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71.
提出了传热与传质单元法间存在类似的概念。据此,不仅可由较易取得的、用于套管换热器传热过程的计算式求得用于填料塔气体吸收操作的有关公式,而且也为这二者间的模拟建立了理论基础。 相似文献
72.
Exo-tetrahydrodicyclopentadiene (exo-TCD) is an important high-energy fuel.Silicotungstic acid (SiW) immobilized on H-type β zeolite (Hβ) at room temperature were used to prepare the Hβ zeolite catalysts with different SiW contents.Catalytic performances of the catalysts were investigated during the preparation of exo-TCD via isomerization of endo-tetrahydrodicyclopentadiene (endo-TCD).The properties of catalysts were characterized by XRD,temperature pro-grammed desorption of ammonia (NH 3-TPD),FT-IR,and N 2-adsorption techniques.SiW was highly dispersed on the surface of Hβ zeolite,and the 10% SiW/Hβ zeolite catalyst had the highest amount of weak acidity among all SiW/Hβ zeolite catalysts.The influence of different factors on isomerization reaction was investigated.At a reaction temperature of 240 ℃,a n(cyclohexane) /n(endo-TCD) ratio of 10,a m(catalyst) /m(endo-TCD) ratio of 0.3,an initial pressure of 1.0 MPa,and a reaction time of 1.5 h in the presence of 10% SiW/Hβ catalyst calcined at 400 ℃,the conversion of endo-TCD reached up to 92.0%,with the yield of exo-TCD equating to 51.0%. 相似文献
73.
硅胶负载磷钨酸催化剂上金刚烷的制备 总被引:1,自引:0,他引:1
采用过量浸渍法制备了一系列硅胶(SiO2)负载磷钨酸(PW)催化剂,考察了催化剂在桥式四氢双环戊二烯(endo-TCD)异构化制备金刚烷反应中的催化性能,并采用XRD、N2吸附和NH3-TPD等手段对催化剂的物化性质进行了表征。结果表明,当PW负载量为40%时,PW仍能在SiO2表面高度分散;随着PW负载量的增加,催化剂的酸量增加,负载量为40%时酸量最大,负载量进一步增大,酸量下降,40% PW/SiO2表现出最高的催化活性。采用40% PW/SiO2为催化剂,考察了各种反应条件对催化性能的影响。实验结果发现,适宜的反应条件为:催化剂活化温度200℃,反应温度260℃,反应时间3h,初始压力1.1MPa。当催化剂与原料的质量比为0.7,溶剂环己烷与原料的摩尔比为5.0时,endo-TCD的转化率达到99.5%,金刚烷的收率达到24.7%。 相似文献