Characterization of Functional Groups of Asphaltenes in Vacuum Residues Using Molecular Modelling and FTIR Techniques

Asphaltenes are components of crude oil, and their average chemical structures are characterized with difficulty. This study shows that simple Fourier transform infrared (FTIR) analysis spectroscopy could be adapted to the determination of aromatic hydrogens in asphaltenes and resins and elucidation of their average molecules. The work demonstrates the existence of a linear correlation in the infrared (IR) intensities of the symmetric and asymmetric aromatic hydrogens in methyl substituted arenes, in the 2,900 to 3,100 cm^-1 region and of the out-of-plane deformation in the 700 to 900 cm^-1 region.     

傅里叶变换红外光谱技术在润滑油监测中的应用综述

傅里叶变换红外光谱技术是油液监测体系中一项重要的技术手段,傅里叶红外光谱技术可以追踪润滑油中化学官能团变化,使得对润滑油的整体质量评估更加完善和准确,从而为是否换油或采取其他措施提供参考。傅里叶红外光谱能够提供积炭、水分、乙二醇、氧化程度、硝化程度、添加剂含量等重要信息,这些信息正是新油逐渐劣化的重要指标;从检测效率来看,目前红外光谱最快的检测速度达到120个样品/小时,完全可以满足大型工矿企业数目众多的设备油液监测需求;定量红外光谱技术已经开发出多种与油样状态相关的多种方法,能够确定油样中的酸、碱及水分等含量。在油品分析中心实验室,这些方法避免了ASTM滴定方法程序的繁杂,扩展了红外光谱技术的总体适用性。论文对基于红外光谱技术的状态监测进行了综述,对该技术已经取得的成绩、未来的发展方向进行了总结,并以加强红外在润滑油分析方面的应用为目的,讨论了最新的定量红外光谱技术、红外光谱存在的问题等内容。     

改性X分子筛甲醇/甲苯共吸附原位红外表征

采用原位红外光谱法表征了负载一定量KOH和H_3BO_3的X分子筛催化剂,分析了不同改性分子筛上甲醇/甲苯吸附的原位红外特征峰,考察了KOH浓度和不同H_3BO_3负载量对改性的X分子筛甲醇/甲苯共吸附的影响,并研究了原位红外光谱定量分析结果与催化剂性能的关联性。实验结果表明,采用甲醇吸附在分子筛上的特征峰(2 824 cm~(-1))和甲苯吸附在分子筛上的特征峰(1 596 cm~(-1))的峰面积和峰面积比值可有效定量X分子筛酸碱性对甲醇/甲苯的吸附能力的影响;原位红外光谱表征结果可与催化剂性能相关联,为开发高性能甲醇/甲苯侧链烷基化反应的催化剂提供了一种重要的研究途径。     

Characterization and Identification of Explosives and Explosive Residues Using GC-MS,an FTIR Microscope,and HPTLC

ABSTRACT

Characterization and identification of explosives and explosive residues collected from different places in India were made using TLC, GC/EI-MS, and GC-FTIR. The explosives used were NG, PETN, TNT, tetryl, RDX, and NH₄NO₃+fuel oil. Quantitative estimation was made using HPTLC. Mass spectra of the samples using selective ion monitoring (SIM) mode based on the relative intensities of the signals X, X + 1 (intensity of the largest fragment X of the explosive, say, RDX [X = 205] was assumed to be 100%, i.e., X = 100%) show no isotopic substitution. The results were confirmed by FTIR spectra. Some physico-chemical aspects of the explosives are discussed.     

