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排序方式: 共有271条查询结果,搜索用时 15 毫秒
1.
在石英毛细管中涂覆α-Al2O3并负载银,制成微反应器,利用毛细管微反应器进行了乙烯环氧化反应的实验。考察了反应温度、乙烯含量、气态空速等因素对乙烯环氧化反应的影响。实验结果表明,在毛细管微反应器中可进行乙烯环氧化反应,在常压、不添加任何助催化剂和抑制剂的条件下,反应温度为230℃时,乙烯的转化率为69.54%,环氧乙烷的选择性和收率分别为82.00%和57.02%;毛细管微反应器的气态空速可达到5600h-1,超过工业装置的水平,缩短了反应时间,减小了深度氧化的几率。 相似文献
2.
润滑油金属清净剂合成机理的剖析 总被引:2,自引:0,他引:2
结合润滑油清净剂合成机理以及微反应器理论的研究成果,认为清净剂合成中的过碱化反应机理与微反应器理论中渗透反应模型所描述的反应机理相一致。过碱化过程是利用有机酸生成的有机盐将水、促进剂、金属氢氧化物包裹起来形成反相胶束微粒(微反应器),二氧化碳通过渗透进入反相胶束微粒与金属氢氧化物反应得到纳米金属碳酸盐粒子的过程。利用微反应器理论对过碱化反应中各种因素的影响结果进行了分析,结果表明,清净剂过碱化反应过程中的现象可通过微反应器理论得到合理的解释。 相似文献
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4.
The decomposition of 1,2-dichloroethane on polycrystalline copper has been studied using a microreactor. The reaction is found to have an activation energy of 81±5 kJ mol–1 generating gaseous ethene and chemisorbed chlorine. The reaction terminates on completion of a monolayer of chemisorbed chlorine and is followed by a much slower reaction. The rate limiting step is thought to be C2H4Cl2(phys)C2H4Cl(ads)+Clads The reaction is compared with a UHV study of the same molecule on Cu(l 11) and the possibility of a negative ion transition state is discussed. 相似文献
5.
Sittidej Teekateerawej Junichi Nishino Yoshio Nosaka 《Journal of Applied Electrochemistry》2005,35(7-8):693-697
Two kinds of porous ceramic disks, having through-holes with diameters of 0.1 and 0.05 mm, were coated with TiO2 using two different starting solutions: titanyl(IV)acetylacetonate and a commercial titania sol (STS-01). The morphology
of these porous ceramics before and after TiO2 coating was observed by SEM. The TiO2-coated porous ceramics were examined as honeycomb photocatalytic microreactors. The photocatalytic activity was evaluated
using the decomposition of methylene blue solution for radiation angles of 0° and 10° with respect to the pore axis. The highest
photocatalytic activity was obtained for the porous ceramic having the pore diameter of 0.1 mm, coated with titanyl(IV)acetylacetonate
and irradiated with a light angle of 0° with respect to the pore axis. 相似文献
6.
J.-M. Commenge T. Obein X. Framboisier V. Schanen M. Matlosz 《Chemical engineering science》2006,61(2):597-604
Industrial-scale performance of gas-liquid reactors can be difficult to optimise for very rapid or highly exothermic reactions. Microstructured reactors for laboratory measurements offer new opportunities for the study of these reactions by enabling precise heat management and fine control of reactor operating conditions. For accurate experimental study, characterisation of the flow conditions within these new reactor devices is essential.The present study examines experimental residence time distributions for the gas phase through a microstructured falling-film reactor, in order to develop an appropriate flow model for further study of gas-phase mass-transfer characteristics in the system. For the gas-phase residence time distribution experiments, the detection system involves a flow of oxygen containing ozone as a tracer gas with continuous monitoring of the concentration by UV-light absorption. The experimental results are used to model the flow behaviour in the gas volume over the gas-liquid contact zone as a series of continuous stirred tank reactors whose number is a simple function of the gas Reynolds number.The experimental results are compared with computational fluid dynamics calculations of the gas flow within the reactor. The comparison indicates a clear correlation of the flow model behaviour with the appearance of recirculation loops in the reaction chamber and the effect of the gas jet at the entrance of the gas-liquid contact zone. 相似文献
7.
