Fate of sulfur compounds in coal during oxidative dissolution in perchloric acid

The sulfur forms in coal (sulfate, pyrite and organic) have been clearly delineated by oxidation with perchloric acid. Perchloric acid was chosen as an oxidizing agent because its oxidizing power can be varied by changing its concentration and subsequent boiling point. Using this property, the stepwise oxidation of an Illinois No. 6 coal, a coal-derived pyrite, and a New Zealand coal (in which almost all of the sufur was organic) was effected. At low temperatures, sulfate was removed without oxidizing the pyrite or organic material. At a moderate temperature (155°C), the pyrite was oxidized to sulfate and a sulfur-containing gas. Little or no organic sulfur was oxidized at 155°C. Boiling concentrated perchloric acid (203°C) converted all the sulfur to sulfate and a sulfur-containing gas. The sulfur-containing gas was produced primarily from the pyrite; organic sulfur produced very small amounts of a sulfur-containing gas as an oxidation product.     

Zapoteca formosa: Sulfur Chemistry and Phytotoxicity

Chemical analysis of Zapoteca formosa extracts show that a variety of volatile sulfur-containing components, including cyclic polysulfides, are responsible for the distinctive odor of its germinating seeds and young plants. The major sulfur-containing compounds include acetyl djenkolic acid, djenkolic acid, taurine, cystine, benzothiazole, dimethyl disulfide, 2,4-dithiapentane, 2-hydroxyethylmethylsulfide, trithiane, 1,2,4-trithiolane, and 1,2,4,6-tetrathiepane. Decreased amounts of djenkolic acid in seedlings and young plants, as compared to the seed, indicate that this is likely the metabolic precursor of the volatile sulfur components. Germination and radicle elongation assays show that germinating seeds of Zapoteca and mixtures of volatile sulfur-containing compounds are highly phytotoxic to Cucumis sativa, Lactuca sativa, Lycopersicon esculentum, and Acacia farnesiana.     

世界硫需求及硫肥状况

阐述世界硫肥的需求状况:到2012年世界农业缺硫量预计每年将达1 100万t,而亚洲和美洲将成为全球最严重的缺硫地区。环境污染控制、集约化农业生产以及低硫高浓度肥料的使用,加剧了全球范围内土壤缺硫状况。缺硫日益成为农业可持续发展和提高肥料利用率的限制因素之一,但也刺激农用硫肥的需求,为肥料工业开发新技术和新产品、开拓市场提供了契机。有3种硫肥,分别是:(1)硫酸盐基;(2)硫磺基;(3)液态硫基,其中硫酸盐基占绝大部分,其具有较好的理化特性,可直接、均衡为作物提供多种养分。本文介绍含硫肥料的种类、各种肥料的性能及目前世界上开发多种新型含硫肥料产品来适应和满足不同作物、土壤的需要。     

含硫磷肥料浆的制备研究

含单质硫的磷肥是一种既能够缓慢提供硫营养又能够提高磷吸收率的肥料,但是其生产技术一直被国外专利保护。研究了一种用棒磨机湿磨硫磺颗粒,以磷肥系统的尾气洗涤液和磷酸作为分散介质,制得分散均匀稳定的含硫料浆的方法。采用上述方法在小型生产装置上制得了含硫料浆,将含硫料浆按比例加入磷酸中,在不影响磷肥生产系统的前提下制得了含硫磷肥。扫描电镜表征表明,制得的含硫磷肥中的硫磺颗粒均匀分布在产品中。     

Elemental Sulfur Identified in Urine of Cheetah, Acinonyx jubatus

The urine of the cheetah, Acinonyx jubatus, is almost odorless, and probably for this reason, it has not attracted much attention from scientists. Using gas chromatography–mass spectrometry, we identified 27 and 37 constituents in the headspace vapor of the urine of male and female cheetah, respectively. These constituents, composed of hydrocarbons, short-chain ethers, aldehydes, saturated and unsaturated cyclic and acyclic ketones, 2-acetylfuran, dimethyl disulfide, dimethyl sulfone, phenol, myristic acid (tetradecanoic acid), urea, and elemental sulfur, are all present in the headspace vapor in very small quantities; dimethyl disulfide is present in such a low concentration that it cannot be detected by the human nose. This is only the second example of elemental sulfur being secreted or excreted by an animal. It is hypothesized that the conversion of sulfur-containing compounds in the cheetah's diet to elemental sulfur and to practically odorless dimethyl sulfone enables this carnivore to operate as if “invisible” to the olfactory world of its predators as well as its prey, which would increase its chances of survival.     

