共查询到20条相似文献,搜索用时 31 毫秒
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M. H. I. Baird 《加拿大化工杂志》1991,69(6):1287-1301
The solvent extraction area is perceived by some chemical engineers as being mature and fully developed. The present review shows that this is not the case. Many chemical engineering problems must be solved before equipment can be confidently designed from first principles. The review also outlines progress in extraction process chemistry, and in new techniques such as membrane extraction. 相似文献
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A mathematical model has been developed to simulate and predict the dynamic behavior of liquid extraction counter current operations in mixer-settler units. Murphree efficiency has been included in the model. The behavior of a multistage glass mixer-settler has been studied under start-up transient conditions. Very good agreement between the simulation results and the experimental findings have been obtained. The simulation results showed that this model can efficiently be used to determine the optimum number of stages, the capacity of each stage, the phase ratio and the time required for each unit to attain steady state conditions. Other controlling parameters in operating such units are investigated. 相似文献
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张文兵 《化学推进剂与高分子材料》2004,2(4):47-48
根据生产实践,总结蒽醌法生产双氧水中影响萃余液中双氧水含量的各种因素,指出萃余液中H2O2超标的危害,找到控制萃余的有效途径。 相似文献
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番茄红素含量测定中提取方法研究 总被引:1,自引:0,他引:1
采用紫外一可见分光光度法测定番茄酱中番茄红素的含量。在提取时间,提取次数,提取剂的选择等方面考察了影响番茄红素测定效果。试验结果表明:影响番茄酱中番茄红素的提取因素主次顺序为:料液比〉混合液〉提取时〉间提取次数:采用乙酸乙酯+乙醇(9+1)做提取剂,料液比为1:2,提取时间为30min.提取次数为1次,为番茄酱中番茄红素测定提取的最优组合。 相似文献
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竹叶黄酮提取分析方法的研究及其新进展 总被引:2,自引:0,他引:2
从竹叶黄酮的基本性质着手,根据其溶解性,显色反应等特性,选取适当的提取方法。综述了五种应用较广泛的提取新方法、新技术,及分析方法,并简要论述了各种新技术和方法的原理以及应用于竹叶黄酮工业生产方面的情况。 相似文献
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Lorenzo RA Carro AM Alvarez-Lorenzo C Concheiro A 《International journal of molecular sciences》2011,12(7):4327-4347
Template removal is a critical step in the preparation of most molecularly imprinted polymers (MIPs). The polymer network itself and the affinity of the imprinted cavities for the template make its removal hard. If there are remaining template molecules in the MIPs, less cavities will be available for rebinding, which decreases efficiency. Furthermore, if template bleeding occurs during analytical applications, errors will arise. Despite the relevance to the MIPs performance, template removal has received scarce attention and is currently the least cost-effective step of the MIP development. Attempts to reach complete template removal may involve the use of too drastic conditions in conventional extraction techniques, resulting in the damage or the collapse of the imprinted cavities. Advances in the extraction techniques in the last decade may provide optimized tools. The aim of this review is to analyze the available data on the efficiency of diverse extraction techniques for template removal, paying attention not only to the removal yield but also to MIPs performance. Such an analysis is expected to be useful for opening a way to rational approaches for template removal (minimizing the costs of solvents and time) instead of the current trial-and-error methods. 相似文献
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Eleni P. Kalogianni Despoina Georgiou Aggelos Charisis Stylianos Exarhopoulos Paraskevi Tzika 《Journal of the American Oil Chemists' Society》2023,100(4):317-327
This work examines the potential valorization of mullet roe by-products for the production of mullet roe oil using mild processes. Three different extraction methods with potential of scale-up for the food industry, namely pressure (PE), supercritical fluid extraction (SFE), and solvent extraction (SE) are examined. Mild temperature conditions to prevent oil oxidation and (wherever applicable) food-grade solvents are used. The oil yield, the composition of oils in fatty acids by GC-FID, the level of oil oxidation (peroxide value (PV), p-anisidine value (AV), K232 K268, TOTOX)) and the antioxidant activity (DPPH, ABTS) are determined. SE provided the highest oil recovery, followed by SFE and PE (68%, 28% and 10% respectively). The extracted oils had a high concentration of EPA and DHA and a total of 20.7%–24.3% of identified PUFAs among the fatty acids. Oxidation was the lowest in the SFE extracted oil followed by PE, PV was <2.5 meqO2, AV≤10 and TOTOX <15 in all examined oil samples. Further research is needed to optimize processing conditions for the increase in oil recovery. 相似文献
