气流床煤气化的Aspen Plus建模：平衡模型和动力学模型

基于Aspen Plus软件建立了GE气流床煤气化的平衡模型和动力学模型,计算了气化的煤气组成和碳转化率。模型分为热解、气化和气液分离三个阶段。其中,气化阶段又分为初步气化和气化重整,从而获得气化产物在恒定温度下的分布。平衡模型的气化阶段使用了吉布斯反应器RGIBBS,基于吉布斯自由能最小化原理对体系内的气化产物进行计算;动力学模型的气化阶段使用了全混流反应器RCSTR,基于煤气化反应的动力学机理对体系内的气化产物进行计算。模拟值与GE气化炉的实际工程数据进行了对比,结果表明,平衡模型可在一定程度上反映气化结果的变化趋势,但预测结果的准确性有所欠缺,而基于气化反应机理建立的动力学模型能很好地预测GE气化炉的气化结果。对动力学模型中的全混流反应器进行反应时间设定,可以对GE气化炉生产提供一定的指导,结果表明：反应停留时间为3.5s时就可以达到很好的气化效果。温度是影响气化反应速率及产物分布的重要因素,利用煤气化的动力学模型模拟了气化温度对气体组成及碳转化率的影响,结果表明：随着气化温度的升高,CO含量逐渐增加,H₂含量基本不变,CO₂含量逐渐减小,碳转化率逐渐升高。     

煤加氢气化的化学热力学模型预测

综合运用化学平衡和热力学平衡对于给定煤种的加氢气化反应建立了通用的热力学数学模型。用于预测气化炉出口的煤气成分、产量等。并利用该模型计算分析了煤加氢气化直接生成CH4的过程,主要分析了反应温度及压力对加氢气化反应的平衡常数和平衡转化率的影响。用化学动力学方法建立数学模型,通过计算获得主要气体产物与反应温度和压力之间的关系,以及气化过程中氢气系数对最终气体产物的影响。     

生物质热解油的热解气化实验研究

采用固定床生物油气化系统对生物油在不同气化温度、停留时间、气化剂等条件下对生物质流化床快速热解油的热解气化特性进行了研究,并对合成气的组成特性进行了分析.研究发现随着热解气化温度的升高,合成气中CO和H2的量快速增加,并在800℃取得最大值;停留时间的过度延长不利于合成气品质的提高,由于生物油的含氧量较高,气化剂O2的加入对合成气中可燃气含量的提高不利.     

煤焦在气化合成气中高温气化反应特性

在固定床管式炉反应器中进行了煤焦在H_2O、CO_2、H_2和CO混合气氛中气化特性的实验研究,考察了反应温度、原料气组成和加煤量对产物气组成以及碳转化率的影响。实验结果表明,在各实验条件下,合成气与煤焦反应后CO流量均增加最多,H_2少量增加。煤焦与CO_2的反应受到明显抑制。混合气体通过与煤焦反应可以提高有效气(CO+H_2)的含量,实验条件下反应出口气体中有效气浓度比反应结束时最多提高3.3个百分点。反应速率受气化剂之间的竞争和气化产物的抑制作用较为明显,在1100℃和1300℃时,煤焦在相同气化剂流量的合成气中的最高反应速率分别只有在纯气化剂(水蒸气或CO_2)中最高反应速率的49%和69%。受到多种气体组分之间的相互影响,气体在孔道里的扩散和吸附对反应影响更加显著,随机孔模型可以较好地拟合此类反应,而不考虑孔结构的均相模型和缩芯模型拟合度较差。     

煤焦在气化合成气中高温气化反应特性

在固定床管式炉反应器中进行了煤焦在H₂O、CO₂、H₂和CO混合气氛中气化特性的实验研究,考察了反应温度、原料气组成和加煤量对产物气组成以及碳转化率的影响。实验结果表明,在各实验条件下,合成气与煤焦反应后CO流量均增加最多,H₂少量增加。煤焦与CO₂的反应受到明显抑制。混合气体通过与煤焦反应可以提高有效气（CO+H₂）的含量,实验条件下反应出口气体中有效气浓度比反应结束时最多提高3.3个百分点。反应速率受气化剂之间的竞争和气化产物的抑制作用较为明显,在1100℃和1300℃时,煤焦在相同气化剂流量的合成气中的最高反应速率分别只有在纯气化剂（水蒸气或CO₂）中最高反应速率的49%和69%。受到多种气体组分之间的相互影响,气体在孔道里的扩散和吸附对反应影响更加显著,随机孔模型可以较好地拟合此类反应,而不考虑孔结构的均相模型和缩芯模型拟合度较差。     

渣油气化工艺流程模拟与优化

利用工艺流程模拟软件Pro II对国内某厂的渣油气化工艺进行模拟,将渣油气化过程分解为燃烧反应区和二次反应区,建立渣油气化过程的热力学反应模型,模拟计算结果并与设计值、生产测量值相比,误差在可接受的正常范围内,说明本模型可用于渣油气化模拟。使用本模型通过模拟计算考察渣油气化工艺中氧油比、蒸汽油比对气化温度、粗煤气组成的影响,给出优化后的建议操作参数。     

生物质快速热解制油试验及流程模拟

使用自主研发的流化床热解反应器对生物质热解制油进行实验研究,通过对不同实验温度450、500、525、550、580、610℃下得到的目标产物进行分析,得到了反应温度对生物油产率的影响规律。实验表明：550℃时,最大液体产率为42.5%（质量）;实验得到的不可冷凝气体的组分以CO、CO₂、CH₄和H₂为主,气相产物产率约为37.7%（质量）。在实验基础上,利用Aspen Plus流程模拟软件,建立了生物质热解制油工艺模拟流程,模拟分析了热解温度对生物油产率的影响,结果表明该模型能准确模拟实际热解过程,具有较好的适用性和可靠性。     

超临界水中葡萄糖气化制氢实验研究

以葡萄糖为生物质模型化合物,在超临界水中进行气化反应,考察不同压力、温度、物料浓度等对气化产物组成及气化制氢效果的影响。实验结果表明,反应器壁温在500—650℃范围内,温度的升高有利于葡萄糖的气化制氢,25MPa、650℃时气化率超过100%。添加适当的催化剂可以有效促进水气转化反应。     

热管式生物质气化炉反应过程的理论分析

将高温热管技术应用于生物质气化过程,发明了一种新型气化装置———热管式生物质固定床气化炉HPBGF(Heat P ipe B iomass Gasification Furnace),以实现无空气生物质高温热解气化工艺。用化学计量关系研究以水蒸气为气化剂的生物质(秸秆)气化反应机理,根据气化产物推导出气化过程中理论上的总反应方程式。通过C H O物系平衡分析,确定温度在气化过程的重要性,得出高温热管的引入对气化产物组成的影响,为进一步研究奠定基础。     

木屑和木屑炭二氧化碳气化研究(摘要)

<正>生物质CO2气化是一项极具开发潜力的技术,该技术为新能源的开发和环境的保护提供了有效途径。本论文主要对木屑和木屑炭的CO2气化进行了研究,利用气化管式炉和热重分析仪进行了实验,通过分析产物产量、产物组分和热重曲线等得出了相关结论,为生物质CO2气化的进一步研究提供了一定的理论基础。主要研究内容和成果归纳如下:1.木屑CO2气化行为研究1)根据管式炉反应和热重分析实验结果得出,提高反应温度,有利于促进木屑CO2气化反应,提高气体产量,提高     

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。