烟气同时脱硫脱氮技术

概述了目前硫氧化物和氮氧化物的危害及污染现状;归纳了烟气同时脱硫脱氮技术(包括干式工艺和湿式工艺两大类)的基本原理及其应用情况;比较分析了同时脱硫脱氮技术的经济适用性水平并指出现有工艺存在的问题.根据烟气脱硫脱氮技术的低成本、高效率的研发趋势,提出该技术存在问题的解决措施和今后的研究方向;并对微波诱导催化技术与活性炭材料联用的脱硫脱氮新技术进行了可行性评价.     

一种新型烟气除尘脱硫脱氮一体化装置

提出了一种新型高效烟气除尘脱硫脱氮一体化装置,该装置将三种先进的技术有机结合,取得了相得益彰的效果:采用独特溢流装置的自激式除尘器进行除尘和脱硫脱氮,采用球面筛板塔进行二次除尘和脱硫脱氮,采用结构新颖的汽水分离器进行进一步除尘和脱硫脱氮。该装置不仅实现烟气的高效脱硫脱氮,而且可实现有用细微粉尘即稀有金属的回收。此类装置还可应用于矿山、化工和建材等领域中的湿法除尘。     

尿素湿法烟气同时脱硫脱氮反应热力学分析

利用热力学原理计算出尿素湿法烟气同时脱硫脱氮、石灰湿法脱硫、亚硫酸铵湿法脱氮吸收反应达到平衡时SO2 和NOX的分压力 ,结果表明 :尿素作吸收剂湿法烟气同时脱硫脱氮是可行的 ,脱硫效果好于石膏法 ,脱氮效果好于亚硫酸铵法 ,而且几乎 1 0 0 %的最大限度地脱除烟气中的SO2 和NOX。     

电子束辐照法净化烟气

矿物燃料燃烧产生的烟气,一般都含有SO_2和NOx,传统的排烟脱硫脱氮技术,通常是对SO_2和NO_x分别进行控制,这在经济及技术上往往是不太合理的。近年来,研究及开发排烟脱硫氮的新技术甚多。其中电子束辐照法排烟脱硫脱氮工艺、效率高、能耗低、工艺简单且无二次污染。电子束辐照法净化烟气的工艺过程,可分为两大类:一类是应用电子束福照加氨     

同时脱硫脱氮处理是我国烟气治理的发展方向

本文通过我国空气污染状况、国外烟气净化处理状况及发展趋势、国内烟气处理状况以及烟气同时脱硫脱氮方法及其特点的论述，提出同时脱硫脱氮净化处理是我国烟气治理的发展方向。     

日本燃煤烟气中NOx处理技术

ＮＯｘ是燃煤烟气中主要污染物质之一，因此烟气脱氮是大气污染控制的一项重要任务。日本在烟气脱氮方面具有先进与实用的技术，本文介绍了几种在日本已取得成功的处理方法，如改良燃烧法，选择性催化还原法，活性炭脱硫脱氮法等。     

氨法烟气联合脱硫脱氮技术工艺

SOx和NOx是燃煤锅炉排放的主要污染物,传统分步脱硫脱氮设备昂贵且效率不高,而氨法烟气脱硫脱氮具有显著的技术优势:脱硫效率高,脱硫脱氮一举两得;不产生废渣、废水;脱硫剂利用充分、耗量小、具有节能功效。因此它具有广阔的应用前景。     

烟气脱硫脱氮技术综述

本文主要介绍了烟气中二氧化硫和氮氧化物的脱除技术。目前二氧化硫的脱除技术有燃烧前脱硫、燃烧中脱硫和燃烧后脱硫三种。燃烧后脱硫技术又称为烟气脱硫技术。烟气脱硫技术有湿法、干法和半干法三种,其中湿法应用最为广泛。NOx的控制技术有选择性催化还原法、选择性非催化还原法、烟道气循环法、低NOx燃烧器法。其中,选择性催化还原法是应用最多、技术最成熟的一种烟气脱氮方式。此外,还有SO2和NOx的一体化脱除技术。     

电子束辐照法净化烟气同时脱硫脱氮

应用电子束辐照法净化含有SO_2和NO_x的烟气,可高效地同时脱除烟气中的SO_2和NO_x.这项新技术,作为工艺过程简单、高效、无二次污染的新型干法排烟脱硫脱氮技术很有希望.     

