Interfacial Tension of CO2 and Organic Liquid under High Pressure and Temperature☆

In order to investigate the effect of organic liquid molecular structure and the intermolecular force operating with CO2 molecules and organic liquid molecules on interfacial tension (IFT) between CO2 ...     

A Statistical Thermodynamic Model of Vapor-Liquid Interfacial Tension for Liquid Mixtures at High Pressure

1 INTRODUCTIONInterfacial tension of pure fluids and their mixtures is an important property for the development,design and simulation of many chemical processes.The interfacial behavior has important prac-tical applications in material science,environment science and chemical engineering separationprocesses as well as in secondary or tertiary recovery of petroleum.Although interfacial phenom-ena are rather complicated,interfacial tension of free vapor-liquid interface is considered as a firstand fundamental step of the study.For example,enhanced carbon dioxide“flooding”technique     

Estimation of Interfacial Tension for Geological CO2 Storage

The effective CO₂ sequestration in saline aquifers as a climate change‐lessening solution is mainly governed by the interfacial tension (IFT) behavior between CO₂ and brine. An innovative and competent decision tree‐based approach called stochastic gradient boosting (SGB) tree algorithm was applied to predict the CO₂‐aquifer brine IFT as a function of temperature, pressure, and brine salinities. The produced results were compared with the previously reported outcomes of other machine learning models, namely, radial basis function networks, multilayer perceptron networks, least squares support vector machine, and adaptive neuro fuzzy inference system. Amongst all models, the developed SGB tree algorithm provided superior outputs and turned out to be the most accurate tool.     

高强电场中电介质溶剂与导电液滴间的界面张力

１前言乳状液膜分离技术中所谓的液膜,是指油相（电介质溶剂＋表面活性剂＋络合剂）与导电水溶液在高速搅拌下形成的Ｗ／Ｏ型乳状液中将导电小液滴分隔开的电介质溶剂。乳状液膜分离技术成败的关键之一乳状液的高电压破乳,其实质是电介质溶剂中的导电小液滴在高强电场中...     

Temperature Dependence of Interfacial Tension of Polymer Melts

A unique behavior of interfacial tension of polymer melts is that, in an ordinary temperature region of strong segregation, the entropy effect of chain molecules on the composition-gradient term in the free energy at the interface can make the interfacial tension increase with increasing temperature. To confirm this role of the entropy, interfacial tension of polystyrene/poly(dimethylsloxane) was measured as a function of temperature, and was found to increase with increasing temperature. Using temperature dependence of the segment-segment interaction parameter, which was evaluated from experimental coexistence curves, it was shown that the entropy effect was responsible for this positive temperature dependence of the interfacial tension. The experimental result was also discussed on the basis of scaled expressions of interfacial tension as a function of segregation strength covering weak, strong, and very strong segregation regimes.     

Effect of Nanoparticles on Viscosity and Interfacial Tension of Aqueous Surfactant Solutions at High Salinity and High Temperature

Surfactant flooding has widely been used as one of the chemically enhanced oil recovery (EOR) techniques. Surfactants majorly influence the interfacial tension, γ, between oil and brine phase and control capillary number and relative permeability behavior and, thus, influence ultimate recovery. Additives, such as nanoparticles, are known to affect surfactant properties and are regarded as promising EOR agents. However, their detailed interactions with surfactants are not well understood. Thus, in this work, we examined the influence of silica nanoparticles on the ability of surfactants to lower γ and to increase viscosity at various temperatures and salinities. Results show that the presence of nanoparticles decreased γ between n-decane and various surfactant formulations by up to 20%. It was found that γ of nanoparticles–surfactant solutions passed through a minimum at 35 °C when salt was added. Furthermore, the viscosity of cationic surfactant solutions increased at specific salt (1.5 wt.%) and nanoparticle (0.05 wt.%) concentrations. Results illustrate that selected nanoparticles–surfactant formulations appear very promising for EOR as they can lower brine/n-decane interfacial tension and act as viscosity modifiers of the injected fluids.     

