LIQUID PHASE CO-OXIDATION OF THIOPHENOL AND STYRENE BY OXYGEN AND t-BUTYL HYDROPEROXIDE

ABSTRACT

Instability problems in both shale and petroleum derived middle distillate jet fuels have been correlated with the presence of peroxidic species. Although a good body of knowledge exists concerning the formation of peroxides in the liquid phase, relatively little is known about the reaction/ decomposition pathways available when other functional groups are present, since sulfur is the most abundant heteroatam present in jet fuels, the reaction of t-butyl hydroperoxide (tBKP) and/or oxygen with thiophenol in the presence of the active olefin, styrene, was examined in deaerated benzene at 120°C. The complex product mixture was analyzed by combined capillary column GC/MS. Major products included acetone, t-butanol and isdbutylene from the tBHP. Thiophenol and styrene combined to form addition products. Phenyl disulfide was observed from the thiophenol. The results indicated that although the product slate was complex, it was possible to explain the product mix in terms of a few competing reactions.     

LIQUID PHASE OXIDATION OF THIOPHENOL AND INDENE BY t-BUTYL HYDROPEROXIDE AND OXYGEN

The tert-butyl hydroperoxide (tBHP) or oxygen initiated oxidation of thiophenol in the presence of the active olefin indene was examined in benzene at 120C. The reaction is kinetically complex, but it was possible to relate the product distribution to a few competing reactions. The product mix was determined for several reaction time periods. The product slate was similar for all time periods, but yields of the individual components varied significantly with increasing reaction time. Gaseous products included isobutylene and a trace of methane. The major product from tBHP was t-butanol. The major product observed from thiophenol was phenyl disulfide. Addition products included the major product 2-phenylthiyl indan. Oxidation products included: indanols, indanones, and the sulfoxide and sulfone of the major product 2-phenylthiyl indan. Solvent participtation was noted by trace amounts of toluene.     

LIQUID PHASE OXIDATION OF HEXYLDISULFIDE BY t-BUTYL HYDROPEROXIDE IN BENZENE

There are inconsistencies in the literature regarding the role of organosulfur compounds in general, and sulfonic acids in particular, on the oxidative instability of middle distillate fuels. Comparison of published results between investigations is complicated by differences in a large number of variables. Variations in fuel composition, heteroatam distribution, reaction surface, hydroperoxide concentration, dissolved oxygen and reaction temperature all contribute to the variation in observed results. In an effort to clarify this situation, we have examined the t-butyl hydroperoxide liquid phase oxidation of hexyldisulfide in deaerated benzene.     

LIQUID PHASE OXIDATION OF HEXYLDISULFIDE BY t-BUTYL HYDROPEROXIDE IN BENZENE

ABSTRACT

There are inconsistencies in the literature regarding the role of organosulfur compounds in general, and sulfonic acids in particular, on the oxidative instability of middle distillate fuels. Comparison of published results between investigations is complicated by differences in a large number of variables. Variations in fuel composition, heteroatam distribution, reaction surface, hydroperoxide concentration, dissolved oxygen and reaction temperature all contribute to the variation in observed results. In an effort to clarify this situation, we have examined the t-butyl hydroperoxide liquid phase oxidation of hexyldisulfide in deaerated benzene.     

LIQUID PHASE OXIDATION OF OCTANAL BY CUMENE HYDROPEROXIDE

Reactions that lead to fuel instability can be closely linked to the presence of active oxygen species. An increasing body of evidence links oxidation reactions of hydroperoxides to the instability observed in fuels. The active oxygen compounds present in fuels are alkyl and aromatic hydroperoxides. Cumene hydroperoxide represents a logical choice for an active oxygen compound that could be present in a middle distillate fuel. This paper reports on the reactions of cumene hydroperoxide with octanal in benzene solvent at 140°C for various time periods. The complete slate of products is presented along with a suggested mechanism to explain the observed products and the implications for fuel instability reactions.     

FUEL INSTABILITY STUDIES: LIQUID PHASE OXIDATION OF TETRAHYDROTHIOPHENE BY TERT-BUTYL HYDROPEROXIDE

ABSTRACT

The reactions that lead to fuel instability are the subject of conflicting reports in the literature. Confusion results from the difficulty in relating differences in fuel composition, temperature, surface effects and dissolved oxygen content that comprise the multitude of reported studies. Model studies offer a means by which the mechanism of an individual reaction can be related to a simple system and then extended to the more complex fuel media. This paper reports a model oxidation study of a cyclic sulfide, tetrahydrothiophene, with an active oxygen species, t-butyl hydroperoxide under mild reaction conditions, 120°C, in a tetradecane model fuel. The major oxidation product was tetrahydrothiophene sulfoxide from the sulfide and t-butanol from the hydroperoxide. The complete suite of products is reported.     