大港减渣超临界萃取物的FTIR分析

通过大量的溶剂选择性实验,选取对大港减渣的16个超临界萃取物都具有优异溶解性能的环己烷为良性溶剂,并对每个萃取物分别进行KTIR分析,探索大港减渣所含基团的规律性。分析结果表明,不同大港减渣超临界萃取物的红外光谱图有一定的类似性,说明其含有的基团接近;大港减渣超临界萃取物含有10余种官能团,其中烷烃的含量最大;不同萃取物中同一种基团的含量不同。     

不同热模拟方式下烃源岩干酪根演化特征红外光谱分析

烃源岩的生烃过程是在地层孔隙空间内有机质受温度、上覆岩层静岩压力和高地层流体压力（PVT-L共控）等多种作用下的一种复杂的物理化学反应过程。然而目前常用的生烃模拟实验（高压釜加水生烃模拟）大多是在一个低流体压力、无静岩压力、相对较大的生烃空间下进行的,与实际地质情况差异较大。选用南襄盆地泌阳凹陷核三段未熟泥岩分别开展了PVT-L共控和常规高压釜方式加水模拟实验,不同演化阶段干酪根的傅里叶变换红外光谱对比分析表明：（1）伴随着脂族结构裂解、含氧基团脱落及芳香结构缩合,干酪根演化明显呈现出缓慢生油、快速生油和结束生油3个阶段;（2）脂肪度参数I_AL、饱芳比参数I_L/R和含氧度参数I_O表明,同等温度条件下常规高压釜加水模拟脂肪链和含氧基团的热裂解反应更为剧烈,PVT-L共控模拟则相对平缓,380℃时仍伴随有较强的生烃能力;（3）PVT-L共控模拟条件下饱和烃的芳构化程度更低,可能与其限定空间内较高的流体压力有关;（4）含氧度在成熟中期间歇的轻微增大,暗示水对干酪根生烃过程也许有重要的作用。2种不同模拟方式下干酪根红外光谱特征上的差别,暗示其在生烃反应机理上存在较大差异,在热模拟实验研究中要根据研究目的合理选择模拟方式,设置实验条件。     

加氢脱硫CoMo/Al_2O_3催化剂的原位FTIR表征

采用等体积浸渍法制备了Mo/γ-Al2O3和CoMo/γ-Al2O3硫化态催化剂,利用原位FTIR方法对催化剂吸附CO前后的结构进行了表征,分析了催化剂活性中心的变化规律。表征结果显示,Mo/γ-Al2O3催化剂中存在未改性的MoS2吸附相;CoMo/γ-Al2O3催化剂中由于加入了助剂Co,可使部分MoS2相转变为CoMoS相,且分散度较高;CoMoS相的形成可增加催化剂活性位的数量、提高催化剂的加氢脱硫(HDS)活性。当CoO含量为3.1%(w)时,CoMo/γ-Al2O3催化剂对4,6-二甲基二苯并噻吩的HDS活性最高,达到56%。     

Transesterification Reaction of Waste Cooking Oil and Chicken Fat by Homogeneous Catalysis

In the last years, biodiesel production has been on a steady increase due to it is renewable and biodegradable fuel. The process to obtain biodiesel can be carried out using different raw materials. It is conlmonly performed by transesterification reaction of vegetable oils with methanol and using a homogeneous or heterogeneous catalyst. This work seeks to compare the results produced in transesterification of wasted cooking oil and chicken fat by homogeneous catalysis with NaOH. Due to in each case triglyceride comes from different raw materials, operation conditions differ slightly, which is more evident in the values used for the temperature. For chicken fat was used temperature variations between 35 ℃ and 55 ℃, varying catalyst in percentages between 0.3% and 0.7% with a molar ratio 6：1 in all cases and a reaction time of I h. Likewise, the conditions used in the tmnsesterification process of waste cooking oil were temperature between 50 ℃ and 60 ℃ with a molar ratio 6/1 and 9/1 for alcohol and oil, and catalyst percentage between 0.5% and 0.7% by weight. The yields obtained were between 78% and 94%, or 83% and 95%, for chicken fat and wasted cooking oil, respectively.     

