分散紫27与分散蓝72在超临界CO2中溶解度的测定

在温度343.15~383.15 K、压力14~22 MPa条件下,采用动态法测定分散紫27、分散蓝72在超临界CO₂中的溶解度。并采用Chrastil半经验模型和AdMST半经验方程对实验结果进行关联,探讨影响分散染料在超临界CO2中溶解度的因素。结果表明:分散紫27在超临界CO₂中的溶解度为2.69×10^-6~7.35×10^-6 mol/mol,压力越高,CO₂密度越大,分散紫27在超临界CO₂中的溶解度越高;随着温度的升高,分散紫27的溶解度先升高后降低;分散蓝72在超临界CO₂中的溶解度为7.17×10^-6~13.38×10^-6 mol/mol,且随着温度的升高而升高,随着压力的升高而升高。     

两种偶氮型分散染料在超临界CO_(2)中溶解度拟合北大核心CSCD

为构建不同染料溶解度数据库,推进超临界二氧化碳(CO_(2))无水染色工业化应用,文章在温度为353.15~393.15 K、压力为12~24 MPa内研究了C.I.分散红54和C.I.分散蓝79的溶解性能。探究了在超临界CO_(2)体系中温度和压力对两种偶氮型分散染料溶解度的影响,并采用Chrastil、Mendez-Santiago-Teja(MST)、Bartle、Kumar-Johnston(K-J)和Sung-Shim(SS)溶解度经验模型进行拟合。结果表明:C.I.分散红54和C.I.分散蓝79的溶解度均随体系压力的升高而增加,5种模型拟合水平(R^(2))均较好;C.I.分散红54的SS模型溶解度拟合精度最好,平均相对偏差(AARD值)为2.88%,能更好地预测实验范围内其溶解度数值;C.I.分散蓝79的Chrastil和SS模型的拟合精度较好,AARD值均为12.92%,能较好地预测染料的溶解度。文章丰富了分散染料溶解度数据库,同时也为染料在超临界CO_(2)中拼色和配色提供了理论指导。     

二氧化碳对啤酒质量的影响及控制措施

二氧化碳是啤酒的重要成分之一,有促进提高啤酒呈味物质的效果,饮用时给人以清爽、刺激的杀口感。1 CO₂的基本性质1)CO₂在水中的溶解性在1个物理大气压下,温度15.5℃时,1体积的水可溶解1体积的CO₂。2)水温与CO₂溶解度的关系在压力不变的情况下,CO₂的溶解度随着水温的下降而增加。反之,则溶解度减少。3)压力与CO₂溶解度的关系:在水温不变的情况下,CO₂的溶解度随着压力的增加而     

苏籽油在超临界CO_2流体中溶解度及其抗氧化性能研究

采用超临界CO_2流体萃取技术分别探讨压力、温度对苏籽油溶解度及得率的影响,利用Chrastil方程对不同萃取条件下苏籽油溶解度进行模型拟合,并利用GC-MS技术对超临界CO_2流体萃取和索氏提取得到的苏籽油进行脂肪酸成分分析,并利用DPPH(1,1-二苯基-2-三硝基苯肼)测定苏籽油的自由基清除能力。结果表明,相同温度下,苏籽油溶解度与得率随压力增大而增大;相同压力下,苏籽油溶解度与得率随温度增大而减小;在313 K,35 MPa条件下,溶解度S最大为16.68 g/L,并得到以温度(T)和CO_2密度(ρ)为相关因素的苏籽油溶解度模型方程;苏籽油中不饱和脂肪酸含量达90%以上,且不同提取方法得到的苏籽油组分差异不大,超临界萃取与索氏提取得到的苏籽油的自由基清除能力的IC_(50)值分别为22.66、27.76 mg/m L。     

孜然精油及其熟制精油的研究

利用超临界CO₂萃取技术提取孜然精油,通过研究原料粒度、萃取压力、萃取温度、萃取时间等因素对孜然油萃取率及品值的影响,确定超临界CO₂萃取最佳工艺参数。另外,采用熟化工艺对孜然原料进行前处理再利用超临界CO₂萃取技术提取,获得具有熟香风味的熟制孜然精油。研究结果表明,超临界CO₂萃取孜然油的最佳工艺参数为:原料粒度30目,萃取压力30MPa,萃取温度60℃,萃取时间2.5h,精油得率约为13.97%,精油中枯茗醛质量分数高达32.75%。熟制孜然精油熟化工艺中最佳焙烤温度为180℃,超临界CO₂最佳萃取条件为原料粒度30目,萃取压力25MPa,萃取温度60℃,萃取时间2.5h,精油得率约为11.38%,精油中枯茗醛质量分数高达31.95%。     

超临界二氧化碳流体中若丹明6G染料溶解度的测定

采用动态流动法测定了荧光染料若丹明6G在超临界CO2流体中的溶解度。实验条件为,压力8．0～24．0MPa,温度308．15和318．15K。结果显示染料的溶解度随着压力的增加而增大,同时也随着温度的升高而增大。还测定了以甲醇为共溶剂条件下的溶解度,甲醇作为共溶剂加入后,显著地提高了染料的溶解度。将实验结果用Chrastil与Sovova模型法进行关联,取得了比较好的关联精度。     

