TiO2-CeO2光催化吸附协同脱除柴油中的有机硫

采用共沉淀法制备TiO₂-CeO₂光催化吸附脱硫材料,通过低温N₂吸附脱附和X射线衍射等技术对TiO₂-CeO₂的物理化学性质进行了表征。结果表明,紫外光辐射显著提高了TiO₂-CeO₂的吸附脱硫性能;柴油中有机硫在TiO₂-CeO₂表面发生了光催化氧化转化为极性较强的砜类,可选择性地吸附在材料表面而被脱除。当TiO₂-CeO₂材料中钛铈物质的量比为9：1、煅烧温度为500℃时,其光催化吸附协同脱硫效果最好;在紫外光辐射下反应5 h,油品中DBT的脱除率高达99.6%。TiO₂-CeO₂光催化吸附协同脱硫工艺可有效解决吸附脱硫工艺中芳烃竞争吸附导致吸附脱硫选择性低的问题;在模拟油品中添加质量分数为25%的甲苯,反应7 h后油品脱硫率仍高达96.6%。TiO₂-CeO₂对不同硫化物的光催化吸附协同脱硫效果顺序为：4,6-DMDBT> DBT> BT。TiO₂-CeO₂经四次再生循环使用后,脱硫率没有明显降低。     

微波辅助脱除煤中有机硫的机理研究

为阐明微波场联合过氧乙酸(PAA)脱除煤中有机硫的机理,选取山西临汾(LF)、宁夏宁东(ND)、山西灵石(LS)和河南洛阳(LY)脱矿物质煤及三种含硫模型化合物苄硫醇(Benzyl mercaptan, BM)、苯并(b)噻吩(Benzo (b) thiophene, BT)和二苯基亚砜(Diphenyl sulfoxide, DS)作为研究对象。微波功率为100 W,并联合PAA,辐照1-5 min,通过X射线光电子能谱仪(X-ray photoelectron spectroscopy, XPS)分析固相中硫形态的变化;通过离子色谱仪(Ion chromatography, IC)分析脱硫后液相中SO_4~(2-)的浓度;通过气相色谱-质谱联用仪(Gas chromatography/mass spectrometry, GC/MS)分析萃取物中硫形态的变化。结果表明,有机硫化物硫的含量高,脱硫率大,LY和LS最大脱硫率分别高达55.06%和45.78%,ND和LF最大脱硫率分别为31.24%和28.21%,煤中的硫醇比噻吩和亚砜更易脱除,且脱硫过程中硫形态逐渐向高价态转化,含硫键在微波场中断裂,最终可被PAA氧化为SO_4~(2-)。     

New procedure for the control of the treatment of industrial effluents to remove volatile organosulfur compounds

We present a new procedure for the determination of volatile organosulfur compounds in samples of industrial effluents using dispersive liquid–liquid microextraction and gas chromatography with flame photometric detection. Initially, the extraction parameters were optimized. These included: type and volume of extraction solvent, volume of disperser solvent, salting out effect, pH, time and speed of centrifugation as well as extraction time. The procedure was validated for 30 compounds. The developed procedure has low detection limits of 0.0071–0.49 μg/L and a good precision (relative standard deviation values of 1.2–5.0 and 0.6–4.1% at concentrations of 1 and 10 μg/L, respectively). The procedure was used to determine the content of volatile organosulfur compounds in samples of effluents from the production of bitumens before and after chemical treatment, in which six compounds were identified, including 2‐mercaptoethanol, thiophenol, thioanisole, dipropyl disulfide, 1‐decanethiol, and phenyl isothiocyanate at concentrations ranging from 0.47 to 8.89 μg/L. Problems in the determination of organosulfur compounds related to considerable changes in composition of the effluents, increase in concentration of individual compounds and appearance of secondary pollutants during effluent treatment processes are also discussed.     

Tartaric acid extraction of organotin compounds from sediment samples

A new extraction method for the determination of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediments based on extraction with tartaric acid and methanol has been developed. Tin species were extracted from sediment samples using focused microwave technology, then ethylated with sodium tetraethylborate (NaBEt₄) and analyzed by isotope dilution (ID) gas chromatography-mass spectrometry (GC-MS). The advantages of such methodology in comparison with other established extraction methods for the routine speciation analysis of organotin compounds are discussed with respect to sulfur interferences co-extracted from complex matrices.Interferences from elemental sulfur are normally found with acetic acid extraction, but with tartaric acid extraction these interferences were eliminated, demonstrating selective extraction.The accuracy of the analytical procedure was established by analyzing a certified reference material (CRM) (PACS-2, marine sediment) and comparing the results to the certified values. Good agreement between determined and certified values for butyltin compounds was obtained. Finally, some complex sediment samples collected from San Vicente's Bay, Chile, were analyzed with the proposed methodology, demonstrating its potential value for monitoring butyltins in environmental samples with high concentrations of sulfur compounds.     

