An infrared spectroscopy study of lipid adsorption from hexane onto an acid-activated bleaching clay

The mode of adsorption of oleic acid (OA) (0.05 M), triglyceride (TG) (0.05 M) and phosphatidylcholine (PC) (0.5 mM) from hexane solution onto 0.5 g of an acid-activated bleaching clay was investigated using diffuse reflectance Fourier transform infrared spectroscopy. OA was mostly weakly adsorbed by bound water, with some OA adsorbed to silanol sites through carboxyl carbonyl groups. TG was hydrogen- bonded to surface silanol groups through ester carbonyl groups. The CH₂ stretches indicated that TG was oriented perpendicular or at an angle to the surface. PC phosphate groups were bound by the surface moisture with little interaction with silanol groups. The adsorption mechanism of these lipids contrasts with the adsorption of carotenoid and chlorophyll under the same conditions. These pigments are bound by chemisorption, with catalytic modification often occurring before adsorption.     

Extraction of Phospholipids from Structured Dry Egg Yolk

Chicken egg yolk is a concentrated source of phospholipids (PL). Extracting egg PL with high efficiency is vital to the availability and economics of this high-valued lipid product. In this study, two types of structured dry egg yolk materials, yolk flakes and pellets, were prepared. Two commonly used solvents, hexane and ethanol, were tested on the extraction of total yolk lipids including the PL. The PL fraction was obtained by the conventional cold acetone precipitation. The drum-dried yolk flakes were shown to be an ideal starting material for total lipid and PL extraction. Anhydrous ethanol can extract almost all the neutral lipids and PL with little change to the individual components of the native PL. A PL product with a purity of more than 90 % and a yield of 99 % can be prepared using this method.     

Multiple Tank Explosions in an Edible‐Oil Refinery Plant: A Case Study

Multiple explosions occurred when five workers were acting on a footbridge structure at the top of crude olive pomace oil tanks. Welding on the tank roofs was performed without previously cleaning the tanks stopping their operation. First, one of the several ～ 650‐m³ reservoirs exploded, provoking a pool fire that spread throughout the tank farm. Roughly 1 h later, two other reservoirs exploded causing the launching of missiles to a distance of 60–80 m and a huge fire that extended throughout the entire tank farm. Four workers were killed instantaneously. The explosion was caused by the unusually high content of hexane in the crude olive pomace oil and, hence, by the inefficiency of the desolventization process which creates a flammable and explosive oil from a combustible one.     

PHASE EQUILIBRIA OF THE CYCLOHEXANE-TOLUENE-SULFOLANE AND HEXANE-TOLUENE-SULFOLANE TERNARY SYSTEMS

Liquid-liquid equilibrium data for two ternary systems were obtained. The experimental data were measured for cyclohexane-toluene-sulfolane at 17, 25 and 50°C, and for hexane-toluene-sulfolane at 18 and 25°C. The NTRL and UNIQUAC models were used to correlate the experimental results and to calculate the phase compositions of the ternary systems. The agreement between the experimental results and the fitted values was equally good with both of the models.     

Liquid–Liquid Coexistence Curve of n-Perfluorohexane–n-Hexane System

The shape of the liquid–liquid phase boundary of the C₆F₁₄–C₆H₁₄ system near the critical solution point has been determined by a γ-ray attenuation technique. According to the measurements, the critical solution temperature and composition are 295.69 ± 0.02 K and 36.1 ± 0.3 mol% C₆F₁₄, respectively. The critical exponent of the liquid–liquid coexistence curve is 0.322 ± 0.008. Midpoints of the coexistence curve exhibit a departure from the law of the rectilinear diameter.     

炼油厂高标溶剂油类别优选研究

通过蒸馏实验对某炼油厂提供的各种石脑油的馏分范围进行测试,并用气相色谱仪对其化学组成进行详一细分析,结果表明抽余油具有制备低芳烃6号溶剂油的物质条件。实验与模拟计算表明：该抽余油经催化加氢分馏可制得芳烃〈10mg/L、d硫〈0．5mg/L的6号溶剂油;对该6号溶剂油进一步精馏则可制得纯度为99%的异己烷和纯度为98％的己烷两种高标溶剂油。与常规溶剂油及D系列溶剂油相比,正已烷价格与石脑油平均差价高达4000元/吨,且差价稳定,因此以抽余油生产正已烷/异己烷可获良好的经济效益。     

Minimization of the Theoretical Error of Input Parameters for a Vapor Permeation Apparatus

All input experimental errors for membrane flux determination were analyzed. The overall error in pressure did not largely influence the determination of membrane flux. The main contribution to errors was ascribed to flow meters and membrane thickness. The choice of an optimal operational range for input parameters led to elimination of at least 2/3 of the theoretical relative error for subsequent evaluation of the permeability of individual species. This is especially valuable for low‐permeable membranes, whereas a very low relative theoretical error can be obtained in the case of highly permeable materials.     

提高己烷、溶剂油中微量水测定的准确性

文中通过分析影响己烷、溶剂油微量水准确性的影响因素，寻求到相应的解决办法，解决了分析过程中经常出现分析结果重复性不好的问题，实际使用后效果满意，满足了现场的分析要求。     

固体酸酸性表征及其正己烷裂化活性考察

采用经改进的指示剂法对ＨＹ、Ｈβ、ＨＺＳＭ－５、ＵＳＹ和磷酸盐分子筛（Ｐ１、Ｐ２）的酸强度和酸强度分布进行了测定,方法简便。用高氯酸反滴淀法测定了酸度,其结果和氨吸附热重法一致。考察了正己烷在上述６种催化剂上的裂化活性,表明正己烷的裂化活性不仅与催化剂的酸强度、酸度有关,而且还和固体酸的结构密切相关。     

Development and Scale-up of Aqueous Surfactant-Assisted Extraction of Canola Oil for Use as Biodiesel Feedstock

Aqueous surfactant-assisted extraction (ASE) has been proposed as an alternative to n-hexane for extraction of vegetable oil; however, the use of inexpensive surfactants such as sodium dodecyl sulfate (SDS) and the effect of ASE on the quality of biodiesel from the oil are not well understood. Therefore, the effects on total oil extraction efficiency of surfactant concentration, extraction time, oilseed to liquid ratio and other parameters were evaluated using ASE with ground canola and SDS in aqueous solution. The highest total oil extraction efficiency was 80 %, and was achieved using 0.02 M SDS at 20 °C, solid–liquid ratio 1:10 (g:mL), 1,000 rpm stirring speed and 45 min contact time. Applying triple extraction with three stages reduced the amount of SDS solution needed by 50 %. The ASE method was scaled up to extract 300 g of ground canola using the best combination of extraction conditions as described above. The extracted oil from the scale-up of the ASE method passed the recommendation for biodiesel feedstock quality with respect to water content, acid value and phosphorous content. Water content, kinematic viscosity, acid value and oxidative stability index of ASE biodiesel were within the ASTM D6751 biodiesel standards.