超临界CO2提取葛缕子精油及其成分分析

目的:优化葛缕子精油的提取工艺并对其成分进行分析。方法:以葛缕子籽粒为原料,采用超临界CO₂技术提取葛缕子精油,并通过气相色谱—质谱(GC-MS)对精油挥发性成分进行分析。结果:超临界CO₂提取葛缕子精油的最佳工艺条件为提取釜温度50℃,分离釜温度40℃,提取釜压力30 MPa,分离釜压力0.4 MPa,二氧化碳流速20 g/min,提取时间90 min,此条件下精油得率为4.79%。与同时蒸馏萃取(SDE)法相比,超临界CO₂流体能快速扩散到样品颗粒内部并充分溶解其中的精油成分,具有提取时间短、得率高、无溶剂残留的优点。超临界CO₂法制备的葛缕子精油中,主要成分为D-柠檬烯(50.96%)和香芹酮(46.65%),挥发性成分种类及含量均高于同时蒸馏萃取法的。结论:超临界CO₂法比同时蒸馏萃取法更适合葛缕子精油的提取。     

油酸-甘油-无水乙醇共混体系与超临界CO2的相平衡

旨在为生物柴油后处理阶段的超临界CO₂提纯工艺提供参考数据,以生物柴油生产过程中后处理阶段体系所含的油酸、无水乙醇及甘油为原料,通过在SYLG-01型超临界流体相平衡实验装置中,观察油酸-甘油-无水乙醇共混体系在温度为308 K下与CO₂达到相平衡状态的过程。结果表明,油酸-甘油-无水乙醇共混体系为液-液两相,与CO₂在相平衡实验装置内最开始是气-液-液态,随着压力的增加,当CO₂达到超临界状态时,不同相之间的流动性和传递性增强,共混体系变成了均一态。因此,改变超临界CO₂的压力,有望将体系中的游离脂肪酸和副产物甘油同时萃取分离。     

超临界CO2处理两种红木的工艺研究

通过超临界CO₂对2种红木进行渗透性改善处理,分析不同含水率和超临界CO₂处理工艺对红木渗透性的影响。结果表明,大果紫檀渗透性要高于巴里黄檀,且大果紫檀渗透性受含水率变化的影响更大。超临界CO₂对大果紫檀渗透性改善效果要优于对巴里黄檀的改善效果。其中,大果紫檀的合适处理工艺条件为处理压力40 MPa,处理温度为60℃,时间为70 min;巴里黄檀的合适处理工艺条件为处理压力20 MPa,温度为40℃,处理时间为70 min。     

超临界CO2逆流萃取分离鲜花椒树脂中挥发油工艺研究

通过单因素及正交试验确定了超临界CO₂逆流萃取鲜花椒树脂挥发油的可行性,并得到了最佳萃取条件及分离条件,其最适萃取条件为萃取时间7 h、萃取温度45℃、CO₂流量600 L/h、萃取压力20 MPa。萃取后的挥发油最适分离条件为分离器Ⅰ压力11 MPa、温度40℃,分离器Ⅱ压力5~6 MPa(由气源决定不可调)、温度55℃,可高效地从鲜花椒树脂中分离出2种香气不同的挥发油。     

分散染料在超临界二氧化碳流体中的溶解性

为更好地筛选适用于超临界二氧化碳(ScCO2)流体染色的分散染料,使用状态方程结合基团贡献法和计算化学法,得到不同工况条件及不同染料结构对分散染料在超临界CO2流体中溶解度的影响规律,建立了分散染料在超临界CO2流体中溶解度预测方法.结果表明:不同工况条件会影响分散蓝79染料的溶解度,其中较低的温度和较高的压力对溶解过...     

C.I.分散棕19在超临界CO2及水中溶解性的分子动力学模拟

为探究分散染料在超临界CO₂和水中各自染色条件下的溶解性,基于分子动力学模拟,采用热力学积分方法分别计算了C.I.分散棕19在2种溶剂中的溶解自由能和结合自由能,并采用平均非键相互作用方法分析了C.I.分散棕19染料分子与2种溶剂分子间的弱相互作用类型及稳定性。模拟结果表明:C.I.分散棕19染料分子在超临界CO₂(24 MPa,130 ℃)和水(0.25 MPa,130 ℃)中的自由能绝对值均较小且相差不大,但其在超临界CO₂中的溶解自由能绝对值稍小,结合自由能绝对值稍大;C.I.分散棕19染料分子与2种溶剂分子间均只存在较弱且不稳定的范德华色散作用,但其与超临界CO₂分子间的弱相互作用相对于水更不稳定。     

