微孔塑料连续挤出加工技术

从发泡剂注入聚合物熔体、均相聚合物／发泡剂形成和微孔发泡三个方面综合评述了微孔塑料连续挤出加工技术的发展状况。     

Surfactant Effects on Aeration Performance of Stirred Tank Reactors

The effect of surfactants on aeration performance in stirred tank reactors (STR) at high rates of foaming is studied. The volumetric oxygen transfer coefficient (k_La) and foaming activity estimated as foaming height (H_f) were determined. Biotechnology of lipopeptide biosurfactants from aerobic organisms, e.g., Bacillus subtilis were addressed. Using model solutions of known foam‐generating properties, high‐molecular weight surfactin and low‐molecular weight sodium dodecyl sulphate (SDS), as well as impellers of different types, with flat and fluid‐foil blades, clues on the concentration dependence of STR oxygen transfer and foaming as well as options for foam reduction in the presence of biosurfactant were sought. In response to a two‐fold decrease of surface tension by surfactin, k_La values decreased up to 30 % but remained within the range expected for the mixing system in water; the experiments with SDS showing stronger dependence on surfactant concentration and surface tension. Mixing of surfactant media by a standard six‐blade disc turbine (RT) imposed rate limitations on gassing. A low‐shear impeller Narcissus (NS) could be used to avoid bulk foam outflow, while preserving k_La values that remained unchanged. The ‘power per unit volume' correlation of k_La in stirred tanks is tested in the presence of surfactin.     

泡沫沥青特性与混合料设计方法的试验研究

介绍了泡沫沥青的发泡原理和评价指标,通过采用德国Wirtgen公司生产的WLBl0泡沫沥青实验机对韩国70号沥青进行发泡试验,分析得出有关发泡特性和最佳发泡条件.并在这种发泡条件下,将泡沫沥青用于沥青路面铣刨料的稳定处理,通过初步的试验研究,提出了一种基于泡沫沥青水稳性的配合比设计方法.     

Enhanced oil recovery by nonionic surfactants considering micellization, surface, and foaming properties

Surfactants for enhanced oil recovery are important to study due to their special characteristics like foam generation, lowering interfacial tension between oleic and aqueous phases, and wettability alteration of reservoir rock surfaces. Foam is a good mobility control agent in enhanced oil recovery for improving the mobility ratio. In the present work, the foaming behavior of three nonionic ethoxylated surfactants, namely Tergitol 15-S-7, Tergitol 15-S-9, and Tergitol 15-S-12, was studied experimentally. Among the surfactants, Tergitol 15-S-12 shows the highest foamability. The effect of NaCl concentration and synthetic seawater on foaming behavior of the surfactants was investigated by the test-tube shaking method. The critical micelle concentrations of aqueous solutions of the different nonionic surfactants were measured at 300 K. It was found that the critical micelle concentrations of all surfactants also increased with increasing ethylene oxide number. Dynamic light scattering experiments were performed to investigate the micelle sizes of the surfactants at their respective critical micelle concentrations. Core flooding experiments were carried out in sand packs using the surfactant solutions. It was found that 22% additional oil was recovered in the case of all the surfactants over secondary water flooding. Tergitol 15-S-12 exhibited the maximum additional oil recovery which is more than 26% after water injection.     

泡沫酸酸化在文明寨油田的应用

本文针对文明寨油井段长，渗透率高，层间矛盾突出，井况恶化，油井负压等特点，采用泡沫酸酸化工艺解除油层污染，实现泡沫暂堵高渗层，沁沫负压排酸，恢复井产能，改善水驱开效果。