正交实验优化超临界流体CO_2反胶团-络合萃取痕量重金属

利用超临界流体CO2反胶团-络合萃取食品中痕量重金属铅、汞和砷,通过正交实验考察了萃取压力、萃取温度、萃取时间和反胶团AOT浓度对痕量重金属萃取率的影响。确定最佳萃取工艺为:萃取压力20 MPa、萃取温度45℃、萃取时间90 min、反胶团AOT浓度0.1 mol.L-1,此时,重金属铅、汞、砷的萃取率分别为93.50%、95.36%、90.47%。表明超临界流体CO2络合萃取时加入反胶团能明显提高痕量重金属的脱除率,萃取效果优于超临界流体CO2反胶团萃取和超临界流体CO2络合萃取。     

超临界CO2体系中的反胶团

本文对超临界CO2反胶团技术的发展状况，包括基本原理，研究方法，应用领域，发展趋势和和了全面阐述。     

反胶团在超临界二氧化碳体系中的研究进展

超临界二氧化碳是一种环境友好型溶剂,它作为有机溶剂的替代品已成功的应用于绿色化学过程的开发。但超临界二氧化碳对极性物质的溶解度小,甚至不能溶解,反胶团的引入为这一问题的解决提供了新的手段。本文阐述了超临界二氧化碳反胶团的基本原理,研究了表面活性剂的选择和设计,讨论了反胶团对水的溶解能力、助表面活性剂以及压力对超临界二氧化碳反胶团性质的影响,最后总结了超临界二氧化碳反胶团在萃取、有机反应及纳米微粒合成等领域的应用。     

溶剂萃取新技术述评

本文就溶剂萃取技术的新进展作一评述,介绍了近年来发展的几种淀粉地取新技术：超临界流体萃取、反胶团萃了 波萃取、微波萃取、电泳萃,磁场协助萃取、等。     

基于表面活性剂的反胶团萃取技术

基于表面活性剂的反胶团萃取技术是一种新型的有发展前途的生物分离技术。介绍了反胶团萃取技术的驱动力、表面活性剂选择和影响因素,提出了反胶团萃取技术目前存在的问题,探讨了反胶团萃取技术在其酶促反应和纳米材料制备方面的应用及其发展方向。     

反胶团萃取分离技术研究进展

简要介绍了反胶团萃取技术理论研究及反胶团萃取体系开发工作，重点综述了反胶团萃取技术在蛋白质、日化和药物等分离分析中的应用研究进展。提出了反胶团萃取技术目前存在的问题、发展方向和应用前景等。     

反胶团萃取蛋白质技术的新进展

反胶团液-液萃取技术具有条件温和、高选择性、易放大等优点,是一种应用前景极好的生化分离方法。本文介绍反胶团的性质、萃取原理,并着重分析了制约反胶团萃取技术实用化的各种因素及研究现状,评述其工业应用前景。     

茶多酚的提取工艺研究

经过对茶多酚的性质及现有提取方法利弊的分析 ,确定采用超临界CO2 萃取技术对茶叶中的茶多酚进行了萃取研究。结果表明 ,超临界CO2 萃取茶叶中的茶多酚在工艺上是可行的 ,并探讨了其较佳的提取工艺参数     

超临界CO_2萃取β-胡萝卜素的实验研究

用超临界CO2技术对β 胡萝卜素进行了萃取试验,考察了CO2用量、萃取压力、温度等对浸膏得率的影响,从而得出了超临界CO2萃取β 胡萝卜素的最佳工艺条件。     

国内超临界CO_2萃取技术工业化现状及存在问题

本文阐述了我国超临界CO2萃取技术及其工业化现状,着重分析了超临界CO2萃取技术大型工业化过程中所存在的问题,并对超临界CO2萃取技术的工业化前景作了分析。     

Liquefied gases and supercritical fluids in oilseed extraction

Soybean oil and numerous other vegetable oils can be extracted from crushed seeds by means of liquefied gases or supercritical fluids. The oils are recovered by lowering the pressure or increasing the temperature, or both. Supercritical carbon dioxide is ideally suited for the food industry as it is nontoxic and nonflammable. Moreover, it can be removed easily from the oil as well as the meal. The oils extracted with supercritical carbon dioxide contain much lower proportions of phospholipids than those obtained by conventional processing with hexane. The addition of acetone or another carrier or entrainer aids in the fractional extraction of lipids differing in polarity. The range of applicability of liquefied gases and supercritical fluids in the extraction and fractionation of lipids should be explored further to develop industrial processes using these solvents.     

