超重力技术在硫酸尾气脱硫中的工业化应用

介绍了超重力机结构和工作原理。浙江巨化股份有限公司硫酸厂2套制酸装置的尾气脱硫系统原采用泡沫塔—复喷复挡装置两级氨法脱硫工艺,技术改造后采用泡沫塔—超重力机两级氨法脱硫工二艺。改造后72h性能考核表明,新脱硫系统排放尾气ρ（SO2）最高429mg/m^3、最低74mg/m^3,ρ（H2SO4）最高31.9mg/m^3、...     

臭氧氧化结合硫代硫酸钠溶液喷淋同时脱硫脱硝

采用臭氧氧化结合湿法喷淋硫代硫酸钠溶液的方法开展模拟烟气同时脱硫脱硝实验研究。结果表明,采用臭氧氧化结合Na2S2O3-Na OH溶液湿法喷淋可以实现NOx和SO_2协同脱除:在O_3/NO摩尔比为1.1~1.2时,溶液中Na2S2O3浓度的增加会提高系统的NO_x脱除效率,烟气中SO2的存在会促进NOx的脱除,当SO2浓度为1030mg·m~(-3)、2.0%Na_2S_2O_3溶液作为喷淋液时可实现较高的SO_2脱除效率,同时NO_x脱除效率可达70%以上;喷淋液p H在2.5~9范围内变化时提高浆液p H有利于NOx的脱除,当p H=9时脱硝效率可达75%。180 min连续同时脱硫脱硝实验结果表明,硫代硫酸钠可有效促进NOx的脱除,并实现SO2较高的脱除效率,同时可实现系统同时脱硫脱硝连续稳定运行,喷淋吸收后烟气中NO_x的主要转化产物为NO~-_2,该方法作为一种有效的同时脱硫脱硝技术,具有一定的工业应用推广前景。     

采用含硫化物的废碱液净化AS系统克劳斯尾气的中试

报道了采用含硫化物废碱液净化处理AS煤气脱硫系统克劳斯尾气的中试研究结果。中试装置设计能力为200m^3/h，实际处理能力最高可达240m^3/h，试验表明，在pH值为8．5－9．0，反应温度为70摄氏度左右，采用含硫化物废碱液脱除AS系统克劳斯尾气中SO2，同时生成H2S是适合的，在试验条件下，SO2脱除率＞98％，总硫脱除率＞98％，由于尾气中CO2参与了系统的化学平衡，实际H2S转化率比理论值高，并使最终以硫磺形式从废碱液中回收硫化物成为可能，该技术对AS煤气脱硫系统用户来说，经济社会效益尤其明显。     

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.     

加热炉烟气与环保装置尾气治理实践与探讨

为应对国家日益严格的排放标准,探讨削减加热炉烟气和工艺尾气的SOx和NOx排放的措施具有重要性和紧迫性。惠州炼化通过对加热炉燃料气进行深度脱硫处理及对加热炉进行低氮燃烧器改造,改造后烟气SO_2排放浓度均控制在20 mg/m3以下,NOx排放浓度均控制在100 mg/m3以下,可以满足特别排放限值地区SO_2和NOx排放限值标准。酸性水罐进行了恶臭气体治理改造,改造后硫化氢和氨满足排放标准要求。将硫磺回收装置液硫脱气塔尾气由入尾气焚烧炉改为入制硫炉,改造后尾气SO_2排放浓度由改造前的440 mg/m3降至285 mg/m3。废酸再生装置尾气增设脱硫系统,净化后尾气SO_2浓度降至20 mg/m3以内。     

过氧化氢与TS-1/2稳定剂法脱硫工艺的生产实践

阐述了过氧化氢与TS-1/2稳定剂法脱硫技术的原理及特点.采用w（H2O2）27.5％的过氧化氢溶液作为吸收剂,回收SO2后可产生w（H2SO4）20％ ～30％的稀硫酸并返回干吸工序使用,脱硫效率高,脱硫后排放的尾气中ρ（SO2） ＜200 mg/m3,远低于新国标规定的排放限值.     

