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测定了工艺条件对甲醇在CM-3-1 型改性分子筛催化剂上脱水生成二甲醚转化率的影响,对现用绝热式反应器进行改进,提出自热型与均温型两类新型二甲醚反应器,设计了两类反应器的结构、尺寸和操作条件。 相似文献
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通过对小型反应器内气相甲醇催化制二甲醚反应进行高温热态实验,探究了反应温度与甲醇质量空速对催化剂床层轴向温度分布的变化规律,同时分析了不同的操作条件对甲醇转化率和二甲醚选择性的影响,从而优化小型反应器的操作参数。研究结果表明:当甲醇质量空速为1 h-1时,在不同反应温度条件下,催化剂床层会出现约1.7~2.9℃的轴向绝热温升,且催化剂床层热点温度接近于催化剂床层轴向中部位置;当反应温度为250℃,甲醇质量空速为1 h-1时,催化剂床层轴向温度分布曲线较为平缓,且甲醇转化率和二甲醚收率均较高,即反应温度为250℃及甲醇质量空速为1 h-1可视为该小型反应较优的操作条件。 相似文献
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二氧化碳催化加氢合成二甲醚的研究 总被引:7,自引:0,他引:7
以自然界广泛存在的二氧化碳为原料,催化加氢制甲醇和二甲醚具有重要的经济价值。采用CNJ202工业合成甲醇催化剂和HZSM-5沸石分子筛为原料制得二氧化碳加氢一步法合成甲醇及二甲醚双功能催化剂。测试结果表明,在实验条件下,该催化剂合适的配比是HZSM-5/ CNJ202=0.5(wt),焙烧温度550℃。还原条件是在以N2为载气,2% H2气氛中,于250℃、常压下还原6小时,催化剂粒度和一定变化的操作空速对二甲醚选择性无明显影响,提高反应温度有利于增大二甲醚的选择性。 相似文献
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介绍了以联醇气为原料合成二甲醚的工业侧流试验,考察了联醇气制二甲醚用催化剂的性能。试验结果表明,该二甲醚合成催化剂的转化率、选择性、稳定性等性能达到了国内同类催化剂的先进水平。 相似文献
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二氧化碳与氢气合成二甲醚催化剂的研制 总被引:1,自引:0,他引:1
以二氧化碳为原料,加氢催化制甲醇和二甲醚具有重要的社会经济意义。研究采用CNJ202合成甲醇催化剂和HZSM-5沸石分子筛制得了二氧化碳加氢一步法合成甲醇及二甲醚双功能催化剂。实验测试结果表明,该催化剂合适的配比是HZSM-5/CNJ202=0.5(wt/wt),合适的焙烧温度550℃,还原条件是在以N2为载气,2%H2气氛中,于250℃、常压下还原6h。催化剂粒度和不太大的操作空速变化对二甲醚选择性无明显影响,提高反应温度有利于增大二甲醚的选择性。测试显示,进一步改进双功能催化剂,可望大幅度提高CO2转化率,获得较高的生成二甲醚的选择性,为工业试验提供了依据。 相似文献
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从一步法制二甲醚双功能催化剂的结构出发,综述了传统复合型和新型双层结构、核壳结构催化剂的制备、结构和性能的研究进展,并展望了双功能催化剂的发展趋势。 相似文献
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本文采用高压固定床反应装置考察了添加2%稀土氧化物(La2O3和CeO2)的Cu-ZnO-Al2O3/HZSM-5催化剂CO2加氢一步合成二甲醚的催化性能。XRD和H2-TPR结果分析发现,添加稀土氧化物后阻止了部分Cu2+还原为非晶态Cu。在513K,反应压力为3.0MPa,反应空速为1000h-1的条件下,考察了CO2加氢一步合成二甲醚的催化性能。结果表明,添加La2O3和CeO2后,催化剂的催化活性以及二甲醚的选择性均大幅提高,反应20h,CO2转化率以及二甲醚选择性变化较小,说明该催化剂稳定性较好。 相似文献
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本文对二甲醚作为替代燃料在燃烧性、气化性、储存和输配、未来能源需求方面的可行性进行了分析,认为是完全可行的。对二甲醚作为替代燃料的优缺点进行了分析,认为二甲醚的优势明显,尤其在经济性方面,具有一定竞争力。 相似文献
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为了降低火炬燃料气费用和企业的安全生产,以二甲醚替代LPG作火炬燃料气试验,采用自动点火、将二甲醚的压力稳定在0.08MPa,助燃风的压力控制在0.1MPa,结果表明:火炬系统完全可以用二甲醚替代液化石油气(LPG)作火炬燃料气。 相似文献
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Hyun Kyu Suh 《Fuel》2008,87(6):925-932
This paper investigates the effect of injection parameters on the characteristics of dimethyl ether (DME) as an alternative fuel in a diesel engine with experimental and analytical models based on empirical equations. In order to study macroscopic and microscopic characteristics of DME fuel, this work focuses on the atomization characteristics of DME and compares experimental and predicted results for spray development obtained by empirical models for diesel and DME fuel. Detailed comparisons of spray tip penetration from three different empirical correlations and from visualization experiments of diesel and DME fuels were conducted under various fuel injection conditions. In comparison with the results of different empirical equations for measured spray tip penetration, the experimental results of this study provide good agreement with the calculation results based on empirical equations, except during the earliest stage of the injected spray sequence. The results of atomization characteristics indicate that DME showed better spray characteristics than conventional diesel fuel. Also, the fuel injection delay and maximum injection rate of DME fuel are shorter and lower than those of diesel fuel at the same injection conditions, respectively. 相似文献
