Supercritical Carbon Dioxide Fractionation of Anhydrous Milk Fat

Supercritical carbon dioxide was used to fractionate anhydrous milk fat. Six fractions were produced at 40, 50 and 60 °C using pressure values of 10, 20, 25, 30, 33 and 36 MPa. The fractions were analyzed for fatty acids, thermal behavior, iodine and color values. Composition and yield of fatty acid methyl esters were evaluated at different fractionation conditions in relation to the original milk fat values. Short chain fatty acids (C₄–C₈), medium chain fatty acids (C₁₀–C₁₄) and total saturated fatty acids were decreased from fraction obtained in the order of 10–36 MPa, while long chain fatty acids (C₁₆–C_18:2) and total unsaturated fatty acids were increased. Fractions obtained in the raffinate stage of the fractionation exhibited higher melting behavior that obtained at the low CO₂ pressures. The higher iodine value of raffinate fraction indicated that fraction was richer in oleic acid. Fractions produced at low pressures had lower melting behavior than those obtained at high pressures. Yellowness Index and b* values increased in raffinate fraction due to concentration of carotenoids.     

超临界CO2精密分离技术提纯薄荷脑

进行了利用超临界CO2精密分离技术从薄荷原油中提纯薄荷脑的研究,分别考察了分馏塔温度梯度、升压速率等操作参数对分离效果的影响.结果表明,分离精馏塔内形成一定的温度梯度或在一定的温度梯度下改变升压速度都可以有效改善分离效果,当塔内温度梯度为20℃、升压速率为0.1 MPa·(15 min)-1时,ω(薄荷脑)＞90%,产物产率为80%;对ω(薄荷脑)=90%的产品进行二次分离,可获得ω(薄荷脑)=99.9%的产物.     

Column Fractionation of Canola Oil Deodorizer Distillate Using Supercritical Carbon Dioxide

Semi-continuous column fractionation of canola oil deodorizer distillate using supercritical CO₂ (SCCO₂) was carried out to determine the feasibility of value-added processing of this feed material for the recovery of bioactive components such as sterols and tocopherols and to determine the effect of operating conditions [pressure (20, 25 MPa using a temperature gradient of 70–100 °C), temperature (70, 100 °C) and a linear temperature gradient (70–100 °C at 25 MPa)] on extract yield and separation efficiency. Total extract yield increased significantly (p ≤ 0.05) with pressure, whereas at isobaric conditions (25 MPa) the highest yield was obtained at the lowest temperature tested (70 °C). Fractionation efficiency was reflected in the composition of fractions and was affected by operating conditions. Residue composition was determined by extract yield in addition to selectivity. Use of the thermal gradient (70–100 °C) decreased the content of volatiles, free fatty acids and tocopherols while increasing sterol content significantly (p ≤ 0.05) to a level of 40% (GC area %) in the residue obtained at 25 MPa. The findings indicate the potential of canola oil deodorizer distillate as a source of sterols and warrant further research on the countercurrent column fractionation to improve the separation efficiency.     

超临界CO2及超临界CO2/乙醇中磷脂酰胆碱的溶解度

利用动态法测定了磷脂酰胆碱(PC)在超临界CO2(SC-CO2)及超临界CO2/乙醇体系中的溶解度。在15~30 MPa压力(p)、313~343 K温度(T)条件下,PC在SC-CO2中的溶解度为x1(PC)=10-6~10-5,在SC-CO2/乙醇多元体系中,PC溶解度x2(PC)可提高至10-4。PC的溶解度与c(CO2)(d)、x(CH3CH2OH)(c)呈指数相关性。根据缔合反应规则,建立了质量作用模型x1(PC)=d3.89e(-2383.63/T-41.64)、x2(PC)=d3.17c0.36e(-1748.03/T-33.73),分别关联PC在SC-CO2、SC-CO2/乙醇中的溶解度,模型计算结果与溶解度实验数据较好吻合,关联误差(AARD)分别为4.31%、3.78%。     

