实验室乙醇-环已烷废液的回收与利用

研究了大学物理化学实验中产生的乙醇-环己烷废液的回收利用方法。以水为萃取剂,萃取分离乙醇和环己烷,得到乙醇水溶液和粗环己烷。粗环己烷经精馏提纯,得到纯度为99．91％的纯品;乙醇水溶液经分馏、CaO脱水后得无水乙醇,纯度达99．74％。回收的环己烷、无水乙醇可再用于物理化学实验。     

异丙醇-环己烷共沸物的分离与节能工艺研究

应用化工过程模拟软件Aspen Plus对异丙醇-环己烷最低共沸物系的连续萃取精馏过程进行了模拟与优化。通过Radfrac模块比较了不同萃取剂在相同条件下的分离效果,筛选出最佳萃取剂为乙二醇。运用灵敏度分析工具确定了最优工艺参数。采用双塔差压工艺进行节能改造,节能7.06%,异丙醇的纯度达99.96%,环己烷的纯度达到99.98%;萃取剂乙二醇的循环补充量为0.4741kg·h-1。     

4,4'-二羟甲基联苯的提纯工艺研究

采用对索式萃取、超声提取和溶液结晶等三种分离提纯4,4＇-二羟甲基联苯的工艺进行了对比实验,确定了合适的分离提纯工艺。并采用单因素实验优化了分离提纯的工艺条件。结果表明产品的纯度达到99.2％,产品收率81．62％。     

丙酮一步法生产MIBK装置的副产物精馏分离研究

针对丙酮一步法生产MIBK装置的副产物（丙酮、异丙醇、水、MIBK混合物）,采用间歇精馏分离得到纯度〉98％的丙酮、纯度〉99％的异丙醇和水恒沸物、纯度〉90％的MIBK。对分离得到的纯度〉99％的异丙醇和水恒沸物用乙二醇作为萃取剂进行萃取精馏分离得到纯度99．5％异丙醇,同时减压精馏回收乙二醇。     

加盐萃取精馏分离环己烷-四氢呋喃的研究

进行了环己烷-四氢呋喃物系的加盐萃取精馏实验研究。将NaSCN、NANO3、KI三种盐溶于N,N-二甲基甲酰胺中进行加盐汽液平衡实验,实验表明NaSCN能最大限度地提高体系的相对挥发度．NaSCN的适宜质量分数为8％-13％;进行了间歇加盐萃取精馏分离环己烷-四氢呋喃的工艺研究．结果表明NaSCN质量分数为13％,溶剂比为1：1,溶剂流率为10mL／min为适宜的实验操作条件。     

ω-腈基十一酸的分离提纯工艺研究

以ω-腈基十一酸(11-CUA)的收率及纯度为目标函数,对三种分离提纯1,1'-过氧化双环已胺裂解所得油水混合物中的11-CUA的工艺进行了对比实验,确定了合适的分离提纯工艺,采用单因素实验与正交试验优化了分离提纯的工艺条件.实验结果表明,合适的分离提纯工艺为:先将裂解产物用氨水(或氨气)氨化、有机溶剂萃取,然后用硫酸(或盐酸)酸化11-CUA铵盐水溶液、再将粗品11-CUA于合适介质中结晶,得到高纯度11-CUA晶体;优化工艺条件为:氨化pH值8.0～10.0、温度25～35 ℃,甲苯为萃取剂,酸化pH值1.5～2.0、温度55～60 ℃,环己烷为结晶介质,粗品11-CUA在环己烷中溶解温度50～55 ℃、与环己烷初始质量比4∶100、结晶前沉降分层时间10 min、结晶温度20℃.采用上述工艺及工艺条件分离提纯11-CUA,产品纯度达99.90%、收率90.22%.     

异丙醇装置副产二异丙醚精制过程模拟研究

对异丙醇装置副产二异丙醚的分离提纯工艺进行模拟与优化,以水作为萃取剂,基于NRTL模型,使用Aspenplus化工模拟软件的Extract和Radfrac模块进行萃取和精馏模拟,并利用灵敏度分析工具对精馏塔工艺参数进行优化。结果表明,以水做萃取剂再经过精馏工艺提纯二异丙醚是可行的。优化得到最佳工艺参数为精馏塔为30块塔板,原料进料位置在第11块。质量回流比为1．5,精馏塔底二异丙醚纯度可达99．99％,模拟和优化结果对工业化设计和生产具有重要的指导意义。     