Oxidation of ZrB2 Nanoparticles at High Temperature under Low Oxygen Pressure

The oxidation of ZrB₂ nanoparticles was observed at high temperature of 1500°C under low oxygen partial pressure of 5 × 10^?2 Pa by an environmental transmission electron microscope. The results demonstrate that the oxidation starts on the surface of ZrB₂ nanoparticles with decomposition of ZrB₂ into ZrO₂ and B₂O₃. The nucleation and growth of ZrO₂ on the surface of ZrB₂ proceed with B₂O₃ being evaporated.     

CO2泡沫压裂液的流变性及井筒摩阻计算方法研究

进行了CO2泡沫压裂液的室内配制、流变性测定以及摩阻计算方法研究。室内实验中观测了CO2泡沫压裂液的形成、动态变化、泡沫结构,测定了CO2泡沫压裂液的流变性,发现其属于假塑性非牛顿流体。推导了CO2泡沫压裂液在油管内流动的摩阻计算公式,计算了不同管径、不同排量、不同泡沫质量时的摩阻曲线,进行了井筒内CO2泡沫压裂液摩阻压降实测,与计算方法相比误差在工程应用允许范围内。该研究所得到的CO2泡沫压裂液流动特性、摩阻压降计算方法、经验图版等,可供工程应用中参考。     

铁系无铬型CO高温变换催化剂在常压系统中的工业应用

铁系无铬型CO高温变换催化剂完全去掉了对人体及环境极其有害的铬组份，在加压变换系统中使用取得了良好的效果，又在常压变换系统中成功使用，数据表明，在常压条件下该同样表现出活性温度低，蒸汽消耗少，生产负荷大，机械强度高等特点，给使用厂带来了明显的经济和社会效益。     

CO_2注入井井筒温度及压力计算

进行二氧化碳混相驱前需要根据井况进行注入方案设计,以确定沿井筒方向二氧化碳温度、压力及相态的变化情况。本文根据垂直管流的能量平衡方程及传热学理论,结合Ramy井筒温度分布计算方法,综合考虑了井筒内压力和温度相互作用下的二氧化碳密度、相态以及摩阻等影响因素,建立了以井底所需混相压力及温度为边界条件的二氧化碳注入井温度压力数学模型,并根据建立的模型开发了应用软件。通过实例计算,分析了注入速度、注入温度、井口注入压力等注入因素对井底压力和温度的影响,可有效指导现场施工。     

Phase Relations and Volume Changes of Hafnia under High Pressure and High Temperature

Using multi-anvil high-pressure devices and synchrotron radiation, X-ray in situ observations of HfO₂ under high pressure and high temperature have been performed to investigate its phase relations and compression behavior. An orthorhombic phase (orthoI) is stable from 4 to 14.5 GPa below 1250°–1400°C and transforms to a tetragonal phase, which is one of the high-temperature forms of HfO₂, above these temperatures. Another orthorhombic phase (orthoII) with a cotunnite-type structure appears above 14.5 GPa. OrthoII is stable up to 1800°C at 21 GPa. OrthoII is quenchable to ambient conditions. The orthoI-to-orthoII transition is accompanied by ∼8 vol% decrease. The bulk moduli of orthoI and orthoII at room temperature are 220 and 312 GPa, respectively. This low compressibility of orthoII indicates that it is a potential candidate for very hard materials.     

高温高压合成N-甲基-2-吡咯烷酮工艺研究

在压力3．0MPa，温度230℃、NMA：GBL=1．2～1．35mol的条件下，采用三釜串并联连续反应生成N-甲基-2-吡咯烷酮，操作简单、平稳，产率高于单釜反应。     

有机物质粘度的加压测定和高压液体粘度与密度的关联方程

对落体式粘度计进行了结构改进.在298.15～348.15K(±0.05K)、由常压至29.5MPa的范围内,测定了四氢呋喃、丙酮、乙腈和苯胺4种纯物质,以及苯+环己烷、正丙醇+正庚烷和正丁醇+正庚烷3种二元混合物的液体粘度共294点.提出了高压液体粘度与密度的关联方程,lnφ=ln(l/μ)=A-lnρ+ξ(3ξ-4)/(1-ξ)~2-Cρ/(RT).用本式对最大压力范围为0.1～500MPa、最大温变幅度为170K的广泛类型物质的液体粘度数据共1049点进行关联和计算,计算值的总平均相对偏差为2.64%,远低于选作比较的Dymond等的关联方程.     