超临界二氧化碳染色过程

针对传统水染工艺不能从根本上解决印染行业水环境污染严重及资源消耗、浪费大的问题，介绍了一种全新的清洁生产技术——超临界CO2染色过程，重点分析了超临界流体和超临界CO2染色工艺的特点，阐述了分散染料在超临界CO2中的溶解和扩散特性以及纤维表面结构及其改性在染色过程中的作用，提出了超临界CO2染色技术研究的若干观点。     

超临界二氧化碳反相微乳技术

介绍了微乳形成的原理及结构类型,分析了超临界二氧化碳(SFC)反相微乳的结构特点,及表面活性剂(SAA)、助表面活性剂(CSAA)、pH、离子强度、温度和压力对SFC反相微乳的影响,讨论了SFC反相微乳聚集体结构的分析和测试方法。综述了SFC反相微乳技术在萃取、合成、清洗等方面的应用。引用文献29篇。     

以超临界CO2为介质合成环己烯酮的工艺研究

介绍了一种合成环己烯酮的新方法。以超临界CO2 作为反应介质 ,以含水过氧化物 (CH3 ) 3 COOH作为氧化剂 ,研究了反应温度、反应压力、投料比、反应时间对产品收率的影响。结果表明 ,合成环己烯酮的最佳工艺条件为 :环己烯∶含水过氧化物 =1∶1 4 (摩尔比 ) ;反应压力为 16MPa ;反应温度为 95℃ ;反应时间为 4h ,产品收率可达到 6 0 1% ,经过后处理产品纯度达到 99%以上。     

The Fractional Extraction of Lipids and Cholesterol from Dried Egg Yolk Using Supercritical Carbon Dioxide

Results from extraction of cholesterol and other lipid components from dried egg yolk using supercritical carbon dioxide at the range of temperature from 40°C to 60°C and pressure between 150 bar und 350 bar for 2.5 hours and 2.7 kg CO₂ consumption is described in this paper. The solubility of lipids and cholesterol increased with the increase of pressure at a constant temperature of 50°C, while at a constant pressure, more cholesterol was removed at 45°C than that at other temperatures. Nearly 60 percent cholesterol was removed at 45°C and 250 bar. Lipids were more efficiently extracted at 60°C than at 40°C at 250 and 350 bar, however, a decrease in the total extracted lipids was observed with the increase in temperature at 150 bar. The removed total lipids from dried egg yolk at 250 bar/55°C was over 80 %.     

超临界二氧化碳化学

本文简要介绍了在超临界条件下，二氧化碳化学的新进展，开发研究动向及其发展趋势。     

超临界二氧化碳流体及其主要应用

综述了超临界流体特性、超临界流体的应用及超临界萃取技术。介绍国内外研究的现状，简述超临界技术的发展方向。     

Regeneration of Activated Carbon Loaded with Toluene by Supercritical Carbon Dioxide

Abstract

Activated carbon loaded with toluene was regenerated by supercritical carbon dioxide. The adsorptive capacities after several regeneration cycles were still close to that of virgin carbon and remained stable. The effects of temperature, pressure, and flow rate on regeneration efficiency were studied. It was found that the operations at higher pressures were more favorable for regeneration, but the optimal operating temperature depended on pressure. The interphase mass transfer resistance was insignificant during regeneration. A one-parameter mathematic model assuming linear desorption kinetics is proposed which agrees well with the experimental data. The adsorption rates of activated carbon regenerated by the supercritical regeneration method and the steam regeneration method are compared in this study. It was found that the supercritical regeneration method is superior to the steam regeneration method.     

超临界CO2中的高分子合成研究进展

介绍了超临界二氧化碳的特殊性质，综述了超临界二氧化碳为介质的高分子合成方面的应用进展情况．皿示出超临界二氧化碳是一种对环境无污染且价廉的绿色介质，具有广阔的应用前景。     

超临界二氧化碳分离乙醇水溶液的模拟计算

使用PR状态方程结合Hurou和Vidal提出的局部组成混合规则,较好地预测了CO_2-C_2H_5OH-H_2O三元体系的汽液平衡数据。在此基础上,模拟计算了超临界CO_2分离乙醇水溶液的过程。对萃取塔的特点和工艺条件作了详细的讨论。     

Dealcoholisation of Cider by Supercritical Extraction with Carbon Dioxide

A study of cider dealcoholisation by supercritical extraction with carbon dioxide using pilot-plant-scale equipment has been carried out. The effects of pressure, temperature and solvent to feed ratio have been examined. Supercritical and liquid carbon dioxide have been used to extract ethanol and aromas from cider at pressures of 80–250 bar and temperatures of 20 and 40°C.     

