干法脱硫过程中活性炭基脱硫剂的放硫

活性炭基干法脱硫过程中的放硫关系到活性炭基脱硫的应用领域,研究避免和降低活性炭基脱硫过程中的放硫非常必要.根据脱硫过程中进口与出口硫化物形态的异同,总结了活性炭基脱硫过程中放硫的现象,重点介绍了脱硫过程中二氧化硫和羰基硫生成的放硫现象.从脱硫过程中气体组成出发,给出了活性炭基脱硫机理和放硫机理.综述了活性炭基脱硫剂本体...     

汽油精制过程中二次硫化物的生成研究进展

在汽油加氢过程中,原料中存在的烯烃和加氢脱硫生成的硫化氢会发生反应生成硫醇和其他硫化物等二次硫化物,使加氢脱硫后油品中硫醇硫及总硫含量升高,这对生产清洁汽油是一个严重的障碍。综述了汽油加氢精制过程中生成二次硫化物的国内外研究进展,并对研究该反应的重要性及未来趋势进行了展望。     

高温煤气脱硫剂的研究进展

高温煤气净化脱硫技术可使发电效率提高,成本降低,流程简化,是许多国家非常重视的研发工作。可再生金属氧化物与硫化氢或其他硫化物的作用机理及其行为是高温煤气脱硫研究中的关键所在。在已有文献工作的基础上,对国内外高温煤气脱硫剂的研究进行了系统总结,着重介绍了含钙、锌、铁、铜和锰等金属氧化物脱硫剂的研究现状,认为研究重点应从性能单一的金属氧化物转向可耐高温的多功能复合金属氧化物,同时具有再生硫回收的特性。     

活性炭担载金属氧化物用于热煤气脱硫

以热煤气脱硫并回收单质硫为目的,考察了活性炭担载金属氧化物(M/AC)在中温范围150—250℃内,催化氧化硫化氢生成单质硫的研究。担载量1%(质量分数)的M/AC通过等体积浸渍法制得,在固定床上评价了其脱硫活性,并考察了温度、反应气氛等工艺条件对脱硫效果的影响。M/AC脱硫的活性顺序为:Mn/ACCu/ACCe/ACFe/ACCo/ACV/AC。通过DTG分析,硫化氢选择性氧化的主要产物是单质硫。M/AC上金属氧化物起主要的催化作用,催化硫化氢和氧气反应生成单质硫,生成的单质硫被吸附在活性炭的孔道中。     

废氧化铁脱硫剂再生工艺进展

目前,中国北方空气污染比较严重,大气颗粒物PM2.5等造成的雾霾天气频繁出现在大城市,严重影响到人们的健康生活。煤炭燃烧过程中产生的SO2、氮氧化合物、PM2.5等是这些雾霾天气产生的重要原因。煤基多联产是一种先进的节能、清洁煤电技术。在这种技术中,煤气化后,产生大量氮氧化物和硫化物气体。在工业生产中,广泛采用脱硫剂,除去有害的硫化氢气体。氧化铁脱硫剂是一种中高温气体脱硫剂,由于储量大、硫容高、价格低、反应活性好,在国内外得到了广泛的研究和应用。脱硫剂脱硫后会形成硫化物,如果不进行再生处理,会导致脱硫成本高。此外,废脱硫剂堆积不仅会占用大量土地,而且对生态环境造成污染。研究脱硫剂的再生工艺不仅可以减少环境的负担,而且可以变废为宝,实现资源的循环利用,带来经济和社会效益。本文将综述脱硫剂中,主要的高温脱硫剂——铁基脱硫剂的再生工艺。     

