生物表面活性剂提高采收率技术室内研究

通过稠油微生物乳化降粘试验,筛选培养出高效的生物表面活性剂菌种,研究影响表面活性剂驱油体系生长的因素,对其现场应用潜力进行了分析研究。通过室内研究,生物表面活性剂能够改善界面润湿性,克服原油吸附功,强化水驱条件下剩余油的启动,与聚合物在驱油机制和功能上实现互补,对微生物采油技术研究也具有重要意义。     

稠油降粘方法的作用机理及研究进展

综述了常用稠油降粘方法的作用机理及优缺点。目前常用的稠油降粘方法主要有加热降粘,掺稀降粘,降凝降粘,加表面活性剂降粘,微生物降粘,改质降粘,油溶性降粘剂降粘,加碱降粘,催化降粘等。并对以上几种方法进行对比和应用前景的展望。     

注射氟橡胶胶料的研究

本文介绍了两种不同门尼粘度很橡胶2601与2605的共用，得到了各项物理机械性能符合GB7040－86，且工艺可行，产品的硫化合格率大于90％的注射胶料。     

Excess properties and spectroscopic studies for binary system polyethylene glycol 600 + dimethyl sulfoxide at T =(298.15, 303.15,308.15, 313.15, and 318.15) K

The work presents density (ρ) and viscosity (η) data of binary system polyethylene glycol 600 (PEG) + dimethyl sulfoxide (DMSO) over the entire concentration range at T =(298.15,303.15,308.15,313.15 and 318.15) K and atmospheric pressure.On the basis of density and viscosity values,the excess properties of PEG (1) + DMSO (2) mixtures,including excess molar volume (VEm),viscosity deviation (△η),excess free energies of activation (△G*E),and isobaric thermal expansion coefficient (αp),were calculated.At the same time,in order to conjecture the density viscosity under different conditions,the density and viscosity data were fitted with the corresponding formula.The calculated results of VEm,△η,and △G*E were fitted with the Redlich-Kister equation to derive coefficients and estimate the standard deviations (σ) between the experimental and calculated values.Moreover,the intermolecular interaction of PEG with DMSO was discussed on the basis of FTIR and UV-Vis spectral results of PEG (1) + DMSO (2) mixtures.The results indicated that there were the hydrogen bonding and interactions of hvdroxvl hydrogen atoms in PEG with oxygen atoms in DMSO.     

Comparison of Water Blanching and High Hydrostatic Pressure Effects on Drying Kinetics and Quality of Potato

Abstract

Drying kinetics and quality parameters of potato cubes were evaluated as affected by high pressure processing and hot water blanching. The potato cubes in 1% citric acid solution as immersion medium were pressure treated at 400 MPa for 15 min. Hot water blanching was conducted in boiling water for 3 min. Drying kinetics and quality parameters (i.e., rehydrability, texture, color and apparent density) were assessed for the high pressure–treated and water-blanched samples and for dehydrated and rehydrated samples. Drying rates were found to be higher (p < 0.05) in the initial period of drying for the pressure treated samples. The Page model was found to better fit drying data of the thermally treated samples, and the two-terms model better described the drying behavior of high pressure–treated samples. High pressure–treated samples had a similar rehydrability to thermally treated samples. It was found that pressure–treated samples had a hardness value close to that of fresh samples, whereas thermal treatment resulted in a softer texture. After rehydration, samples of both treatments returned their texture before drying. The total color difference for the thermally blanched samples was higher (p < 0.05) than for pressure–treated samples before drying and after drying. High pressure–treated and dried potato cubes had a color close to that of fresh potato cubes. High pressure–treated and air-dried samples were found to have higher (p < 0.05) apparent density than thermally treated samples.     

Paste Residence Time in a Spouted Bed Dryer. III: Effect of Paste Properties and Quality Interactions

The aim of this study was to evaluate the effects of paste properties on residence time during drying in a spouted bed dryer with inert bodies. The effect of paste solids content, surface tension, and viscosity on the residence time distribution and the mean residence times were studied using factorial experimental designs. The inert bodies used were glass and polyethylene beads. The mean residence times varied from 13.6 to 16.3 and 12.2 to 17.7 min for drying on glass and polyethylene beads, respectively. The analysis of variance showed that mean residence times significantly depended on solids content and surface tension for glass beads and also on viscosity for polyethylene beads. The residence time distributions for all conditions studied fitted well to the perfect mixing cell when applying the continuous stirred vessels in series model analysis. The powder density, flowability, and particle size depended on paste properties and inert type.     