气-固-固流化床用于燃煤电厂尾气同时脱硫脱硝

采用新型干法气–固–固流化床反应器进行模拟燃煤电厂尾气的高效同时脱硫、脱硝. 在内径53 mm的流化床中,以砂粒作为固相介质、自制的K2CO3/Al2O3为吸附剂,考察了温度、吸附剂粒径、吸附剂活性组份(K)与气相中污染组份(SO2,NO)的摩尔比、模拟气中SO2/NO摩尔比等工艺条件对脱硫脱硝效率的影响. 在无氨条件下同时脱硫、脱硝的效率可分别达到100%和92%. 大量数据表明,尾气中的SO2对吸附剂表面NO的脱除反应有显著促进作用.     

采用硫化碱处理克劳斯装置尾气的中试开发研究

本文报道了一种采用硫化碱对克劳斯尾气进行脱硫净化的技术开发过程。在实验室半连续装置上研究采用硫化碱脱除SO2 同时制取H2 S的适宜条件 ,SO2 吸收动力学及CO2 的存在对脱除SO2 同时制取H2 S的影响。进而在实验室小型连续装置上进行了验证 ,并确定了一个最佳SO2 /Na2 S进料摩尔比 ;依据实验研究结果 ,进行了 2 0 0m3 /h的中试装置放大设计 ,经 3个月的连续运行 ,试验表明中试装置工艺设计合理 ,采用Na2 S脱除SO2 同时制取H2 S在技术上可行。经济分析显示 ,采用本法每处理 1m3 尾气仅耗费 0 0 39元人民币 ,显示出有很好的社会经济综合效益     

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.     

300 kt/a硫磺制酸装置尾气脱硫技改设计及运行

介绍了300 kt/a硫磺制酸装置尾气脱硫技改情况,重点阐述了二级脱硫改造工艺流程、设备选型及相关运行数据,改造后硫酸装置尾气中的颗粒物(ρ)由30 mg/m^3降到5 mg/m^3,ρ(SO2)由120mg/m^3降到20 mg/m^3以下,达到了环保要求,取得了良好的效果。     

臭氧氧化—钙法吸收同时脱硫脱硝的试验研究

针对国内某石化企业CFB锅炉烟气特点,进行实验室烟气模拟,采用臭氧氧化—钙法吸收同时脱硫脱硝工艺进行小试研究.实验采用臭氧将NO氧化为NO2,再通入鼓泡反应器中与Ca（OH）2浆液发生吸收反应,达到同时脱硫脱硝的目的.实验结果表明：NOx脱除率与臭氧投加量成正比,当臭氧投加量为1.1时,NOx脱除率可达到90％以上;SO2初始浓度的变化对NOx脱除率影响不大;NO初始浓度和烟气含氧量对SO2脱除率影响效果均不显著;烟气含氧量的增大有利于NOx的脱除.     

An indirect electrochemical process for the removal of NOx from industrial waste gases

The development of a new electrochemical process for the absorption of NOx from industrial waste gases is described. Conversion of NO was performed by an indirect outer cell process using dithionite as the redox mediator and Fe(II)EDTA as the complexing agent. The absorption process, involving complex formation with Fe(II)EDTA in the absence and presence of dithionite, was investigated using a packed bubble column. In semibatch experiments the dependence of different system parameters on the degree of NO conversion was studied: concentration of dithionite and Fe(II)EDTA, gas flow rate, oxygen content, and temperature. The reaction products in the gas phase and in the liquid phase were analyzed using gas chromatography and ion chromatography, respectively. This analysis proved that, instead of N2 or N2O, ammonia and amidosulfonic acid are the main reaction products in the solution. The kinetics and the conditions for the regeneration of dithionite by electrochemical reduction of sulfite were studied on RDE and by experiments in a divided cell. For the dithionite production a current efficiency of about 80% was found in 0.2 m Na2SO4 at pH 5.6. By combining the chemical NO absorption in a gas/liquid contactor with the electrochemical regeneration of dithionite in a divided plate and frame cell a degree of NO conversion better than 90% under continuous operation can be obtained.     