Classification of petroleum origin and integrity by FTIR

A method was developed for classifying petroleum into four types according to their origin and integrity: marine, non-marine, degraded and thermally transformed. The method was based on the relative proportions of functional groups measured by FTIR spectroscopy. Twenty-one petroleum samples were used for model calibration and six for validation, which were pre-classified. Aliphatic functional group absorption maxima were used at 2919, 2856, 1457 and 1376 cm^?1, as well as at 1700  and 811 cm^?1 for aromatic groups, and at 1152 and 1030 cm^?1 for polar groups (sulphonyl and ether, respectively). Using hierarchical cluster and discriminate analyses, three canonic functions were obtained that classified the samples according to their origin and integrity, with a prediction efficiency of 100%, for both calibration and validation. The canonic functions derived from the discriminate analysis had correlation coefficients of 0.994, 0.900, and 0.867, among the variables studied and the classification factor. The method is efficient for the proposed classifications and can be useful for a range of applications.     

Gaseous Products of Dinitromethane Decomposition Determined by DTA/FTIR

Gaseous products of the thermal decomposition of dinitromethane and potassium dinitromethanide were investigated by simultaneous DTA/FTIR analyses. Both isothermal and non-isothermal DTA regimes were applied. Nitrous oxide and carbon dioxide were detected by FTIR.     

红外光谱测定固体酸催化剂表面酸性

利用固体酸催化剂吸附吡啶表征固体酸催化剂的性质,以测定其表面酸性部位的类型(L酸、B酸)、强度和酸量。采用抽真空系统、红外光谱(fTIR)方法,根据固体酸催化剂红外光谱的峰面积计算B酸、L酸的含量。     

煤成烃反应机制的红外光谱证据

应用傅里叶变换红外光谱（FTIR）分析及计算机分峰拟合技术,对不同温度下热模拟煤样的脂肪族、芳香族官能团含量及其化学结构热演化特征进行了精细表征与分析。研究表明,除了热裂解反应,脂肪族芳构化反应与芳香族缩聚反应在煤成烃过程中同样占有重要地位。煤样脂肪氢及芳香氢的含量变化均为多种不同类型化学反应综合作用的结果,单一的官能团含量分析并不能准确反映煤的成烃反应机制及潜力。进一步对煤样脂肪族及芳香族化学结构热演化特征分析发现,煤成烃初期以活化能较低的长链脂肪族结构断裂脱落、生成液相产物为主,并在325℃到达生油高峰;325~400℃阶段,前期断裂脱落的长链脂肪族结构除了进一步热裂解生成气态烃产物,还有相当一部分发生了芳构化反应,导致煤样芳香氢含量升高。随着热模拟温度的升高,芳环上的短链脂肪族取代基首先从苯环β位开始断裂脱落,发生甲基化作用;随后甲基、桥键等在高温作用下进一步从苯环上断裂脱落,发生去甲基化作用。煤成烃过程中芳香族缩聚反应具有明显的阶段性,其中300~400℃阶段主要为脂肪族芳构化产物的缩聚。而煤样原有芳香族结构由于芳环取代基及桥键的阻碍作用,其缩聚反应则依赖去甲基化作用的进行,主要发生在500~600℃高温阶段。     

FTIR法测定含氰废气中的氮氧化物

建立了一种通过FTIR测定含氰废气中氮氧化物的方法,采用经典最小二乘法建立了含氰废气中氮氧化物的定量分析模型,优化了方法的分析条件,考察了方法的精密度与准确度,并对实际试样进行了分析.实验结果表明,在扫描范围650～4000 cm-1、分辨率0.5 cm-1、扫描次数64次、扫描时间为1 min条件下,各组分的相关系数...     

Stabilization Studies of Middle Distillate Fuels: Structural Composition of Insoluble by FTIR Spectroscopy

For reducing the supply-demand gap of diesel fuel, blending of cracked stocks is essential with straight run products. This enhances the instability problem. This problem can be reduced using various stabilization procedures. In the present paper blends of cracked stocks light cycle oil (LCO) with straight run gas oil (SRGO) were stabilized by methanol extraction and hydrostabilization techniques. The insoluble from these fuels as such and their blends were stabilized and characterized using FTIR spectroscopy.     

