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1.
研究了三相床反应器中合成气一步法制二甲醚的工艺条件,催化剂是由甲醇合成催化剂与甲醇脱水催化剂均匀混合组成的双功能催化剂.在温度220~265℃、压力4~5MPa、空速1~2 L/(g·h)的条件下,分别考察了温度、压力和空速对二甲醚合成反应中CO转化率及二甲醚选择性的影响.结果表明,在上述各因素相应的范围内,,随着反应温度的升高,CO转化率、DME选择性逐渐增加;随着压力的升高,CO转化率、DME选择性逐渐增加;CO转化率、DME选择性随空速的提高而逐渐减小.与固定床实验结果相比,三相床反应器中CO转化率略低于固定床反应器.  相似文献   

2.
浆态床合成气合成二甲醚的工艺研究   总被引:1,自引:0,他引:1  
考察了反应温度、反应压力、进料空速对浆态床合成二甲醚反应过程的影响,结果表明,在245~300℃范围内,随着反应温度的升高,一氧化碳转化率、二甲醚选择性和时空收率逐渐增加,在265℃时达到最大值后开始下降;在3.0~5.0MPa范围内,随压力的升高,一氧化碳转化率、二甲醚选择性和时空收率逐渐增加;在700~2500h-1范围内,一氧化碳转化率、二甲醚选择性随空速的增加而逐渐减小,空速以1200h-1为宜。  相似文献   

3.
生物质合成气合成二甲醚的研究   总被引:1,自引:1,他引:0  
在加压固定床反应装置上进行了生物质合成气合成二甲醚(DME)的研究.采用机械混合法制备二甲醚合成双功能催化剂.考察了组成为V(H_2):V(CO):V(CO_2):V(CH_4)=52:24:23:1的生物质合成气在不同反应温度、空速、压力下对合成二甲醚反应的影响.同时进行了102 h的催化剂的稳定性实验.结果表明,在260-300℃范围内,随反应温度的升高,CO转化率和二甲醚的选择性均先增大后减小;随反应压力的升高,CO转化率和二甲醚选择性都随之升高;原料气中高浓度的CO_2可导致铜基催化剂较快的失活.  相似文献   

4.
本文叙述了反应条件对合成甲醇铜基催化剂活性(时空收率和 CO 转化率)的影响.时空收率和 CO 转化率均随反应压力的升高而增加;在一定空速范围内,时空收率随空速增大而增加,而CO 转化率随空速的增大而降低;反应温度为250℃时,时空收率和 CO 转化率均达最高值.  相似文献   

5.
胡叶林  赵毅 《河南化工》2012,(18):12-13
考察了Ni-Fe/A12O3催化剂上HPA加氢反应工艺条件。结果表明,当反应压力高于4MPa时,HPA转化率维持不变;随温度的升高HPA转化率逐渐增加,60℃时HPA转化率达到80%;空速也是影响HPA转化率的重要因素,在实验范围内(0.8-2.8h^-1)呈线性下降关系。  相似文献   

6.
气固相催化羟醛缩合合成α-氯丙烯酸甲酯的研究   总被引:1,自引:0,他引:1  
研究了以V/P摩尔比为1:2.8,浸渍时间3h,活化温度为450℃的负载型催化剂V2O5-P2O5/SiO2作为催化剂,在气固相催化羟醛缩合合成α-氯丙烯酸甲酯,考察了对反应条件的优化,解释和分析了反应条件中诸因素对合成α-氯丙烯酸甲酯的影响。实验结果给出常压下合成α-氯丙烯酸甲酯的最佳反应条件:空速l200h^-1,反应温度300℃,氯乙酸甲酯/甲缩醛摩尔比为2.4:1。最佳反应条件下,所得甲缩醛转化率为76.2%,α-氯丙烯酸甲酯的选择性为58.5%,收率为44.58%。  相似文献   

7.
以丙烯醛水合产物3-羟基丙醛(HPA)水溶液为原料,在Ni/SiO2/Al2O3催化剂作用下与高压氢气反应生成1,3-丙二醇(1,3-PDO)。实验结果表明:1,3-PDO收率随温度的升高而提高,但反应温度不宜超过70℃;随氢气压力的升高而提高,在4.0~7.0MPa范围内呈线性升高关系;随空速的增加而降低,在2.25~6.75h^-1范围内呈线性下降关系。正交实验得到较佳反应条件为:反应温度为50℃、压力为7.0MPa、空速为2.25h^-1,其中空速为最主要影响因素。  相似文献   

8.
生物质气一步法合成二甲醚中试实验   总被引:1,自引:0,他引:1  
在列管式连续固定床中试系统上,采用自制二甲醚(DME)合成催化剂,以玉米芯经两段式固定床富氧气化合成气为气源,进行一步法合成DME实验研究.考察了催化剂反应温度(210-295℃)、空速(650-3 000 h-1)对合成过程的影响.并对合成DME催化剂反应前后进行XRD表征.实验结果表明:反应空速为1 200 h-1时,最佳反应温度为270℃时.此时CO转化率最高为73.55%;空速在650-3 000 h-1时,CO转化率为82.00%~67.74%,时空产率为124.28~281.24 kg/(m3·h).  相似文献   

9.
反应条件对混合C5催化反应的影响   总被引:1,自引:0,他引:1  
由宏君 《辽宁化工》2003,32(7):280-281,312
以混合C5气体为原料,利用D005大孔阳离子交换树脂作催化剂。对混合C5气体进行催化反应,考察了温度、分子比和空速对转化率的影响。实验结果表明,在温度65℃、压力0.5MPa,甲醇和叔戊烯的分子比为1:1、叔戊烯空速0.5h^-1(体)的条件下,2MC4-1^m转化率为92.54%,2MC4-1^m和2MC4-2^m转化率为62.48%,TAME选择性为72.43%。  相似文献   

10.
合成甲异丁酮的工艺研究   总被引:6,自引:0,他引:6  
介绍了采用固床反应器由丙酮缩合加氢合成甲基异丁基酮的工艺。详细考查了反应温度、压力、空速及原料含水量等条件对反应的影响。结果表明反应温度120℃、压力6Mpa、空速1.0h^-1,原料含水量小于0.5%为最适宜的反应条件,在此条件下丙酮转化率为40%、甲基异丁基酮的选择性为94%。  相似文献   

11.
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.  相似文献   

12.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

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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.  相似文献   

18.
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.  相似文献   

19.
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。  相似文献   

20.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.  相似文献   

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