冷柱头程序升温进样-气相色谱/质谱法研究新鲜大蒜中的有机硫化合物

采用冷溶剂提取新鲜大蒜中的有机硫化合物,结合冷柱头程序升温进样,对大蒜原始组分进行了气相色谱/质谱分析 。该法实现了从提取到色谱分离的“冷过程”,因而可以准确地鉴定大蒜提取液在热分解前的原始组分。分析结果表明, 在大蒜提取液中含有3-乙烯基-1,2-二硫杂-5-环己烯及其异构体2-乙烯基-1,3-二硫杂-4-环己烯两种主要组分以及少量 的S-甲基甲烷硫代亚磺酸酯、二烯丙基二硫醚、二烯丙基三硫醚。对大蒜的冷溶剂提取液和水蒸气蒸馏提取的大蒜油中 的有机硫化合物进行了比较,对一些主要有机硫化合物的形成进行了初步探讨。     

炼焦过程氧化铅高温焦炉煤气均相脱硫的研究

考察了焦煤中少量氧化铅添加剂对炼焦过程高温焦炉煤气硫化氢浓度以及对焦炭质量的影响。实验表明，煤中添加少量的氧化铅，可以达到焦炉粗煤气脱硫的目的，并且对焦炭的质量影响很小。针对实验所用的煤种，相当于焦煤质量的0.6％的氧化铅添加量在炼焦前期具有最佳的抑制硫释放的效果。炼焦后期，半焦中的硫化铅分解或铅转变为气态铅。气态铅和硫化氢在离开炼焦室时，由于煤气降低温度，又生成硫化铅。从而实现均相脱硫。焦炭中超过一半的铅可以挥发出去。在炼焦收缩阶段，半焦中过多的铅的存在不利于硫化铅的分解。     

柴油非加氢脱硫技术研究中样品的选择

利用气相色谱/原子发射光谱检测器（GC/AED），对小型加氢装置的加氢脱硫柴油样品及氧化/萃取前后样品油中含硫化合物进行了分析，对色谱图中出现的几个可疑峰进行了分析和推测，表明这几个峰是由元素硫产生的，并通过无硫油样中加入硫磺和对样品进行汞洗等实验进行了验证。此外，对于加氢柴油中元素硫产生原因以及对硫质量分数测定和对实验分析的影响，在氧化脱硫等非加氢脱硫实验中样品的选择等问题进行了讨论。     

Development of a simple desulfurization procedure for the determination of butyltins in complex sediment samples using gas chromatography-pulsed flame photometric detection

In this study a rapid solid phase extraction (SPE) procedure was developed to minimize the effect of different sulfur species for the determination of butyltin in sediments. The organosulfur species and organotins were firstly retained on C8 cartridges and then organotins were selectively eluted and analyzed by gas chromatography-pulsed flame photometric detection (GC-PFPD). Optimal conditions for the SPE procedure were obtained using an experimental design approach. The method's accuracy was established by analyzing a certified reference material (CRM), BCR-646 freshwater sediment. The experimental values were found to be in agreement with the assigned values for butyltins. Finally, complex sediment samples collected from a Chilean harbor were analyzed using this methodology to demonstrate its analytical potential for the determination of butyltin in environmental samples.     

渣油超临界萃取馏分中硫化物的分离富集研究

采用选择性氧化与色谱结合的方法分离渣油中的硫醚硫化物和噻吩硫化物,该法是基于不同类型硫的选择性氧化、氧化组分与未氧化组分间极性的差异实现的。首先用高碘酸四丁铵在不氧化噻吩硫的情况下将硫醚硫选择性氧化为高极性的亚砜,经色谱柱分离富集后,利用红外色谱和硫元素分析仪,研究了馏分中硫化物的类型分布。结果表明,在俄罗斯渣油中噻吩硫和硫醚硫的质量分数随组分变重均呈增长趋势,噻吩硫相对质量分数(指硫醚硫+噻吩硫)随馏分变重呈下降趋势,相对质量分数在70%以上,噻吩硫是俄罗斯渣油中硫的主要存在形态。     