转化吸收型氧化锌基脱硫剂脱除H2S和COS性能

以前驱物工业活性ZnO和碱式碳酸锌分解的ZnO为脱硫剂活性组分,在引入结构助剂γ-Al_2O_3、碱性助剂K2CO3改性的基础上,制备出转化吸收型氧化锌基脱硫剂。在300℃、空速2000h–1及常压下,考察了活性组分ZnO前驱物种类及不同前驱物制备的助剂γ-Al_2O_3对氧化锌基脱硫剂脱除硫化物性能的影响。结果表明:改性氧化锌基脱硫剂的孔隙结构和碱性显著影响其脱硫性能。与工业活性ZnO制备的氧化锌脱硫剂相比,以碱式碳酸锌分解的ZnO制备的脱硫剂对硫化氢的脱除效率和穿透硫容更高,穿透硫容约增加10倍。不同前驱物制备的γ-Al_2O_3对氧化锌基脱硫剂脱硫性能有较大影响。其中,拟薄水铝石分解的γ-Al_2O_3显著提高了氧化锌基脱硫剂脱硫性能,穿透硫容达12.18%。以碱式碳酸锌分解ZnO为活性组分,添加拟薄水铝石分解的γ-Al_2O_3和碱性助剂K2CO3制备的改性氧化锌基脱硫剂对COS的脱除起到转化与吸收作用,COS转化率达99.98%,穿透硫容为4.03%。     

凹凸棒石黏土-活性金属氧化物复合脱硫剂对脱H2S效果的影响

介绍了凹凸棒石黏土–活性金属氧化物复合脱硫剂在常温常压下脱除高浓度硫化氢气体,研究了凹凸棒石黏土含量、活性金属氧化物含量、焙烧温度等因素在硫化氢脱除中对脱硫效率和硫容量的影响。通过IR、XRD及BET等测试手段,初步分析了复合脱硫剂的结构及其对脱硫效果的影响。结果表明,以凹凸棒石黏土为主原料、添加20 %～30 %的活性金属氧化物后的复合脱硫剂具有稳定、良好的硫化性能,是一种良好的常温脱硫剂,对高浓度低流速的硫化氢气体具有较高的脱除效率和较大的硫容量。     

铁基离子液体湿法氧化硫化氢的反应性能

以氯化丁基甲基咪唑(BmimCl)和六水合三氯化铁(FeCl3.6H2O)为原料合成了铁基离子液体。分析表明,铁基离子液体具有非定量组成[Bmim]Fe0.9Cl4.7,表现出较强的疏水特性,而且具有良好的氧化性和热稳定性。以铁基离子液体为脱硫剂,对其氧化脱除硫化氢及再生工艺进行了初步研究,考察了硫化氢流量、硫化氢浓度、反应温度和氧气流量对脱硫效率的影响。结果表明,铁基离子液体的硫容达到0.31g.L-1,氧化脱硫过程中无须添加辅助试剂和调控pH值,反应温度和硫化氢流量是对脱硫率影响最为显著的两个因素,铁基离子液体脱硫剂可以在氧气中再生并循环使用。因此,铁基离子液体作为脱硫剂可以氧化硫化氢生成硫磺并在氧气中再生并生成水。基于产物水与疏水脱硫剂的不溶性,可以构建基于疏水性铁基离子液体作为脱硫剂的非水相湿法氧化脱硫新工艺,避免了水相湿法氧化脱硫过程中二次污染及操作复杂的难题,对研究发展绿色湿法脱硫工艺具有积极意义。     

复合金属氧化物脱除羰基硫的研究

采用共沉淀法制备铁锰复合金属氧化物脱硫剂,从温度、空速和羰基硫浓度几个方面考察对脱硫剂脱硫性能的影响.实验结果表明,该脱硫剂在250℃～350℃,强还原性气氛下,具有较高的有机硫脱硫精度和较大硫容.实验还考察了氧化锌、氧化铜、氧化镍和氧化铈几种添加剂对脱硫剂脱硫效果影响,结果表明,脱硫剂中添加氧化镍和氧化铈后脱硫精度有较大提高,出口羰基硫浓度低于0.1×10-6,添加氧化铜和氧化锌的脱硫精度为0.2×10-6;此外,添加氧化锌脱硫剂硫容较大,穿透硫容为25%,而添加氧化铈的脱硫剂硫容相对较小.     

