乳液体系中影响分散相粒子大小及分布的因素——cmcO及cmcW的协同作用

用马尔文MastersizerMicroplus型激光粒度仪对液体石蜡及环氧树脂E-20与甲苯等有机溶剂以不同比例所形成的体系经乳化后的粒子大小及分布进行研究,结果表明,随着油溶性表面活性剂在油相中溶解性的改善,分散相的粒子大小及分布也明显得到改善.cmcO及cmcW的协同作用对获得理想的分散相粒子大小及分布起到了至关重要的作用     

The Possibility of Wax Formation in Gas Fields： a Case Study

Natural gas production from a gas reservoir(Reservoir A)located in the south of Iran,presents solids deposition during processing because the condensate contains suspended and dissolved solids.Solids deposition occurs not only in the transportation lines from the wells to the separators but also in the various operating units of gas streams and condensate stream.In this study,the multisolid-phase model has been used to predict the wax precipitation from gas and gas condensate fluids.The properties of gas and liquid phases are described using the Soave-Redlich-Kwong(SRK)equation of state.The model is then used to predict the possibility of the wax formation in Reservoir A gas facilities,located at the south of Iran.Solid deposition which occurred in the various streams of that facility confirmed the calculated results.Finally,the wax appearance temperature(WAT),the weight percent of wax formation and the effects of pressure and temperature on the wax formation were also predicted.     

Effect of the carbon dioxide modifier on the lipid composition of wool wax extracted from raw wool

Wool wax or lanolin is a unique substance secreted by sheep and forms a natural protective coating on wool fibres. It is widely used in pharmaceutical and cosmetic formulations. However, different systems of wool wax recovery from scouring liquour provide a dark impurified greasy product. This product has a lipid composition that differs from the wool wax present on wool fibres. The wool wax extraction method from raw wool with pressurised CO₂ and different modifiers at constant pressure and temperature was studied. Thin-layer chromatography coupled to an automated flame ionisation detection system (TLC/FID) was used to analyse the different lipid classes present in the collected extracts. Moreover, a detailed structural comparison of the cholesteryl esters and hydroxycholesteryl esters was carried out by means of sub-ambient pressure chromatography mass spectrometry in the electron impact and in the ammonia positive chemical ionisation modes. For comparison, qualitative and quantitative analyses of the lanolin extracted in Soxhlet with dichloromethane and commercial cosmetic lanolin were carried out. Differences in the quantity of wool wax extraction and in the lipid composition of different wool wax extracts were detected by changing the modifier polarity.     

气相色谱-质谱法测定变压器油正构烃含量

环烷基油是生产高性能变压器油的优质原料,以此为基础油生产的变压器油其凝点一般都小于-40℃,而变压器油在使用过程中对凝点(即低温流动性)有着非常高的要求,凝点的高低直接影响着油品的物理化学性能及电器性能。而油品的低温流动性与其组成中的正构烃(蜡)含量密切相关,据有关     

Analytical scale supercritical fluid fractionation of a low molecular weight,high density polyethylene wax with carbon dioxide

This paper reports on the use of supercritical carbon dioxide to fractionate a low molecular weight, high density polyethylene into very narrow molecular weight distributions (MWDs). A simple extraction system was developed that allowed relatively trouble free extractions of the polyethylene samples. Fractions were collected at successively higher densities of CO₂ at constant temperature and then analyzed by capillary supercritical fluid chromatography (SFC), or high temperature gel permeation chromatography (GPC) and/or differential scanning calorimetry (DSC). Fractionations were performed at three different temperatures (60,80, and 100°C). Higher temperatures were found to yield greater recoveries and higher MWDs at any given density. Reducing the increment between successive extraction steps resulted in polydispersities being reduced to nearly “monodisperse” levels. Total recoveries ranged from 12 to 33% depending on the temperature, and the highest molecular weight fraction extracted by the CO₂ was centered around 1500.     

