异丙醇-环己烷萃取精馏过程模拟与优化

利用化工流程模拟软件Aspen Plus对异丙醇-环己烷共沸物系的双塔连续萃取精馏过程进行了模拟计算与优化。首先根据溶剂相似相溶原理,先初选出糠醛和硝基苯作为备选溶剂,再通过汽液平衡试验及ChemCAD模拟筛选,确定糠醛为最适宜溶剂,选择NRTL模型作为物性方法,使用RadFrac模块进行模拟计算,并利用灵敏度分析模块对各工艺参数进行优化。结果表明,最适宜工艺方案为：萃取精馏塔理论塔板数为30,原料在第26块板进料,溶剂在第12块板进料,物质的量回流比为1.8,溶剂质量比为3∶1;溶剂回收塔理论板数为15,进料位置在第10块板,物质的量回流比为1.0。分离效果可达到环己烷质量分数为99.74%,异丙醇质量分数为99.61%。模拟和优化结果为分离过程的优化操作和设计提供了依据。     

液液萃取分离乙酸甲酯与甲醇水溶液的模拟计算

设计了乙酸甲酯和甲醇水溶液错流萃取分离工艺,通过实验确定了以甘油和水的复合溶液作为分离乙酸甲酯和甲醇水溶液的最佳萃取溶剂。以UNIQUAC方程为计算活度系数的模型,采用色谱法测定了甲醇在甘油中的无限稀释活度系数,并利用单参数法计算UNIQUAC方程中的模型参数。采用相分配系数和物料守恒方程模拟错流萃取分离过程,建立了模拟计算程序框图。将模拟值和实验值进行比较,相对误差仅为0.01%。模拟结果表明:在理论级数N=3时,经过一次萃取乙酸甲酯质量分数可达99.7%以上,收率达97.0%,此结果为进一步研究提供理论依据。     

反应精馏和液液萃取结合合成二甲氧基甲烷

以对甲苯磺酸为催化剂,以甲醇、甲醛为原料,采用反应精馏合成二甲氧基甲烷,二甲氧基甲烷的质量分数达到92%以上;采用液液萃取法对产物进一步提纯,研究液液萃取过程中,转速、搅拌时间、静置时间、溶剂比等因素对分离过程的影响,二甲氧基甲烷的收率可以达到90%以上;经一级萃取,二甲氧基甲烷的纯度可达到97%以上,二级萃取纯度可达到99.3%以上,萃取剂经处理,可循环使用;并对结果进行关联,关联和实验结果平均相对误差均小于1%,其结果为进一步放大实验研究提供依据。     

连续液-液萃取法制备高含量液体姜辣素

以超临界二氧化碳萃取所得的姜树脂为原料,采用连续液-液萃取法进行分离提纯,高效制备高含量液体姜辣素。考察了萃取时间、溶剂与溶质质量比、萃取溶剂流量、萃取温度等对产物姜辣素、 6-姜酚含量及收率的影响。结果表明,以80%乙醇水溶液为溶剂,姜树脂为溶质,溶剂与溶质的质量比为6∶1;正己烷为萃取溶剂,萃取溶剂流量为1.0 L·h-1,萃取温度为30℃,萃取时间为3 h,此条件下萃取结果最好,可将姜辣素含量从50.29%提高至83.59%,对应6-姜酚的含量从34.77%提高到68.62%,姜辣素和6-姜酚的收率分别达90.96%和86.01%。     

双水相萃取分离稻壳黄酮的工艺研究

以浓缩后的稻壳粗提液为原料,采用乙醇/硫酸铵双水相体系对稻壳黄酮分离纯化,以确立双水相萃取稻壳黄酮的工艺参数。通过单因素试验法探讨了硫酸铵质量分数、乙醇质量分数、粗提液加入量、温度、pH值对稻壳黄酮萃取效应的影响,并以萃取率为考察指标,正交实验法优选出最佳萃取工艺条件。结果表明,在自然pH值及45℃条件下,当乙醇质量分数为29%、硫酸铵质量分数为18%、粗提液加入量为3m L时,稻壳黄酮萃取率达96.26%。此法条件温和,操作简便,可作为从稻壳粗提液中分离纯化稻壳黄酮的一种有效手段。     