Apparent Molar Volumes of N,N – Disubstituted Monoamides: A Convenient Tool to Interpret Iron(Iii) Extraction Profiles from Hydrochloric Acid Solutions

New iron(III) extraction data involving two N,N-disubstituted monoamides, N-ethyl-N-phenyloctanamide (EPHOA) and N-ethyl-N-cyclohexyloctanamide (ECHOA), from hydrochloric acid media, are presented and discussed. These, and earlier results obtained with other similar N,N-disubstituted monoamides, are interpreted in this work through their apparent molar volumes in 1,2-dichloroethane, and all the information is being used to screen for solute-solute and solute-diluent interactions. The results collected help to understand why N-cyclohexyl monoamides are generally more efficient than their N-phenyl analogues as liquid-liquid extractants for iron(III) from 3 to 5 M hydrochloric acid solutions, and clearly denote that N-phenyl monoamides are essentially monomeric whereas N-cyclohexyl monoamide derivatives have a tendency to aggregate in the organic solution.     

VISCOMETRIC MEASUREMENT OF CHROMIUM(III)-POLYACRYLAMIDE GELS†

Gelled polymers are being used increasingly to modify the movement of injected fluids in secondary and enhaced oil recovery processes. A common gelation process involves the reduction of Cr(VI) to Cr(III) in the presence of polyacrylamide. The Cr(III) reacts or interacts with the polymer to form a gel network. Although correlations of gelation time with principal process variables have been obtained, viscometric data have not been reported during or after gelation. These data are needed for fluid flow calculations in surface equipment and estimation of flow behaviour in reservoir rocks.

A Weissenberg Rheogoniometer, with cone and plate geometry, was used to obtain viscometric data for the gelation of polyacrylamide and chromium (III). Solutions consisting of polyacrylamide polymer, sodium dichromate-dihydrate and sodium bisulfite were gelled under a steady shear field at constant temperature. The shear stress versus time profile for the galation process was interpreted to define a gelation time and to determine the apparent viscosity of the gelled fluid. The gelation time decreased as the applied shear rate increased up to about 14.25 sec^?1 and was affected by shear rate history. Viscometric properties of the gelled solutions were determined. Apparent viscosity of the gelled solutions decreased as the shear rate under which they were formed increased.

Post gelation studies indicated that gels exhibited a residual stress at zero shear rate and behaved as Bingham plastics under steady shear. Gels formed at low shear rates were more viscous than gels formed at high shear rates. However, the structure of these gels was susceptible to shear degradation.     

A VISCOSITY-TEMPERATURE RELATION FOR NEWTONIAN LIQUIDS

The lack of success of existing theories in describing viscosity of molecular liquids appears to be due to at least two difficulties. The mechanisms of viscous momentum transfer have not been identified, and the thermal motions of molecules can not be described until the spatial arrangement of molecules in a shearing liquid is known. This paper presents the results of an effort to identify the mechanisms of viscous momentum transfer. A model is proposed and a relation is derived from it that precisely fits viscosity data for a wide variety of Newtonian liquids. The effects of the spatial distribution of thermal motions and of intermolecule attraction are represented as parameters together with a Debye-like temperature. Values of these parameters are found from fitting the relation to published data. The parameters are found to be sensitive to molecular weight and to molecular configuration. Frequencies of interaction of molecules in the direction of the velocity gradient are of the order E 10 s ^?1. Abrupt shifts in these parameters with increasing temperature are found for paraffins at temperatures slightly above their melting points that are interpreted as disaggregation of molecules. Other abrupt shifts in the parameters at high temperatures for mercury and alcohol are interpreted as a change in the momentum transfer mechanism. Correlation of the parameters of the relation with molecular properties promises to provide predictive value. The relation provides a framework for further theoretical development.