正十二烷-水乳液吸收丙烷的传质增强作用(英文)

A one-dimensional unsteady heterogeneous parallel mass transfer (ODUHPMT) model was developed for the absorption enhancement of volatile organic compounds (VOC) by the dispersed droplets. An analytical solution for enhancement factor was obtained based on surface renewal theory and the Laplace domain transformation. The absorption rate of propane into water at dif-ferent stirring speeds with the added micro dodecane droplets was investigated experimentally in a thermostatic stirred tank. The mass transfer flux across the gas-liquid interface and the enhancement factor were measured. The results showed that the dodecane has an obvious enhancement effect on propane absorption into water, the maximum enhancement factor reached 11. The enhance-ment factor increased with increasing dodecane volume fraction and decreased with increasing stirring speed. The experiment data agreed well with the model predictions and showed high prediction accuracy of ODUHPMT model.     

稠油/水乳状液表观粘度实验研究

通过实验研究稠油/水乳状液的表观粘度与分散相液滴直径、含水率和温度的关系。分散相液滴直径越大,表观粘度越小;与轻质油/水乳状液不同,稠油/水乳状液在较低的含水率时即表现出很强的剪切稀释性;温度变化对稠油/水乳状液的表观粘度有显著影响而对相对粘度影响很小。在考虑了剪切率的相对粘度预测模型中,Pal(1989)模型的预测结果与实际测量值较为接近。     

Surface pH and stability of oil-water emulsions derived from laurate solutions

Emulsion stability, electrophoretic mobility, and interfacial tension of chloroform, cyclohexane, and n-hexadecane-potassium laurate solution were determined as a function of acidification by concentrated HCl. The stability of these emulsions were related to the presence or absence of lauric acid at the interface. It was found that a lauric acid-laurate interfacial film was responsible for the enhanced stability in the case of cyclohexane and n-hexadecane emulsions, while no such mixed film existed in the case of chloroform. The interfacial ionization markedly affects the distribution of ions in solution closer to the interface. The concept of surface pH was applied. Differences of up to 2 pH units between bulk and surfaces were found with these systems. Both cyclohexane and hexadecane have major stability peaks which lie at ca. the same surface pH of 5.9 ± 0.2, irrespective of the initial potassium laurate concentration or bulk pH. It is concluded that the stability of these emulsions can be explained when the role played by the interfacial ionization is taken into consideration.     

SiO2改性聚丙烯纤维棉对油水乳状液的高效分离

利用纳米SiO2颗粒对聚丙烯(PP)纤维棉进行了亲(疏)水改性,构建了系列不同润湿性和粗糙度的PP纤维棉,探究了不同孔隙度和表面能的PP纤维棉对W/O及O/W型乳状液的分离性能.结果表明,经过亲(疏)水改性的PP纤维棉对水/正己烷和水/甲苯乳状液的分离效率都高于99.5％,分离通量高于700 L/(m2·h),并针对不同形式油-水乳状液阐释其相应的分离机制,为后续油-水乳状液分离材料的科学设计和可控制备提供了理论依据.     

超小型油水分离旋流管的研究

论述了一种超小型旋流管的研究过程。该新型旋流管具有双进口、弧锥体的结构特征。设计了两种规格HL2 8和HL1 8(即公称直径分别为 2 8mm和 1 8mm)。通过对新型旋流管进行实验测试 ,HL2 8型优于国际上正在采用的Thew型双锥体和Amoco型单锥体旋流器 ,并且HL1 8型比HL2 8型旋流管有更高的分离效率。     

油水乳液分离吸附材料的分离原理、构建方法和分离性能

采用吸附材料进行油水分离是经济且非常有效的方法。吸附材料主要有无机材料、合成高分子材料和天然有机纤维材料等。相比较而言，天然有机纤维材料为可再生生物质资源，来源广泛、生物降解性好，可有效防止二次污染，具有良好的发展潜力，备受关注。本文首先简要介绍了油水乳液稳定性的影响因素，然后综述了油水分离材料的分离原理、构建方法和分离性能等研究进展，并总结了油水乳液分离材料的表征及其分离性能的评价指标。特别地，重点总结了天然有机纤维基吸附材料分离油水乳液的研究进展。最后指出研究智能响应型天然有机纤维基油水乳液分离吸附材料是重要的发展方向。     

微乳液的油水分离和机理探讨及应用

用特种表面活性剂使热力学稳定的微乳液变成热力学不稳定的乳状液,并发现该种特种表面活性剂与聚合物复配后能使微乳液油水分离。通过透射电镜(TEM)分析发现含有不溶性有机物的透明脱墨造纸废水的分散颗粒远远小于可见光的波长,呈现微乳液状态,以该种透明废水作为实验对象,用特种表面活性剂与聚合物LYPW-301复配后分离该种微乳液状废水, 通过化学需氧量(COD)测定表明:这种分离方法能够有效降低该种微乳液状废水的COD值。通过TEM分析微乳液和乳状液显微状态的变化探讨了微乳液的油水分离机理。这种分离方法能够有效地应用于其他各种造纸透明废水和油田透明废水的分离中。     