SIMULATION AND PROCESS OPTIMIZATION OF A MEMBRANE-BASED DENSE GAS EXTRACTION USING HOLLOW FIBER CONTACTORS

Supercritical fluid and membrane technology coupling is a relatively new concept applicable to solvent separation and solute extraction. In these processes a hydrophobic or hydrophilic macroporous membrane is used as a two-different-nature solutions contactor. This methodology is an alternative to conventional liquid solution supercritical fluid extraction processes, which are associated with high investment costs. In the present work, a membrane-based supercritical fluid extraction module is modeled, simulated, and optimized as an independent industrial-scale operational unit. UniSim design suite R390 software from Honeywell was used as the platform for the simulation. Acetone and ethanol literature extraction results and methanol experimental extraction results (27.6% to 14.5% with a 10 wt.% aqueous solution; 7.1% to 5.9% with a 500 ppm aqueous solution) were used for validation of the model and definition of the semi-empirical equation parameters. The generated industrial-scale system optimization, which used a modular membrane arrangement, was strongly dependent on thermodynamic, economic, and energetic variables (higher mass transfer resistance in the carbon dioxide phase increased the number of membranes needed; process feasibility was affected by the number of membrane units, carbon dioxide flow rate, and product added value; compression energy requirements affected the optimization result). The modeled system proved to be an important aid in the design, scaling, and optimization of systems that use membranes as phase contactors in liquid solution supercritical carbon dioxide extraction.     

Trainable cascade-forward back-propagation network modeling of spearmint oil extraction in a packed bed using SC-CO2

Supercritical extraction (SE) is a separation technique utilizes near or above critical properties of the solvents. In this technique, modeling of yield and solubility of materials are crucial points in supercritical fluid extraction processes. Generally, mathematical modeling of the supercritical oil extraction is a very difficult task since a highly nonlinear relation exists between process variables and solubility. Considering these facts, in the present study, a trainable cascade-forward back-propagation network (CFBPN) was proposed to correlate the yield of spearmint oil extracted by supercritical carbon dioxide. The results revealed the applicability of the proposed model to correlate the yield of spearmint oil extraction with an acceptable level of accuracy. Finally, the obtained results were compared to mathematical models namely Goodarznia & Eikani and Kim & Hong. The comparison between the results of proposed network and mathematical models demonstrated a better predictive capability of the proposed network.     

超临界流体技术及其在生物工程中的应用

介绍了在生物工程有着广泛的应用前景的多种超临界流体技术，包括提取生物活性物质的超临界流体萃取，超临界条件二氧化碳中制备手性药物制备和淀粉水解制取葡萄糖的非水酶催化反应，超临界水条件下纤维素水解制备葡萄糖，超临界流体中的细胞破碎，制备缓释药物和色说载体的超临界流体溶液快速膨胀和气体抗溶剂结晶和沉淀技术。     

超临界二氧化碳乳液聚合技术的研究进展

采用超临界二氧化碳(ScCO2)作为反应介质进行乳液聚合是高分子材料合成与加工的一种绿色技术,具有无毒无害,聚合反应速率快,产物易分离和高选择性等特点。介绍了ScCO2乳液聚合技术的发展状况及其国外最新进展,指出ScCO2技术与乳液聚合相结合制备高分子合成材料,可避免使用有毒或挥发性有机溶剂、减少环境污染、提高材料性能和简化加工生产工艺,具有广阔的应用前景。     

Effects of supercritical carbon dioxide on waste banana peels for heavy metal removal

The effects of supercritical carbon dioxide (CO₂) on waste banana peels for copper adsorption were evaluated. Supercritical CO₂ was employed both in a solvent extraction for antioxidant compound recovery and in an emerging biomass treatment to increase the subsequent heavy metal-removal step; the latter is termed “explosion with supercritical CO₂”. This lignocellulosic biomass was analyzed before and after being subjected to both processes by scanning electron microscopy and X-ray patterning. Thermal gravimetric and differential scanning calorimetry analyses were performed to understand the different effects of supercritical carbon dioxide employed in these two processes on banana peels. The explosion with supercritical CO₂ process resulted in a more pronounced effect on the vegetable structure. Nevertheless, no increase in the copper-removal capacity was achieved. The adsorption studies showed similar behaviors for fresh and extracted samples, demonstrating that banana peels previously extracted with supercritical CO₂ retained their adsorption capacity for subsequent heavy metal removal.     

超临界CO2在聚合反应中的应用

对超临界CO2在溶液聚合、悬浮聚合、乳液聚合、沉淀聚合、分散聚合等聚合反应中的应用进行了综述。超临界CO2已广泛应用于萃取和生物工程等方面,由于其作为聚合反应介质具有无毒、无污染的特性．在聚合物制备中已得到越来越广泛的重视。     

Cell removal with supercritical carbon dioxide for acellular artificial tissue

BACKGROUND: The objective of this work was to decellularize artificial tissue without using surfactant solutions. For this purpose, supercritical carbon dioxide was used as the extraction medium. RESULTS: Supercritical carbon dioxide containing a small amount of entrainer was a suitable medium to extract both cell nuclei and cell membranes from artificial tissue. Under gentle extraction conditions (15 MPa, 37 °C), cell nuclei were satisfactorily extracted from tissue within 1 h. In contrast, the efficiency of phospholipid removal depended strongly on the transfer rate of carbon dioxide in the interior of the tissue. Mechanical strength of tissue was not decreased even with prolonged treatment. CONCLUSION: Acellular artificial tissues could be prepared quickly by treatment with a carbon dioxide/entrainer system. The prepared acellular tissue could be obtained in absolutely dry condition. This is advantageous from the viewpoint of long‐term preservation without putrefaction and contamination. Copyright © 2008 Society of Chemical Industry