萃取精馏分离乙腈-正丙醇混合物模拟研究

利用Aspen Plus化工流程模拟软件采用萃取精馏法,以1,4-丁二醇(BDO)为萃取剂,对乙腈-正丙醇的分离进行模拟研究。最优工艺条件:萃取精馏塔理论板数45,混合物进料位置37,萃取剂进料位置3,回流比1.8,溶剂比7;溶剂回收塔理论板数17,进料位置7,回流比1.6。在上述条件下得到乙腈和正丙醇质量分数分别为99.81%和99.22%。     

萃取精馏分离四氢呋喃-水共沸物的模拟研究

利用化工流程模拟软件Aspen Plus,以DMSO为萃取剂,模拟研究四氢呋喃-水共沸物的分隔壁萃取精馏和单塔侧线采出萃取精馏过程。分隔壁萃取精馏优化后工艺参数为:主塔22块理论板,萃取剂3块理论板处进料,原料17块理论板处进料,回流比0.5,溶剂比0.45;副塔10块理论板,回流比2.4。可得到摩尔分数为99.90%的四氢呋喃和99.19%的水,回收萃取剂的摩尔分数为99.72%。和常规双塔萃取精馏相比,冷凝器热负荷降低18.63%,再沸器热负荷降低15.58%,实现了有效节能。而单塔侧线采出萃取精馏不能实现四氢呋喃和水的有效分离。     

异丙醇-异丙醚-水三元物系分离的模拟与研究

提出了非均相层析-萃取精馏分离工艺,并基于Aspen Plus对该分离过程进行模拟研究,以得到质量分数为98.3%的异丙醚和99%的异丙醇,水相异丙醚的质量分数小于2×10-5,异丙醇的质量分数小于1×10-4为目标,确定了粗馏塔、醚精制塔、异丙醇精制塔、乙二醇回收塔最佳工艺参数。粗馏塔的理论塔板数为26,进料板位置为第13块理论板,摩尔回流比为0.14。醚精制塔的理论塔板数为23,进料板位置分别为第3和15块理论板,摩尔回流比为0.92。异丙醇精制塔的理论塔板数为25,进料板位置为第3和第18块理论板,摩尔回流比为2.85。乙二醇回收塔的理论塔板数为40,进料板位置为第15块理论板,摩尔回流比为0.08。总体工艺具有流程简单、产品纯度高、易于操作的特点。     

乙醇脱水分壁式萃取精馏工艺研究

利用Aspen Plus过程模拟软件,采用乙二醇作萃取剂,模拟研究了分壁式萃取精馏对摩尔分数为82%乙醇溶液脱水的分离过程。建立了分壁式萃取精馏模型,得到了优化的工艺参数,主塔理论板数为11块,精馏段理论板数为5块,回流比为0.10;副塔原料进料位置为第14块板,萃取剂进料位置为第4块板,隔板在副塔第18块板底端,萃取精馏段回流比为0.419,溶剂比为1.1。比较了分壁式萃取精馏和常规双塔2种流程下的能耗。模拟结果表明,采用分壁式萃取精馏,再沸器能耗降低了15%,节能效果明显。     

丙酮-氯仿共沸体系萃取精馏过程模拟与优化

应用化工过程模拟软件Aspen Plus对丙酮-氯仿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Aspen物性分析,筛选出合适的萃取剂为二甲基亚砜。确定了双塔连续萃取精馏的工艺流程,并利用灵敏度分析工具考察了萃取精馏塔的理论塔数、回流比、原料进料位置、萃取剂进料位置、溶剂比(萃取剂对原料的物质的量比)对分离效果的影响。确定的最佳工艺方案为:全塔理论板数为45,原料和萃取剂分别在第11块和第3块理论板进料,回流比为2.5,溶剂比为1.9。在此工艺条件下:萃取精馏塔塔顶丙酮的分离效果达99.95%,萃取剂回收塔塔顶氯仿的纯度达到98.34%;萃取剂二甲基亚砜的循环补充量为5.557mol/h。模拟与优化结果为丙酮-氯仿共沸物连续萃取精馏分离过程的设计和操作提供了参考。     