利用热蒸发烃色谱分析技术识别油水过渡带的油水层——以萨南开发区为例

利用热蒸发烃色谱分析资料,与试油资料相结合,研究了油水过渡带油水层的谱图特征,认为利用谱图的峰型、基线形态、碳数范围、主峰碳、储集层纵向变化等参数识别储集层流体性质效果明显,具有很好的应用价值。     

Using image analysis in the study of multiphase gas absorption

For the air-water-calcium alginate beads system, the effect of the presence of solids on the mass transfer characteristics in a bubble column was experimentally studied.Volumetric liquid side mass transfer coefficient, k_La, specific interfacial area, a, and hence liquid side mass transfer coefficient, k_L, were determined under different solid concentrations (0, 5, and 10 vol%), superficial gas velocities (up to 0.27 cm/s) and solid sizes (1.2 and 2.1 mm diameter). The bubble characteristics, namely the interfacial area, were obtained using an image analysis technique.This technique proved to be a suitable and practical method to characterize mass transfer phenomena in bubble columns for the range of operating conditions used. The solids affect negatively k_La, decreasing both a and k_L, the effect being more pronounced for the smaller particles. For these particles the variation of k_La is due to the variation of its two components, while for larger particles k_La variation is due, essentially, to changes in k_L as no significant differences in a were observed.     

Rate of gas absorption into a slurry accompanied by instantaneous reaction

The problem of gas absorption into a slurry is theoretically treated by classifying it into six cases according to the concentration profiles of the absorbed gas and the dissolved solid in the liquid phase. For each case, a mathematical model for the rate of gas absorption with the necessary condition is given based on the film concept. A numerical example is given to illustrate the treatment of a practical problem.     

基于pH测量的CO2吸收到钠基溶液动态实验及模型

采用基于pH测量的CO₂吸收速率研究方法。将pH与溶液中的成分相关联,采用分段拟合获得CO₂吸收速率,获得溶液成分对吸收速率的影响规律。对于低浓度的NaOH来说,吸收速率一直保持不变直到CO₂物理吸收到NaHCO₃溶液中。对于高浓度的NaOH,NaOH完全转化成Na₂CO₃时,吸收速率降低。但在两个吸收阶段中,吸收速率不变,CO₂物理吸收到NaHCO₃中时,吸收速率随CO₂饱和度的增加而降低。对CO₂吸收到NaOH中,CO₂和钠离子浓度都促进吸收,钠离子浓度影响更大;对于CO₂吸收到Na₂CO₃中,当Na₂CO₃浓度大于0.05mol/L,吸收速率不随浓度增加;对于CO₂吸收到NaHCO₃中,低浓度的钠可以促进CO₂吸收,而高浓度的钠抑制CO₂吸收,这主要由于析盐的作用。为避免CO₂大量吸收,优先选择0.5mol/L以上浓度的NaHCO₃。     

A visual study of the breakdown of emulsions in porous coalescers

A two-dimensional photoetched glass flow cell was used to observe the process by which an emulsion was broken down by a granular porous coalescer. The effects of wettability, emulsion and collector zeta potentials, and emulsion droplet size on the coalescence phenomenon were studied. The possible use of a graded medium or a coalescer with mixed wettability to enhnce the coalescence process was also examined. Based on these visual studies, a set of guidelines was developed to aid in the selection of a porous coalescer for a given separation duty.     

Kinetics and new mechanism study of CO2 absorption into water and tertiary amine solutions by stopped-Flow technique

