The effects of Cl-induced alloying in Pt–Sn/Al2O3 catalysts on butane/H2 reactions

The effects of oxidation/reduction regeneration treatments, with and without 1,2-dichloropropane present as a chlorinating agent, on the structure of Pt(3%)–Sn(4.5%)/Al₂O₃ catalysts have been correlated with selectivities for butane/H₂ reactions. Particles of Pt⁰ fin Cl-free catalysts were partly covered by Sn⁰, but retained exposed ensembles of Pt atoms which were active for isomerisation, hydrogenolysis and dehydrogenation reactions, the latter becoming dominant at high reaction temperatures. Coking reduced Pt ensemble size and, hence, also favoured high selectivities for dehydrogenation as hydrogenolysis and isomerisation sites became poisoned. In contrast, the addition of 1,2-dichloropropane in an oxychlorination step before reduction promoted 1:1 Pt⁰–Sn⁰ alloy formation after reduction, the proportion of the total Pt in alloy being enhanced by increasing 1,2-dichloropropane concentration and oxychlorination temperature. The alloy surfaces were inactive for isomerisation and hydrogenolysis reactions, giving dehydrogenation as the sole catalytic reaction.     

Dehydrocyclization of 1-hexene to benzene on Cu3Pt(111)

The disproportionation ofn-butane (and of isobutane) was catalyzed by sulfated zirconium oxide containing 1.5 wt% Fe, 0.5 wt% Mn, and 4.0 wt% sulfate at 2.0 atm and temperatures in the range of 30–60C. The reaction accompanies isomerization, which under some conditions is as much as one or two orders of magnitude faster than disproportionation. The conversion to each of the products increased with time on stream in a flow reactor, and then declined. The time on stream for maximum conversion was the same for each product. The results suggest that the disproportionation and isomerization reactions proceed through a common C₈ intermediate. Rates of the disproportionation reaction were determined at the time on stream corresponding to the maximum conversion at each temperature; for example, the rate of conversion ofn-butane into isopentane at 60C with ann-butane partial pressure of 0.58 atm was about 1×10^–7 mol/(g of catalyst s).     

2,2-二(4-羟基苯基)丁烷的催化合成

以活性炭固载磷钨杂多酸为催化剂,苯酚和丁酮为原料,催化缩合了2,2-二(4-羟基苯基)丁烷(双酚B),并使用红外光谱法鉴定了产物的化学结构。通过正交试验筛选出最优反应条件,在此基础上考察了助催化剂巯基乙酸对产物收率的影响及催化剂的稳定性。最终确定的反应条件为:苯酚与丁酮摩尔比为8∶1,催化剂用量为反应物总质量的12%,助催化剂巯基乙酸与丁酮的摩尔比为0.014∶1,反应温度为130℃,反应时间为7 h,产物收率可达56.7%。     

利用重整装置丙丁烷生产环保制冷剂R600a工艺设计

本文介绍了利用重整装置丙丁烷为原料,生产环保制冷剂R600a的工艺生产过程。通过确定原料、工艺流程,利用工艺设计软件Aspen plus对该生产装置进行了模拟计算。并提出了该生产装置关键设备的工艺设计方法及设计要点,塔设备的具体操作条件、最佳进料位置的确定,以及建该装置的意义。     

我国C_4烃和芳烃及其下游产品发展机会分析

对我国C4烃和芳烃及其下游产品的生产和消费做了分析,并针对其未来发展机会给出了建议。     

在V-Mg-O催化剂上丁烷氧化脱氢制丁二烯和丁烯Ⅰ.反应器的影响

采用惰性膜反应器（IMR）和固定床反应器（FBR）研究了V－Mg-O催化剂上丁烷氧化脱氢制丁二烯和丁烯的反应，采用在陶瓷膜上部分涂釉方法得到的惰性膜的渗透率符合实验要求，用多级全混流模型描述IMR中丁烷氧化脱氢反应，数学模型的计算结果与实验结果相差较小，分析了IMR和FBR中轴向气体分压，反应速率及瞬时选择性的分布，结果表明，用惰性陶瓷膜管作为空气分布器的膜反应器，可以降低丁烷氧化脱氢反应中催化剂床层的氧气分压，提高C4烯烃（丁二烯和丁烯）的选择性。     

Heat transfer from an impinging premixed butane/air slot flame jet

Experiments were performed to study the heat transfer characteristics of a premixed butane/air slot flame jet impinging normally on a horizontal rectangular plate. The effects of Reynolds number and the nozzle-to-plate distance on heat transfer were examined. The Reynolds number varied from 800 to 1700, while the nozzle-to-plate distance ranged from 2d_e to 12d_e. Comparisons were made between the heat transfer characteristics of slot jets and circular jets under the same experimental conditions. It was found that the slot flame jet produces more uniform heat flux profile and larger averaged heat fluxes than the circular flame jet.     

丁烷氧化脱氢 V-Mg-O 系催化剂的研究

利用无氧脉冲技术并结合 FTIR 和 XPS 对丁烷在 V-Mg-O 系催化剂上的氧化行为进行了研究,结果表明:V-Mg-O 系催化剂对丁烷具有互相独立的完全氧化和选择性脱氢两种活性位;当钒含量达一适当比例时,催化剂具有较高的反应活性,证实了正钒酸镁不是这种催化剂的活性组分.本文亦研究了温度对反应的影响,初步探讨了催化剂的结构与其活性间的关系.