萃取法分离提取深层富钾卤水中的硼

采用溶剂萃取法分离提取江陵凹陷深层富钾卤水中的硼,研究了萃取剂种类、体积分数、萃取时间、萃取相比、反萃剂体积分数、反萃相比和反萃时间等因素对萃取和反萃取的影响。结果表明:2-乙基-1,3-己二醇是较合适的硼萃取剂;在以体积分数为15%的2-乙基-1,3-己二醇、35%异辛醇的混合醇为萃取剂,50%磺化煤油为稀释剂,萃取相比为1∶1,萃取时间为15min的条件下,硼单级萃取率达95%以上,实现了硼与卤水中钾、钠、钙和镁的有效分离;在反萃剂NaOH浓度为0.625mol/L,反萃相比为2.5∶1,反萃时间为15min的条件下,硼单级反萃率达94%;最优的反萃取条件在确保反萃率较高的同时,提高了反萃液中B2O3质量浓度,由原料的8.33g/L富集到反萃液的19.10g/L,有助于后续硼酸蒸发浓缩阶段能耗的降低。     

错流萃取分离二乙氧基甲烷与乙醇的模拟及实验研究

设计了二乙氧基甲烷和乙醇水溶液的错流萃取分离工艺,实验确定了以多元醇和水为复合萃取溶剂分离二乙氧基甲烷-乙醇体系适宜的比例.采用相分配系数法对该过程进行了模拟计算及萃取实验.实验及模拟结果表明:当原料与2种溶剂进料体积比为1:1:1时,经过3级错流萃取分离后,萃余相中二乙氧基甲烷质量分数可达99.9%,收率达99.0%...     

错流萃取糠醛水溶液溶剂比的研究

本文研究了原料／溶剂（体积比）对错流萃取糠醛的影响，通过四级错流萃取试验并采用相分配系数法用UNIQUAC模型进行模拟计算，确定以溶剂比2．5：1错流萃取糠醛较合适，且模拟计算结果与试验结果误差较小。     

水中1,1,1-三氯乙烷的三种去除工艺方法

该文对水中1,1,1-三氯乙烷的三种去除方法进行了研究。结果表明曝气吹脱能有效去除水中1,1,1-三氯乙烷。当初始浓度为14 mg/L时,曝气流量越大,去除率越高,在固定的曝气流量下,曝气时间越长,去除效果越好,当曝气时间达到35 min时去除率达到100%;当气水比为3.5时,剩余污染物浓度可以满足国标限值要求;在相同的曝气流量下,1,1,1-三氯乙烷去除效果随着温度的升高而增大;pH值对1,1,1-三氯乙烷去除无影响。水源水条件下,当1,1,1-三氯乙烷初始浓度为1 mg/L、粉末活性炭投加量为20 mg/L、吸附时间为120 min时,1,1,1-三氯乙烷吸附达到平衡,30 min去除率达42%。1,1,1-三氯乙烷初始浓度为5 mg/L,煮沸,2 min后即可达到国标限值以下,5 min后去除率可达80%。     

多级错流液液萃取法分离醋酸水溶液的研究

以醋酸正丙酯—正丙醇—NaCl的复合溶液为萃取剂,采用多级错流液液萃取法对醋酸水溶液进行分离。考察了静置时间、溶剂比及萃取级数对分离效果的影响。实验结果表明:当静置时间为60 min,溶剂比(S/F)为3∶1时,经过三级错流液液萃取后,萃余相中醋酸的质量含量为0.54%。文章研究结果为进一步研究提供了基础数据。     

Liquid–liquid equilibrium extraction of ethanol with mixed solvent for bioethanol concentration

The extraction of ethanol with the solvents of aldehydes mixed with m-xylene was studied for the bioethanol concentration process.Furfural and benzaldehyde were selected as extraction solvents,with which the solubility of water is small,expecting large distribution coefficient of ethanol.The liquid–liquid two-phase region was the largest with m-xylene solvent,followed by benzaldehyde and furfural.The region of two liquid–liquid phase became larger with the mixed solvent of m-xylene and furfural than that with furfural solvent.The NRTL model was applied to the ethanol–water–furfural–m-xylene system,and the model could well express the liquid–liquid equilibrium of the system.For any solvent used in this study,the separation selectivity of ethanol relative to water decreased as the distribution coefficient of ethanol increased.The separation selectivity with m-xylene was the largest among the employed solvents,but the distribution coefficient was the smallest.The solvent mixture of furfural and m-xylene showed relatively high distribution coefficient of ethanol and separation selectivity,even in the higher mass fraction of m-xylene in the solvent phase.The ethanol extraction with a countercurrent multistage extractor by a continuous operation was simulated to evaluate the extraction performance.The ethanol content could be concentrated in the extract phase with relatively small number of extraction stages but low yield of ethanol was obtained.     