The objective of the present work was to find the accurate kinetic models and mechanism for CO₂ absorption into tertiary amine solution, aiming at understanding the contribution of the CO₂ reaction with H₂O, OH⁻, and tertiary amines on the overall reaction rate. First, the kinetics of CO₂ absorption into water instead of a buffer solution were studied using the stopped-flow technique at 293–313 K, with initial CO₂ molar concentration of 1.1–37.3 mM. The experimental first-order reaction rate constant () was determined to be about 1000 times larger than the value for CO₂ absorption into buffer solution reported in the reference. The was then correlated by a proposed semiempirical model and a simplified theoretical model, giving the activation energy for CO₂ reacting with H₂O as fitted by the simplified theoretical model in good agreement with the value of previous research. Also, the pH values and hydroxyl ion concentrations of aqueous Diethylaminoethanol (DEEA) solutions were determined at 293–313 K, with DEEA molar concentration of 0.1–0.4 M and CO₂ loading of 0–0.626 mol/mol. In addition, the observed first-order reaction rate constant ( k_{0_DEEA} ) of binary DEEA-H₂O solution with DEEA molar concentration of 0.1–0.4 M reacting with CO₂ was determined at 293–313 K. It should be pointed out that the kinetic experiments of CO₂ absorption into DEEA solution was done with the molar ratio of DEEA to CO₂ fixed at 20. The values of k_{0_DEEA} were then fitted and predicted by four models (i.e., termolecular model, base-catalyzed model, the improved model, and Khalifah model). The results show the improved model and Khalifah model can predict k_{0_DEEA} well with an average absolute relative difference (AARD) <5%. The predicted results indicate that the contribution of OH⁻ to k_{0_DEEA} cannot be ignored for the absorption of CO₂ into tertiary amine solutions, and could be responsible for 50–70% of the total absorption reaction rate. Furthermore, the k₀ value of CO₂ absorption into aqueous triethanolamine and CO₂-loaded DEEA solution were further investigated and comprehensively discussed, suggesting that both pK _a and the CO₂ solubility affect k₀ , with pK _a having a much more significant effect. © 2018 American Institute of Chemical Engineers AIChE J, 65: 652–661, 2019     

流态化吸收式烟气脱硫技术研究

在参考国内外大量湿法脱硫、脱硝、除尘的研究经验的基础上,提出了一种适合我国国情的烟气脱硫技术路线：石灰／石灰石流态化吸收式烟部硫工艺。建立了处理烟气量２０００ｍ＾３／ｈ的热态实验装置,进行了大量烟气肿硫试验研究,总结了流态化反应器的脱硫性能及其影响因素。试验结果表明：流态化反应器脱硫效率随着浆液浓度、喷射管插入深度、搅拌速度等的增加而增加。当浆液ｐＨ值为５～８、喷射管插入深度１６０～２００ｍｍ（相     

A comparison of lycopene and astaxanthin absorption from corn oil and olive oil emulsions

The effect of different oils on the absorption of carotenoids was investigated in mesenteric lymph duct cannulated rats. Sixteen treatment emulsions containing increasing concentrations of either lycopene (LYC) or astaxanthin (AST) (5, 10, 15, 20 μmol/L) were prepared with olive oil or corn oil and continuously infused into the duodenum of the rat. Absorption of carotenoids into the mesenteric lymph duct was determined. Absorption of LYC and AST from both oils increased with the amount infused into the duodenum. The average recovery of AST in the lymph from the olive oil emulsion was 20% but was decreased to 13% from emulsions containing corn oil. Lycopene was not as well absorbed as AST. The average recovery of LYC was 6% from olive oil emulsions but only 2.5% when infused with corn oil. The LYC used in this study was isolated from tomato paste and was primarily in the all-trans form. We did not observe any significant isomerization of all-trans LYC to 9-cis LYC during absorption. We conclude that the type of oil with which a carotenoid is consumed can influence its absorption.     

Preparation and power consumption of surfactant-fuel oil-water emulsions using axial, radial, and mixed flow impellers

Surfactant-oil-water emulsions could have applications in enhanced oil recovery and the bio-desulfurization process applied to crude oil and some fractions. A simple way to prepare oil in water (O/W) emulsions is using a tank and an agitation device. The aim of this work is to propose a technology to prepare surfactant-fuel oil-water emulsions by means of a system involving a tank equipped with baffles, and an agitation device. The employed fuel oil was a high-viscosity fraction, which makes it difficult to handle. Axial, radial, and mixed flow impellers were assessed in the preparation of O/W emulsions, with and without the presence of baffles. Sixteen commercial surfactants were evaluated on the O/W emulsion formation. The effect of the storage temperature on the emulsions stability was assessed. The presence of salt on the surfactant-fuel oil-water emulsion was also investigated. Power vs. Reynolds numbers, extremely important data for the scaling up of the process, were calculated in basis of the power drawn when preparing the emulsions. Total consumption energy applied to the system, as well as pumping capacity were measured and related to the quality of the O/W emulsions obtained.     

轻烃燃气氨水吸收式热泵的可行性模拟研究

为了缓解天然气能源供应不足,解决在冬季低温环境下吸收式热泵的持续运行问题,首先分析了轻烃燃气氨水吸收式热泵在原理上的可行性,再对系统设备在结构、压力、大小方面进行了可行性分析,最后利用Aspen Plus软件对系统进行流程模拟。根据天然气吸收式热泵的文献数据,验证模拟流程吸收式热泵循环系统的正确性,再分析系统在效率上的可行性。考察了轻烃进料、制冷剂进水温度、冷媒水进水温度对系统效率的影响,结果表明:系统在供热和制冷工况下能达到一定的效率,轻烃燃气氨水吸收式热泵是可行的。