吸附分离含硫化合物的进展

从烃料流，合成气或废卸中脱除含硫化合物是石油化工的重要分离过程，也是环境保护的一项重要措施。本文根据近年来的文献资料，综述了吸附分离含硫化合物，包括二氧化硫，充化氢，二硫化碳，硫醇和硫醚等的方法。活性碳纤维作为新型碳材料，在这方面的应用具有广阔的前景。     

含硫有机溶剂在锂离子电池中的应用研究进展

电解液是锂离子电池的关键组成之一,它直接影响电池的性能。介绍了含硫化合物作主体电解液的应用,该化合物的加入改善了锂离子电池的安全性能、拓宽电池的工作温度范围,综述了此方面以及含硫化合物的成膜机理等研究进展。     

DHS-GC-MS结合主成分分析法分析绿茶香气成分

采用动态顶空(DHS)-气质联用(GC-MS)结合主成分分析法(PCA)对全国11个产区的绿茶香气成分进行研究。结果表明:在11个产区绿茶中共分离鉴定出206种挥发性成分,主要包含醇类、醛类、酮类、酯类、酸类、杂氧化合物、碳氢化合物和其他类化合物,其中碳氢化合物种类最多,相对含量最高,其次是醇类、醛类和酮类化合物;利用主成分分析法对绿茶香气中的50种共有挥发性成分进行分析,鉴定出27种特征香气成分,包括7种碳氢化合物、7种醛类、4种酮类、8种醇类、1种含硫化合物,这些成分是决定绿茶香气的重要组分。     

杂原子化合物及抗磨剂对柴油润滑性影响探讨

应用高频往复试验仪测定了催化柴油、直馏柴油、加氢精制柴油的润滑性,考察了馏程与柴油润滑性的关系,并以加氢精制柴油为原料,通过添加不同含硫、含氮、含氧杂原子化合物,考察其对柴油润滑性的影响,采用傅立叶红外光谱仪剖析了四种柴油抗磨剂的分子结构并进行了加剂试验考察抗磨效果。结果表明:柴油馏分随着馏程的升高润滑性越好;含硫杂环化合物不能降低柴油润滑性,含氮、含氧酸性杂环化合物是改善柴油润滑性的主要物质之一;抗磨剂分子结构对润滑性起着重要作用,极性越强,抗磨效果越好。     

硫氰化物测银法

废定影液中银的定量测定,有光度法、Ag_2S沉淀后的浊度法和电位法等。这些方法需要特殊仪器和试剂。而测定银较普遍的方法是滴定法,其中硫氰化物法是测定银的重要滴定法之一。但由于废定影液中含有较多的杂质,特别是含硫的化合物,在溶液酸化时,生成的黑褐色胶体状况沉淀物妨碍用硫氰化物法直接滴定。因此,须预先进行银的分离。我们采用在氨性溶液中使银成为Ag_2S沉淀分离的方法。测定银的回收率为99.5％以上,误差0.6％,变动系数在0.3％左右,重现性良好,样品测定时间为     

汽油脱氮技术前景研究

汽油是一种重要的石油产品,它广泛的应用于汽车、船舶等各个行业。随着人们环保意识的增强,对汽油产品提出了更严格的要求。提高汽油的品质就需要最大限度的脱除汽油产品中的含硫及含氮化合物。汽油产品中氮化物可分为碱性和非碱性两大类。     

高效液相色谱分析磷脂研究进展

天然磷脂是含磷酸的类脂化合物，广泛存在于自然界中，在工业生产、食品科学、医药学、生命科学等研究方面都有重要的作用。磷脂的研究手段多样，高效液相色谱在磷脂的分离、检测方面具有优势。结合近年来国内外对高效液相色谱分离磷脂的研究报道，分析了液相色谱分离磷脂所用固定相、流动相、检测器等关键因素，认为液相色谱与质谱联用是未来液相色谱分析磷脂的技术方向。     

油气集输储罐的腐蚀与防护方法的探讨

文章通过对含硫原油储罐中的活性硫（硫化氢、硫、硫醇）与腐蚀产物—铁锈反应生成不同形式的硫铁化合物（FeS、Fe2S3、FeS2）及硫化亚铁的氧化和自燃机理进行了分析和评估，同时结合实际情况提出了一些切实可行的防护措施。     

大分子自组装体系及自组装功能膜结构的研究

本文主要介绍了３种大分子自组装体系，含硫化合物的在重金属表面的自组装功能膜、聚合物在溶液状态下的自组装体系和聚合物基材上的自组装功能膜。文中还介绍了表征自组分析方法，着重介绍了用于自组装功能膜表面、界面结构分析的两种，红外光谱法和原子力显微镜。     

更有力的分析工具——用于石化样品的二维气相色谱分析

二维气相色谱分析是一项强有力的分析技术，它根据化合物的挥发性和极性将其分离后进行分析。在分离过程中，根据所使用的两个不同柱式加热炉的保留机理，对化合物的沸点和极性等物理和理化特性进行独立的处理。[编者按]     