异辛基乙二胺-CF3SO3型质子化离子液体作为液体石蜡添加剂的摩擦学性能

以异辛基乙二胺-CF₃SO₃[HEtHex(TFS)]型质子化离子液体作为钢/钢摩擦副的润滑油添加剂, 考察了不同HEtHex(TFS)含量的液体石蜡(LP)在不同温度和载荷下的摩擦学性能. 通过扫描电子显微镜和X射线能谱仪对钢球表面磨斑的形貌及所含元素进行了分析与表征. 结果表明, 加入HEtHex(TFS)添加剂可明显增大LP的最大无卡咬负荷(P_B)值, 改善LP的减摩抗磨性能. HEtHex(TFS)在LP中添加的最佳质量分数为0.75%, 在25 ℃, 294 N时其减摩效果最好; 在25 ℃, 196 N时其抗磨效果最佳. 元素分析结果表明, 加入HEtHex(TFS)添加剂后在钢球表面形成了一层摩擦保护膜, 从而起到了减摩抗磨的作用.     

DCD／C4H9OH／LP／H2O体系溶致液晶的润滑性能

测定了月桂酸二乙醇胺（ＤＣＤ）／正丁醇（Ｃ４Ｈ９ＯＨ）／石腊油（ＬＰ）／水体系的相图．在液晶区选取两个样品点，用２ＨＮＭＲ技术和偏振光显微镜测定了这两样品点的微相结构．把液晶涂在铝合金表面测定不同负荷量下的磨痕宽度，并与十二羟基锂基脂等体系进行比较．结果表明，层状液晶在铝合金表面平行方向上的摩擦阻力较小，而在垂直方向上的负荷量高，是一种理想的润滑剂     

Prediction Model Based on the Grey Theory for Tackling Wax Deposition in Oil Pipelines

1. Introduction Wax deposition from crude oil is an age-long prob- lem in the petroleum industry. This problem includes progressive precipitation and accumulation of waxes at the sand-face and perforations, tubings, surface production lines and storage tanks, thus limiting the production capacity of these facilities. Depending on the severity, wax deposition may lead to loss of production, mechanical failure of tubular equipment, increased production downtime, increased handling costs and mini…     

Phase change materials based on low-density polyethylene/paraffin wax blends

Phase change materials, based on low-density polyethylene blended with soft and hard paraffin waxes respectively, were studied in this paper. DSC, DMA, TGA and SEM were employed to determine the structure and properties of the blends. The blends were able to absorb large amounts of heat energy due to melting of paraffin wax, whereas the LDPE matrix kept the material in a compact shape on macroscopic level. The hard paraffin wax was, however, much more miscible with LDPE because of co-crystallization than the soft paraffin wax. LDPE blended with hard paraffin wax degrades in just one step, while blends containing soft paraffin wax degrade in two distinguishable steps. SEM showed completely different morphology for the two paraffin waxes and confirmed the lower miscibility of LDPE and soft paraffin wax. DMA analyses demonstrated the toughening effect of the waxes on the polymer matrix. This technique was also used to follow the thermal expansion as well as the dimensional stability of the samples during thermal cycling. The most visible expansion could be seen in the first cycle, probably due to a totally different thermal history of the sample. With further cycling the dimensions stabilized after two and four cycles for soft and hard paraffin wax, respectively. Controlled force ramp testing on DMA confirmed poor material strength of the blends containing soft wax, especially at temperatures above wax melting.     

Hydrocracking of Heavy Fischer–Tropsch Wax Distillation Residues and Its Blends with Vacuum Gas Oil Using Phonolite-Based Catalysts

The Fischer–Tropsch heavy fraction is a potential feedstock for transport-fuels production through co-processing with fossil fuel fraction. However, there is still the need of developing new and green catalytic materials able to process this feedstock into valuable outputs. The present work studies the co-hydrocracking of the Fisher–Tropsch heavy fraction (FT-res.) with vacuum gas oil (VGO) at different ratios (FT-res. 9:1 VGO, FT-res. 7:3 VGO, and FT-res. 5:5 VGO) using phonolite-based catalysts (5Ni10W/Ph, 5Ni10Mo/Ph, and 5Co10Mo/Ph), paying attention to the overall conversion, yield, and selectivity of the products and properties. The co-processing experiments were carried out in an autoclave reactor at 450 °C, under 50 bars for 1 and 2 h. The phonolite-based catalysts were active in the hydrocracking of FT-res.:VGO mixtures, presenting different yields to gasoline, diesel, and jet fuel fractions, depending on the time of reaction and type of catalyst. Our results enable us to define the most suitable metal transition composition for the phonolite-based support as a hydrocracking catalyst.