萃取精馏分离甲醇-四氢呋喃共沸体系的流程模拟

应用化工过程模拟软件Aspen Plus V7.3对甲醇-四氢呋喃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Aspen物性分析,筛选出合适的萃取剂为二甲基亚砜。确定了双塔连续萃取精馏的工艺流程,并利用灵敏度分析工具考察了萃取精馏塔的理论塔数、原料进料位置、萃取剂进料位置、回流比、溶剂比(萃取剂对原料的物质的量比)对分离效果的影响。确定的最佳工艺方案为:全塔理论板数为32,原料和萃取剂分别在第26块和第4块理论板进料,回流比为3,溶剂比为1.9。在此工艺条件下:萃取精馏塔塔顶四氢呋喃的分离效果达99.98%,萃取剂回收塔塔顶甲醇的纯度达到99.96%;萃取剂二甲基亚砜的循环补充量为8.58 mol/h。模拟与优化结果为甲醇-四氢呋喃共沸物连续萃取精馏分离过程的设计和操作提供了参考。     

以苯胺为萃取剂萃取精馏分离苯-环己烷共沸体系

利用Aspen Plus流程模拟软件,模拟了以苯胺为萃取剂,萃取精馏分离苯-环己烷体系的工艺流程,考察了溶剂比、全塔理论塔板数、原料进料位置、萃取剂进料位置等因素对分离效果的影响。确定了最佳工艺操作参数为:萃取精馏塔的全塔理论板数为32,原料和萃取剂进料位置分别为第25块和第5块理论板,回流比为1.5,溶剂比为2.5。产品环己烷的纯度达到99.66%,苯的纯度达到99.66%,再生的萃取剂苯胺的纯度达到99.99%。     

从工业废液中回收四氢呋喃及正丁醇的工艺研究

利用Aspen Plus软件对含有四氢呋喃、正丁醇、γ-丁内酯和水的工业废液的分离提纯工艺进行了确定和模拟。确定使用1,4-丁二醇作为萃取剂,采用四塔流程分离该工业废液,回收四氢呋喃和正丁醇。四氢呋喃的回收使用萃取精馏,溶剂比为0.9,回流比为5,所需塔板数为28块,废液和萃取剂分别从第16块板和第5块板以泡点进料;正丁醇的回收使用两塔共沸精馏,所需脱水塔塔板数为7块,回收塔塔板数为5块。在此操作参数下,模拟所得四氢呋喃回收率可达99.9%,质量分数为99.99%,正丁醇回收质量分数达到99.99%。通过实验结果与模拟结果的比较,验证了本工艺的可行性和模拟结果的可靠性。     

发酵液中β-苯乙醇精制过程模拟研究

利用Aspen plus软件,对β-苯乙醇-乙醇-水体系的分离过程开展模拟研究,以1000 kg/h的处理量为例,对精馏分离的影响因素,如回流比、压力等进行分析探讨,获得β-苯乙醇精制工艺适宜的工艺条件为:粗蒸塔理论板数为18,适宜进料位置为第5块理论板,回流比为0. 8;萃取塔理论板数为15,萃取剂进料量为380 kg/h;精蒸塔理论板数为20,适宜进料位置为第6块理论板,回流比为0. 6;在此条件下β-苯乙醇分离精制的能耗为14吨蒸汽/吨β-苯乙醇。     

C5馏分萃取精馏模拟研究

以异戊二烯为目标产物,采用Aspen plus模拟软件对C5的萃取精馏过程进行模拟与优化。以乙腈为萃取剂,重点研究了萃取塔进料位置、理论板数、回流比以及剂料比对产品收率及纯度的影响。优化二次萃取工艺为一次萃取工艺,得到聚合级异戊二烯。萃取塔的适宜操作条件为：压力200 kPa,理论塔板数60块,进料位置为第25块塔板,回流比4,剂料质量比5.0。该操作条件下,异戊二烯收率及纯度分别为99.48%、99.70%。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.