Adsorption and separation of carbon dioxide and methane on carbonaceous adsorbents

Adsorption and separation of carbon dioxide and methane on different carbonaceous adsorbents were analyzed and compared. Coconut shell-based activated carbon has the highest adsorption capacity for two gases. Sips model describes the adsorption isotherms best. The separation factor on coconut shell-based activated carbon is the highest under various conditions, reaching about 3.8. The adsorption capacity of the two gases is closely related to the specific surface area and micropore volume of the adsorbent. The adsorbed amount of each component in the mixture is less than that of the pure component under the same condition, indicating that there is a competition in the adsorption process. The total adsorbed amount of the two gases decreases as the proportion of carbon dioxide decreases, implying that the adsorption process is dominated by carbon dioxide adsorption. Additionally, the separation factor decreases with increasing temperature. Understanding the adsorption behaviors of pure and binary carbon dioxide and methane is important in treating biomass gas using carbonaceous adsorbents.     

金属有机骨架材料在气体吸附与分离中的应用研究进展

金属有机骨架材料(MOFs)因具有超高比表面积、较大的孔隙率、多样化且可调的孔道结构及相对温和的制备条件等优势,目前已成为化学和材料等学科的研究热点之一。概述了MOFs材料的制备方法及其用于气体(含碳、含氮及含硫)吸附与分离方面的研究进展,并对其在该方面今后的发展趋势和应用前景进行了展望。     

Multi-functional sorbents for the simultaneous removal of sulfur and lead compounds from hot flue gases

A multi-functional sorbent is developed for the simultaneous removal of PbCl(2) vapor and sulfur dioxide from the combustion gases. The sorbent is tested in a bench-scale reactor at the temperature of 700 degrees C, using simulated flue gas (SFG) containing controlled amounts of PbCl(2) and SO(2) compounds. The removal characteristics of PbCl(2) and SO(2), individually and in combination, are investigated. The results show that the mechanism of capture by the sorbent is not a simple physical adsorption process but seems to involve a chemical reaction between the Ca-based sorbent and the contaminants from the simulated flue gas. The porous product layer in the case of individual SO(2) sorption is in a molten state at the reaction temperature. In contrast, the combined sorption of lead and sulfur compounds generates a flower-shaped polycrystalline product layer.     

The process window for diamond deposition from the vapor phase with sulfur in the C–H–O feed gas mixtures

Theoretical predictions using a modified radical species ternary diagram for C–H–O system indicate that addition of sulfur expands the C–H–O gas phase compositional window for diamond deposition. Sulfur addition to no-growth domain increases the carbon super-saturation by binding the oxygen and the addition of sulfur to the non-diamond domain reduces the heavy carbon super-saturation by decreasing C_nH_m species concentration in the gas phase. The overall effect of sulfur addition to gas phase mixtures is characterized as that of oxygen addition to the C–H system, i.e. expansion of the compositional window over which diamond can be deposited from the gas phase. In addition, the increasing sulfur concentration to diamond domain feed gases beyond 2000 ppm did not affect the steady state gas phase composition but the quality of diamond was reduced.     

Adsorption of selected volatile organic vapors on multiwall carbon nanotubes

Carbon nanotubes are expected to play an important role in sensing, pollution treatment and separation techniques. This study examines the adsorption behaviors of volatile organic compounds (VOCs), n-hexane, benzene, trichloroethylene and acetone on two multiwall carbon nanotubes (MWCNTs), CNT1 and CNT2. Among these VOCs, acetone exhibits the highest adsorption capacity. The highest adsorption enthalpies and desorption energies of acetone were also observed. The strong chemical interactions between acetone and both MWCNTs may be the result from chemisorption on the topological defects. The adsorption heats of trichloroethylene, benzene, and n-hexane are indicative of physisorption on the surfaces of both MWCNTs. CNT2 presents a higher adsorption capacity than CNT1 due to the existence of an exterior amorphous carbon layer on CNT2. The amorphous carbon enhances the adsorption capacity of organic chemicals on carbon nanotubes. The morphological and structure order of carbon nanotubes are the primary affects on the adsorption process of organic chemicals.     

Control of acid gases using a fluidized bed adsorber

During incineration, secondary pollutants such as acid gases, organic compounds, heavy metals and particulates are generated. Among these pollutants, the acid gases, including sulfur oxides (SO(x)) and hydrogen chloride (HCl), can cause corrosion of the incinerator piping and can generate acid rain after being emitted to the atmosphere. To address this problem, the present study used a novel combination of air pollution control devices (APCDs), composed of a fluidized bed adsorber integrated with a fabric filter. The major objective of the work is to demonstrate the performance of a fluidized bed adsorber for removal of acid gases from flue gas of an incinerator. The adsorbents added in the fluidized bed adsorber were mainly granular activated carbon (AC; with or without chemical treatment) and with calcium oxide used as an additive. The advantages of a fluidized bed reactor for high mass transfer and high gas-solid contact can enhance the removal of acid gases when using a dry method.On the other hand, because the fluidized bed can filter particles, fine particles prior to and after passing through the fluidized bed adsorber were investigated. The competing adsorption on activated carbon between different characteristics of pollutants was also given preliminary discussion. The results indicate that the removal efficiencies of the investigated acid gases, SO(2) and HCl, are higher than 94 and 87%, respectively. Thus, a fluidized bed adsorber integrated with a fabric filter has the potential to replace conventional APCDs, even when there are other pollutants at the same time.     