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Coking occurs easily and would significantly degrade the electrochemical performance for hydrocarbon‐fueled solid oxide fuel cells (SOFCs). Here, we report an integrated device combining a SOFC and a stainless steel tubing as catalyst for hydrocarbon pyrolysis in the upstream of the fuel cell. Considerable carbon nanotubes (CNTs) are grown around the outside of the stainless steel tubing when dimethyl ether (DME) is fed to the device, which dramatically reduces the C:O ratio in the fuel reaching the cell anode. Correspondingly, the carbon‐removal reforming significantly prolongs the performance stability of the fuel cell compared to that directly fueled by DME. The present results suggest that hydrocarbons can be utilized more efficiently and economically by combining a SOFC and a fix‐bed reactor containing catalysts for CNTs formation, accompanying with the co‐generation of electric power and CNTs. 相似文献
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Fengzhan Si Xiumei Chen Liang Liang Chenyang Li Jianhui Liao Changpeng Liu Xinbo Zhang Wei Xing 《Electrochimica acta》2011,(17):5966
Two types of Pt nanowires (NWs)/C catalysts with different aspect ratios and one type of Pt nanoparticles/C catalyst are successfully synthesized, and DME electrochemical performance on different extent consecutive surfaces is investigated. The morphology and crystallization are confirmed with electron microscopes and XRD. The electrochemical tests show that the nanowire catalysts, especially the one with higher aspect ratio, possess higher electrochemical surface areas, higher absorption capacity of DME, higher CO tolerance, higher electron transfer coefficient, and higher activity towards DME electrooxidation than those of the nanoparticle catalyst. The results prove that the consecutive surface favors for direct dimethyl ether fuel cell (DDFC) anodic catalyst, which are contributive to the study of the mechanism of DME electrooxidation on Pt surface and designing an effective catalyst for anodic DDFC. 相似文献
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DME (dimethyl ether, CH3OCH3) is both a good alternative fuel for transportation and power generation and an LPG substitute owing to its cleanliness, multi-source productivity and the ease with which it is transported. This study was conducted to verify whether DME is a good fuel for gas turbines and to identify potential problems in fuelling a commercial gas turbine with DME. In this study, the GE7EA gas turbine of the Pyong-tak power plant in Korea was selected as the target of DME application. Combustion performance tests were conducted by comparing DME with methane, which is a major component of natural gas. Most results of the combustion performance tests show that DME is very clean and efficient fuel for gas turbines. However, other results have shown that it is necessary to retrofit a fuel nozzle to the combustor in consideration of the combustion properties of DME in order to enhance the availability and reliability of DME fired gas turbines. 相似文献
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Christoph Noack Josef Kallo Andreas K. Friedrich 《Journal of Applied Electrochemistry》2012,42(10):833-841
The behavior of a polybenzimidazole-based high-temperature polymer electrolyte membrane fuel cell using dimethyl ether (DME) as fuel was investigated under stationary and dynamic load conditions. The power density was enhanced significantly with an increase of both operating temperature and anodic water stoichiometry. Likewise, the power density decreased with increasing DME stoichiometry. The characterization of the dynamic operation showed a strong qualitative similarity to low-temperature direct methanol fuel cells. The development of the cell voltage after a spontaneous change of cell current density could be assigned to the electrochemical oxidation of an intermediate species. 相似文献