不同硫源对小球诺卡氏菌R-9生长和脱硫活性的影响

用氯化钡沉淀结合傅里叶变换红外光谱法，证明小球诺卡氏菌（Nocardia globerula）R-9从二苯并噻吩中脱除的含硫产物以硫酸盐的形式存在于水相.比较了R-9分别以二苯并噻吩、硫酸钠和二甲基亚砜作为惟一硫源时的生长和脱硫活性.结果表明，二苯并噻吩、硫酸钠和二甲基亚砜均可以作为R-9的生长硫源，且高浓度（25 mmol•L^-1）硫酸钠和二甲基亚砜对细胞的生长不产生抑制作用.2 mmol•L^-1左右的硫酸钠或二甲基亚砜作为硫源时培养的细胞脱硫活性最高.提高硫源和碳源浓度可以提高R-9在发酵罐中的比生长速率和细胞浓度(OD600).     

Sulfur compounds affecting processing of rapeseed

A characteristic feature of cruciferous oilseeds is a high level of sulfur compounds as sulfur-containing amino acids and glucosinolates which determine the nutritional value of rapeseed meal and affect processing factors in oil mills. During rapeseed processing, products of glucosinolate splitting are liberated and attack metal and, as a result, a specific sulfur corrosion of oil mill equipment develops. The most exposed are cooker, toaster and transporters of wet meal. The results of industrial investigation of sulfur corrosion are described and the sensitivity to corrosion of several construction steels during rapeseed processing is considered. A high content of sulfur-containing compounds in starting oil significantly depressed the nickel catalyst activity and influenced the kinetics of rapeseed oil hydrogenation. Removal of these compounds by refining and its influence on the rate of oil hydrogenation are discussed.     

Hierarchically porous sulfur-containing activated carbon monoliths via ice-templating and one-step pyrolysis

Hierarchically porous sulfur-containing activated carbons were prepared by ice-templating from an aqueous sodium poly(4-styrenesulfonate) (Na-PSS) solution followed by a single 800 °C pyrolysis step. This thermal treatment induced crosslinking, with the in-situ generation of Na₂SO₄ (activating agent), before carbonization and activation. The thermal treatment also resulted in the formation of sulfur salts, which could be converted to elemental sulfur upon a simple HCl acid wash. The sulfur content in the monoliths measured by microanalysis could be increased from 17.07 wt. % to 39.74 wt. % by incorporating additional Na₂SO₄ into the monoliths prior to pyrolysis. The sulfur was uniformly dispersed within the micropores of the carbon, and could be selectively removed by degassing (heating under vacuum) at different temperatures, revealing specific surface areas of up to 1051 m² g⁻¹. The materials were characterized by various techniques and were also evaluated for their potential as cathode materials for the lithium–sulfur battery. This work may open up new and facile routes to prepare sulfur-containing porous carbons for applications where its presence is beneficial.     

Synthesis of stereoisomers of 6β- and 7β-(benzylthio)-3-(p-tolyl) tropane-2-carboxylic acid methyl ester

To develop new ^99mTc-labelled agents to evaluate dopamine transporters (DAT) involved in Parkinson's disease, by in vivo SPECT imaging, we have synthesized six new sulfur-containing ligands with the tropane skeleton. We have introduced the complexing sulfur atom far from the three sites of recognition by DAT of these tropane derivatives. The 6β-substituted tropinone has been obtained by a double Mannich condensation followed by the introduction of the moieties for molecular interactions at the binding site on C2 and C3, leading to the six stereoisomers.     

锌湿法冶炼硫渣中硫磺化学富集工艺

对锌精矿富氧直浸产生的硫渣中硫磺进行化学富集. 基于硫渣物理化学性质分析,得出影响硫磺品位的主要杂质是SiO2和FeS2,并进一步提出了HF溶液脱除SiO2, Fe2(SO4)3酸性溶液分解FeS2以提高硫磺品位的技术思路,研究了相应的技术条件. SiO2脱除的较佳条件为：HF溶液浓度20%(w)、温度55℃、时间3 h、液固比4 mL/g;FeS2分解的较佳条件为：Fe3+离子浓度1.5 mol/L、H2SO4浓度1.5 mol/L、Fe2(SO4)3用量为理论量2倍、温度98℃、时间5 h. 硫渣经两步处理后,硫磺含量可从70%提高至86.2%. 该工艺具有一定的工业应用价值.     

Radiation-chemical synthesis of phosphorus- and sulfur-containing polymers

Phosphorus- and sulfur-containing polymers were obtained by radiation-chemical synthesis from elementary phosphorus and sulfur in benzene. The structure and composition of the products were studied by solid-phase ³¹P NMR spectroscopy, MALDI mass spectroscopy, and other physicochemical analytical methods. The reactivity ratios of inorganic monomers, phosphorus and sulfur, were determined.     