Stabilization Studies of Middle Distillate Fuels: Structural Composition of Insoluble by FTIR Spectroscopy

Abstract

For reducing the supply-demand gap of diesel fuel, blending of cracked stocks is essential with straight run products. This enhances the instability problem. This problem can be reduced using various stabilization procedures. In the present paper blends of cracked stocks light cycle oil (LCO) with straight run gas oil (SRGO) were stabilized by methanol extraction and hydrostabilization techniques. The insoluble from these fuels as such and their blends were stabilized and characterized using FTIR spectroscopy.     

GC/FTIR法和GC/MS法联合分析裂解碳五馏份的组成

在两根分离机理完全不同的色谱柱上，即ＨＰ－１０１柱（分配色谱）和Ａｌ３Ｏ２／ＫＣｌＰＬＯＴ柱（吸附色谱），对乙烯装置裂解碳五产品进行了较完全的分离，联合使用毛细管气相色谱－傅立叶红外光谱法和毛细管气相色谱－质谱法进行定性，在氢火焰离子化检测器上得到归一化的定量结果。同时，也推出了两种能分析单体烃及其二聚物组份的裂解碳五组成的色谱方法。     

固体香精组成的剖析

采用红外及色—红联用技术分析固体香精组成，用面积归一法定量，方法简便快速，重复性良好。     

FTIR and thermodynamic study of Pakistani and international crude oils in 1,4-dioxane

This paper is the continuation of our previous paper, which concerned the viscosity of crude oils in 1,4-dioxane. In this paper, we present the Fourier Transform Infrared (FTIR) spectroscopy and thermodynamic study of Pakistani and International crude oils. Degree of branching, chain length, and degree of substitution in aromatic by FTIR data were calculated. Thermodynamic parameters viz., energy of activation (E_η), free energy change of activation (ΔG^*), latent heat of vaporization (L_v), and entropy change of activation (ΔS^*) have also been evaluated.     

复合离子液体C_4烷基化催化性能的红外光谱判据研究

采用傅里叶变换红外光谱(FTIR)对[(C_2H_5)_3NH]Cl/xAlCl_3-yCuCl 复合离子液体进行了表征,着重比较了 CuCl 含量不同的复合离子液体的 FFIR 谱图;在288 K、搅拌转速1 500 r/min、异丁烷与2-丁烯摩尔比为10:1的条件下,考察了复合离子液体催化剂对异丁烷/2-丁烯烷基化反应的催化性能。实验结果表明,当复合离子液体的 FTIR 谱图在1636～1685 cm~(-1)区域内仅在1 636 cm~(-1)处出现吸收峰时,烷基化产物中三甲基戊烷(TMP)的质量分数小于40%,而当1636～1685 cm~(-1)区域内出现分裂峰(1 636,1 685 cm~(-1)处)时,产物中 TMP 的质量分数大于80%。根据复合离子液体的 FTIR 谱图在1636～1685 cm~(-1)区域内的变化,可以判断复合离子液体中是否存在大量 Al-Cu 配位离子,并可作为评价复合离子液体催化剂烷基化性能的判据。     

Determination of edible bird's nests by FTIR and SDS-PAGE coupled with multivariate analysis

Edible bird's nests (EBNs) have been traditionally regarded as a kind of medicinal and healthy food in China. Nowadays, EBNs in market are graded by some conventional features presented by EBN products, such as material purity, geographical origin, production environment or color. Since different EBNs have various prices, two common types of fraud with EBN, namely substituting the EBN ingredient with cheap non-EBN materials and mislabeling of a country of origin or production environment, have occurred for a long time. To explore a feasible method for identifying EBNs, Fourier Transform Infrared Spectroscopy (FTIR) system and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) combined with multivariate analysis were employed. The results showed that FTIR could discriminate between authentic and fake EBNs since there were big differences in spectra of these samples. On the other hand, protein band data obtained by SDS-PAGE could be used for distinctly identifying geographical origin of house nests and the production environment of EBNs. It is concluded that FTIR in combination with SDS-PAGE is a promising method for comprehensive determination of EBNs.