Catalytic oxidation of gaseous reduced sulfur compounds using coal fly ash

Activated carbon has been shown to oxidize reduced sulfur compounds, but in many cases it is too costly for large-scale environmental remediation applications. Alternatively, we theorized that coal fly ash, given its high metal content and the presence of carbon could act as an inexpensive catalytic oxidizer of reduced sulfur compounds for "odor" removal. Initial results indicate that coal fly ash can catalyze the oxidization of H(2)S and ethanethiol, but not dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) at room temperature. In batch reactor systems, initial concentrations of 100-500 ppmv H(2)S or ethanethiol were reduced to 0-2 ppmv within 1-2 and 6-8 min, respectively. This was contrary to control systems without ash in which concentrations remained constant. Diethyl disulfide was formed from ethanethiol substantiating the claim that catalytic oxidation occurred. The presence of water increased the rate of adsorption/reaction of both H(2)S and ethanethiol for the room temperature reactions (23-25 degrees C). Additionally, in a continuous flow packed bed reactor, a gaseous stream containing an inlet H(2)S concentration of 400-500 ppmv was reduced to 200 ppmv at a 4.6s residence time. The removal efficiency remained at 50% for approximately 4.6h or 3500 reactor volumes. These results demonstrate the potential of using coal fly ash in reactors for removal of H(2)S and other reduced sulfur compounds.     

氮气吸附技术在气体纯化中的应用研究进展

介绍了吸附法脱除N2的工业应用,包括空分行业中O2/N2分离、煤层气和天然气中CH4的浓缩、高纯气中N2的深度脱除以及制N2工艺。N2的吸附脱除工艺主要采用PSA技术,吸附剂主要包括天然及合成沸石分子筛、改性分子筛(离子交换及不同Si/Al比改性)、活性炭、金属有机化合物等。     

Limitations to the use of solid-phase microextraction for quantitation of mixtures of volatile organic sulfur compounds

A study of the range of volatile organic sulfur compounds produced by brassica plants has highlighted limitations to the use of Carboxen/PDMS fibers for their analysis by solid-phase microextraction (SPME). These fibers are sometimes advocated for the analysis of sulfur gases, but a quantitative comparison of analytical data derived by SPME and by direct gas sampling of standard mixtures of volatile low molecular weight sulfur compounds at 0.01-10 mg/L has identified potential errors associated with their use. Higher molecular compounds displace lower molecular weight compounds as a consequence of competition for active sites on the fiber, and the relative proportions of the components adsorbed onto the fiber depend on their ratio in the headspace. As their relative concentrations change from sample to sample, the varying interactions result in irregular analytical responses, reflected in erratic calibration curves. Standards containing single components are not valid; only a standard containing all components found in the sample to be analyzed, and at the same relative concentrations, is appropriate. In practice, this may preclude the use of the fibers for quantitative analysis of multicomponent mixtures.     

Can breath isoprene be measured by ozone chemiluminescence?

Isoprene, involved in the biosynthetic pathway to cholesterol, is the prevalent hydrocarbon in breath. Breath isoprene measurement is of great interest as a measure of basal cholesterol production rate. We investigated the merits and pitfalls of isoprene measurement via its chemiluminescence (CL) reaction with ozone. For many subjects, apparent concentrations measured are higher than those obtained by a gas chromatography (GC) reference method that can be traced to ozone-induced CL with simultaneously present lower olefins and sulfur compounds. A warm column preconcentration method eliminates the lower olefins and greatly improves sensitivity while a silver-form, ion-exchange resin can remove the sulfur gases. The breath sample is captured on a miniature synthetic carbon sorbent column maintained at 55 degrees C, under which conditions ethylene, propylene, and water vapor are not significantly captured while the preconcentration process greatly improves the limit of detection for isoprene to 0.6 ppbv (S/N=3). The captured isoprene is released by heating the column to 150 degrees C. Breath samples from different subjects were collected both before and after meals and analyzed in a double-blind fashion in two laboratories, with the second laboratory performing quantitation by cryofocusing GC-flame ionization detection with parallel measurement by mass spectrometry to provide identity confirmation. For all individuals studied, the CL and the GC results agreed when both warm column preconcentration and passage through Ag+-form cation-exchange resin, which removes divalent sulfur gases, were implemented prior to CL measurement. The intensity of CL from the reaction with ozone can be much higher for some sulfur gases than for isoprene. Even though present at lower concentrations than isoprene, unless removed prior to CL measurement, for some individuals sulfur gases can cause unacceptably large (up to 500%) errors, making the sulfur gas removal step critical.