8.
《International Journal of Hydrogen Energy》2021,46(78):38887-38902
Recently, microreactor designs have been receiving significant attention in the nuclear industry due to their potential advantages in certain applications. These nuclear reactor designs have been considered to provide reliable and sustainable power for on-site installation and operation. Microreactors may be utilized to provide heat and power to hydrogen production, remote communities, and industrial facilities such as military installations, disaster relief zones, and are being considered for underwater and deep space operation as well. However, these designs and concepts remain largely untested and unproven in the commercial industry. Further research and development are still required to prove microreactor designs are safe and reliable for commercial use. Different cooling technologies have been taken into consideration for microreactor concepts since the 1960s, mainly for federal space reactor projects such as LEGOLRCS, HOMER, and KRUSTY. This work provides thermal hydraulics and analysis for the Idaho National Laboratory's MAGNET (Micro-reactor Agile Non-nuclear Experimental Testbed) facility. The MAGNET facility is currently being developed to duplicate a microreactor design using heat pipe cooling technology. Our main goal is to examine the response of the test facility under steady-state and transient operation conditions. We constructed our own estimated model of the MAGNET geometry using a software coupling method made up of MOOSE/SAM software systems. The steady state results of this work have been published in a former article. The new results mainly focus on the transient states. By communicating with the Idaho National Laboratories, we upgraded the geometry of MAGNET heat pipes. This not only verifies the design of the facility under such conditions but also benchmarks the modeling capability of the MOOSE/SAM code system that can be potentially used to model other microreactor concepts in the future. 相似文献
9.
Aiichiro Nagaki Yiyuan Jiang Hiroki Yamashita Naoshi Takabayashi Yusuke Takahashi Jun-ichi Yoshida 《化学工程与技术》2019,42(10):2113-2118
The lithiation of 5,5′‐dibromo‐2,2′‐bithiophene with one equivalent of an alkyllithium such as n‐BuLi or s‐BuLi was studied by varying the residence time in flow microreactors. With a short residence time, the product 2,2′‐bithiophene (3) derived from dilithiation was obtained preferentially and a significant amount of the starting material 5,5′‐dibromo‐2,2′‐bithiophene remained unchanged. An increase in the residence time caused a higher yield of the product 5‐bromo‐2,2′‐bithiophene derived from monolithiation with expense in the yields of 2,2′‐bithiophene and 5,5′‐dibromo‐2,2′‐bithiophene. The lithiation using MeLi gave the product 5‐bromo‐2,2′‐bithiophene preferentially even with a very short residence time. 相似文献
10.
Ma'moun Al‐Rawashdeh Xander Nijhuis Evgeny V. Rebrov Volker Hessel Jaap C. Schouten 《American Institute of Chemical Engineers》2012,58(11):3482-3493
The barrier‐based distributor is a multiphase flow distributor for a multichannel microreactor which assures flow uniformity and prevents channeling between the two phases. For N number of reaction channels, the barrier‐based distributor consists of a gas manifold, a liquid manifold, N barrier channels for the gas, N barrier channels for the liquid, and N mixers for mixing the phases before the reaction channels. The flow distribution is studied numerically using a method based on the hydraulic resistive networks (RN). The single phase hydraulic RN model (Commenge et al., 2002;48:345–358) is extended for two phases gas‐liquid Taylor flow. For ReGL <30, the accuracy for the model was above 90%. The developed‐model was used to study the effects of fabrication tolerance and barrier channel dimensions. A design methodology has been proposed as an algorithm to determine the required hydraulic resistance in the barrier channels and their dimensions. This methodology is demonstrated using a numerical example. © 2012 American Institute of Chemical Engineers AIChE J, 2012 相似文献