FUEL INSTABILITY STUDIES: LIQUID PHASE OXIDATION OF TETRAHYDROTHIOPHENE BY TERT-BUTYL HYDROPEROXIDE

The reactions that lead to fuel instability are the subject of conflicting reports in the literature. Confusion results from the difficulty in relating differences in fuel composition, temperature, surface effects and dissolved oxygen content that comprise the multitude of reported studies. Model studies offer a means by which the mechanism of an individual reaction can be related to a simple system and then extended to the more complex fuel media. This paper reports a model oxidation study of a cyclic sulfide, tetrahydrothiophene, with an active oxygen species, t-butyl hydroperoxide under mild reaction conditions, 120°C, in a tetradecane model fuel. The major oxidation product was tetrahydrothiophene sulfoxide from the sulfide and t-butanol from the hydroperoxide. The complete suite of products is reported.     

氧化苯乙烯液相催化重排合成苯乙醛的研究

介绍了氧化苯乙烯液相重排合成苯乙醛的方法,考察了催化剂及其用量、溶剂和反应时间等因素对苯乙醛产率的影响.试验结果表明,在SAS-2固体酸催化剂存在下,催化剂投料为氧化苯乙烯重量的15%,反应物与溶剂环已烷的体积比为1:8,苯乙醛产率可达98.2%.     

苯乙烯精馏阻聚剂DNBP的液相色谱分析

建立苯乙烯精馏过程中阻聚剂DNBP的HPLC分析方法。苯乙烯精馏塔塔釜样品采用沉淀分离提取法,分离除去样品中的高分子聚合物,以四氢呋喃溶解样品后再用甲醇作沉淀剂对DNBP进行提取,提取液进行HPLC定性及定量分析。试验结果证明,DNBP浓度为0.005~2 mg/m L时,与峰面积呈良好的线性关系。标样的回收率为92.5%~103.4%,相对标准偏差为9.1%,最低检测限为0.5 mg/L。     

氧化苯乙烯液相重排制苯乙醛的固体酸催化剂

研究了 SAS型固体酸和几种分子筛上氧化苯乙烯液相重排成苯乙醛的反应 ,考察了催化剂的活性、选择性和和稳定性。用碱中毒法探讨了催化剂的活性中心和作用机理。试验结果表明 ,SAS型固体酸催化剂上的质子酸中心是氧化苯乙烯液相重排反应的主要活性中心 ,失活的催化剂经高温焙烧即可再生 ,再生后催化剂的活性基本恢复 ,氧化苯乙烯转化率接近 98% ,苯乙醛选择性大于 92 %。     

液相空气氧化法制备氟代苯甲酸工艺研究

从氟代甲苯出发,以醋酸为溶剂,采用液相空气氧化法,在钴锰盐和1,1,2,2-四溴乙烷催化体系存在下,合成了氟代苯甲酸,采用升华方法进行精制。探讨了反应压力、催化剂配比及用量、溶剂比及溶剂浓度对氧化反应的影响,当反应压力为0.8～1.0 MPa、反应温度160～220℃、溶剂比4:1,钴锰催化剂质量比为2:1时,反应转化率接近100％;在真空度98 kPa下升华,总质量收率大于97％。     

反相液相色谱法测定聚醚中的聚乙二醇

采用反相液相色谱技术,建立了纺织油剂聚醚中聚乙二醇的测定方法。     

有机概念图及IOB值的反向液相色谱法标定

介绍了有机概念图的意义与应用,并在岛津LC-6A液相色谱仪上应用反向液相色谱法建立了某些系列化合物保留时间与无机性有机平衡值(IOB)之间的关系。从而提供了以实验方法标定有机物或化工产品组分的IOB值,由此可推测其性质与用途。     

苯和乙烯液相烷基化合成乙苯的研究及其新工艺的开发

报道了苯和乙烯在ＡＥＢ型分子筛催化剂上进行液相烷基化反应合成乙苯的研究开发结果。通过研究反应温度、压力、苯／惭烯摩尔比及空速等反应条件对烷基化反应过程的影响,确定了适当的反应条件。进行了苯和乙烯液相烷基化的２０００ｈ活性稳定性试验,乙烯转化率、乙苯选择性、惭基化选择性分别平均为１００％、９４．５％和９９．０％。进行了苯和多乙苯液相烷基转移反 的２０００ｈ活性稳定性试验,二乙苯转化率、多乙苯转化率、     

INVESTIGATION AND EVALUATION OF PETROLEUM ASPHALT AGING PROPERTY ON OXYGEN ABSORPTION BY INVERSE GAS LIQUID CHROMATOGRAPHY

