能源化学(英文版)

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Direct Dimethyl Ether Synthesis

Takashi Ogawa;Norio Inoue;Tutomu Shikada;Yotaro Ohno

2003, 12 (4): 219-227.

摘要 ( 10418 )

PDF(664KB) ( 4940 )

Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various elds as a fuel such as power generation, transportation, home heating and cooking, etc. It contains no sulfur or nitrogen. It is not corrosive to any metal and not harmful to human body. An innovative process of direct synthesis of DME from synthesis gas has been developed. Newly developed catalyst in a slurry phase reactor gave a high conversion and high selectivity of DME production. One and half year pilot scale plant (5 tons per day) testing, which was supported by METI, had successfully nished with about 400 tons DME production.

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Catalytic Combustion of Methane over MnOx/ZrO2-Al2O3 Catalysts

Xiufeng Xu;Yanfei Pan;Yanxia Liu;Zhanghuai Suo;Shixue Qi;Lidun An

2003, 12 (4): 228-232.

摘要 ( 7790 )

PDF(377KB) ( 1969 )

Abstract: MnOx/Al2O3 and MnOx/ZrO2-Al2O3 catalysts were prepared by incipient wetness impregnation of Mn(CH3COO)2 on the corresponding supports, followed by the characterization using X-ray diraction (XRD), temperature programmed reduction (TPR) and BET surface area techniques. The result shows the BET surface area of ZrO2-Al2O3 is lower than that of Al2O3 due to the loading of ZrO2. However the resulted MnOx/ZrO2-Al2O3 catalyst exhibits higher activity for methane combustion than MnOx/Al2O3, because the addition of ZrO2 onto Al2O3 is benecial for the dispersion of Mn species and the improvement of the lattice oxygen activity in MnOx, subsequently the activation of methane during combustion. The optimum loading of Zr in MnOx/ZrO2-Al2O3 is in the range of 5%{10% correlated with the calcination temperatures of catalyst supports.

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A Kinetic Study of Selective Hydrogenation of Carbon Monoxide to C2 Oxygenates on Rh-Mn-Li-Fe/SiO2 Catalyst

Hongmei Yin;Yunjie Ding;Hongyuan Luo;Daiping He;Weimiao Chen;Zhiyong Ao;Liwu Lin

2003, 12 (4): 233-236.

摘要 ( 8216 )

PDF(309KB) ( 1961 )

The kinetics of CO hydrogenation for the synthesis of C2 oxygenates over Rh-Mn-Li-Fe/SiO2 was investigated. Kinetic parameters for the formation of ethanol, acetaldehyde, C2 oxygenates, methanol and methane were obtained. The activation energy, H2 and CO dependence orders for ethanol and acetaldehyde formation diered greatly, the large dierence seemed to imply that they were formed through dierent intermediates.

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A Thermodynamic Analysis on the Catalytic Combustion of Methane

Weicheng Liu;Yunpeng Xu;Zhijian Tian;Zhusheng Xu

2003, 12 (4): 237-242.

摘要 ( 8222 )

PDF(322KB) ( 2407 )

Abstract: Chemical equilibria involving 10 species and adiabatic reaction temperature of methane combustion in air under various conditions have been calculated in detail by means of total Gibbs energy minimization of the system. The calculation data show that the adiabatic combustion temperature of CH4 and air at stoichiometric ratio is up to about 2200 K, and the equilibrium concentration of NO is about 0.0018, however that of NO2 is only 1.10-6. A large amount of carbon deposition emerges when the CH4 concentration is above 26.5%. The NO and NO2 appear only when the CH4 concentration is below 16%. The maximum equilibrium concentrations of NO and NO2 are 0.0028 and 2.10-6 2 respectively, at about 8%CH4 concentration. The NO and NO2 concentrations increase with the system temperature at a low CH4 concentration. However, both of them can be decreased when CO2 or steam is introduced into the system, which also decreases the adiabatic combustion temperature. The decrease in adiabatic temperature caused by CO2 addition is more appreciable than that caused by the addition of H2O. Pressure does not have a notable effect on the system equilibrium at a low methane concentration.

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Effect of Temperature on the Deactivation of a Pd-Fe/Al2O3 Catalyst for CO Coupling to Diethyl Oxalate

Jingang Fang;Zhenghua Li;Genhui Xu;Baowei Wang;Tieli Xiang

2003, 12 (4): 243-246.

