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1.
A Study on the Kinetics of the Catalytic Reforming Reaction of CH4 with CO2: Determination of the Reaction Order 下载免费PDF全文
ChunyangJi LihongGong JiaweiZhang KeyingShi 《天然气化学杂志》2003,12(3):201-204
The kinetics of the catalytic reforming reaction of methane with carbon dioxide to produce synthesis gas on a Ni/(α-A1203 and a HSD-2 type commercial catalyst has been studied. The results indicate that the reaction orders are one and zero for methane and carbon dioxide, respectively, when the carbon dioxide partial pressure was about 12.5-30.0 kPa and the temperature was at 1123-1173 K. However, when the carbon dioxide partial pressure was changed to 30.0-45.0 kPa under the same temperature range of 1123-1173 K, the reaction orders of methane and carbon dioxide are one. Furthermore, average rate constants at different temperatures were determined. 相似文献
2.
Sang-Wook Park Byoung-Sik Choi Dae-Won Park Jae-Wook Lee 《Reaction Kinetics and Catalysis Letters》2007,90(2):215-223
Carbon dioxide was absorbed in an organic solutions of glycidyl methacrylate (GMA) in a semi-batch stirred tank with a plane
gas-liquid interface at 101.3 kPa to obtain the absorption rate of carbon dioxide, from which the reaction kinetics of the
reaction between carbon dioxide and GMA as studied using tetraoctylammonium chloride as catalyst. The reaction rate constants
were estimated from the mass transfer mechanism accompanied by the pseudo-first-order reaction with respect to the concentration
of carbon dioxide. An empirical correlation formula between the reaction rate constants and the solubility parameters of solvents
such as toluene, N-methyl-2-pyrrolidinone, and dimethyl sulfoxide is presented. 相似文献
3.
研究了超临界二氧化碳中α-氨基酸催化二氧化碳与环氧化物环加成反应合成环状碳酸酯,发现组氨酸的催化活性最高.在二氧化碳压力为8MPa、反应温度130℃、反应时间48h、组氨酸加入量为0.8mol%的条件下,二氧化物可以顺利的与各种环氧化物反应,以高的选择性和产率生成相应的环状碳酸酯. 相似文献
4.
The coupling reaction of carbon dioxide with epoxides was investigated using naturally occurring α-amino acids as the catalyst in supercritical carbon dioxide and it was found that L-histidine is the most active catalyst. In the presence of 0.8 mol% of L-histidine at 130 °C under 8 MPa of CO2, the reaction of carbon dioxide with epoxides proceeded smoothly, affording corresponding cyclic carbonates in good to excellent yields. 相似文献
5.
In the reaction of trans-2,4-disubstituted azetidine, trans-2, 5-disubstituted pyrrolidine, or trans-2,6-disubstituted piperidine with diphenylthiophosphinic chloride or diphenylselenophosphinic chloride in acetonitrile in the presence of potassium carbonate at room temperature, an unexpected carbon dioxide insertion produced carbamic diphenylthiophosphinic or diphenylselenophosphinic anhydride in good yield. The same product could be also obtained when the reaction was carried out under carbon dioxide atmosphere using potassium hydroxide or triethylamine as a base. This is a very simple reaction process related to the fixation of carbon dioxide without a metal catalyst. 相似文献
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Sang-Wook Park Byoung-Sik Choi Dae-Won Park Jae-Wook Lee 《Research on Chemical Intermediates》2008,34(8-9):881-889
The ionic liquid (IL) of 1,1,3,3-tetramethyl guanidinum trifluoroacetate, which was synthesized by reacting 1,1,3,3-tetramethylguanidine (TMG) and trifluoroacetic acid, was used as a catalyst of the reaction between carbon dioxide and glycidyl methacrylate (GMA)., The initial absorption rate of carbon dioxide into GMA solutions containing IL was measured in a semi-batch stirred tank with a plane gas-liquid interface at 101.3 kPa to obtain the reaction kinetics. The reaction rate constants of the reaction between carbon dioxide and GMA were evaluated from analysis of the mass transfer mechanism accompanied by the elementary reactions based on the film theory. Solvents such as toluene,N-methyl-2-pirrolidinone and dimethyl sulfoxide affected the reaction rate constants. 相似文献
8.
Increasing energy demand in the world leads to more electricity generation mainly at fossil fuel power plants. Greenhouse gases are thus produced and mostly emitted to the atmosphere directly, resulting in global warming and climate change. Carbon dioxide is believed to be a main pollutant among greenhouse gases responsible from global warming. Conventional systems using mostly amine solutions to capture carbon dioxide at the source have some disadvantages, and alternatives are constantly being searched. In this work, a benign system of aqueous calcium acetate solution was investigated for this purpose. Calcium acetate is easy to produce, relatively cheap, environmentally friendly, nonhazardous, and noncorrosive. These properties make it a great alternative for use in capturing carbon dioxide. This absorption process is accompanied by chemical reaction. Therefore, the reaction kinetics needs to be investigated before its use in absorbers. A stirred cell reactor was used in the experiments using aqueous calcium acetate solution of different concentrations (2-20% w/w) and different carbon dioxide concentrations in gas mixtures (4.5-100% v/v dry carbon dioxide) at temperatures ranging from 286 to 352 K. The Gibbs free energy change for the overall reaction between carbon dioxide and aqueous calcium acetate solution was found to be –2.75 kJ/mol that shows the reaction is exergonic and occurs spontaneously. It was also found out that the reaction is pseudo–first order with respect to carbon dioxide which was also proven by calculating the Hatta number. Activation energy and Arrhenius (frequency) constant were also determined experimentally. 相似文献
9.