焦炉荒煤气脱硫化氢技术开发与应用

河钢宣钢焦化厂研究了开发新型非水相离子液焦炉煤气脱硫工艺。此工艺利用专有的铁基非水相离子脱硫剂,在脱硫塔内与煤气硫化氢接触反应,使硫化氢氧化成单质硫,单质硫进入脱硫液中形成脱硫富液,富液经富液泵打入再生塔中氧化,形成脱硫贫液,贫液经贫液泵打入脱硫塔脱硫,循环使用。脱下的硫经板框压滤机分离入熔硫釜熔化成硫黄液体,冷却后变成硫黄。没有废液外排,脱硫剂和催化剂为无毒无害,所产生的硫膏没有气味,为绿色处理工艺。从运行过程中看,可将硫化氢含量降低到20mg/m~3以下,该技术工艺具有投资适中,运行效果好,不产生二次污染,综合运行成本低等特点。     

羰基硫催化水解气氛效应及动力学研究进展

羰基硫催化水解是从原料气中间接脱除羰基硫的主要过程,在合成原料气精脱硫技术中起重要作用。从合成原料气主要构成如CO、CO_2、H_2、O_2、水蒸汽、H_2S和羰基硫等对羰基硫催化水解活性的影响,揭示了羰基硫催化水解的气氛效应,并综述了羰基硫催化水解动力学。认为改进催化剂活性组成和孔隙结构以及复杂气氛下动力学是羰基硫催化水解研究的主要领域。     

Removal of sulfur at high temperatures using iron-based sorbents supported on fine coal ash

This paper deals with the simultaneous removal of H₂S and COS in the temperature range of 400-650 °C at 1 bar by using iron-based sorbents. The iron-based sorbents were prepared using iron oxide and cerium oxide with coal fine ash as the support. Simulated coal gas was used in the sulfidation experiments and 5% O₂ in N₂ gas was used for regeneration of sorbents. Both sulfidation and regeneration experiments have been carried out using a fixed-bed quartz reactor. The product gases were analyzed using a GC equipped with a TCD and a FPD. The results demonstrated that both H₂S and COS can be effectively reduced using the iron-based sorbents supported on fine coal ash. XRD analysis shows that Fe_1−xS phase has formed during sulfidation indicating a high sulfur capacity of the sorbent. The mechanism of the removal of COS simultaneously with H₂S is also discussed.     

不同前驱体对中温铁基脱硫剂性能的影响

分别以硝酸铁和草酸铁分解产物及分析纯氧化铁为活性组分进行脱硫剂制备,在固定床活性评价装置上对其硫化性能进行考察。结果表明,CF750、NF750和F750脱硫剂的孔结构和比表面积相差不大,但以硝酸铁和草酸铁为前驱体分解得到的活性组分粒径小于氧化铁,硝酸铁和草酸铁分解产物制备的脱硫剂对H_2S的脱除活性优于分析纯氧化铁,脱硫剂对硫化过程中出现的COS具有相同的脱除规律,硝酸钾的改性提高了脱硫剂的还原温度,减弱了CO_2与H_2S的竞争吸附能力,抑制了CO的歧化反应,有利于H_2S和COS脱除能力的改善。     

常温可再生精脱硫催化剂的开发与应用

介绍了KT-312型新型精脱硫催化剂的小试、侧流试验和工业应用结果。该催化剂在常温下操作,可多次再生,并能同时脱除H₂S和COS。该催化剂还解决了含高浓度CO₂工业气流的脱H₂S和COS难题。     

半焦对富含甲烷气体转化制备合成气的作用(Ⅲ)半焦中硫在焦炉煤气转化过程中迁移和转化

采用一个管式炉反应器分别考察了焦炉煤气中的组分H2和CO对半焦脱硫的作用.结果表明,H2气氛能促进半焦中的硫以H2S的形式析出,但对半焦热解过程中产生COS的过程没有影响,H2气氛下半焦的脱硫率约为0.6%;CO气氛能明显促进半焦中的硫以COS的形式析出,在CO气氛下半焦中硫的脱除率能达到2%～4%.H2和CO等还原性气体与半焦中硫作用,可以增加产物气体中气态硫组成的含量,但脱除的量很低,半焦中硫的转化进入气相对生成的合成气中硫含量增加的影响很小.     

