糠醛液相催化加氢制糠醇金属催化剂的研究进展

糠醛催化加氢是将糠醛转化为生物燃料、医药农药中间体等精细化学品的最常用的反应之一,如糠醇、2-甲基四氢呋喃、内酯、乙酰丙酸盐、环戊酮等皆由糠醛催化加氢制取.当前糠醛催化加氢的过程主要有液相、气相以及催化转移加氢等.综述了近年来糠醛液相催化加氢制备糠醇的不同金属基催化剂的研究进展.从不同过渡金属和贵金属作为催化活性中心制备的单金属及双金属催化剂着手,讨论了部分金属基催化剂用于糠醛液相催化加氢制糠醇反应过程的催化性能.     

小氮肥厂的多种经营——用合成放空气制备糠醇

糠醇工业上的主要来源是糠醛催化加氢。糠醛加氢制糠醇路线有常压气相法,中压液相法和高压液相法三种工艺路线。目前国内糠醇生产所需氢气,无论是常压法还是加压法均系由电解法(电解水或电解食盐水)制取,此法成本高并且耗用大量电能,利用小氮肥厂的合成放空气对糠醛加氢制糠醇,不仅经济效益较大,也节约了能源又防止了空气污染。因此,用合成放空气对     

糠醇生产技术进展

国外糠醇生产正在用糠醛的气相加氢法取代液相加氢法。铜催化剂改良后,提高了加氢效率、选择性和使用寿命。并对我国的糠醇生产提出了建议。     

糠醛液相加氢催化剂的研制及工业应用

通过扫描电镜(SEM)、压汞和X射线衍射 (XRD) 分析了制备条件对QKJ-01改性Cu-Cr糠醛液相加氢催化剂性能的影响。得出适宜的制备条件为：pH＝4～6.7，沉淀温度30～40 ℃, 450 ℃焙烧2 h。工业应用表明，QKJ-01糠醛液相加氢催化剂使用量少, 糠醛转化率大于99.96%，糠醇选择性大于98.4%。     

糠醛气相加氢制糠醇

糠醛气相加氢制糠醇一项具有国内领先水平的化工科研新成果一糠醛气相加氢制糠醇，在吉林化学工业公司研究院开发成功。吉化公司研究院开发成功的糠醛气相加氢制糠醇新工艺可达到低消耗生产高纯度糠醇的目的。若以年产２０００吨糠醇汁，年利润可达１８７．８９万元。专家...     

低压液相加氢制糠醇

本文介绍了糠醛低压液相加氢生产糠醇新工艺中所采用的催化剂，溶剂，压力，温度等条件及其注意事项。     

铬形态及使用条件对糠醛催化加氢反应产物分布的影响

采用共沉淀法制备系列Cu-Cr糠醛加氢催化剂,考察不同铬形态对催化剂反应性能的影响。采用管式连续流动固定床积分反应器, 研究糠醛在Cu-Cr催化剂上的气-液相加氢反应规律。结果表明,制备催化剂时的铬原料不同,将极大地影响催化剂的加氢活性和产物选择性,以硝酸铬形式加入制备的催化剂对糠醇的生成较为有利,而以醋酸铬形式加入制备的催化剂对甲基呋喃的形成有利;在(70～110) ℃,随着温度升高,糠醛转化率和糠醇选择性增加,2-甲基呋喃选择性降低;糠醛流速为(0.01～0.06) mL·min^-1时,随着流速的增加,糠醛转化率下降,0.03 mL·min^-1时糠醇选择性出现极大值,而副产物2-甲基呋喃和呋喃类则在此处出现极小值。副产物戊二醇和四氢康醇的选择性则随着糠醛流速的增大上升。     

糠醛液相化学选择性加氢制糠醇的研究

本文主要介绍了间歇式反应釜中糠醛在Cu-Zn/γAl2O3催化剂条件下在不同温度、时间、糠醛浓度和溶剂体系中的催化加氢制糠醇,从糠醛转化率和糠醇选择性两方面对加氢效果进行比较。通过实验,我们得到了糠醛加氢制糠醇的最佳工艺条件为反应温度为160℃、反应时间为3 h、催化剂用量为糠醛的7wt%、糠醛浓度为5wt%~25wt%、溶剂为甲苯时,糠醛的转化率和糠醇的选择性最好,分别为99%和98%。     

国内外化工简讯

糠醛气相加氢制糠醇通过鉴定一项具有国内领先水平的化工科研新成果─—糠醛气相加氢制糠醇，日前在吉林化学工业公司研究院开发成功，并正式通过省级技术鉴定。利用玉米芯水解制成糠醛，再进一步加工成糠醇、糠醒树脂、吹哺树脂，是提高产品附加值，增加经济效益的重要途径之一。吉化公司研究院开发成功的糠酸气相加氢制糠醇新工艺即可达到低消耗地生产高纯度糠醇的目的。若以年产2000吨糠醇计，年利润可达187.89万元。专家鉴定认为，该项成果提供的技术资料齐全，数据准确可靠，可以指导生产、应用。采用列管反应器，常压下糠醇气相催化加…     

催化剂

▲北京化工大学研制出糠醛液相加氢制糠醇的无铬铜系催化剂,替代现用铜铬系催化剂,减少铬污染,降低成本,提高糠醇产品质量。 ▲吉化研究院试制成功乙烯水合制异丁烯的磷酸球型催化剂、油脂加氢催化剂,可以替代进口,分别     

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。