共查询到17条相似文献,搜索用时 500 毫秒
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双功能催化剂是一步法合成二甲醚的关键。双功能催化剂两种活性组分之间处于最佳匹配关系时,可获得较高的二甲醚收率。二甲醚合成过程中,不仅要求分子筛表面分布较多的酸活性位,而且还要有合适的酸强度。合成二甲醚过程中,优化脱水催化剂使其与甲醇合成催化剂产生"协同效应"是研究重点。为获得较高的二甲醚收率,甲醇脱水催化剂具有合适的酸性是双功能催化剂改性的一个方向。 相似文献
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综述了CO2加氢直接制二甲醚双功能催化剂的研究进展情况,重点介绍了双功能催化剂中甲醇合成活性组分、甲醇脱水活性组分和双功能催化剂的制备方法.CuO-ZnO基复合氧化物是最常用的甲醇合成活性组分,其铜锌比、制备方法和条件及助剂等显著影响双功能催化剂的性能.由于反应体系中含有较多的水,HZSM-5分子筛比γ-Al2O3更适合作为双功能催化剂的甲醇脱水活性组分. 相似文献
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合成气一步法制二甲醚催化剂的有效导热系数 总被引:1,自引:1,他引:0
使用稳态热流法测量了220℃~260℃范围内XNC-98型甲醇合成催化剂及CNM-3型甲醇脱水催化剂的导热系数,实验结果显示,在上述温度范围内两种催化剂的导热系数与温度成线性关系。提出由两种催化剂均匀混合而成混合催化剂的并联传热简化模型和导热系数的计算式,测量了甲醇合成催化剂和甲醇脱水催化剂的质量比分别为1∶1和2∶1时合成气一步法制二甲醚的双功能催化剂的导热系数,计算值与实验值的最大误差不超过2%。实验结果表明该模型可以用于计算混合催化剂的导热系数。 相似文献
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甲醇合成催化剂使用经验总结 总被引:8,自引:0,他引:8
甲醇合成催化剂在山东齐鲁石化第二化肥厂使用时存在寿命短、产量低等问题。通过对催化剂进行剖析研究 ,找到了原因 ,并采取了相应的改进措施 ,最终使甲醇合成催化剂使用寿命从半年延长到一年半 ,单炉催化剂甲醇产量从 3万t增加到 9 9万t,催化剂的甲醇生产能力达到了 5 5 0 0t/m3 cat,从而解决了甲醇合成催化剂使用寿命短、产量低的问题。 相似文献
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Abstract Four bifunctional catalysts were prepared by physical mixing of a commercial methanol synthesis catalyst (JC207 catalyst, a catalyst for methanol synthesis, which has been industrialized in China) with zeolite HZSM-5 (Si-Al ratios of 25, 38, 50, 150) as a methanol dehydration catalyst. The bifunctional catalyst (JC207/HZSM-5 [Si/Al = 38]) showed better performance, which can be attributed to more acidic sites with moderate strength of zeolite, and which can control methanol dehydration rate, which is a rate determining step. 相似文献
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采用不同水蒸气处理温度制备了一系列 HZSM-5分子筛,考察了其催化甲醇脱水反应的性能,并以其为甲醇脱水活性组分与铜基甲醇合成活性组分(Cu-ZnO-Al2O3 )组成双功能催化剂,考察了其对合成气直接制二甲醚反应的催化性能。结果表明,随着水蒸气处理温度的提高,HZSM-5分子筛的酸性逐渐减弱,从而使甲醇脱水反应的二甲醚选择性逐渐增大。对于催化合成气直接制二甲醚反应,当HZSM-5分子筛在适当温度(500℃)下进行处理时,可使反应产物中 CO2副产物的选择性明显下降,目的产物二甲醚的选择性显著提高。当处理温度过高(600℃)时,CO的转化率和二甲醚的选择性均明显降低。相同温度下的水蒸气和氨水蒸气处理对 Cu-ZnO-Al2O3/HZSM-5双功能催化剂催化合成气直接制二甲醚反应的性能几乎无影响。 相似文献
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Makarand R. Gogate Annabelle Foos Sunggyu Lee Conrad J. Kulik 《Petroleum Science and Technology》1991,9(8):949-975
In the liquid phase dimethyl ether (DME) synthesis process, both the methanol synthesis catalyst )composed of CuO, ZnO, and Al2O3) and the methanol dehydration catalyst (composed of gamma-alumina) are slurried in the inert oil phase. Various long-term activity checks were conducted on these dual catalysts to characterize the crystal growth and the thermal aging behavior. X-ray powder diffraction, X-ray fluorescence and elemental intensity compositions, and the crystallite size distributions of the aged catalysts were examined. Based on the current investigation, it was established that the crystal growth and the catalyst deactivation problems in the methanol synthesis catalyst are less severe when it is used along with the methanol dehydration catalyst. 相似文献
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Makarand R. Gogate Annabelle Foos Sunggyu Lee Conrad J. Kulik 《Petroleum Science and Technology》2013,31(8):949-975
ABSTRACT In the liquid phase dimethyl ether (DME) synthesis process, both the methanol synthesis catalyst )composed of CuO, ZnO, and Al2O3) and the methanol dehydration catalyst (composed of gamma-alumina) are slurried in the inert oil phase. Various long-term activity checks were conducted on these dual catalysts to characterize the crystal growth and the thermal aging behavior. X-ray powder diffraction, X-ray fluorescence and elemental intensity compositions, and the crystallite size distributions of the aged catalysts were examined. Based on the current investigation, it was established that the crystal growth and the catalyst deactivation problems in the methanol synthesis catalyst are less severe when it is used along with the methanol dehydration catalyst. 相似文献