从油田轻烃中萃取精馏回收环己烷

引　言环己烷是重要的基本有机化工原料和有机溶剂 .国内现有环己烷及其衍生制品都是苯加氢法生产 ,成本高 ,生产能力小 .从油田轻烃萃取精馏获取高纯度环己烷具有巨大的潜能和广阔的前景[1～ 3 ] .早期萃取精馏回收环己烷采用单组分溶剂 ,它对相对挥发度改变不大 ,环己烷与烃的互溶度不好 ,分离效果不佳 .为了克服单溶剂萃取精馏的缺点 ,人们开始了双组分溶剂萃取精馏回收环己烷的研究 .Cines[4 ] 建议在一个双液相区操作的萃取精馏塔内用环丁砜 /水为溶剂从沸点相近的石蜡烃中分离环烷烃 .这是个可行的方法 ,但由于环己烷在环丁砜中的溶…     

异戊二烯生产工艺技术研究进展

介绍了国内外异戊二烯生产技术的研究进展,详细叙述了萃取精馏法生产异戊二烯的工艺,简要介绍了近年来开发的催化合成、膜分离异戊二烯等新型工艺,并分析了各种生产工艺的优缺点。指出开发新型萃取剂、膜分离和直接催化合成是今后异戊二烯生产技术发展的新方向。     

苋菜红色素提取工艺的研究进展

从苋菜中提取的色素是一类重要的绿色天然色素,可取代对人体健康有危害的合成色素。本文简要介绍了苋菜红色素的性质与应用,综述了其近年来提取工艺的研究进展状况,并展望了苋菜色素的发展前景。     

工业生产中醋酸甲酯回收技术的研究进展

综述了聚乙烯醇和精对苯二甲酸生产过程中分离回收醋酸甲酯的主要方法,并对加盐萃取精馏等盐效分离方法、催化精馏方法和萃取精馏方法进行比较研究。结果表明,加盐萃取精馏方法能分离出高纯度醋酸甲酯,且生产工艺简单,有较好的应用前景。     

带有中间储罐的塔用于间歇萃取精馏

Batch extractive distillation was studied in a column with a middle vessel. The process was simulated by a constant holdup model and solved by two point implicit method. Acetone and methanol mixture was separated in such a setup using water as solvent. The simulation agrees well with experimental results. The experimental and simulation results show that the solvent at the bottom and the product at the top of the column can be withdrawn simultaneously for a long period of time. It needs more time for the solvent to reach high purity than that required for the more volatile component to reach high purity, so that the time to withdraw solvent from the bottom is delayed.     

新型分离法回收制药废液中四氢呋喃

为了从制药废液中回收四氢呋喃 ,研究了萃取精馏技术和加盐萃取精馏技术在分离甲醇 四氢呋喃 水体系中的应用 ,选择了萃取精馏及加盐萃取精馏所用溶剂 ,设计了工艺流程 ,确定了操作条件 ,采用以上技术从废液中回收的四氢呋喃 ,纯度可达到 99.5 % (质量 )     

NMP萃取精馏分离芳烃和非芳烃

通过常压气液平衡和萃取精馏工艺实验说明NMP是分离芳烃和非芳烃的有效溶剂,且满足当前生态化工的要求。利用NMP中加水能够降低沸点的特点,对普通的萃取精馏双塔流程进行了改进。改进后的计算结果表明苯的收率从94．2％提高到98．2％,且整个改进过程不复杂。     

萃取精馏法回收苯和环己烷的溶剂研究

本文讨论了用萃取精馏法从油田轻烃中回收环己烷的工艺过程,并以某油田6号溶剂油为研究对象,利用无限稀释条件下的选择因数S∞,为从某油田6号溶剂油中回收苯和环己烷的萃取精馏工艺选择了适宜的溶剂NMP,最后,应用NRTL方程预测了某油田轻烃中的关键组分,在溶剂作用下的相对挥发度的变化情况。     

Evaluation of Barros and Wolf Efficiency Correlations for Conventional and Extractive Distillation Columns in Bioethanol Production Process

In view of the increasing environmental concern, the use of renewable and less pollutant energy sources has been encouraged. In this context, bioethanol has been used as fuel in the anhydrous form, blended with gasoline. In this work, simulations of the extractive distillation process in anhydrous bioethanol production were carried out in Aspen Plus® using nonequilibrium stage model and equilibrium stage model with Barros and Wolf efficiency correlations for plate and component. Equilibrium stage model with plate efficiency determined through Barros and Wolf efficiency correlation showed a satisfactory agreement with results predicted by the nonequilibrium stage model for anhydrous bioethanol production process.     

Determination of a suitable index for a solvent via two-column extractive distillation using a heuristic method

The traditional approach to solvent selection in the extractive distillation process strictly focuses on the change in the relative volatility of light-heavy components induced by the solvent. However, the total annual cost of the process may not be minimal when the solvent induces the largest change in relative volatility. This work presents a heuristic method for selecting the optimal solvent to minimize the total annual cost. The functional relationship between the relative volatility and the total annual cost is established, where the main factors, such as the relative volatility of the light-heavy components and the relative volatility of the heavy-component solvent, are taken into account. Binary azeotropic mixtures of methanol-toluene and methanol-acetone are separated to verify the feasibility of the model. The results show that using the solvent with the minimal two-column extractive distillation index, the process achieves a minimal total annual cost. The method is conducive for sustainable advancements in chemistry and engineering because a suitable solvent can be selected without simulation verification.