萃取精馏分离苯-环己烷-环己烯的二元混合溶剂研究

采用N,N-二甲基乙酰胺(DMAC)、N-甲基吡咯烷酮(NMP)和γ-丁内酯萃取分离苯-环己烷-环己烯近沸程物系,考察了3种单一溶剂的分离性能,数据表明DMAC性能相对更优。在此基础上,研究了以DMAC为基础溶剂,NMP和γ-丁内酯为助溶剂的二元混合溶剂对苯-环己烷-环己烯物系的分离性能,结果表明:混合溶剂提高了从环己烷-环己烯中萃取分离苯的能力,但增大了从环己烷中分离环己烯的难度。当NMP和γ-丁内酯在二元混合溶剂中的质量分数分别为10%和25%时,其分离性能优于单一溶剂,整体分离效果也达到最优。     

萃取精馏分离丙酮-四氢呋喃的研究

为了分离丙酮-四氢呋喃共沸混合物,研究了萃取精馏在丙酮-四氢呋喃物系中的应用。通过溶剂选择原理初选出乙苯作为萃取精馏分离此共沸物系的溶剂,同时采用NRTL模型对常压下丙酮-四氢呋喃物系和加入溶剂乙苯后的汽液平衡进行模拟和实验验证,模拟结果与实验数据吻合较好。然后进行了间歇萃取精馏分离此共沸物的实验研究来进一步考察所选萃取剂的效果。结果表明:乙苯能够消除丙酮-四氢呋喃共沸物系的共沸点,采用有40块理论板的填料塔,回流比为5,溶剂摩尔比为2.5∶1时塔顶可以得到质量分数为99.34%的丙酮产品,说明采用乙苯作萃取剂分离丙酮-四氢呋喃共沸物是可行的。最后又对连续和间歇萃取精馏分离丙酮-四氢呋喃共沸物的流程进行了模拟,得到的工艺参数将为进一步的工业应用提供了理论依据。     

SEPARATION OF TAXANE COMPOUNDS BY LIQUID-LIQUID EXTRACTION

Experimental and numerical studies on liquid-liquid extraction of taxane compounds that are extracted from yew needles by solid-liquid extraction are carried out. In the treatment, the materials are classified to three components, and separation of component C from components A and B is discussed. In experiments, distribution coefficients and selectivities of those components are measured with various solvents. Based on the experimental results, numerical simulation of the countercurrent multistage liquid-liquid extraction process for separating the components is carried out with various operating conditions. Then, the fractional countercurrent multistage liquid-liquid extraction process is examined, and the effect of reflux operation on separation performance of the fractional liquid-liquid extraction process is studied. Based on the numerical results, it is found that the fractional countercurrent multistage liquid-liquid extraction with reflux is superior to the other extraction processes for separating taxane compounds.     

SEPARATION OF TAXANE COMPOUNDS BY LIQUID-LIQUID EXTRACTION

Experimental and numerical studies on liquid-liquid extraction of taxane compounds that are extracted from yew needles by solid-liquid extraction are carried out. In the treatment, the materials are classified to three components, and separation of component C from components A and B is discussed. In experiments, distribution coefficients and selectivities of those components are measured with various solvents. Based on the experimental results, numerical simulation of the countercurrent multistage liquid-liquid extraction process for separating the components is carried out with various operating conditions. Then, the fractional countercurrent multistage liquid-liquid extraction process is examined, and the effect of reflux operation on separation performance of the fractional liquid-liquid extraction process is studied. Based on the numerical results, it is found that the fractional countercurrent multistage liquid-liquid extraction with reflux is superior to the other extraction processes for separating taxane compounds.