改性活性焦脱硫脱氮性能的研究

针对国内外烟气脱硫脱氮现状 ,研制出了以普通煤为主要原料 ,加入一定量金属氧化物制成改性煤质活性焦 ,并针对大气中主要气态污染物SO2 和NOx 进行了脱硫、脱氮性能的研究     

烧结烟气湿式氨法同时脱硫脱硝实验研究

在鼓泡反应器中进行烧结烟气湿式氨法同时脱硫脱硝的实验研究,考察了添加剂/NO物质的量比、吸收液NH3-NH+4浓度和烟气性质对烧结烟气脱硫脱硝的影响。实验结果表明:随着添加剂/NO物质的量比、烟气温度和NO浓度的增加,脱硝率均呈现先增大后减小的趋势。脱硝率随着吸收液中NH3-NH+4浓度的增大而增大。随着SO2浓度的增大,脱硝率逐渐减小。在所有实验条件下,脱硫率均接近或达到100%。在最佳实验条件下,脱硝率可达61.49%。通过添加添加剂部分氧化烧结烟气,可使烧结烟气湿式氨法脱硫工艺的脱硝率提高20%~30%。     

V_2O_5/TiO_2催化剂用于烟气同时脱硫脱硝的研究

研究了用V2O5/TiO2催化剂同时脱除烟气中的SO2和NO,考察了H2还原温度及其它反应条件对SO2和NO脱除率的影响。结果表明,经H2还原后所制得的V2O5/TiO2催化剂可以提高脱硫脱硝活性,最佳还原温度为700℃;在450～500℃的烟气温度范围内,该催化剂有较佳的脱硫脱硝活性;在相同反应温度下,空速越大,SO2和NO的脱除率越低;烟气中的氧气可大大提高V2O5/TiO2的脱硫脱硝活性,且氧气体积含量在5%～10%范围内变化时,对SO2和NO脱除率的影响较小。     

Simultaneous removing SO2 and NO by a new system containing cobalt complex

Absorption and catalytic oxidation of nitric oxide can be achieved by using cobalt（Ⅲ） ethylenediamine （Co（en）3^3＋. When simultaneous absorbing SO2 and NO, the precipitation of Co2（SO3）3 will be yielded and the NO removal will be decreased. A new catalyst system using Co（en）3^3＋ coupled with urea has been developed to simultaneous remove NO and SO2 in the flue gas. NO is absorbed and catalytically oxidized to nitrite and nitrate by Co（en）3^3＋. The dissolved oxygen in scrubbing solution from the feed stream acts as oxidant. Urea restrains the precipitation of Co2（SO3）3 by oxidizing SO3^2-to SO4^2- as COSO4 is more soluble in water. The experimental results proved that nearly all SO3^2- can be oxidized to SO4^2- and the high NO and SO2 removal could be obtained with the new system. The NO removal is influenced by gas flow rate, the concentration of Co（en）3^3＋ and urea in the absorption solution, the temperature of the scrubbing solution and the content of oxygen in the flue gas. The low gas flow rate is favorable to increase the NO removal. The experiments proved that the NO removal could be maintained at more than 95% by the system of 0.02 mol/L Co（en）3^3＋ and 1% urea at 50℃ with 10% O2 in the flue gas.     

Mass transfer in the absorption of SO2 and NOx using aqueous euchlorine scrubbing solution

Attempts have been made to generate euchlorine gas by chlorate-chloride process and to utilize it further to clean up SO2 and NOx from the flue gas in a lab scale bubbling reactor.Preliminary experiments were carried out to determine the gas and liquid phase mass transfer coefficients and their correlation equations have been established.Simultaneous removal of SO2 and NOx from the simulated flue gas using aqueous euchlorine scrubbing solution has been investigated.Euchlorine oxidized NO into NO2 completely and the later subsequently absorbed into the scrubbing solution in the form of nitrate.SO2 removal efficiency of around 100% and NOx removal efficiency of around 72 % were achieved under optimized conditions.Mass balance has been confirmed by analyzing the sulfate, nitrate, euchlorine and chloride ion using ion chromatograph/auto-titrator and comparing it with their corresponding calculated values.     

