共查询到19条相似文献，搜索用时 156 毫秒
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研究了大学物理化学实验中产生的异丙醇-环己烷废液的回收利用方法.先以水为萃取剂,对异丙醇-环己烷混合物进行萃取分离,得到粗环己烷和异丙醇水溶液,粗环己烷经精馏提纯,得到纯度为99.80%环已烷产品;异丙醇水溶液经恒沸精馏得纯度为99.55%异丙醇. 相似文献
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研究物理化学实验异丙醇-环己烷废液的回收提纯方法,先以水为萃取剂,对异丙醇-环己烷混合物进行萃取分离,得到粗环己烷和异丙醇水溶液,经精馏提纯得到纯环己烷和含有少量环己烷的异丙醇,环己烷精制后纯度达99．3％～99．67％,收率69．5％,萃取后的异丙醇水溶液经精馏脱水后可以制成无水异丙醇,纯度达98．42％,一次性收率在67．02％． 相似文献
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赵若冬 《兰州石化职业技术学院学报》2006,6(1):3-4
采用氯乙酸和碳酸钠反应生成氯乙酸钠,控制氯乙酸钠溶液PH值为8～9,在70～75 ℃下与等摩尔硫代硫酸钠反应生成Bunte盐,加入反应物重量10%的硫酸,控制温度为80～90 ℃,时间为80min进行酸化反应;再加入反应物重量2%的Zn粉在40～50 ℃下还原80min,得到粗产品;萃取、精馏后巯基乙酸纯度可达98.6%,收率可达到89.7%. 相似文献
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研究以天然β-蒎烯为原料经化学合成制得紫苏醛。采用乙腈为介质,以氯化亚铜-苯甲酸铜为催化剂,β-蒎烯与过氧化苯甲酰在65±2℃反应16h,得到的紫苏醋酸酯进一步水解、水汽蒸馏得粗品,减压精馏得纯度为96%的紫苏醇,收率为73%;紫苏醇在二氯乙烷中,用K2S2O8-NaOH-H2O,在40℃催化氧化反应9h,经酸化、静置分层、水洗、干燥、回收溶剂后得紫苏醛,GC分析含量91.2%,收率85.5%。合成紫苏醛的总收率62%(以-β蒎烯计)。经分析测试证明产物与文献报道值相符。 相似文献
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以酸化油水解废水经过脱酸、脱胶等预处理后得到的粗甘油为原料,采用Aspen plus软件对减压精馏过程进行模拟优化,除去粗甘油中含有的有机、无机杂质。模拟显示对应的甘油纯度可以达到99.9%,水的去除率为99.99%。减压精馏后得到的甘油为淡黄色液体,为了得到无色透明的纯净甘油用活性炭对甘油进行脱色,通过正交实验得出影响100目活性炭脱色率的主次因素为:脱色时间>脱色温度>活性炭用量,最佳脱色时间为70min,最佳的脱色温度为80℃,最佳活性炭用量为甘油含量的1.0%。在此条件下,粗甘油的平均脱色率可达91.87%。 相似文献
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利用N-甲基甲酰胺（NMF）作萃取剂,萃取精馏分离醋酸和水混合物。利用Aspen Plus流程模拟软件对分离过程进行了模拟计算,确定了理论板数、加料板位置、回流比、加料比等最佳工艺条件及工艺参数。结果表明,利用NMF作萃取剂可以较好的实现醋酸和水的分离,醋酸的纯度可达99.94%,萃取剂可以循环利用;与普通精馏法相比,相同分离任务下,萃取精馏工艺的再沸器热负荷降低了60.4%,生产每吨醋酸再沸器消耗蒸汽量由7.1吨降低到2.8吨。说明萃取精馏法分离醋酸和水优于普通精馏法,节能效果明显,为工业化装置提供了重要的理论依据和设计参考。 相似文献
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以氯仿为萃取剂,选取UNIQUAC相平衡模型,以ASPEN PLUS过程模拟软件对采用萃取-精馏技术回收废水中N,N-二甲基酰胺（DMF）的过程进行模拟计算;讨论了萃取过程的萃取级数、萃取比及精馏过程的回流比、塔板数和进料位置变化对回收过程的影响,优化了DMF废水回收过程中的主要工艺参数;同时对萃取-精馏与普通精馏技术的能耗进行了比较,萃取-精馏技术节约能耗可达80%。 相似文献
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《实验室研究与探索》2017,(2):76-79
采用过程工程的序贯模块法设计并组建了乙二醇连续萃取精馏乙醇-水恒沸物系的实验装置。由UNIQUAC活度系数模型预测汽液相平衡,结合萃取传质动力学MESHRF模型优化设计精馏塔,采用θ环填料和透明塔体组装成溶剂回收、精馏和提馏三段式连续萃取精馏实验装置,将萃取精馏和萃取剂回收双塔流程优化为单塔流程,以便于学生可独立设计和操作。实验结果表明:所研制教学装置能实现恒沸物系的萃取精馏分离,99%乙醇收率达91.6%,萃取剂回收率94.3%。 相似文献
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Azeotropic liquid mixture cannot be separated by conventional distillation. But extractive distillation or combination of the two can be valid for them. An experiment to separate benzene and cyclohexane by batch extractive distillation was carried out with N,N-dimethylformide (DMF), dimethyl sulfoxide (DMSO) and their mixture as extractive solvent. The effect of the operation parameters such as solvent flow rate and reflux ratio on the separation was studied under the same operating conditions. The results show that the separation effect was improved with the increase of solvent flow rate and the reflux ratio; all the three extractive solvents can separate benzene and cyclohexane, with DMF being the most efficient one, the mixture the second, and DMSO the least. In the experiment the best operation conditions are with DMF as extractive solvent, the solvent flow rate being 12.33 mL/min, and the reflux ratio being 6. As a result, we can get cyclohexane from the top of tower with the average product content being 86.98%, and its recovering ratio being 83.10%. 相似文献
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三种方法提取八角茴香精油及其抗菌活性研究 总被引：1，自引：0，他引：1