Catalytic synthesis of methanethiol from hydrogen sulfide and carbon monoxide over vanadium-based catalysts

The direct synthesis of methanethiol, CH₃SH, from CO and H₂S was investigated using sulfided vanadium catalysts based on TiO₂ and Al₂O₃. These catalysts yield high activity and selectivity to methanethiol at an optimized temperature of 615 K. Carbonyl sulfide and hydrogen are predominant products below 615 K, whereas above this temperature methane becomes the preferred product. Methanethiol is formed by hydrogenation of COS, via surface thioformic acid and methylthiolate intermediates. Water produced in this reaction step is rapidly converted into CO₂ and H₂S by COS hydrolysis.

Titania was found to be a good catalyst for methanethiol formation. The effect of vanadium addition was to increase CO and H₂S conversion at the expense of methanethiol selectivity. High activities and selectivities to methanethiol were obtained using a sulfided vanadium catalyst supported on Al₂O₃. The TiO₂, V₂O₅/TiO₂ and V₂O₅/Al₂O₃ catalysts have been characterized by temperature programmed sulfidation (TPS). TPS profiles suggest a role of V₂O₅ in the sulfur exchange reactions taking place in the reaction network of H₂S and CO.     

Preparation and selection of Fe-Cu sorbent for COS removal in syngas

A series of iron-based sorbents prepared with iron trioxide hydrate, cupric oxide by a novel method was studied in a fixed-bed reactor for COS removal from syngas at moderate temperature. In addition, the sorbents mixed with various additives in different ratios were tested. The effects of additive type and ratio on the breakthrough capacity and desulfurization performance, as well as the influence of operating conditions on sulfidation behavior of the sorbent, were investigated. The simulate gas contained 1% COS, 5% CO₂, 20%–30% CO and 60%–70% H₂. The outlet gases from the fixed-bed reactor were automatically analyzed by on-line mass spectrometry, and the COS concentration before breakthrough can be kept steady at 1 ppmv. The result shows that the breakthrough sulfur capacity of the sorbent is as high as 25 g-S/100 g. At 700 K and space velocity of 1000 h⁻¹, the efficiency of sulfur removal and breakthrough sulfur capacity of the sorbent increase with the increase of copper oxide with an optimum value. The result shows that the species and content of additives also affect desulfurization performance of the sorbent.     

中低温羰基硫催化水解技术研究进展

对羰基硫水解催化剂、水解反应动力学和反应机理等研究现状进行了评述。指出添加抗中毒助剂制备高活性催化剂、将醇胺脱硫体系与水解法相结合以及采用水滑石吸附法同时脱除H₂S和COS是未来这一领域的研究热点。     

Correlation of H<Subscript>2</Subscript>S and COS in the hot coal gas stream and its importance for high temperature desulfurization

Thermodynamic analysis of the correlation of H₂S and COS has been carried out at the temperature range of 400–650 °C at which high temperature desulfurization of coal gas is usually performed. The correlation of the two sulfur species is mainly through the reaction H₂S+CO→COS+H₂. Simulated coal gas with the following composition CO 32.69%, H₂ 39.58%, CO₂ 18.27%, N₂ 8.92% and H₂S 0.47% was used in this study, and the equilibrium concentrations of the two species at different temperatures were calculated. The results of Fe-based sorbents during sulfidation were compared with calculations. It is concluded that the above reaction may reach equilibrium concentration in the presence of the Fe-based sorbents, which means the Fe-based sorbents may effectively catalyze the reaction between H₂S and CO. Because of the correlation of the two sulfur species, both can be effectively removed at high temperatures simultaneously, offering high temperature desulfurization some advantages over low temperature desulfurization processes.