Experimental study on simultaneous desulfurization and denitrification based on highly active absorbent

Simultaneous removal of SO2 and NO from flue gas by the highly active absorbent prepared from fly ash, lime and a few oxidizing manganese compound additive was studied using a flue gas circulating fluidized bed （CFB） under different experimental conditions. The effects influencing the removal effiencies were discussed. The optimal flue gas temperature, flue gas humidity, gas velocity of CFB and Ca/（S＋N） molar ratio with this process were approximately 110℃, 6%, 1.8 m/s and 1.05, respectively. Removal efficiencies of 92.3% for SO2 and 60.88% for NO were obtained under the optimal experimental conditions. While the spent absorbent appeared in the form of dry powder, the mechanism of removal for SO2 and NO based on the highly active absorbent was investigated by a scanning electron microscope （SEM）, a X-ray energy spectrometer and the chemical analysis methods. The valuable references can be provided for industrial application by the process. The foreground of application will be vast in China and in the world.     

Study on the removal of NOx from simulated flue gas using acidic NaClO2 solution

The study on the removal of NOx from simulated flue gas has been carded out in a lab-scale bubbling reactor using acidic solutions of sodium chlorite. Experiments were performed at various pH values and inlet NO concentrations in the absence or presence of SO2 gas at 45℃. The effect of SO2 on NO oxidation and NO2 absorption was critically examined. The oxidative ability of sodium chlorite was investigated at different pH values and it was found to be a better oxidant at a pH less than 4. In acidic medium, sodium chlorite decomposed into C102 gas, which is believed to participate in NO oxidation as well as in NO2 absorption. A plausible NOx removal mechanism using acidic sodium chlorite solution has been postulated. A maximum NOx removal efficiency of about 81% has been achieved.     

CeCl3/活性炭纤维去除模拟烟气中单质汞的实验研究

运用等量浸渍法制备了一系列CeCl3/ACF去除剂,研究了不同负载量、不同温度和不同烟气成分对其脱汞效果的影响,并采用BET和XRD 等手段对去除剂的理化性质进行了表征.结果表明,负载CeCl3后显著改善了活性碳纤维的脱汞能力,在本实验条件下,CeCl3的最佳负载量为5%(质量分数);当反应温度低于140°C时,去除剂的脱汞效率随着温度的升高而升高,当反应温度超过140°C后,去除效率随温度的升高而下降; 通过考察NO、SO2和水蒸气对ACF脱汞效果的影响发现,NO对单质汞脱除具有一定的促进作用,不同浓度的NO与单质汞的脱除效率之间存在正相关关系;SO2对单质汞的脱除具有抑制作用,且脱除效率随着SO2浓度的增加而下降;水蒸气对单质汞的脱除具有阻碍作用.     

正脉冲电晕和氨水对SO2、NO脱除的实验研究

采用ＳＯ２,ＮＯ和空气混合而成的模拟烟气和纳秒级脉冲电源进一步研究正脉冲电晕和氨水对ＳＯ２、ＮＯ的脱除情况,以了解脱除效率与氨水添加量、电晕和温度之间的关系。实验获得了９５％的脱硫效率,即使烟气温度较,也可以适当增加氨投入量而获得９５％的脱硫效率。脉冲电晕促进了氨对硫氧化物的吸收,并使产物的热稳定性提高。氨水体身对ＮＯ没有脱除作用。电晕对ＮＯ的氧化效率达到３１％。     

软锰矿浆烟气同步脱硫脱硝资源化利用新工艺

燃煤烟气中的SO2和NOx是大气中重要的污染物,开发高效、经济的同步脱硫脱硝技术是环保领域的研究热点。针对现有同步脱硫脱硝技术存在的氧化剂成本较高和产物不能资源化利用等突出问题,提出了软锰矿浆烟气同步脱硫脱硝,并副产硫酸锰和硝酸锰的资源化新工艺。研究结果表明:软锰矿浆可以有效的脱除烟气中的SO2和NOx,反应产物分别为硫酸锰和硝酸锰。在烟道中注入臭氧,将难溶于水的NO快速氧化为NO2,可大大提高脱硝效率,在O3/NO=1.2的条件下可以达到72%的脱硝率、90%的脱硫率和85%的锰浸出率;吸收液经过空气氧化除铁和加入铜试剂除重金属后,结晶分离溶液得到的硫酸锰和硝酸锰可分别达到HG/T 2962—1999标准的硫酸锰产品和HG/T 3817—2006标准的工业硝酸锰产品要求。该工艺实现了SO2和NOx污染治理与低品位软锰矿资源化利用的双重目的,为SO2和NOx的资源化污染治理技术的开发和应用提供了新的思路。