八角茴香精油及其单体成分具有多种生物活性,广泛应用于食品防腐领域.本文采用三种方法提取八角茴香精油,比较得出最优提取方法,并以大肠杆菌、金黄色葡萄球菌、枯草杆菌等作为供试菌种,对精油的抗菌效果、精油抗菌的稳定性进行了研究.结果表明,采用水蒸气蒸馏法提取八角茴香精油的最佳条件为:原料粉碎程度40目,料液比为1∶10,蒸馏2h,得率为9.194%;采用超临界CO2萃取法提取八角茴香精油的最佳条件为:压力为2000PSI、温度为30℃、萃取2.5h,得率为4.5%.乙醇回流法提取八角茴香精油最佳工艺条件为:料液比为1:10(g/mL),回流次数为3,回流时间为3h,得率最高可达34.52%;乙醇浸提法提取八角茴香精油最佳条件为:料液比1∶20(g/mL),浸提时间3h,粉碎程度60目,最高得率为20.38%.精油对大肠杆菌的抑制效果最好,其次是酵母. 相似文献
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为研究生姜精油的提取及对大肠菌群的影响作用,通过对提取时间、提取剂用量和浸泡时间做单因素试验,再以精油提取率为评判指标进行正交优化,确定了索氏提取法和常压蒸馏法的最佳提取条件。以抑菌圈直径为判定指标测定所提取的精油对大肠菌群的影响。结果表明：索氏提取法提取生姜精油的最优提取条件为提取剂用量12 mL/g,提取时间3.0 h和提取温度50℃;常压蒸馏法提取生姜精油的最优提取条件为提取剂用量20 mL/g,浸泡时间1.0 h和提取时间3.0 h。索氏提取法提取的生姜精油对大肠菌群的抑菌圈平均直径为73.66 mm;常压蒸馏法提取的生姜精油对大肠菌群的抑菌圈平均直径为25.48 mm。索氏提取法提取出的精油树脂抑菌效果好于常压蒸馏法提取的生姜精油的抑菌效果。 相似文献
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Ming-mei Liu Bin Qi Zheng-xu Liu Jin-shun Zhan Kang Zhan Guo-qi Zhao 《Journal of Zhejiang University. Science. B》2017,18(10):878-885
The aim of this study was to optimize the conditions for the extraction of low-abundance proteins (LAPs) and the removal of abundant proteins (APs; β-conglycinin and glycinin) from soybean meal. Single factor and orthogonal experiments were designed to determine the effects of four factors (isopropanol concentration, total extraction time, ultrasonic power, and ultrasonic time) on protein concentration in isopropanol extracts. Proteins in the isopropanol supernatant and the cold acetone precipitate of isopropanol were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). The results showed that the optimal conditions were 50% isopropanol, ultrasonic pretreatment for 15 min at 350 W, and a total extraction time of 1 h. Under these conditions, the protein concentration in the isopropanol extracts reached 0.8081 g/L. Many LAPs were detected, including β-amylase, soybean agglutinin, soybean trypsin inhibitor, fumarylacetoacetase-like, phospholipase D alpha 1-like, oleosin, and even some unknown soybean proteins. The soybean APs (β-conglycinin and glycinin) were not found. The method may be useful for discovering new soybean proteins and extracting enough LAPs of soybean to allow further studies of their physiological effects on animals without the influence of APs. 相似文献
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The pulse-control operation technique which alternates between total reflux operation and total efflux operation in batch distillation was studied along with the minimum amount of slop cut. Total reflux time was confirmed by dynamic simulation, and total efflux time was adopted by statistic method. For the mixture of hexane and cyclohexane and the traditional constant reflux ratio operation strategy, the amount of slop cut is 1.8-2.1 times of the minimum amount of slop cut; whereas for the pulse-control operation strategy, it is 1.2-1.4 times of the minimum amount of slop cut. So compared with the traditional constant reflux ratio operation, the pulse-control operation can decrease the amount of slop cut and operation time, and meanwhile, enhance separation efficiency and yield. 相似文献
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以茶叶籽为原料,采用超临界CO2萃取得到茶叶籽油,通过分子蒸馏富集提取茶叶籽油中抗氧化成分,并采用UHPLC-TOF-MS分析其组成。结果表明,CO2流速对萃取速率影响较大,采用超临界CO2梯度萃取的模式,不同萃取阶段得到的茶叶籽油的酸价存在一定规律,在萃取初期,茶叶籽油的酸价较高,随着萃取过程的进行,酸价逐渐降低,说明游离脂肪酸更容易溶解在超临界CO2中。茶叶籽油分子蒸馏馏出物中主要的抗氧化成分包括：山茶甙C,表儿茶素没食子酸酯,表阿福豆素,表儿茶素及表没食子儿茶素等5种。 相似文献
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生物样品中短链脂肪酸提取测定及其应用进展 总被引：2，自引：0，他引：2
综述了不同样品（尿液、血液、生物培养液等）中短链脂肪酸的测定方法,讨论了气相色谱、高效液相色谱、毛细管电泳、原子吸收分光光度测定方法的优缺点,并讨论了短链脂肪酸在营养生理、疾病以及肠道菌群中的应用研究进展. 相似文献