Africa if compared to similar developing countries. The waste hierarchy adopted by many African countries clearly shows that waste recycling and composting projects are generally the most sustainable. This paper undertakes a sustainability assessment for practical waste treatment and disposal scenarios for Africa and makes recommendations for consideration. The appraisal in this paper demonstrates that mechanical biological treatment of waste becomes more financially attractive if established through the CDM process. Waste will continue to be dumped in Africa with increasing greenhouse gas emissions produced, unless industrialised countries (Annex 1) fund carbon emission reduction schemes through a replacement to the Kyoto Protocol. Such a replacement should calculate all of the direct and indirect carbon emission savings and seek to promote public–private partnerships through a concerted support of the informal sector.     

Emission of dioxins/furans and other U-POPs from test burns of non-POP pesticides in a hazardous waste incinerator

This paper presents the results of test burns for obsolete pesticides (OPs) of the permethrin group in a high temperature incinerator (HTI) in Southeast Asia. Three test burn runs were conducted, a baseline run when no OP was fed to the incinerator, and two test runs with different mixtures of OP compounds (formula 1 and 2, refer to Table 1 for detail) containing chlorine in the feeding wastes. The unintentional formed persistent organic pollutants (U-POPs) including 17 dioxins/furans, 12 dioxin-like PCBs and 12 chlorobenzenes (CBs) were monitored in all input materials and all discharges (flue gas, scrubbing liquid and solid residues). The results show relatively high levels of the U-POPs in the flue gas emission with total dioxins/furans of 4.4, 3.4, and 8.4 ng I-TEQ/m³ in the baseline, test run 1 and test run 2, respectively, which are above international acceptable emission levels. The PCB levels in flue gas were, respectively, 0.01, 0.3 and 0.4 ng I-TEQ/m³. The baseline thus had similar U-POPs levels with the OP test runs.In stack emission, approximately 90% of the U-POPs and 100% of CBs were present in gas phase. The emission factors, mass of pollutants per metric ton (tonne) of input waste, of U-POPs associated with fly ash (from bag house) were the highest, followed by flue gas and bottom ash while those associated with scrubbing liquid were relatively low. Among the waste input material only the black toner power contained U-POPs, but at low levels. The profiles of the dioxins/furans and PCBs in the toner waste were significantly different from that in the discharges. Despite the overall good destruction and removal efficiency of permethrin (better than 90%) the high emission of U-POPs and CBs from the test burn is of another more serious concern. To our best knowledge the findings of this study are the first of this kind for the Southeast Asia. The findings emphasize that if not properly conducted a standard destruction technology of a non-POP chemical can lead to a release of a range of more dangerous U-POPs into the environment.     

Study of the VOC emissions from a municipal solid waste storage pilot-scale cell: comparison with biogases from municipal waste landfill site

The emission of volatile organic compounds (VOCs) from municipal solid waste stored in a pilot-scale cell containing 6.4 tonnes of waste (storage facility which is left open during the first period (40 days) and then closed with recirculation of leachates during a second period (100 days)) was followed by dynamic sampling on activated carbon and analysed by GC–MS after solvent extraction. This was done in order to know the VOC emissions before the installation of a methanogenesis process for the entire waste mass. The results, expressed in reference to toluene, were exploited during the whole study on all the analyzable VOCs: alcohols, ketones and esters, alkanes, benzenic and cyclic compounds, chlorinated compounds, terpene, and organic sulphides.The results of this study on the pilot-scale cell are then compared with those concerning three biogases from a municipal waste landfill: biogas (1) coming from waste cells being filled or recently closed, biogas (2) from all the waste storage cells on site, and biogas (3) which is a residual gas from old storage cells without aspiration of the gas. The analysis of the results obtained revealed: (i) a high emission of VOCs, principally alcohols, ketones and esters during the acidogenesis; (ii) a decrease in the alkane content and an increase in the terpene content were observed in the VOCs emitted during the production of methane; (iii) the production of heavier alkanes and an increase in the average number of carbon atoms per molecule of alkane with the progression of the stabilisation/maturation process were also observed.Previous studies have concentrated almost on the analysis of biogases from landfills. Our research aimed at gaining a more complete understanding of the decomposition/degradation of municipal solid waste by measuring the VOCs emitted from the very start of the landfill process i.e. during the acidogenesis and acetogenesis phases.     

Comparing the greenhouse gas emissions from three alternative waste combustion concepts

Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO₂-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.     

Evaluation of landfill gas production and emissions in a MSW large-scale Experimental Cell in Brazil

Landfill gas (LFG) emissions from municipal solid waste (MSW) landfills are an important environmental concern in Brazil due to the existence of several uncontrolled disposal sites. A program of laboratory and field tests was conducted to investigate gas generation in and emission from an Experimental Cell with a 36,659-ton capacity in Recife/PE - Brazil. This investigation involved waste characterisation, gas production and emission monitoring, and geotechnical and biological evaluations and was performed using three types of final cover layers. The results obtained in this study showed that waste decomposes 4-5 times faster in a tropical wet climate than predicted by traditional first-order models using default parameters. This fact must be included when considering the techniques and economics of projects developed in tropical climate countries. The design of the final cover layer and its geotechnical and biological behaviour proved to have an important role in minimising gas emissions to the atmosphere. Capillary and methanotrophic final cover layers presented lower CH₄ flux rates than the conventional layer.