Sulfur Versus Non-Sulfur Containing Polyimide Adhesives for Bonding Steel

Due to their superior thermal and chemical stability, polyimides are often used as adhesives in harsh environments. This study examines the effect on bond strength of thioether sulfur in the polyimide backbone. Bonds were made using steel that was believed to catalyze the oxidation of sulfur. In addition, non-sulfur containing polyimides with similar T_g were also studied for comparison. The polymer/metal interface was studied using both the T-peel and wedge tests. No apparent effect was observed in the T-peel test with steel where the T-peel strengths of non-sulfur and sulfur containing polyimides were similar. In the wedge test, however, the sulfur-containing BDSDA/ODA bonded to steel had the smallest initial crack length of 34 mm. However, the BTDA/APB bonds tested in a dry environment had the smallest crack growth. The sulfur-containing BTDA/ASD performed best of the bonds tested in a wet environment. Metal-catalyzed oxidation of sulfur was observed to take place in the steel case, but not to an extent to have a noticeable effect on peel strength.     

含硫油品储罐腐蚀机理研究

综述了原油中活性硫和非活性硫的来源及分布情况、引起含硫油品储罐的腐蚀原因,重点剖析了含硫油品储罐的腐蚀机理,最后介绍了两种预防含硫油品储罐腐蚀的措施。     

含硫纤维素衍生物的研究进展

简述了近年来在含硫纤维素衍生物方面的研究进展。将含硫纤维素衍生物分为巯基纤维素与费原酯棉、水溶性含硫纤维素衍生物和聚硫醚纤维素三大类，对含硫纤维素衍生物的合成、应用及其与金属离子作用机理作了论述。     

Chemical desulfurization of petroleum fractions for ultra-low sulfur fuels

An improved desulfurization process for removing sulfur from hydro treated diesel oil based on the oxidation of thiophenic type sulfur-containing compounds with H₂O₂ and acetic acid (AcOH) using H₂SO₄ as catalyst has been studied. The experimental results show that the sulfone content in the oxidation product increased rapidly with an increase in acetic acid and sulfuric acid ratios from 1:0 to 2:1 mole ratios. The maximum DBT conversion (wt.%) was at 2:1 mole ratio of acetic acid/sulfuric acid. This oxidation process is found to be capable of removing up to 90% of the sulfur compounds in hydro treated real fuels and can provide an alternative way to meet the future sulfur environmental requirements.     

Effects of Ca-based additives on desulfurization during coal pyrolysis

The effects of different Ca-based additives on the sulfur removal of coals during pyrolysis up to 900 °C have been studied in a fixed-bed reactor. It was found that Ca(OH)₂ and CaO were quite effective to capture the sulfur-containing gases, 95% of the sulfur evolved from untreated coal was retained in the char by the use of additives. Both the tar yield and the sulfur content of the tar decreased with addition of Ca-based additives. The effect of Ca(OH)₂ was better than that of CaO due to its higher activity, but CaCO₃ had little effect because of its higher decomposition temperature (−900 °C) than the peak temperature range (400–500 °C) of sulfur-containing gases emission. There is remarkable sulfur retention effect with Ca(OH)₂ prepared by impregnation and ultrasonic treatment due to the higher dispersion in coal particles than by simple mechanical mixing. The ultrasonic treatment is the best method with regard to the lowest SO₂ release during the char combustion. XRD results showed that the sulfur captured by Ca-based additives during pyrolysis turned into CaS. FeS detected in pyrolysis char without additives disappeared in chars with additives, which indicated that CaO could react with FeS through solid-solid reaction. When the chars with calcium-additives were burned in fixed bed reactor, they gave out less SO₂ than the raw coal added with same additives. The best total desulfurization efficiency could reach to about 85%.     

含硫肥料的开发

介绍了含硫肥料开发的现实意义以及目前的硫肥品种。详细概述了涂硫尿素的生产工艺及其特点。     

渣油中硫化物的测定方法研究进展

渣油中硫化物的存在对石油加工和石油生产带来很多不利条件,渣油中的主要硫化物为硫醚硫和噻吩硫,总硫与硫醚硫的差值即为噻吩硫。对硫化物定量研究,可以为渣油加工提供理论依据和数据基础。本文概述了渣油中硫醚硫的测定方法,并对各种方法的优缺点进行了讨论,在实际应用中应结合实际条件选择合适的方法对硫化物进行研究。     

影响高温变换催化剂放硫速度的因素分析

对影响低含硫高温变换催化剂的放硫速度问题,从催化剂制造、放硫过程的动力学、影响高温变换催化剂放硫的工业因素(还原及放硫温度、空速、汽气比、压力)进行了分析。认为催化剂本体硫含量应尽可能降低,催化剂使用企业应充分保证还原和放硫温度、放硫空速、汽气比、适当降低还原及放硫过程系统压力,以保证还原质量,缩短放硫时间。