气相色谱-原子发射光谱联用技术测定柴油中硫化物

采用气相色谱－原子发射光谱（GC－AED）联用技术对柴油中硫化物进行了定性定量研究，考察了柴油加氢脱硫处理前后硫化物的变化及不同柴油原料硫化物的分布情况。结果表明，1＃柴油可定性出33类硫化物，经加氢脱硫处理后，1－1＃和1－2＃样品硫含量可由1497mg/L分别降到165.1mg/L和90.4mg/L，平均脱除率为89.0%和94.0%。其中噻吩或苯并噻吩的脱除率为100％；C1二苯并噻吩的肿除率为90.0%和96.2%;C2二苯并噻吩的脱除率为80.6%和91.7%；C3二苯并噻吩的脱除率为72.6%和84.4%；C4二苯并噻吩的脱除率为79.0%和90.3%;C5或C6二苯并噻吩的脱除率为58.4%和68.4%；未知硫化物脱除率95.7%和97.9%。噻吩类脱除率视取代基的大小、个数和取代位置的不同脱除率不同；不同原料 总硫和各种硫化物含量差别很大，应根据其硫化物的分布特点，有针对性地研制开发加氢脱硫的催化剂及选择合适的加工工艺。     

Detection of traces of oxidized and reduced sulfur compounds in small samples by combination of different high-performance liquid chromatography methods

Depending on the sulfur species, picomoles of different inorganic sulfur compounds can be detected and separated by HPLC in one arrangement in a sample volume less than 50 μl. The combination of fluorescence labelling of reduced inorganic sulfur compounds such as sulfide (S²⁻), sulfite(SO₃²⁻ and thiosulfate (S₂O₃²⁻) with monobromobimane followed by an extraction of elemental sulfur (S°) by chloroform treatment enables the detection of all mentioned sulfur compounds as well as sulfate (remaining aqueous phase) in the same sample. While the derivatized sulfur compounds could be detected by their fluorescence emission at 480 nm, elemental sulfur is identified by its UV absorption at 263 nm. Sulfate in the remaining aqueous phase is detected by HPLC with indirect UV detection at 254 nm. Detection ranges for the different sulfur compounds examined are as follows: sulfide (5 μM to 1.5 mM), sulfite (5 μM to 1.0 mM), thiosulfate (1 μM to 1.5 mM), elemental sulfur (2 μM to 32 mM) and sulfate (5 μM to >1 mM).     

汽油馏分的硫化物形态分布研究

采用气相色谱和硫化学发光检测(GC-SCD)技术,经过对色谱条件的优化,建立了汽油馏分中硫化物形态分布的测定方法。用标准物质的保留时间辅以化学法脱除硫醇、硫醚的方法对107个硫化物进行了定性;标准硫化物保留时间重复测定结果的相对标准偏差(RSD)≤0.25%。用内标法对主要的硫化物和总硫含量进行了定量,方法的加标回收率为96%~115%;同一样品重复测定5次,含硫大于7 mg/kg的硫化物组分重复测定结果的RSD≤8.9%。所建立的方法可用于不同装置的汽油馏分的硫化物形态分布规律的研究。     

催化裂化汽油中硫化物类型分布的气相色谱-硫化学发光检测的方法研究

采用气相色谱-硫化学发光检测器(GC-SCD),建立了催化裂化汽油(FCC汽油)中各种硫化物类型分布的分析方法。考察了色谱条件对催化裂化汽油中各种硫化物分离的影响,定性了某催化裂化汽油中的58个硫化物。采用该方法,硫化物中的硫在其质量浓度为0.5~800.0 mg/L时,其峰面积与质量浓度呈较好的线性关系,相关系数达0.999,其响应与硫化物的类型无关。FCC汽油中几种主要硫化物(噻吩、正丁硫醇、2-甲基噻吩、3-甲基噻吩、2,4-二甲基噻吩)的浓度测定值的相对标准偏差(RSD)均小于5.0%。当信噪     

Advanced Methodologies for Adsorption/Thermal Desorption with Tenax-TA for the Analysis of Polycyclic Aromatic Hydrocarbons and Sulfur Compounds

We have evaluated an analytical method for the determination of polycyclic aromatic hydrocarbons (PAHs) and sulfur compounds in air by means of adsorption/temperature-programmed thermal desorption (ATPTD) with small bed volume (0.08g) Tenax-TA cartridges, followed by a cryogenic trap in a precolumn with liquid nitrogen as an appropriate concentration method before capillary gas chromatography is described. The enriched components from the adsorption cartridges are transferred to the capillary column with a valveless switching system. Recoveries were determined for the complete ATPTD method. Desorption recoveries near 100% were found for various of polycyclic aromatic hydrocarbons and sulfur compounds. The sulfur compounds known to cause nuisance odors in the atmosphere near sulfur recovery and sewerage treatment works were also determined.     