摘要 ( 9360 )

PDF(319KB) ( 2113 )

Destructive tests of the catalyst was carried out to study the eect of temperature on the catalytic activity of CO coupling to diethyl oxalate (DEO) over a Pd-Fe/Al2O3 catalyst. It was found that a temperature jump could cause the deactivation of the Pd-Fe/-Al2O3 catalyst. The catalyst deactivated at dierent temperatures has dierent characteristics. After deactivation the crystal structure of -Al2O3 did not change, but the Pd particle size was enlarged. Most of the Pd0 were oxidized to Pd2+, and Fe2+ was oxidized to Fe3+ on the surface of the deactivated catalyst. The catalyst could be regenerated, but its original activity could not be recovered completely.

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Highly Efficient Oxidative Coupling of Methane over LiCl-B2O3/MnO2 and Li2SO4-MnxOy/TiO2 Catalysts

Yingying Gu;Chengyong Dai;Qinghai Cai;Yongkui Shan

2003, 12 (4): 247-253.

摘要 ( 10383 )

PDF(1370KB) ( 1966 )

Because of the ever-increasing consumption of crude oil, the role played by the natural gas as a raw material has become more and more important in chemical industry and the potential of methane used as a source for the production of ethylene has attracted much attention. In this paper, the LiCl- B2O3/MnO2 and Li2SO4-MnxOy/TiO2 catalysts for Oxidative Coupling of Methane (OCM) have been studied, and the results show that the catalysts exhibit high activity and selectivity. Furthermore, The in uence of the components in the catalyst and the reaction conditions on OCM performance has been studied and a possible active new component, cubic Li4B7O12Cl, has been found.

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Effects of Promoters on a Ru/Sepiolite Catalyst for Carbon Dioxide Methanation

Laitao Luo;Songjun Li;Yan Ouyang

2003, 12 (4): 254-258.

摘要 ( 8428 )

PDF(346KB) ( 2042 )

In this work, CO2 methanation has been investigated over Ru-based catalysts. The eects of promoters on the activity, selectivity and reduction properties of the Ru/sepiolite catalyst were analyzed by kinetic and thermodynamic methods. The catalysts were characterized by means of TPD, and the results revealed that the addition of Mo, Mn or Co improved the properties of the Ru/sepiolite catalyst. The eects of promoters could aect the change of enthalpy, entropy and chemical potential.

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Preparation, Characterization and Application of ZnAlLa-Hydrotalcite- Like Compounds

Xianmei Xie;Xia An;Xiulan Wang;Zhizhong Wang

2003, 12 (4): 259-263.

摘要 ( 8969 )

PDF(390KB) ( 1981 )

The preparation of ZnAlLa-hydrotalcite-like compounds [ZnAlLa-HTLcs] was studied. ZnAlLa-HTLcs were synthesized by a method of variable pH with the raw materials of Zn(NO3)2, Al(NO3)3, La(NO3)3, and NaOH. The eects of some factors (i.e. pH values, the mole ratio of Al3+ to La3+, temperature and the period of hydrothermal treatment) on the preparation of HTLcs were discussed systematically. XRD, TG-DTA, FT-IR spectroscopy, and ICP were performed to characterize ZnAlLa-HTLcs samples, and the thermal stability of HTLcs was also discussed. It was shown that unique ZnAlLa-HTLcs with high crystallinity can be prepared, under the conditions of pH=5.5-6.5, n(Zn2+)/n(Al3++La3+)=2 and the atomic ratio of La3+ to Al3+ ranging from 0.07 to 2, hydrothermal treatment at 120oC for 5 h. When the calcination of the HTLcs is performed at temperatures above 200oC , ZnO phase is detected with Al2O3 and La2O3 spreading on its top. The complex metal oxides derived from ZnAlLa-HTLcs at 500oC have higher catalytic activity and selectivity than those from ZnAl-HTLcs for the esterification of acetic acid with n-butanol under the same reaction conditions.

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Selective Catalytic Reduction of NO with Methane

Xiang Gao;Qi Yu;Limin Chen

2003, 12 (4): 264-270.

摘要 ( 6015 )

PDF(546KB) ( 2299 )

The removal of nitrogen oxides from exhaust gases has attracted great attention in recent years, and many approaches have been developed depending on the application. Methane, the main component of natural gas, has great potential as a NO reductant. In this paper, a number of catalysts previous reported for this catalytic reduction of NO have been reviewed, including a direct comparison of the relative activities and eective factors of the catalysts. Reaction mechanisms have also been explored preliminarily.

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