活性分散黄染料对涤纶/棉混纺织物的超临界CO2同浴染色

为解决涤纶/棉混纺织物水浴染色能耗大、水污染严重的技术难题,并拓宽超临界CO₂染色技术的应用范围,研究了活性分散黄染料对涤纶/棉混纺织物在超临界CO₂流体中的染色性能。分析了染色温度、压力、时间、助剂用量和CO₂流速对涤纶/棉混纺织物染色效果的影响,得到最佳染色工艺条件:染色温度为100 ℃,压力为20 MPa,染色时间为80 min,CO₂流量为20 g/min,二甲基亚砜质量分数为80%。结果表明:与天然染料相比,利用活性分散黄可以显著提升涤纶/棉混纺织物的染色深度和色牢度;同时,二甲基亚砜处理与“乙醇助溶剂+N-甲基吡咯烷酮(NMP)预处理”法相比,K/S值提升了2倍以上,色牢度达到4~5级,获得了较好的染色效果。     

Mathematical modelling of soybean oil solubility in supercritical carbon dioxide

The solubility of soybean oil in supercritical carbon dioxide has been determined in the pressure range of 100–300 bar and in the temperature range of 313–323 K. The obtained values (from 0.0005 to 0.02055 g L^?1) have been correlated using four different empirical equations proposed correspondingly by Chrastil, del Valle and Aquilera, Adachi and Lu and Sparks et al. Since the Sparks et al. equation provided the lowest average absolute relative deviation (AARD) (10.25%) than other models in the examined experimental range, a modified equation of Sparks et al. model was developed for predicting the solubility of soybean oil in supercritical carbon dioxide as a function of temperature and density. An improved equation showed the lowest deviation (2.15%) between experimental data than the other empirical equations considered in this study. The proposed equation was also applied for correlating the solubility of linoleic acid (AARD was 2.40%).     

The solubility of apricot kernel oil in supercritical carbon dioxide

The solubility of kernel oil from apricots (Prunus armeniaca L.) in supercritical carbon dioxide at 313.15, 323.15 and 333.15 K and at 15, 30, 45, 52.5 and 60 MPa was determined. Appropriate models were fitted to the data and the crossover pressure of apricot kernel oil was found to be between 20 and 30 MPa. Crossover pressure is a pressure value at which the effect of temperature on the solubility changes. Solubility increased as the temperature increased above the crossover pressure but decreased when temperature increased below the crossover pressure. It increased with an increase in pressure over all of the temperature range. The solubility data were well represented by models based on density but the best was found to be the Adachi & Lu equation. An empirical model that did not require density data for CO₂ was proposed to relate solubility to temperature and pressure and it was found equally successful to the Adachi & Lu equation.     

Solubility and absorption rate of carbon dioxide into non-respiring foods. Part 3: Cooked meat products

The solubility and diffusion of carbon dioxide into cooked meat products (cooked ham and meat sausage with different pH-levels) was determined at different starting pressures and gas to product volume ratios by monitoring pressure changes over time in a closed chamber at constant temperatures (0, 4, and 8 °C). Good correlation of the CO₂ solubility between the packaging parameters (gas to product volume ratio and initial partial pressure) and the meat products water content was found. The solubility of CO₂ followed Henry’s law and the initial partial pressure of CO₂ influenced the solubility mostly. Only small variations in the diffusion constants and absorption rates were found within the experimental design. A pH difference of 0.5 in the two meat sausage types did not influence either solubility or diffusion significantly.     

Extraction of Poppy Seed Oil Using Supercritical CO2

ABSTRACT: Extraction of poppy seed oil with supercritical carbon dioxide (SC-CO₂) was performed and the effect of extraction conditions on oil solubility and yield as well as oil composition was evaluated. Within the temperature (50 to 70 °C) and pressure (21 to 55 MPa) ranges studied, 55 MPa/70 °C gave the highest oil solubility (24.1 mg oil/g CO₂) and oil yield (38.7 g oil/100g seed). Fatty acid composition of the oil obtained with SC-CO₂ at 55 MPa/70 °C was similar to that of petroleum ether-extracted oil ( p > 0.05) with linoleic acid making up 69.0 to 73.7% of fatty acids. Tocol content of the SC-CO₂-extracted oils varied from 22.37 to 33.35 mg/100 g oil, which was higher than that of petroleum ether-extracted oil (15.28 mg/100 g oil). Poppy seed oil may have potential in the rapidly growing specialty oil market.     

亚麻粗纱的超临界CO2煮漂工艺

针对亚麻粗纱传统煮漂工序的高耗水和环境污染问题,利用超临界CO₂代替水介质对亚麻粗纱进行煮漂。系统研究了复配生物酶(木聚糖酶和纤维素酶)质量分数、温度、压力和时间对亚麻粗纱白度的影响,并利用响应面分析法对粗纱煮漂工艺条件进行优化,通过Box-Behnken中心组合实验和响应面法研究了自变量及其交互作用对白度的影响,得到粗纱白度的二次多项式回归方程的预测模型。确定了亚麻粗纱超临界CO₂煮漂最佳工艺条件:复配生物酶质量分数为3%,温度为50 ℃,压力为13 MPa,时间为60 min。在最优工艺条件下,超临界CO₂煮漂亚麻粗纱与原样相比,白度达到40.8%、残胶率为16.68%、断裂强度为17.12 cN/tex、断裂伸长率为4.23%、分裂度为1 072 Nm。与传统煮漂效果相比,超临界CO₂煮漂工艺仍存在一定差距,需进一步提高。