加盐萃取精馏分离苯-环己烷

测定不同萃取剂和盐对苯-环己烷共沸物相对挥发度的影响,研究不同质量分数的盐和萃取剂与原料液体积比对苯-环己烷体系相对挥发度的影响以及萃取剂加入速率和回流比对加盐萃取精馏的影响,按实验确定的最佳工艺条件进行重复实验。结果表明:采用N,N-二甲基甲酰胺(DMF)作为萃取剂,加入质量分数为15%的KAc,萃取剂与原料液体积比为0.75,萃取剂加入速率为6 mL/min,回流比为3,可得到纯度大于98%的环己烷。与常规萃取精馏相比,加盐萃取精馏所需萃取剂与原料液体积比小,所得环己烷的纯度较高。塔底釜液经减压精馏,可得质量分数大于99.5%的苯和苯质量分数小于0.15%的加盐萃取剂。     

离子液体萃取精馏分离乙醇-环己烷共沸物

在0.101 MPa压力下,测定了不同离子液体对乙醇-环己烷共沸物相对挥发度的影响,研究了溶剂比(萃取剂与原料液体积比)对体系相对挥发度、离子液体加入速率和回流比对萃取精馏的影响,按实验确定的最佳工艺条件进行了重复实验. 结果表明,离子液体作为萃取剂可以消除乙醇-环己烷物系的共沸点,提高该物系的相对挥发度. 采用[bmim]PF6作为萃取剂,溶剂比为0.5,离子液体加入速率为6 mL/min,回流比为3,可得到纯度大于99.8%的环己烷. 釜液采用闪蒸分离回收乙醇和离子液体,乙醇的回收率达99.9%以上. 离子液体的循环使用不影响分离性能.     

加盐反应萃取精馏分离醇水溶液

将加盐萃取精馏和反应萃取精馏结合起来提出了加盐反应萃取精馏分离醇水溶液的新方法。由异丙醇－水体系的汽液平衡试验结果表明加盐反应萃取精馏比单独的加盐萃取精馏更优,工艺试验证明当溶剂为1：1时,容易得到产品纯度96％以上的异丙醇。     

新型己内酰胺萃取剂的筛选和评价

Mixed solvent of 1-octanol and cyclohexane with 60% （by mass） 1-octanol content was selected as a new extractant for caprolactam extraction. Compared with benzene or toluene, the new extractant has larger extraction capacity and much lower toxicity. Although the extraction capacity of the new extractant is smaller than that of pure 1-octanol, 1-octanol solubility of the new extractant in aqueous phase is much smaller. Because of its physical properties of lower density, lower viscosity, and higher interfacial tension, the new extractant performed much better phase separation ability than pure 1-octanol. The new extractant showed certain selectivity when dealing with lactam oil. The mixed solvent of 1-octanol and cyclohexane with 60% （by mass） 1-octanol content is a promising extractant for caprolactam extraction.     

Simulation of Multicomponent Distillation Using a Nonequilibrium Stage Model

Abstract

A nonequilibrium stage model is used to predict composition profiles for binary and multicomponent distillation in a column of spheres and cylinders with a known interfacial area. The profiles generated by the model are compared with experimental data for the binary systems methanol—isopropanol, methanol—water, and isopropanol—water, and for the ternary systems methanol—isopropanol—water and acetone—n—hexane—cyclohexane. The model predicts with a high accuracy the experimental data with an average deviation lower than 1 mol%.     

Capillary reactor for cyclohexane oxidation with oxygen

Cyclohexane oxidation is the first step in the currently used technology for production of Nylon-6 and Nylon-6,6 which employs a two-stage process. In the first stage 80% selectivity to two main products, cyclohexanol and cyclohexanone (KA oil) is obtained at 4–8% cyclohexane conversion in staged bubble columns or stirred tanks. There have been reports that increased oxygen concentration in the gas phase or pure oxygen is beneficial to cyclohexane oxidation and this was confirmed in our previous study (Jevtic et al., 2009). To fully utilize this advantage here, we present a novel, safer capillary reactor for cyclohexane oxidation with pure oxygen. The discrepancy between the experimental and modeling results was attributed to lower than expected mass transfer achieved in the capillary. With a better design for gas–liquid mixing and contacting this type of a reactor could potentially become attractive for gas–liquid reactions of similar nature.     

Separation of isopropanol from aqueous solution by salting‐out extraction

A novel salting‐out extraction process has been developed to separate isopropanol from aqueous solution. Potassium carbonate was experimentally shown to be effective in modifying the liquid–liquid equilibrium (LLE) of an isopropanol/water/hexane system in favour of the solvent extraction of isopropanol from an aqueous solution with hexane, particularly at suitable salt concentrations. Potassium carbonate enlarged the area of the two‐phase region. This effect essentially increased the distribution coefficient of isopropanol between hexane and water and increased the separation factor for isopropanol vs water, which is an important consideration in designing a solvent extraction process. The effects of potassium carbonate concentration, temperature and pH on the LLE were studied. Finally, a ?30 mm × 1200 mm reciprocating plate column (RPC) was tested to separate isopropanol from an aqueous solution. When isopropanol in an aqueous solution with composition of isopropanol/water = 1:0.95 (wt/wt) was extracted by hexane assisted with 30% (wt%) potassium carbonate aqueous solution, the alcohol–water ratio increased to 11:1 in the extract. © 2001 Society of Chemical Industry     