超临界CO2萃取烟草中茄尼醇

研究了萃取时间、解析温度、萃取压力等因素对超临界CO2萃取烟草中茄尼醇萃取率的影响。结合皂化等预处理措施,并通过正交实验得到了提取茄尼醇的最佳工艺条件,即以体积分数90%的乙醇为夹带剂,在萃取压力为35 MPa、萃取温度为50℃、解析温度为40℃时,萃取3 h后,产品茄尼醇质量分数为40.14%,萃取率达到98.53%。     

超临界二氧化碳流体萃取分离技术

超临界流体的扩散系数比一般液体的扩散系数高一个数量级,而粘度要低一个数量级。与液-液萃取系统相比,超临界流体萃取系统具有较快的传质和萃取速度,因此能有效地对固体样品进行萃取分离。常用的超临界流体有乙烯、氙气、一氯三氟乙烷、二氧化碳、乙烷、一氧化二氮、一氟甲烷、丙烷、氨等,应用领域也从早期的天然香料提取扩展到食品、环境保护、农药、烟草、中药等行业,超临界萃取技术越来越受到国际科技届的广泛关注。但该技术应用于工业化生产尚需一定时日,还需要进一步降低操作成本和设备的造价。     

超临界二氧化碳萃取技术

超临界流体萃取(Supercritical Fluid Extraction)技术是一种新型的化工分离技术.本文综述了超临界流体萃取技术的发展.超临界流体的特性,介绍了超临界二氧化碳萃取技术在中草药,食品工业,香料工业和环保技术方面的应用,并对超临界二氧化碳萃取技术的现状和前景进行了分析.     

超临界二氧化碳中反胶束体系的研究方法

在超临界CO2中加入合适的表面活性剂后形成反胶束体系,是一种提高极性、亲水性以及高相对分子质量物质在超临界CO2中溶解性的有效方法。目前对超临界CO2中反胶束的研究主要集中在对其结构信息的研究,就反胶束结构分析测试以及反胶束模型模拟计算的常用方法进行了简要介绍,如动态光散射法(DLS)、小角中子散射法(SANS)、小角X光散射法(SAXS)、核磁共振光谱法(NMR)、Monte Carlo格子模拟法等方法。     

Reaction Calorimetry in Supercritical Carbon Dioxide

Summary: Reaction calorimetry is an efficient tool used to obtain kinetic, thermodynamic and safety data. A reaction calorimeter, RC1e‐HP350, developed in collaboration with Mettler‐Toledo GmbH, allows investigating chemical reactions under supercritical conditions. The main technical difference, compared with a classical liquid system, is that the whole reactor volume is occupied by the media. Heat transfer analysis in supercritical carbon dioxide (scCO₂) by the Wilson plot method shows that the behavior of the internal heat transfer coefficient in scCO₂ is the opposite of the one observed for classical liquid. In scCO₂ the lower the temperature (above the critical point) the better the internal heat transfer coefficient. The evolution of scCO₂ thermodynamical and transport properties near the critical point are responsible for this behavior. The dispersion polymerization of methyl methacrylate in scCO₂, with the polydimethylsiloxane monomethacrylate as stabilizer, is used as a model reaction. A polymerization reaction enthalpy of ?56.9 ± 2.2 kJ · mol^?1 is determined, being in good agreement with previously reported data. The results presented illustrate the accuracy of the heat balance model used and emphasize the potential of reaction calorimetry for the promotion of supercritical fluids technologies.

Technical comparison between liquid and supercritical reaction calorimetry.