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61.
The compound metal oxide Lax Pby Mnz O used as support was prepared by the sol-gel method, and the catalyst in which Pd was used as active component and Sn as co-active component for direct synthesis of diphenyl carbonate (DPC) with heterogeneous catalytic reaction was obtained by co-calcination and precipitation respectively. The catalyst was characterized by XRD, SEM and TEM respectively. The specific surface area of catalysts was measured by ChemBET3000 instrument, and the activity of the catalysts was tested by the synthesis of DPC in a pressured reactor. The results showed that when the co-active component Sn was added by co-calcination method A, its loading content was equal to 14.43% and active component Pd was loaded by precipitation, the yield and selectivity of DPC could reach 26.78% and 99% respectively. 相似文献
62.
Hydrogen peroxide (H2O2) precipitation from sodium aluminate (SA) solution at close-ambient temperature is an efficient method to synthesize boehmite and its derived alumina with high surface area, but the precipitation yield of Al2O3 is usually below 50% in highly alkaline SA solutions. Here the synthesis of boehmite is enhanced through a precarbonization-assisted H2O2 route in highly alkaline SA solutions. It is found that the crystal structure of the precipitation product is evidently influenced by the precipitation conditions. As the precipitation temperature increases from 273 to 325 K, a small amount of gibbsite by-product is formed. As the aging temperature increases from 301 to 333 K, the crystallinity of boehmite decreases and part of the boehmite dissolves due to an increase in the pH value. Based on the above results, a precarbonization-assisted H2O2 route is proposed to obtain pure boehmite with more complete recovery of Al2O3 from highly alkaline SA solutions. The route includes a controllable precarbonization step of SA solutions with a molar ratio of Na2O to Al2O3 higher than 2︰1, followed by the H2O2-precipitated step with a molar ratio of H2O2 to Al2O3 less than 7︰1. Because of its facile operation conditions, no extraneous impurity, time saving and a possible recycle of the filtrate, the route has great potential to be an alternative method for preparation of boehmite and its derived alumina. 相似文献
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借助Aspen模拟软件平台,对以环己酮、过氧化氢为原料,B2O3/γ-Al2O3固体酸两步催化合成ε-己内酯的产物体系的精馏分离工艺进行了模拟计算。在考虑各组分特性的基础上,采用UNIQ-NTH物性方法、RadFrac严格模型,分别对精馏塔的串联流程及并联流程进行了模拟计算。结果表明:并联流程优于串联流程,模拟计算结果能够满足工艺及产品的分离精度要求。通过对并联流程各精馏塔进行详细的模拟计算,得到了可为实际分离工艺设计和生产操作过程提供依据的数据。 相似文献
66.
本文研制出一种填料型催化剂,通过催化填料吸收塔实现了对模拟船舶内燃机尾气中NO的络合吸收和络合液的耦合再生,提高了络合脱硝的效率及络合液催化再生的能力.通过对填料型催化剂制备工艺研究显示,催化剂中钯含量为1.20%,操作温度为40℃时,整体脱硝效果最好.其脱硝性能评价表明,在模拟烟气的气流量为150 L/h,NO的含量为700 ppm,O2的含量为10%,催化剂用量为150 g,填料装填高度为30 cm,络合液初始浓度为0.05 mol/L以及pH值为6的条件下,在脱硝率达80%以上,催化剂可以连续运行120 min. 相似文献
67.
结合固相分散法和液相浸渍法的优点,提出一种耗时短、负载量高、分散性和稳定性好的低温离子浓缩交换法,并将其用于Ag/Cu-ZSM-5分子筛催化剂的制备,即在超声波作用下进行低温离子浓缩交换,然后采用微波马弗炉焙烧,使Ag、Cu离子在分子筛的铝羟基和桥联羟基上进行离子交换,并可使更多的离子交换到活性更高的铝羟基上,从而提升了催化剂的脱硝活性和反应空速.通过对催化剂的表征以及脱硝活性的评价,表明:当硅铝比为38、硝酸银和分子筛质量比为0.453、Ag和Cu摩尔量比值为1时,Ag/Cu-ZSM-5催化剂处理NO的效果最佳.在空速为4000~4500 h-1、NO体积含量为2000 ppm(平衡气为N2)、O2体积分数为5%、温度为310~440℃的反应条件下,NO的分解率均在45%以上,在反应温度为390℃时,NO的分解率为78.1%. 相似文献
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为了推广填料在工业上的应用,对新型TP环状填料的几何参数及水力学性能进行了测定,并对所测数据进行了分析和讨论,通过对简便简化的修正,得到了适用本填料的填料层压降计算式。 相似文献
70.
非均相催化一步合成碳酸二苯酯的研究(VI)Sn 的添加量对Pd-Sn催化性能的影响 总被引:1,自引:0,他引:1
The compound metal oxide LaxPbyMnzO used as support was prepared by the sol-gel method, and the catalyst in which Pd was used as active component and Sn as co-active component for direct synthesis of diphenyl carbonate (DPC) with heterogeneous catalytic reaction was obtained by co-calcination and precipitation respectively.The catalyst was characterized by XRD, SEM and TEM respectively. The specific surface area of catalysts was measured by ChemBET3000 instrument, and the activity of the catalysts was tested by the synthesis of DPC in a pressured reactor. The results showed that when the co-active component Sn was added by co-calcination method A, its loading content was equal to 14.43% and active component Pd was loaded by precipitation, the yield and selectivity of DPC could reach 26.78% and 99% respectively. 相似文献