甲醇尾气吸收塔的改造设计

利用ASPEN PLUS流程模拟软件,对甲醇尾气的吸收塔进行吸收模拟,根据模拟结果设计吸收塔的塔径、塔高、填料高度。新塔投用后解决了实际气体排放超标问题。     

基于修正PSRK和RKSWS状态方程的低温甲醇洗吸收塔模拟研究

低温甲醇洗是大型煤化工中常用的气体净化工艺。吸收塔是低温甲醇洗工艺中的核心设备,是整个流程模拟的关键塔。基于PSRK和RKSWS状态方程,修正部分缺省的计算方法,对低温甲醇洗吸收塔进行模拟研究,将模拟结果和运行数据进行对比。结果表明,修正后的PSRK及RKSWS状态方程可应用于低温甲醇洗吸收塔的工艺模拟计算和实际生产操作条件的优化。     

基于非平衡级速率模型的低温甲醇洗吸收塔模拟研究

针对低温甲醇洗吸收塔的特点,建立了采用新物性计算方法的非平衡级速率模型,与传统采用PSRK(Predictive Soave-Redlich-Kwong)物性计算方法的平衡级模型模拟结果和实际生产数据进行对比,对低温甲醇洗吸收塔进行模拟研究。研究表明:通过采用新的物性计算方法并优化物性组分参数,非平衡级速率模型较好地反映了实际工况,证明该模型可以应用于低温甲醇洗系统的工艺计算、实际生产的模拟分析以及操作条件的优化,为此装置设计提供可靠技术支持。     

低温甲醇洗吸收塔模拟及内件优化设计

吸收塔是低温甲醇洗工艺中的核心设备,内件对吸收塔性能至关重要。本文采用规整填料替代以往设计中四溢流塔盘,降低塔径和塔高,以优化设计、节省投资;采用Aspen Plus和DRP软件分别对低温甲醇洗吸收塔工艺参数和塔内件进行模拟和对比;在流程工艺模拟基础上对吸收塔进行水力学计算。模拟计算结果表明,采用规整填料比四溢流塔盘具有优势。     

基于非平衡级模型的低温甲醇洗流程模拟

对于多级分离过程的模拟通常都采用平衡级模型,而实际化工过程的非理想性使其应用受到了很大限制。本文引入非平衡级模型,采用修正的PSRK物性方法用Aspen plus软件对低温甲醇洗流程的吸收塔及CO2解吸塔进行模拟研究,并将其模拟结果与平衡级模型作对比。该模型下对吸收塔及CO2解吸塔的模拟结果都与设计值吻合很好。并将该流程吸收塔的非平衡级模型计算结果与本文作者教研组前期工作中研究的吸收塔的非平衡级模型结果作对比。研究结果表明,非平衡级模型可以应用于低温甲醇洗流程的模拟计算,为低温甲醇洗流程的设计计算提供了可靠的技术支持。     

低温甲醇洗吸收塔的计算机模拟

应用PRO/II工程模拟软件对某60万t/a煤气化制甲醇项目低温甲醇洗酸性气体吸收塔进行了模拟,通过对比不同热力学模型的模拟结果,明确了H2-CO2-CH3OH三元体系偏离高压和低温条件下的气液平衡是模拟误差较大的原因.将修正后的SRK-SIMSCI热力学模型用于吸收塔的计算,结果表明,该模型能够较好地反映该工艺装置的实际操作状况.     

低温甲醇洗吸收塔工艺模拟与过程参数优化

低温甲醇洗汽液平衡数据的测定难度大,而文献报道又极少。利用ASPEN PLUS软件,采用UNIFAC基团贡献法预测该体系汽液平衡,建立了低温甲醇洗吸收塔的过程模拟。模拟结果表明,该模型能够较好地反映该工艺装置的实际操作状况。在此基础上,考查了甲醇流量以及甲醇温度等参数对分离过程的影响,获得了低温甲醇吸收塔的最佳工艺参数。     

低温甲醇洗吸收塔模拟及分析

利用PRO/Ⅱ软件对低温甲醇洗工艺中的吸收塔进行了模拟,选择适合体系的SRKMWilson方程,拟合文献数据得到热力学模型中的二元交互作用参数,模拟计算结果与原设计值吻合良好。分析了塔内温度和气相组分随塔板数的变化,考查了甲醇流量对分离过程的影响。     

低温甲醇洗吸收塔模拟及内件优化设计

本文采用规整填料替代以往设计中四溢流塔盘、降低塔径和塔高的优化设计。用Aspen Plus和DRP软件分别对低温甲醇洗吸收塔工艺参数和塔内件进行模拟和对比。在流程工艺模拟基础上对吸收塔进行水力学计算。结果表明,采用规整填料比四溢流塔盘具有优势。     

低温甲醇洗全贫液与半贫液流程模拟及对比

低温甲醇洗全贫液与半贫液流程吸收塔有2个关键不同点:(1)吸收塔上部脱碳段全贫液流程吸收液为1股,半贫液流程为2股;(2)全贫液流程吸收塔CO2吸收段分3段,半贫液流程吸收塔CO2吸收段分2段。采用Aspen Plus和DRP软件分别对低温甲醇洗全贫液和半贫液流程的吸收塔塔内件进行模拟和对比。在流程工艺模拟基础上对吸收塔进行水力学计算。模拟计算结果表明,全贫液流程吸收塔能量消耗比半贫液流程高,总体循环量比半贫液流程小,吸收塔上段塔径比半贫液流程塔径小。液相负荷是吸收塔设计的决定因素,降液管液泛为塔盘限制因素。塔盘间距与塔径成反向关系,在设计时合理增大降液管面积和塔盘间距以缩小塔径,使吸收塔总体造价降低。     

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.     

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.     

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。