高压环境下垂直管内汽液搅混流相界面特征

采用数值计算方法,基于流体体积模型(VOF)分别对5.07,10.13,17.22 MPa高压环境下垂直管内水蒸汽-水搅混流进行数值模拟,研究了环境压力、汽速和液速对汽液搅混流界面波临界振幅、形成周期和相界面稳定性的影响。采用通过实验结果验证的数学模型进行了模拟计算,结果显示,伴随压力的增大,汽液相界面的稳定性得到显著提高,界面波的形成周期也随之延长。界面波临界振幅随环境压力的增大而增大,液速的降低或汽速的提高有利于降低界面波临界振幅,但是环境压力越大,这种影响越小。根据汽液两相流动特性,分析认为出现以上现象是由于汽液物性的不同所导致的。     

高温高压条件下不锈钢的氢损伤

综述了高温高压条件下氢致不锈钢损伤的研究进展情况,重点介绍了不锈钢力学性能和微观结构的变化,并就压力和温度对氢损伤敏感性影响作了简单的讨论。     

高温煤气化转化CO2为CO

针对CO2难处理、难利用的特点,提出了1种新的CO2资源化利用途径,即将CO2取代水蒸汽作为煤高温气化剂生产CO.通过实验验证了动力学可行性,用ASPEN Plus模拟验证了工艺可行性,并建立了CO2的0排放生产模型和效益分析.     

Surface Tension of Some Liquid Oxides and Their Temperature Coefficients

Surface-tension data are reported for liquid Al₂ O₃, B₂ O₃, GeO₂, P₂ O₅, and SiO₂. Abnormal positive temperature coefficients for B₂ O₃, GeO₂, and SiO₂ are shown to be due mainly to changes in the liquid structure (dissociation) with temperature.     

高压低温下H2O-H2O2-CO2三元体系CO2气体水合物的分解动力学

研究了非纯水体系H2O-H2O2-CO2中CO2气体水合物分解的动力学,测定了高压低温条件下CO2气体水合物分解过程的液相组成. 依据实验数据建立了CO2气体水合物分解动力学模型,模型计算值与实验值吻合良好. 确定了3个温度下气体水合物分解的速率常数,计算得出CO2气体水合物分解的活化能为97.17 kJ/mol.     

低界面张力抗温抗盐YUDP型起泡剂性能评价

针对吉林油田低渗高温高盐的特点,开发出适合该类型油藏含有羟基、酰胺基的磺酸盐耐温耐盐型起泡剂-YUDP。考察了起泡剂浓度、溶液矿化度、温度、pH、钙镁离子总含量、残余油饱和度对起泡剂起泡能力、稳泡能力以及油水界面张力的影响。结果表明,YUDP耐温(75℃)、耐盐(总离子质量浓度31037.9 mg/L)、耐碱(pH=10)、耐钙镁离子(总质量浓度60mg/L)、耐残余油(原油质量分数15%)。实验表明,YUDP在高温高盐的环境下依然能将油水界面张力保持在10~(–2)mN/m的数量级,达到低界面张力驱油的要求。在YUDP质量分数为0.4%时,起泡体积达250m L、半衰期达25.7min、泡沫强度达4818.75m L·min、油水界面张力为2.61×10~(–2)mN/m,均达到吉林油田低界面张力泡沫驱的要求。     

52万吨/年尿素装置CO2压缩机高压缸改造

本文通过对现国内52万吨/年产尿素装置CO_2压缩机运行状况分析,提出改造方案,并在辽河化肥厂开车成功。实现了彻底改造CO_2压缩机组运行不稳定的缺陷。