添加金属氧化物的V2O5/AC在烟气脱SO2及脱SO2后H2再生制备硫磺的活性研究

干法脱除烟气SO2的多种催化剂均可在H2气氛中再生,直接制备硫磺。该过程的实现不仅要求再生尾气循环,而且要求催化剂具有双重功能,即在脱硫过程中催化氧化SO2为H2SO4以及在再生过程中将催化还原释放出的SO2进一步转化为硫磺。添加有金属氧化物的V2O5/AC催化剂具备双重功能。着重考察了添加Ce、W、Fe、Co 等氧化物的V2O5/AC催化剂烟气SO2脱除能力及脱除SO2后经H2再生制备硫磺的能力,并对添加Co的催化剂进行了优化。结果表明,在这类催化剂中,对烟气脱SO2起主要催化氧化作用的是V2O5,对H2再生硫磺制备起作用的是添加的金属氧化物。除Ce2O3外,WO3、Fe2O3和CoO都提高了再生中的硫磺收率,CoO的作用最为显著。较合适的催化剂组成是1%V2O5和0.5%CoO。这些金属氧化物在AC上的担载方法,对烟气脱SO2和H2再生结果的影响不明显。硫磺的生成需要CoO向CoS2的转变,再生后催化剂上残余有部分CoS2,且残余硫量还与V2O5量有关。     

Reaction mechanism of direct episulfidation of caryophyllene and humulene

Direct episulfidations of caryophyllene or humulene with elemental sulfur were examined by means of gas chromatography. Caryophyllene-6,7-episulfide was formed at an early stage in a reaction of the caryophyllene and elemental sulfur at 120 degrees C. Caryophyllene-3,6-sulfide and polymer compounds were formed after the episulfidation. Formations of the these compounds were related to the disappearance of the caryophyllene-6,7-episulfide. Isomerization from the caryophyllene to isocaryophyllene was also observed during the reaction. In the reaction of humulene with elemental sulfur, humulene-6,7-episulfide was initially produced and then converted to humulene-9,10-episulfide. It was assumed that the polymer compound in the reaction of humulene with sulfur was related to the disappearance of the both humulene episulfides.     

The Analysis of Sulfur Compounds by Solid Adsorbent Tenax GR Preconcentration and Gas Chromatography with Flameless Sulfur Chemiluminescence Detection

Gas chromatography using flameless sulfur chemiluminescence detection was applied to the analysis of sulfur compounds in air. A trap employing the solid adsorbent Tenax GR was used to enrich ambient levels of volatile sulfur compounds. The sulfur gases were then thermally released according to programmed temperature from the adsorbent trap and re-collected in a column cooled with liquid nitrogen. The sulfur compounds were revolatilized and directly transferred to the system of PLOT-column gas chromatograph/flameless sulfur chemiluminescence detector for analysis. The PTV injector has been used as a thermal resorption chamber for analysis of sulfur compounds. The sulfur gaseous compounds known to cause nuisance odors in the air from sewerage treatment works were determined.     

氧化-萃取脱除柴油中噻吩类硫化物研究进展

近年来针对柴油中噻吩类硫化物的脱除问题国内外进行了多种非加氢脱硫技术研究,其中氧化脱硫、萃取脱硫、氧化-萃取脱硫技术是研究较多、具有应用前景的脱硫方法。本文从柴油氧化-萃取脱除噻吩类硫化物的反应机理出发,重点概述了有机酸、酸酐催化体系、离子液体催化体系及分子筛催化体系氧化-萃取脱除噻吩类硫化物获得低硫柴油的最新研究成果,并提出了目前存在的问题及该领域未来的研究方向。     

Vanadium(IV) catalysed oxidation of organosulfur compounds in heavy fuel oil

The deleterious effects of refractory polyaromatic hydrocarbons found in fuels such as organo-sulfur compounds are such that they emit SO_x to the environment when combusted, thereby reducing air quality. Herein, oxidative desulfurization (ODS) which is a complementary step to hydrodesulfurization (HDS) was carried out in an attempt to eliminate sulfur compounds in fuels. Refractory organosulfur compounds were oxidized using tert-butyl hydroperoxide as an oxidant and a poly[VO(allylSB-co-EGDMA)], (vanadium(IV) functionalized polymer of 6,6′-(1E,1′E)-(1,2-phenylenebis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)bis(2-allylphenol) crosslinked with ethyleneglycol dimethacrylate) as a catalyst to convert sulfur compounds to polar sulfones. Some of the organosulfones were adsorbed via the use of molecularly imprinted polybenzimidazole nanofibers. The sulfur in heavy fuel oil after the oxidation/adsorption method fell below 8900 ± 200 ppmw S from the initial value of 17 920 ± 100 ppmw S.     

NEW SULFUR CHEMISTRY SYMPOSIUM. INTRODUCTORY REMARKS

Abstract

It is most appropriate to have a symposium on sulfur chemistry at a Southwest Regional Meeting. The Frasch sulfur process was first tried out and developed on the Gulf Coast. Organosulfur compounds are present in petroleum, which is produced in large amounts in this area, and also in the extensive lignite deposits in Texas. The chemistry of organosulfur compounds is important in many ways, for example: removal of organosulfur compounds from petroleum and lignite, pollution/environmental concerns, polymer chemistry, materials research, agriculture, medicinal uses, etc.