化工生产过程中的尾气处理工艺技术分析

在化工生产过程中,会排放含有污染物质的有害气体,所以国家规定了化工企业的尾气排放标准。介绍了化工企业尾气处理的主要内容,并对尾气处理的相关技术提出了相关建议措施,从回收处理尾气的流程,到回收装置的保养要求,尾气处理工艺的优化等,根据相关的知识,为化工企业提出建议,以为化工行业更好地发展。     

硫磺回收装置尾气排放超标解决方案

分析了兖矿国泰化工有限公司甲醇车间硫磺回收尾气SO2排放超标的原因.介绍了相应的改造解决办法:[1]加氢反应采用高纯度H2;[2]改造气体流程;[3]采用聚乙二醇二甲醚作为硫磺回收尾气吸收的溶剂,并改造溶液再生流程;[4]将加氢反应器N2升温过程进行优化改造等.流程改造后,成功解决了硫回收尾气SO2排放超标的问题.     

膜法和变压吸附法在氯乙烯回收过程中的应用

四平昊华化工有限公司5万t/a PVC装置采用膜法系统回收氯乙烯尾气,20万t/a PVC装置采用变压吸附系统回收氯乙烯尾气。膜法回收工艺适合氯乙烯尾气含量高的回收,5万t/a PVC装置尾气排放流量是生产流量的20%,     

硫磺回收装置降低尾气中氮氧化物及二氧化硫排放的措施

对于石油化工生产过程中的尾气排放,不允许造成环境污染。因此,研究应用硫磺回收装置降低尾气中氮氧化物及二氧化硫排放的技术措施,有利于化工生产尾气排放达到规定标准,实现环保的指标。通过对装置的操作条件进行变革,达到最佳的控制指标,提高石油化工生产效率。     

氨法脱硫技术在硫回收系统中的应用

兖矿国泰化工有限公司300 kt/a甲醇系统采用四喷嘴新型气化炉制气,NHD脱硫,脱硫富液再生后产生的H2S气体经克劳斯硫回收装置生产硫磺产品.硫回收装置的硫回收系统运行情况较好,但尾气加氢反应系统、尾气洗涤系统等运行不稳定（尾气加氢炉经常出现积炭、炉壁烧穿等情况,尾气焚烧炉检修频繁）,导致排放尾气中SO2含量高（1300～2600 mg/m3）,不能够实现达标排放,环保压力较大.为此,公司通过对改造硫回收装置尾气系统与新建尾气氨法脱硫装置进行比选,决定新建氨法脱硫装置以脱除硫回收尾气中的SO2,实现硫回收尾气的达标排放.     

膜分离与无动力深冷分离技术在聚乙烯尾气回收上的应用

聚乙烯装置生产出的气体中含有烃类,气体中的部分烃类和氮气被直接排放到火炬中形成了浪费。介绍了目前常用的尾气回收方法,并针对某公司45万t/a聚乙烯装置的实际生产情况,选用合适工艺对该装置的尾气回收系统进行改造。改造后对尾气回收效果进行了标定测算,尾气回收效果达到设计值,能够有效降低全装置的物耗、能耗和异戊烷单耗,很大程度提高了企业的经济效益。     

提高克劳斯工艺硫磺回收率技术探讨

通过对克劳斯硫磺回收工艺技术的改进,提高硫磺的回收率,减少硫磺对环境的污染,使化工生产的尾气排放,达到环保的指标。经过改进处理,使化工生产的尾气中硫磺的回收率达到99.5%以上,持续气相催化工艺技术措施的应用,使硫磺达到非常好的回收效果。     

一种热能回收技术在甲醛尾气处理中的应用

正0前言浙江晋巨化工有限公司甲醛装置生产过程中产生的尾气采用尾气锅炉法进行处理,即利用甲醛尾气作为燃料,空气为助燃剂进行燃烧,燃烧后的高温烟道气与水进行换热副产0.5 MPa低压蒸汽,换热后的烟道气现场高空排放。经对排放后的烟道气温度进行测量,发现烟道气的排放温度较高,存在热能损失的现象。为了进一步降低烟道气的排放温度,对烟道气的热能进行充分回收,决定采用梯级热能回收工艺对甲醛尾气锅炉热能回收流程进行工艺技术     

UNIPOL工艺聚乙烯装置尾气回收技术改造和应用效果

UNIPOL工艺聚乙烯装置在日常的生产活动中,由脱气仓对黏附在树脂上的烃类进行脱除,由脱气仓排出的气体进入到排放气压缩机系统,经过二级压缩冷却,将部分烃类气体回收,但其中仍含有烃类气体未能完全回收,而且由于这部分烃类导致以氮气为主的这部分气体只能排放至火炬而无法回收利用,通过尾气回收技术改造,可以进一步回收烃类气体,并将氮气提纯回收利用。     