烧结烟气活性炭脱硝机制

烧结烟气氮氧化物(NOx)排放占钢铁行业NOx排放总量的50％以上,随着环保法规的日益严格,现有及新建烧结机只有装设烟气脱硝装置才能满足排放法规的NOx排放要求.而活性炭微孔丰富、比表面积大、吸附能力强,低温时即可同时脱除烟气中的SO2、NOx、粉尘及其他有害气体.因此,低温烧结烟气活性炭脱硝具有显著的特点及技术优势,...     

Ce-Fe/ZSM-5催化剂用于燃机烟气SCR脱硝的性能

采用浸渍法制备了一系列Ce?Fe/ZSM-5催化剂,基于燃机烟气工况研究了Fe含量及Ce掺杂量对Fe/ZSM-5催化剂的中高温脱硝性能的影响,并结合一系列表征技术对其物化性能进行研究。结果表明,Fe含量为4wt%时,Fe/ZSM-5催化剂在550℃下NOx转化率为77.11%。掺杂Ce后Ce?Fe/ZSM-5催化剂的高温脱硝效果明显提升,Ce负载量为1wt%时,550℃时NOx转化率仍保持95.92%,催化剂有优异的中高温催化活性,比Fe4/ZSM-5提高了18.81%。同时改变烟气中的NO2和O2含量,发现NO2和O2浓度增加均可提高催化剂的脱硝性能,水热老化测试表明Ce1?Fe4/ZSM-5催化剂具有优异的水热稳定性,分别在10vol% H2O, 600℃和10vol% H2O, 800℃条件下老化后,在450?550℃内NOx转化率保持约90%。适量掺杂Ce后催化剂表面Lewis酸含量及强度增强,表面吸附氧比例增大,Ce与Fe元素间的协同作用提高了催化剂的高温氧化还原能力,提升了高温活性,因此促进了中高温条件下SCR反应的进行。     

移动床活性焦烟气净化工艺中废活性焦的形成与特征分析

移动床活性焦低温干法烟气多污染物脱除技术在钢铁烧结烟气脱硫脱硝工艺中具有良好的适用性,但烟气净化过程中活性焦的损耗成为制约该技术推广应用的关键因素之一。以宝钢烧结烟气脱硫脱硝工艺中所产生的废活性焦为研究对象,通过考察其比表面积、孔容结构、灰分中重金属及碱金属含量、表面官能团特征及脱硫脱硝性能,探究烟气净化过程中活性焦组成、结构及表面性质的变化。结果表明,与新鲜活性焦相比,废活性焦粒度集中分布在0.2?5 mm,其表面的氮、氧、硫元素及过渡金属氧化物含量显著增加,比表面积由191.0 m2/g增加至499.0 m2/g,使废活性焦颗粒在150℃下脱硝率由20%提升到70%,120℃下穿透硫容由0.27 mg SO2/g提升至11.08 mg SO2/g,显示了良好的再利用潜力。     

烟气气相组分及Ca(OH)_2对KMnO_4氧化NO的影响机理

在固定床反应器中考察了KMnO₄氧化烟气中NO的过程,分析了烟气组分H₂O、O₂及SO₂对NO氧化过程的影响规律,得到了Ca（OH）₂对KMnO₄氧化NO的影响机理。实验结果表明,H₂O是KMnO₄氧化NO的必要条件;在含H₂O条件下,O₂可以提高NO氧化率。SO₂与氧化剂反应生成无水钾镁钒类复盐K₂Mn₂（SO₄）₃对NO氧化具有负面作用;Ca（OH）₂的加入提高了氧化剂表面的固体碱度从而促进氧化过程进行;通过添加Ca（OH）₂可以降低SO₂对NO氧化过程的负面影响。根据气体成分和产物分析可知,KMnO₄在钙基吸收剂表面氧化烟气中NO的机理可能是KMnO₄以离子态将吸附在氧化剂表面的NO和SO₂氧化为NO₂和SO₃,生成的NO₂、SO₃再传递到氧化位临近的碱性位被吸收。     

