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以非均相碱性催化剂CaO催化废餐饮油与甲醇酯交换反应制备生物柴油为目标反应.研究不同金属氧化物掺杂对CaO催化性能影响.首先,利用CaO分别研究了醇油摩尔比、催化剂用量、反应时间和反应温度对反应产率的影响,实验结果表明,该反应最佳操作条件:醇油摩尔比为6,反应温度75℃.反应时间2 h,ω(催化剂)=4%,生物柴油的产率达到83.58%.采用浸渍法制备了以CaO为载体的负载型固体碱催化剂K2O/CaO和ZnO/CaO,通过对比发现氧化物对CaO的催化效果有提高作用,生物柴油产率均可达96%以上. 相似文献
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用氢氧化钾作催化剂,考察了反应温度、催化剂用量、醇油摩尔比、反应时间对棕榈油和甲醇制备生物柴油产率的影响。结果表明,最佳反应条件为:反应温度40℃,催化剂用量0.6%,醇油摩尔比6∶1,反应时间2.0 h。此时,生物柴油产率可达97.82%。 相似文献
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废弃油脂超临界法制备生物柴油研究 总被引:2,自引:0,他引:2
以废弃油脂为原料,利用超临界法制备生物柴油.通过单因素实验及正交实验研究了醇油摩尔比、反应压力、催化剂用量、反应时间、反应温度等因素对生物柴油产率的影响.结果表明,在实验范围内各影响因素对生物柴油产率作用的大小依次为:反应温度>反应压力>催化剂用量>反应时间>醇油摩尔比.废弃油脂超临界法制备生物柴油的最佳工艺条件为:反应温度240℃,反应压力10MPa,反应时间6min,催化剂用量0.06%,醇油摩尔比40/1.在此条件下,生物柴油产率达到99.37%. 相似文献
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采用溶胶-凝胶法制备了二氧化硅负载的高氯酸(HClO4-SiO2)固体酸催化剂,并用于催化大豆油与乙醇的酯交换反应制备生物柴油,研究了催化剂的处理温度、醇油摩尔比、催化剂用量、溶剂正庚烷用量和回流反应时间对酯交换反应的影响.在最优条件下,即催化剂处理温度为100℃、醇油摩尔比为8∶1、催化剂用量为油质量的5.0%、正庚烷用量为油质量的30.0%、回流反应时间为8 h,生物柴油的产率达到59.80%. 相似文献
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松香深加工残渣制备生物燃油的研究 总被引:2,自引:1,他引:1
以活性白土、硅藻土、高岭土等作为催化剂,使松香生产及松香深加工利用过程中形成的残渣(俗称黑松香)中所含的部分松香树脂酸、氧化松香树脂酸、树脂酸酯、不皂化的中性物质等发生催化裂解反应,从而制备得到生物燃料油。实验结果表明,活性白土1#和4#的催化效果良好,比较适宜的反应条件为:活性白土1#催化剂,用量为原料质量的5%~7%、反应时间9 h、反应温度285℃。黑松香裂解反应所得裂解产物中热值最大的达到42.20 MJ/kg,比原料的热值提高了9.66%,该产物动力学黏度(30℃)为880 mPa·s,可满足作为生物燃料油的使用要求。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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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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. 相似文献
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Peter A. Edwards Grant Striemer Dean C. Webster 《Journal of Coatings Technology and Research》2005,2(7):517-527
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins.
Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol.
The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and
cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on
the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to
determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model
amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate
functional group is more reactive than a glycidyl ether group.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago,
IL. 相似文献