蒽油加氢尾气回收技术改造研究

蒽油加氢尾气回收装置无法对低压硫化氢进行回收,因此需要对尾气回收装置进行改造。通过对尾气回收装置中的水洗塔、硫氢化钠反应器进行改造,使尾气全部回收,减少硫化氢气体排放,并提高硫氢化钠产量,取得良好的社会及经济效益。     

A Model to Characterize and Predict Fugitive Emissions from Flange Joints

The new model describing the gaseous transport through graphite gaskets is based on the assumption of a flow in the transition regime through nano‐scale capillaries, using the Maxwellian wall‐slip boundary condition for rarefied gases. Together with an earlier published model describing the liquid transport in graphite gaskets, it enables the characterization of fugitive emissions of volatile organic compounds from fluid‐charged flange joints in chemical and petrochemical plants as a function of medium properties, pipe pressure, and gasket stress. Additionally, combination of the models allows predicting the emission rates of gases by experiments with liquids as the emitting fluid. Finally, recommendations are made to improve the gaskets with respect to their sealing performance towards gases.     

含氰化氢废气治理研究进展

氰化氢（HCN）是一种危害人体健康和大气环境的剧毒污染物,任何含氮物质和含氮燃料的燃烧、化工生产、冶金、汽车尾气排放等都能释放含HCN的废气。本文综述了近年来脱除HCN方面的研究进展,评述了各种脱氰方法包括吸收、吸附、燃烧、催化氧化、催化水解等技术的原理、适用对象及各种方法的优缺点。结果表明：吸收和燃烧法具有净化效率高、工艺简单等优点,对处理高浓度含氰废气有较大优势;其它方法的脱氰剂虽起活温度高、再生较为困难,但二次污染小,适用于气体的精细脱氰。今后各种技术的联合应用不仅能实现复杂气分下工业废气中HCN的逐级净化,而且能综合回收利用尾气中高浓度CO作为燃料和化工原料气。虽然各技术的联合应用在投资成本和工艺控制方面还有一定难度,但却具有较大的发展前景,是今后含氰化氢废气脱除的新趋势。     

Der Einsatz von Sprühdüsen zur Reduzierung diffuser Staubemissionen

Spray nozzles have been used for a long time for the purpose of reducing dust emissions in exhaust gas streams. Therefore gas scrubbers are used to generate a defined water spray in a defined gas flow to reduce particle concentration in the most effective way by low energy consumption. Droplet size, pressure and water flow rate are adaptable to the exhaust gas flow's properties. In case of using spray nozzles to reduce fugitive dust emissions, e.g. in bulk material handling, the determining factors for emission reduction effectiveness, in contrast to the defined gas flow, vary. A variety of different spraying systems made it necessary to make a selection for different fields of application in relation to their dust‐reducing effects when applying in the bulk handling.     

环境治理中泄漏排放的监测及控制方法初探

对监测及控制泄漏在环境治理中的重要性进行了总结,进而对于泄漏排放的来源作了简要阐述,在国内外对于泄漏排放的监测及控制的前提下进行了详述,总结出了对于泄漏排放有效的监测及控制。     

Application of a FIGAERO ToF CIMS for on-line characterization of real-world fresh and aged particle emissions from buses

On-line chemical characterization of real-world particle emissions from 13 transit buses was performed using a chemical ionization mass spectrometer (CIMS) equipped with a filter inlet for gases and aerosols (FIGAERO). In addition to the fresh emissions the emissions were artificially aged using a potential aerosol mass reactor (Go:PAM). The buses studied were running on different fuel types (diesel, compressed natural gas, and rapeseed methyl ester) and exhaust after-treatment systems (selective catalytic reduction (SCR), exhaust gas recirculation (EGR), and a three-way catalyst). When evaluating emissions from passing exhaust plumes using the FIGAERO ToF-CIMS, two technical features were highlighted from this work, the use of high mass calibrants and the factor enhancement method to be able to filter important compounds from mass spectra including hundreds of species. Here, acetate was used as the reagent ion to enable detection of highly oxygenated species in the exhaust particle emissions with potential high toxicity and/or secondary organic aerosol formation (SOA) potential. The acetate ionization scheme accounted for 4% to 46% of the total emitted particulate mass through identification of 61 species in the spectra. For aged emission the various fuel types provided overlapping species that could explain up to 19% of the aged emissions. This is hypothesized to come from the oxidation of engine lubrication oil, thus a common source for various fuels which was further supported by laboratory measurements. Specific markers from the SCR technology, such as urea oxidation products and further byproducts from hydrolysis were identified and attributed to reactions of isocyanic acid.