Experimental study on SO2 recovery using a sodium-zinc sorbent based flue gas desulfurization technology

A sodium–zinc sorbent based flue gas desulfurization technology (Na–Zn-FGD) was proposed based on the experiments and analyses of the thermal decomposition characteristics of CaSO3 and ZnSO3·2.5H2O, the waste products of calcium-based semi-dry and zinc-based flue gas desulfurization (Ca–SD-FGD and Zn–SD-FGD) tech-nologies, respectively. It was found that ZnSO3·2.5H2O first lost crystal H2O at 100 °C and then decomposed into SO2 and solid ZnO at 260 °C in the air, while CaSO3 is oxidized at 450 °C before it decomposed in the air. The ex-perimental results confirm that Zn–SD-FGD technology is good for SO2 removal and recycling, but with problem in clogging and high operational cost. The proposed Na–Zn-FGD is clogging proof, and more cost-effective. In the new process, Na2CO3 is used to generate Na2SO3 for SO2 absorption, and the intermediate product NaHSO3 reacts with ZnO powders, producing ZnSO3·2.5H2O precipitate and Na2SO3 solution. The Na2SO3 solution is clogging proof, which is re-used for SO2 absorption. By thermal decomposition of ZnSO3·2.5H2O, ZnO is re-generated and SO2 with high purity is co-produced as well. The cycle consumes some amount of raw material Na2CO3 and a small amount of ZnO only. The newly proposed FGD technology could be a substitute of the traditional semi-dry FGD technologies.     

The use of rice hulls for sustainable control of NOx emissions in deep space missions

The use of the activated carbon produced from rice hulls to control NOx emissions for future deep space missions has been demonstrated. The optimal carbonization temperature range was found to be between 600 and 750 degrees C. A burnoff of 61.8% was found at 700 degrees C in pyrolysis and 750 degrees C in activation. The BET surface area of the activated carbon from rice hulls was determined to be 172 m2/g when prepared at 700 degrees C. The presence of oxygen in flue gas is essential for effective adsorption of NO by activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of the NO in the flue gas was removed for more than 1.5 h when 10% oxygen was present and the ratio of the carbon weight to the flue gas flow rate (W/F) was 15.4 g min/L. Reduction of the adsorbed NO to form N2 could be effectively accomplished under anaerobic conditions at 550 degrees C. The adsorption capacity of NO on the activated carbon was found to be 5.02 mg of NO/g of carbon. The loss of carbon mass was determined to be about 0.16% of the activated carbon per cycle of regeneration if the regeneration occurred when the NO in the flue gas after the carbon bed reached 4.8 ppm, the space maximum allowable concentration. The reduction of the adsorbed NO also regenerated the activated carbon, and the regenerated activated carbon exhibited an improved NO adsorption efficiency.     

Performance with Respect to Flue Gas Composition of a Combined Desulfurization／Denitration Process Using Powder-Particle Fluidized Bed

A new combined desulfarizatinn/denitraticon (DeSOx/DeNOx) procees was teeted in this study. The procees uses the so-called powder-partlcle fluidized bed (PPFB) as the major reactor in which a coarse DeNOx catalyst, several hundrsd micrometers in size, is fluidized by flue gas as the fluidization medium particles while a contlnuogsly supplied fine DeSOx sorbent, several to tens of micrometers in dianteter, is entrained with the flue gas. Ammonin for NOx reduction is fed to the bottom of the bed, thus, SOx and NOx are simultaneously removed in the single reactor.By adopting a model gas, SO2-NO-HaO-N2-air, to simulate actual flue gas in a laboratory-scale PPFB, simultaneous SO2 and NO removals were explored with respect to various gas components of flue gas. It was found that the vaxlations of SO2 removal with concentrations (fractions) of oxygen, water vapor, SO2 and NO in flue gas are little affected by the simultaneous NOx reduction. However,the dependencles of NO removal upon such gas components are clveely related to the inter-actions between DeSOx sorbent and DeNOx catalyst.