Kinetics and Thermodynamics of Oil Extraction from Olive Cake

The kinetics of oil extraction from olive cake by using ethanol 96% was studied for different solvent-to-solids ratios and temperatures. The thermodynamic aspect of the extraction process was also examined. In the kinetic study, the results produced by the model of So and Macdonald (a model involving two main mechanisms of oil extraction: a washing process and a diffusion process with two stages) were found to be in good agreement with the experimental data. The yield of oil in the extract increased with increasing contact time, solvent-to-solids ratio and extraction temperature. The calculated values of the mass transfer coefficients of various stages of the extraction were found to increase linearly with solvent-to-solids ratio and temperature. In all cases, the predominant mechanism in the extraction was the washing of the oil occurring on the particle surface. The values of the activation energy were 8.56 kJ mol⁻¹ for the washing stage, 9.88 kJ mol⁻¹ for the first stage of diffusion and 17.55 kJ mol⁻¹ for the second stage of diffusion by changing temperature from 20 to 50 °C. Further, the results obtained from thermodynamic study of extraction process gave positive values of enthalpy and entropy changes and negative values of change in free energy. Under the equilibrium conditions, the temperature coefficient was found to be 1.02.     

The concentration of tocols from rice bran oil deodorizer distillate using solvent

Tocols (tocopherols + tocotrienols) have been concentrated efficiently from rice bran oil (RBO) deodorizer distillate using solvent at low temperature. The levels of total tocols, total tocopherols, and total tocotrienols in RBO deodorizer distillate (starting material) were 31.5, 14.9, and 16.6 mg/g, respectively. Nine different solvents were tested, and acetonitrile was selected as the optimal solvent for concentrating tocols from the RBO deodorizer distillate. There was a significant (p <0.05) increase in the tocol level of the liquid fractions with decreasing temperature, for incubation temperatures up to –20 °C. In addition, significant differences (p <0.05) were observed in the relative percentages of α‐tocopherol, γ‐tocopherol, α‐tocotrienol, and γ‐tocotrienol between the raw sample and liquid fractions obtained at different temperatures using acetonitrile as the solvent. The concentration of the tocols from the RBO deodorizer distillate was temperature dependent, and a maximum of 89.9 mg/g was attained in the liquid fraction at – 40 °C. The relative percentage of tocotrienol homologs in the liquid fraction obtained at – 40 °C was approximately 80%. With acetonitrile as the solvent, the optimal temperature for concentrating the tocols from RBO deodorizer distillate was –20 °C when yield was considered.     

The use of solvents for purifying industrial naphthalene from coal tar distilled oils

The organic chemistry industry is based on organic compounds derived from coal, petroleum and gas. Coal tars derived from the carbonisation process are complex mixtures, of which the polycyclic aromatic hydrocarbons (PAH's) are the main component. One of the most important PAH's is naphthalene, which represents between 10 to 12% of the sample. In recent years, new applications for industrial naphthalene have been developed. However, the naphthalene required for high level industry must be extremely pure. New routes in the purification process are being studied to reduce the economic cost and environmental impact resulting from the increase in demand for pure naphthalene. Any alternative method to that of sublimation for purification in the distillation process and/or catalytic hydrogenation must improve the quality of industrial naphthalene, to make it suitable for the new applications. In the present work, an alternative method for purifying industrial naphthalene has been investigated. A new process based on extraction with solvents such as phosphoric acid and acetic acid is reported and discussed. Industrial naphthalene was purified by means of a new technique and the stability and good properties of the product were verified.     