Copyright © 2019 The Author(s). Published with license by Taylor &; Francis Group, LLC     

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.     

Computer aided estimation of fugitive emission rates and occupational air concentration in process design

European Union directives such as the Integrated Pollution Prevention and Control (IPPC) require inclusion of safety, environmental and health analyses in process design as part of strategies towards achieving sustainable process development. In petrochemical and organic chemical industries, which mostly handle volatile compounds, the most significant contributor to atmospheric releases is fugitive emissions that are mainly contributed by piping fittings and components. Fugitive emissions are not only of economic and environmental concern, but also a major source of background inhalative exposure to workers that may lead to various diseases including cancer. More people die every year from occupational diseases as compared to the number killed in industrial accidents. Therefore the estimation of occupational air concentration due to fugitive emission needs to be done early when developing a new process. Several methods for fugitive emissions estimation have been introduced which mostly involve manual calculations. Computer-based tools for such purpose however, are still lacking. Besides, the current methods mainly focus on the emission rates only but not on the process air concentrations. Computer aided methods for fugitive emissions assessment are highly in need, since now most of the design work is done by using computer aided process engineering (CAPE) tools. Therefore in this paper computer aided methods for quantifying fugitive emission rates and occupational air concentration are presented. Three methods are proposed for early design stages based on data available from simple process flow diagrams (PFDs), detailed PFDs or piping and instrumentation diagrams (P&IDs). The method becomes more comprehensive as it progresses from simple PFDs to P&IDs, since more process data are available later, which include plot plan, coordinates of the emission sources and local wind speed. Users however, can choose which method to use depending on the process information available in hand. The methods are demonstrated in a case study of product distillation system of toluene hydrodealkylation.     

石化企业挥发性有机物无组织排放监测技术进展

无组织排放占石化企业挥发性有机物（VOCs）排放的主导地位,排放点多、面广、量大、分散、无规则,总体表现为大型面源或体积源,监测难度很大。本文评述了点、线和面(通量)等VOCs无组织排放监测技术及应用进展,总结了石化企业VOCs无组织排放监测存在的主要问题与难点,提出了石化企业VOCs无组织排放监测体系及适用监测技术。总体上,石化企业VOCs无组织排放监控存在排放清单质量不高、源头监测及溯源困难、排放烟羽及其迁移扩散途径无定形、厂界等开放空间难以封闭监测、常规监测的时间和空间覆盖有限等问题或技术难点,可复合应用点、线、面及通量监测技术,结合常规离线、实时在线、排放通量、移动快速响应等监测设计,构建覆盖排放与环境影响的多元化、网络化、立体化监控体系。未来石化企业VOCs无组织排放监控将向多层级、智能化和大数据应用发展。     

Gaswaschanlagen für saure und basische Abgase unter Berücksichtigung der neuen TA-Luft

Gas scrubbing plants for acid and caustic exhaust gases with consideration of the new TA-Luft . When designing gas scrubbing plants for acid and caustic exhaust gases from manufacturing plants of the chemical and pharmaceutical industry it is important to pay special attention to the aerosol formation which occurs in the exhaust gas systems and absorbers if the emission values should remain under the determined limit values stated in the Technical Instructions for air-pollution control (TA-Luft). The present study explains under what conditions aerosols can occur, how its formation can be prevented, and which gas scrubbers are appropriate for a combined gas-/aerosol separation. A comparison between two exhaust air scrubbing plants of several stages shows that a gas scrubbing plant for an exhaust air pick-up system with separation of the acid and caustic components as well as with source exhaust air pick-up of the highly charged gas flows is considerably more favourable with respect to price than the alternative scrubbing plant for an integrated exhaust air system in which large quantities of fine salt aerosols occur and have to be separated with high energy consumption.     

活性炭纤维吸附装置在发泡剂CFCs回收中的应用

在冰箱拆卸过程中，聚氨酯硬质泡沫会释放出大量CFCs，而CFCs是重要的温室气体之一，因此，冰箱拆卸过程中尾气中CFCs回收受到大家重视。本文介绍了利用活性炭纤维回收家电拆卸过程中释放出氟里昂的装置。该装置自动运行，工艺先进，并且利用高效的吸附剂一活性炭纤维。运行实践表明，利用该装置可以有效的处理冰箱拆卸过程中释放出的CFCs。