Sang-Wook Park Byoung-Sik Choi Dae-Won Park Jae-Wook Lee 《Reaction Kinetics and Catalysis Letters》2007,91(1):101-110
A soluble polymer-supprted catalyst containing pendant trioctylammonium chloride was synthesized by the radical copolymerization
of p-chloromethylated styrene with styrene followed by the addition reaction of the resulting copolymer with trioctylamine. Absorption
rate of carbon dioxide into glycidyl methacrylate (GMA) solutions containing the catalyst was measured using a semi-batch
stirred tank with a plane gas-liquid interface at 101.3 kPa. The reaction kinetics of the reaction between carbon dioxide
and GMA was evaluated using the absorption rate and the mass transfer mechanism of carbon dioxide. Solvents such as toluene,
N-methyl-2-pyrrolidinone, and dimethyl sulfoxide influenced the reaction rate constants. Furthermore, this catalyst was compared
to the monomeric tetraoctylammonium chloride under the same reaction conditions. 相似文献
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The dehydrogenation of isobutane (IB) to produce isobutene coupled with reverse water gas shift in the presence of carbon dioxide was investigated over the catalyst Cr2O3 supported on active carbon (Cr2O3/AC). The results illustrated that isobutane conversion and isobutene yield can be enhanced through the reaction coupling in the presence of carbon dioxide. Moreover, carbon dioxide can partially eliminate carbonaceous deposition on the catalyst and keep the active phase (Cr2O3), which are then helpful to alleviate the catalyst deactivation. 相似文献
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Ruilong YANG Diyu ZHANG Kangwei ZHU Huanlin ZHOU Xiaoqiu YE Aart W. KLEYN Yin HU Qiang HUANG 《物理化学学报》2019,35(3):292-298
Currently, worldwide attention is focused on controlling the continually increasing emissions of greenhouse gases, especially carbon dioxide. To this end, a number of investigations have been carried out to convert the carbon dioxide molecules into value-added chemicals. As carbon dioxide is thermodynamically stable, it is necessary to develop an efficient carbon dioxide utilization method for future scaled-up applications. Recently, several approaches, such as electrocatalysis, thermolysis, and non-thermal plasma, have been utilized to achieve carbon dioxide conversion. Among them, non-thermal plasma, which contains chemically active species such as high-energy electrons, ions, atoms, and excited gas molecules, has the potential to achieve high energy efficiency without catalysts near room temperature. Here, we used radio-frequency (RF) discharge plasma, which exhibits the non-thermal feature, to explore the decomposition behavior of carbon dioxide in non-thermal plasma. We studied the ionization and decomposition behaviors of CO2 and CO2-H2 mixtures in plasma at low gas pressure. The non-thermal plasma was realized by our custom-made inductively coupled RF plasma research system. The reaction products were analyzed by on-line quadrupole mass spectrometry (differentially pumped), while the plasma status was monitored using an in situ real-time optical emission spectrometer. Plasma parameters (such as the electron temperature and ion density), which can be tuned by utilizing different discharge conditions, played significant roles in the carbon dioxide dissociation process in non-thermal plasma. In this study, the conversion ratio and energy efficiency of pure carbon dioxide plasma were investigated at different values of power supply and gas flow. Subsequently, the effect of H2 on CO2 decomposition was studied with varying H2 contents. Results showed that the carbon dioxide molecules were rapidly ionized and partially decomposed into CO and oxygen in the RF field. With increasing RF power, the conversion ratio of carbon dioxide increased, while the energy efficiency decreased. A maximum conversion ratio of 77.6% was achieved. It was found that the addition of hydrogen could substantially reduce the time required to attain the equilibrium of the carbon dioxide decomposition reaction. With increasing H2 content, the conversion ratio of CO2 decreased initially and then increased. The ionization state of H2 and the consumption of oxygen owing to CO2 decomposition were the main reasons for the V-shape plot of the CO2 conversion ratio. In summary, this study investigates the influence of power supply, feed gas flow, and added hydrogen gas content, on the carbon dioxide decomposition behavior in non-thermal RF discharge plasma. 相似文献
14.
de Petris G Cartoni A Rosi M Troiani A Angelini G Ursini O 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(24):6411-6421
A hitherto unknown, atmospherically relevant, isotope-exchange reaction was studied in ionised gaseous mixtures containing carbon dioxide and monoxide. The mechanism of the O exchange, proceeding over a double-minimum potential-energy surface, was positively established by mass spectrometric and theoretical methods that also allowed the identification and characterisation of the C2O3+ intermediate. The increase of internal energy displaces the observed reactivity towards an endothermic reaction path that involves only CO2 and represents an indirect route to the dissociation of carbon dioxide. 相似文献
15.