Solvent impregnated resins for the removal of low concentration phenol from water

The focus of this investigation is the development of a solvent impregnated resin for phenol removal from dilute aqueous solutions. Using a solvent impregnated resin (SIR) eliminates the problem of emulsification encountered in liquid–liquid extraction. Impregnated MPP particles and impregnated XAD16 particles are successfully used for phenol extraction. Impregnated MPP particles are preferred, as impregnated XAD16 particles show less mechanical strength and are more expensive. Impregnated MPP particles perform better compared to other synthetic adsorbents and basic ion exchangers. The maximum phenol capacity of impregnated MPP particles with 0.99 mol Cyanex 923 kg⁻¹ SIR is 4.1 mol kg⁻¹ SIR (386 mg g⁻¹ SIR) and of MPP particles containing 1.47 mol Cyanex 923 kg⁻¹ SIR it is 5.08 mol kg⁻¹ SIR (478 mg g⁻¹ SIR). The regenerability of impregnated MPP particles is easy and complete, and the particles are stable during several cycles. The equilibrium constants for the extraction of phenol are determined as K_chem = 37 L mol⁻¹ and K_phys = 18 (mol L⁻¹) (mol L⁻¹)⁻¹. With these values the SIR isotherms can be satisfactorily described.The results indicate that SIR technology is a promising alternative for the conventional phenol removal technologies at low phenol concentration levels.     

中空纤维膜气体溶剂的吸收分离过程

测定了不同条件下聚丙烯疏水性中空纤维膜组件中ＣＯ２－ＮａＯＨ体系气体溶剂吸收过程的总传质系数．建立了溶剂吸收过程总传质系数的计算模型．以此模型为基础,结合实验结果对气体溶剂吸收过程进行了分析,提出了提高总传质系数的有效方法．     

钨钼混合溶液萃取平衡的测定与研究

采用一套溶剂萃取平衡测定装置,在酸性介质中,选择D2EHPA[二－（2－乙基己基）磷酸酯]为萃取剂,煤油为稀释剂,仲辛醇为改质剂,EDTA为络合剂,系统完整地测定了不同条件下两种浓度范围的含大量钨和少量钼的溶液的钨钼萃取分离平衡数据,分析和研究了各种因素对钨钼萃取分离的影响．分别用萃取平衡的经验模型和化学模型对该萃取体系进行了关联计算,得出了一套可以在工业计算中使用的经验模型和化学模型,为工业过程设计、工程优化和计算机模拟提供了基础．     

石油渣油制备活性炭研究：溶剂浸取对活性炭性能的影响（一）

石油渣油生产活性炭是劣质石油渣油增值利用的有效途径,对于合理利用石油资源,开发优质活性炭都具有一定的意义,本文对劣质石油渣油制备活性炭进行了研究,研究结果表明,劣质石油渣油经：氧化→溶剂浸取→不熔化→炭化→活化处理,可以获得比表面大、吸附性能好的活性炭。     

Separation of Indium from Acid Sulfate-Containing Solutions by Ion Exchange with Impregnated Resins

Indium separation using ion exchange resins from acidic polymetallic and very diluted solutions are investigated. Since the selectivity of commercial ion exchange resins have proven to be too low for an effective separation from solutions with high content of other metals, Lewatit® TP 208 was impregnated with common extractants to enhance its properties. By resin impregnation with D2EHPA and Cyanex 272, not only the selective indium recovery was reached but also the resin capacity was increased approx. two times. The best loading and elution performance were shown by Cyanex 272-impregnated Lewatit® TP 208, increasing the indium purity in the eluate from 0.75 % to 85 %.     

“鱼促Ⅳ”生产中的溶剂回收

本文介绍了在鱼生长促进剂Ⅳ号研制中,环氧氯丙烷等溶剂在缺乏平衡数据情况下,用精馏加以分离回收的方法.     

Selective separation of cobalt and nickel by supported liquid membranes

The selective separation of cobalt from acidic media, containing both equimolar and nonequimolar mixtures of cobalt and nickel, was examined by supported liquid membranes using Alamine 336 as mobile carrier dissolved in various diluents. The membrane support was microporous hydrophobic polypropylene Celgard 2500 (25 μm thick, 0.209 × 0.054 μm pore size and 55% porosity). Acetic acid-Na acetate buffer was used for the adjustment of the feed pH which was critical. Various parameters were experimentally studied and the optimum conditions were determined.