Isopropanol as a solvent for extraction of cottonseed oil

Phase equilibrium data for the system; cottonseed oil-isopropanol-water were determined at 30°C. and compared with data for the system; cottonseed oilethanol-water. The relative phase distribution of fatty acids and cottonseed oil in mixtures with isopropanol and water was studied under varying conditions of water and fatty acid concentrations. These tests showed the fatty acids to be highly concentrated in the alcohol-water phase. Flaked cottonseed meats were extracted in continuous extraction apparatus with 91% isopropanol, 99% isopropanol, and mixtures of commercial hexane and isopropanol. Analytical data on the extractions show that 91% isopropanol is an efficient solvent for extracting active gossypol along with the oil. Rat and swine feeding tests of the isopropanol extracted meal showed it to be highly superior to hydraulic meal as a source of protein. A method was developed for treatment of the cottonseed-isopropanol miscella by liquid-liquid extraction to separate purified oil and fatty acid fractions from other materials in the extract.     

Extraction of rubidium by t-BAMBP in cyclohexane

4-Tert-butyl-2-(α-methylbenzyl) phenol (t-BAMBP) was used in cyclohexane in the extraction of rubidium from brine sources containing lithium. The effect of t-BAMBP concentration and aqueous phase pH on the rubidium and lithium extraction equilibrium was studied. t-BAMBP/cyclohexane was efficient and selective for rubidium extraction with optimal operating conditions being pH of 13.0 and initial t-BAMBP concentration of 1.0 mol·L?1. The stoichiometry of the complex of t-BAMBP with rubidium is 4:1. The apparent extraction equilibrium constant of rubidium was calculated by fitting the experimental data.     

高PC含量的大豆磷脂的制备研究

提出了制备高磷脂酰胆碱 (PC)含量的大豆磷脂的新工艺。用异丙醇作溶剂 ,通过正交实验得出优化的分离条件为 :抽提时间 5min ;抽提温度 - 5℃ ;m(磷脂 )∶m(异丙醇 ) =12∶15 7;异丙醇的体积分数 φ(异丙醇 )≈ 10 0 % ;HPLC分析结果表明 ,抽提后产品中PC的含量可以从原料中的w(PC) =2 5 6 %提高到w(PC) =6 6 8%。收率为 2 2 4%。     

正己烷–异丙醇共沸体系液液相平衡数据测定及关联

为了给溶剂萃取分离正己烷–异丙醇混合物的过程设计和流程模拟计算提供基础数据,以二甲亚砜、1,4-丁二醇、1,2-丙二醇、乙腈、糠醛和N,N-二甲基甲酰胺为萃取剂,测定了30℃下萃取分离正己烷–异丙醇混合物的液液相平衡数据,并利用分离因子评价不同萃取剂的萃取分离性能。根据Hand方程对实验数据进行一致性和可靠性检验,拟合方程的相关系数都在0.98以上。随后,采用Aspen Plus软件选取NRTL活度系数模型对相平衡数据进行关联,得到相应的二元交互作用参数,并以此计算相应的相平衡组成。结果显示,计算值和实验值的均方根偏差小于1.0%,表明NRTL模型能够准确描述三元体系的液液相平衡。     

Ambient-temperature extraction of rice bran oil with hexane and isopropanol

Hexane and isopropanol were compared as solvents for use in ambient-temperature equilibrium extraction of rice bran oil (RBO). Isopropanol was as effective as hexane in extracting RBO when 20 mL of solvent was used to extract 2 g of bran. Free fatty acid levels were 2–3% in both solvents and similar to that previously reported for hexane extraction of RBO hexane extraction by this method. Larger-scale extractions with 30 g of bran and 150 mL of solvent produced oil with a similar free fatty acid content and a phosphorus level of approximately 500 ppm. The oil extracted with isopropanol was significantly more stable to heat-induced oxidation than hexane-extracted oil. Antioxidants that are more easily extracted by isopropanol than hexane may be responsible for the increased stability.     

PW/SiO2-Al2O3负载型催化剂用于萘异丙基化反应性能研究

以自制PW/SiO_2-Al_2O_3为催化剂,研究载体及其负载量对萘异丙基化反应转化率和选择性的影响,并考察反应时间、活化温度和反应温度对催化剂性能的影响。结果表明,以异丙醇和萘[n(异丙醇)∶n(萘)=2]为原料,环己烷为溶剂,在活化温度和反应温度均为250℃及反应时间5 h条件下,磷钨酸(PW)负载质量分数40%时,PW/SiO_2-Al_2O_3负载型催化剂对萘异丙基化反应的催化效果最好,萘转化率87. 97%,DIPN选择性41. 41%,DIPN中β,β-DIPN占比达到59. 82%。