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分析了煤溶剂萃取的研究现状,对比了微波溶剂萃取、超临界流体萃取和超声波萃取3种新技术在萃取过程中的优劣及萃取结果,对如何有效、经济、合理地利用煤的问题给予启示.基于当前煤化工的发展状况,对煤的溶剂萃取研究前景进行了展望. 相似文献
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有机废水的萃取处理技术 总被引:7,自引:0,他引:7
萃取技术对于有机废水的处理具有高效性.综述了有机废水的络合萃取、双溶剂萃取、膜萃取和萃取置换等工艺过程的特点及应用.指出萃取新工艺的研究开发和强化将为有机废水处理提供有效的途径. 相似文献
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Two-Stage Countercurrent Enzyme-Assisted Aqueous Extraction Processing of Oil and Protein from Soybeans 总被引:4,自引:2,他引:2
Juliana Maria Leite Nobrega de Moura Lawrence A. Johnson 《Journal of the American Oil Chemists' Society》2009,86(3):283-289
Enzyme-assisted aqueous extraction processing (EAEP) is an increasingly viable alternative to hexane extraction of soybean
oil. Although considered an environmentally friendly technology where edible oil and protein can be simultaneously recovered,
this process employs much water and produces a significant amount of protein-rich aqueous effluent (skim). In standard EAEP,
highest oil, protein and solids yields are achieved with a single extraction stage using 1:10 solids-to-liquid ratio (extruded
flakes/water), 0.5% protease (wt/g extruded flakes), pH 9.0, and 50 °C for 1 h. To reduce the amount of water used, two-stage
countercurrent EAEP was evaluated for extracting oil, protein and solids from soybeans using a solids-to-liquid ratio of 1:5–1:6
(extruded flakes/water). Two-stage countercurrent EAEP achieved higher oil, protein and solids extraction yields than using
standard EAEP with only one-half the usual amount of water. Oil, protein and solids yields up to 98 and 96%, 92 and 87%, and
80 and 77% were obtained when using two-stage countercurrent EAEP (1:5–1:6) and standard single-stage EAEP (1:10), respectively.
Recycling the second skim obtained in two-stage countercurrent EAEP enabled reuse of the enzyme, with or without inactivation,
in the first extraction stage producing protein with different degrees of hydrolysis and the same extraction efficiency. Slightly
higher oil, protein and solids extraction yields were obtained using unheated skim compared to heated skim. These advances
make the two-stage countercurrent EAEP attractive as the front-end of a soybean biorefinery. 相似文献
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对浆叶旋转式和筛板振动式两种机械搅拌萃取塔进行了传质方面的研究。通过测试大量的实验数据。及计算绘制的图表,校系统地考察分析了旋转(振动)频率,筛板振幅,两相界面,停留时间即取样时间等因素对传质效果的影响,并确定出了最适宜的操作条件。 相似文献
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文章以年产52万t尿素为例,分别从尿素生产的各个单元介绍Stamicarbon的CO2气提工艺和Snamprogetti的NH3气提工艺,通过对比分析,以便读者进行比较选择。 相似文献
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本文利用均匀各向同性湍流特性分析连续相湍流脉动液滴大小的影响,得出搅拌强度和液滴平均直径之间的关系,根据所使用的三种塔几何结构所得的实验数据检验。理论分析结果与实验所得结果较好地相符。本文也讨论了分散相存留分数对平均液滴直径的影响。 相似文献
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The process of hot water extraction of tar sand was modified and adapted for removal of heavy oil from bottom tank petroleum sludges, and was submitted to a laboratory feasibility study. This process can also be utilized to clean beach sands contaminated by accidental heavy oil spills. In the case of oil contaminated sands, a single stage extraction has yielded a 99% recovery of hydrocarbons and clean sands (containing less than 0.1% of hydrocarbons) which are thus safe to be returned to the environment. In the case of petroleum bottom tank sludge, it was necessary to proceed with a double stage extraction with the addition of a wetting agent. A dosage of a Na2 Si O3 aqueous solution of 1% by weight has proven efficient, allowing an 82% recovery of hydrocarbons, with only 0.5% of hydrocarbons content in the solid residues. 相似文献