Regeneration of amorphous NiB/SiO2 catalysts deactivated in cyclopentadiene hydrogenation

An amorphous NiB/SiO₂ catalyst, deactivated in the partial hydrogenation of cyclopentadiene to cyclopentene, was regenerated by an oxidation–reduction method. After regeneration, the activity was recovered and the selectivity almost recovered. The data of BET, H₂ uptake and XPS measurements on the regenerated catalyst are almost the same as the original counterpart. XRD and DSC tests revealed that some crystallization had occurred over the regenerated catalyst, which led to the selectivity decreasing slightly. This regeneration was repeated several times, but the structural and chemical properties were nearly the same as after the first operation. © 2000 Society of Chemical Industry     

Partial hydrogenation of cyclopentadiene over amorphous NiB alloy on α-alumina and titania-modified α-alumina

Amorphous nickel–boron alloys supported on α-alumina (NiB/Al₂O₃) and on titania-modified α-alumina (NiB/TMA) with titania loadings ranging from 1·25 to 10 wt% were prepared by a reductive impregnation method, which resulted in a highly dispersed NiB amorphous alloy on the support. When used as catalysts for partial hydrogenation of cyclopentadiene to cyclopentene in a flow fixed-bed reactor at atmospheric pressure, the NiB/Al₂O₃ showed higher activity than Ni/Al₂O₃ and Pd/Al₂O₃ but the NiB/TMA with 5 wt% of titania loading (NiB/TMA5) showed the highest activity of all for the production of cyclopentene in a temperature range of 80–200°C with 10 g gcat⁻¹ h⁻¹ of cyclopentadiene feed. The maximum yield of cyclopentene was 97% on NiB/TMA5, 92% on NiB/Al₂O₃, 60% on Ni/Al₂O₃ and 23% on Pd/Al₂O₃, respectively. The catalytic stability of the amorphous NiB/TMA5 was also excellent with time on stream. The catalyst samples were characterized by ICP, XRD, XPS, BET, TEM and O₂ adsorption. The probable modification mechanism is discussed. © 1998 SCI     

碳五馏分分离方法及其下游产品开发方向研究进展

介绍了C5馏分在世界各地的资源分布及主要C5分离企业情况,并着重介绍了C5馏分分离技术及下游深加工情况,指出了C5馏分工业利用研究开发的发展趋势。     

环戊二烯选择催化加氢制备环戊烯的研究

在固定床反应装置上,以Pd/Al2O3为催化剂,考察了其在环戊二烯(CPD)选择加氢反应中影响催化效果的因素。实验表明,当催化剂的还原温度为180℃,用质量比1:1的石英砂稀释后,可以使CPD转化率达到97.5%,环戊烯(CPE)的选择性达到93.9%,收率提高到91.6%,且Pd/Al2O3能长时间置于室温下的空气中而不失活。     

环戊二烯加氢制环戊烯的工艺条件优化研究

以环戊二烯为原料,使用PdCl3为催化剂,甲苯为溶剂,采用间歇式高压反应釜,常温条件加氢制备环戊烯。采用正交实验对环戊二烯加氢过程进行研究,确定了反应温度、催化剂用量、压力、反应时间等因素对加氢过程的影响。优化工艺条件为:反应温度25℃,催化剂比例1.0%(m/m),压力1.5 MPa,反应时间4 h,此时环戊烯的收率达85.5%。     

双环戊二烯的气相高温解聚中试

进行了双环戊二烯气相高温解聚中试研究。物料采用上进下出的方式,考察了解聚温度、停留时间、物料配比等因素对解聚过程的影响。中试连续运转６００ｈ没有出现反应器结焦现象,产品总收率大于９０％,纯度在９８％以上。     

乙二醇甲基辛基醚的合成及应用

为使环戊二烯甲基化反应顺利进行。合成具有特定功能的高沸点溶剂乙二醇甲基辛基醚,将此溶剂进行功能性应用实验;制备钠砂,对环戊二烯钠盐具有络合作用,与制成的甲基环戊二烯容易分离等都取得较好效果。同时,介绍乙二醇甲基辛基醚的制备方法,总收率达66．2％。     

双环戊二烯制备戊二醛工艺的中型试验

进行了利用乙烯裂解副产物双环戊二烯 ( DCPD)经高温气相解聚、选择加氢、催化氧化制备戊二醛的中型试验 ,确定了 DCPD高温解聚工艺条件 :反应器管壁温度 3 50～ 3 70℃ ,n ( DCPD)∶ n ( N2 ) =1 .0∶ ( 1 .0～1 .5) ,停留时间 3 .5～ 1 0 .0 s,环戊二烯 ( CPD)收率大于 90 % ;CPD选择加氢转化率 1 0 0 % ,环戊烯 ( CPE)选择性达 97% ,精制单元总收率 95% ;CPE氧化制戊二醛的收率达 60 %。戊二醛过程总收率达 50 % ,经应用实验表明 ,产品达到市场同类产品水平。     

密度泛函理论和从头计算法研究环戊二烯衍生物气态酸度及其取代基效应

用B3LYP／6-311G(2df,p)／／B3LYP／631 G*和MP2／6-311G(d,p)／／B3LYP／6-31 G*方法准确地预测了9个系列的环戊二烯衍生物(R=CN,CF3,CHO,C283,F,SiH3,H,CH3,OH,NH2)的C-H键的酸度。环戊二烯衍生物气态酸度的范围从284.9 kcal／mol (化合物5a)到357.24kcal／mol(化合物7j),分析取代基的电性、数量以及位置的影响得到了9个QSAR方程。这些数据有助于我们设计以及合成一些有机酸,并有助于深刻理解相关反应中环戊二烯衍生物的性质。     

我国C5分离利用迎来发展机遇

介绍我国C5馏分分离产业现有水平及发展趋势,从C5馏分中分离出的双环戊二烯、异戊二烯、间戊二烯的消费现状及市场前景.