The reactions of propargylamine derivatives with carbon dioxide and carbon disulfide have been systematically examined in the presence of transition-metal catalysts. Pd(OAc)(2) is the best catalyst for the formation of the corresponding oxazolidinones. In addition, we found that, in the reaction of propargylamine with carbon dioxide catalyzed by palladium(0) metal catalyst in toluene, both oxazolidinone 1 and imidazolidinone 2 could be obtained under mild reaction conditions at the same time. The reaction of 1 with primary and secondary amines has been examined. A plausible reaction mechanism for the formation of 2 was proposed. In addition, in this paper, we first disclosed the ligand's effect on this reaction. Using PBu(t)(3) as a ligand with Pd(2)(dba)(3), 1 was exclusively formed in 90% yield. 相似文献
16.
Palladium-Catalyzed Addition of Carbon Monoxide and Carbon Tetrachloride to 1-Octene in Supercritical Carbon Dioxide 总被引:1,自引:0,他引:1
The Pd-catalyzed addition of carbon monoxide and carbon tetrachloride to 1-octene gave coadduct [alkyl 2-( 2, 2, 2-trichloroethyl)octanoate] as the major product in supercritical carbon dioxide by using pyridine as the base. It was found that the selectivity and the yield of coadduct were greatly affected by the pressure of carbon dioxide, the reaction temperature and the amounts of alcohol and base used. 相似文献
17.
甲烷氧化细菌催化二氧化碳生物合成甲醇的研究 总被引:2,自引:0,他引:2
甲烷氧化细菌中包含的甲烷单加氧酶(MMO)、甲醇脱氢酶(ADH)、甲醛脱氢酶(FaldDH)、甲酸脱氢酶(FateDH)经过一系列反应能够把甲烷深度氧化生成二氧化碳,并生成一定的能量物质.把二氧化碳还原为甲醇是一个需要能量的过程,目前还没有已知的有机体在温和条件下完成这一反应.研究发现,甲基弯菌Methylosi-nus trichosporium IMV 3011可以催化二氧化碳生物转化生成甲醇.在休眠的悬浮细胞中充人二氧化碳后,反应一段时间在反应液中检测到了甲醇.二氧化碳转化成甲醇是一个需要能量推动的反应,为了补充反应所消耗的能量.反应一段时间后需要用甲烷进行再生,以恢复细胞中的还原当量NADH.我们进行了反应再生的交替连续批式反应,甲醇积累量能够维持在一个比较稳定的水平.理论上,反应不会增加温室效应,这是一个有效的、环境友好的、可恢复的反应过程. 相似文献
18.
二氧化硫与戊烷的气相光化学反应研究 总被引:3,自引:0,他引:3
Baclock等^[1]的研究表明,在SO2与烃的光化学反应体系中,单重态SO2通过系间窜跃转化为三重态SO2参与光化学反应,Penzhorn等^[2,3]的研究表明,在SO2与C4以下气相烃的光化学反应中有多种产物存在,产物的复杂性预示反应为自由基链反应。Smith等^[4]等认为体系中存在烃的逐步氧化,同时证明SO2与烷烃光化学反应中自由基链反应的重要性,文献报道的研究多以凝聚态产物为切入点^[5],为避免器壁对光化学反应的影响,本文以气相物质为研究对象,对挥发性烷烃中结构最简单的戊烷与二氧化硫的光化学反应的气相反应产物,反应机理和影响因素等进行了研究。 相似文献
19.
V. P. Talzi 《Russian Journal of Organic Chemistry》2016,52(7):927-931
The compositions of aqueous 2-aminoethanol solutions used in industry for absorption of carbon dioxide resulting from combustion of natural gas have been determined by 1H and 13C NMR spectroscopy. The absorption process does not involve generally accepted paths of thermal decomposition of the absorbent in the reaction with carbon dioxide, but the main path is non-oxidative decomposition of 2-aminoethanol into ammonia and ethylene oxide. Splitting of the NMR signals of carbamate anion formed by reaction of 2-aminoethanol with carbon dioxide has been rationalized by specific structure of the anion due to intramolecular hydrogen bonding. 相似文献
20.
Critical temperatures and pressures of reacting mixture in synthesis of dimethyl carbonate with methanol and carbon dioxide 总被引:1,自引:0,他引:1
Xing Cui Guo Zhang Feng Qin Guo Fu Wang Jian Guo Wang 《中国化学快报》2008,19(2):249-252
Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide (quaternary mixture of carbon dioxide + methanol + water + DMC) were measured using a high-pressure view cell. The results suggested that the critical properties of the reacting mixture depended on the reaction extent as well as its initial composition (initial ratio of carbon dioxide to methanol). Such information is essential for determining the reaction conditions when one intends to carry out the synthesis of DMC with CO2 and methanol under supercritical conditions. 相似文献