ABSTRACT

The aging mechanisms and performances on oxygen absorption of ten petroleum asphalts were studied and evaluated by the inverse gas liquid chromatography with the Aging Comprehensive Index, the Aging Subtraction Number, the Aging Total Area and the Aging Character Factor methods based on the changes of the retention coefficients of analytical compounds in the petroleum asphalt chromatographic column during continuous aging caused by oxygen absorption under an oxygen flow rate of 15～30 ml/min at 140°C, after the inert support was evenly coated with toluene-dissolved petroleum asphalt and packed into the chromatographic column. The relative polarity of petroleum asphalt and the retention coefficients of analytical compounds increase after absorbing oxygen and the changes of the retention coefficients of the oxygen-containing analytical compounds, especially phenol are evidently greater than those of the nitrogen and sulfur-containing and aromatic analytical compounds. There are obvious differences between the retention coefficients of analytical compounds in the petroleum asphalt columns from different sources and between their changes with the aging on oxygen absorption. The repeated determinations of these evaluation methods show that the standard deviations are less than 1.63 and the variable coefficients under 0.2. The test data are found.to be reliable by Grubhs examination at 95% confidence level. Of the four evaluation methods the Aging Subtraction Number method is the most simple and convenient in operation and takes least time in evaluation.     

INVESTIGATION AND EVALUATION OF PETROLEUM ASPHALT AGING PROPERTY ON OXYGEN ABSORPTION BY INVERSE GAS LIQUID CHROMATOGRAPHY

The aging mechanisms and performances on oxygen absorption of ten petroleum asphalts were studied and evaluated by the inverse gas liquid chromatography with the Aging Comprehensive Index, the Aging Subtraction Number, the Aging Total Area and the Aging Character Factor methods based on the changes of the retention coefficients of analytical compounds in the petroleum asphalt chromatographic column during continuous aging caused by oxygen absorption under an oxygen flow rate of 15∼30 ml/min at 140°C, after the inert support was evenly coated with toluene-dissolved petroleum asphalt and packed into the chromatographic column. The relative polarity of petroleum asphalt and the retention coefficients of analytical compounds increase after absorbing oxygen and the changes of the retention coefficients of the oxygen-containing analytical compounds, especially phenol are evidently greater than those of the nitrogen and sulfur-containing and aromatic analytical compounds. There are obvious differences between the retention coefficients of analytical compounds in the petroleum asphalt columns from different sources and between their changes with the aging on oxygen absorption. The repeated determinations of these evaluation methods show that the standard deviations are less than 1.63 and the variable coefficients under 0.2. The test data are found.to be reliable by Grubhs examination at 95% confidence level. Of the four evaluation methods the Aging Subtraction Number method is the most simple and convenient in operation and takes least time in evaluation.     

在分子筛催化剂上苯和多乙苯液相烷基交换反应的数学模型研究

研究了３种层次不同的苯和多乙苯烷基交换反应数学模型，包括两种动力学模型和一种可计算在不同条件下多乙苯转化率的经验数学模型。结果表明，二级反应动力学模型虽可给出正向及逆向反应速率常数ｋ值，但计算精度低；类二级反应动力学模型既可给出正向及逆向反应ｋ值，还能使多乙苯转化率的计算平均相对误差降到５％以下。经验数学模型可给出多乙苯转化率与过程变量关系的等值线图。     

反相液相色谱法测定二硫化硫醇基苯并噻唑的纯度

介绍了反相液相色谱法定量分析橡胶硫化促进剂二硫化硫醇基苯并噻唑的纯度分析方法。用 HP1100型高效液相色谱仪,ZORBAX RX-C18(250 mm×4.6 mm,5μm)色谱柱,流动相 V(甲醇):V(水)=3:1,λ=280 nm,流速1.0 mL/min,柱温25℃,对二硫化硫醇基苯并噻唑纯度进行定量测定。该法重复性好,相对标准偏差为0.11%,标准回收率在99.8%～100.2%,定量结果准确度高。     

液相催化氧化3-甲基吡啶制备烟酸

在反应温度为170～180℃、压力为1．5 MPa时,在钴盐、锰盐、溴化物和自由基引发剂存在下,由氧气氧化3-甲基吡啶制备烟酸,产率为81．3%;以乙酸和芳香性卤代烃的混合物做溶剂时,对不锈钢反应釜没有腐蚀作用,其中乙酸的含量保持在15%～20%。     

FREE RADICALS FORMED IN HYDROTREATED COAL LIQUID AND INFLUENCE OF OXYGEN

The behavior of radicals formed in hydrotreated coal liquid with heat treatment and the influence of oxygen have been investigated by electron spin resonance (e.s.r.) spectroscopy. A set of e.s.r. spectral lines identified as phenalenyl radical appears from 50^°C as the oil is heated in argon atmosphere. The radical concentration is enhanced with temperature, reaches a maximum between 130 and 150^°C and then decreases at higher temperatures. The radical is very stable even at 200^°C for the sample hydrotreated under mild condition, whereas the radical in the sample treated under severe conditions disappears drastically from 150^°C. When oxygen is introduced in the oil, the radical is converted into semiquinone and/or aryloxy radicals and stable molecules. The treatment in the presence of oxygen at higher temperatures is considered to accompany the formation of other aryloxy radicals by the reaction of aromatic hydrocarbons and oxygen.