Kinetic study of the deep hydrodesulfurization of dibenzothiophene over molybdenum carbide supported on a carbon black composite: Existence of two types of active sites

Hydrodesulfurization (HDS) is part of the hydrotreating process, which is an ensemble of several reactions (HDN, HDO, HDS, etc.) taking place simultaneously at the industrial scale. Only sulfur is currently submitted to drastic Europeans specifications and conventional commercial catalysts cannot reach the specifications at low cost. This paper presents the behavior of a potential substitute catalyst tested for the deep HDS of a model molecule such as the dibenzothiophene (DBT). The substitute is molybdenum carbide supported on a mesoporous carbon black composite of surface area 240 m² g⁻¹. A global kinetic study of the deep HDS of DBT (300 ppm S) was performed at 623 K and 5.0 MPa and a global kinetic model was proposed as well as global rate constants were calculated to obtain theoretical plots of concentration versus contact time to compare with the experimental data. The kinetic model and global kinetic orders were confirmed as an acceptable correlation was found between calculated and experimental data. Furthermore, the determination of the global kinetic orders indicated that two types of active sites must be present on the surface in order to explain the observed results.     

二硅化钼用于钼基的耐热涂层

介绍ＭｏＳｉＯ２用于钼基的耐热涂层，进行涂层的动力、金相学和添加剂的分析。     

微电机与微加工

简述了和微电机相关的微加工生产中的方法，介绍了微型机电部件成型的实现途径。     

整体成型钼园舟研究

本研究采用特殊的方法制取钼园舟，研究结果表明，获得了满意的结果。     

钼的高灵敏显色反应及其应用

本文提出了钼的高灵敏显色反应[Mo（Ⅵ）－SCN－Morin－BPR－Twwen80体系]和在测定微量钼的应用。研究了Mo（Ⅵ）、SCN、桑色素（Morin）、溴邻苯三酚红（BPR）和吐温80（Tween80）显色配位体系的特性，该体系的最大吸收峰为565nm，最佳酸度为0．10～0．35mol／LH2SO4介质中，摩尔吸光系数ε＝3．5×106L·mol(-1)·cm(-1)，在565nm波长处空白值最低。配合物的组成比为Mo（Ⅵ）：SCN：Morin－BPR－1：6：3（在Tween80存在下）。0～2．50μgMo(6 )／50mL范围内，服从郎伯－比尔定律。回收率为98％～102％。应用此法测定土壤和头发中微量钼，获得满意的结果。     

高温用（SiC—AlN）Mo功能梯度材料的加工

讨论了热屏蔽用（SiC－AIN）／Mo功能梯度材料的粉末冶金加工。利用钼作为基体材料，以承担结构强度和连接可能性。根据在1000K温差内的完全热传递，研究了组分配置的设计，并且以最佳的组分配置成功地加工出了（SiC－AIN）／Mo功能梯度材料的烧结坯料。     

金线断口的分析

运用扫描电子显微镜技术，对金线断口观察分析，讨论金线在拉伸过程中断裂时断口形貌及断裂的原因，发现，断裂是由于金锭中的气体和杂质引起的，并提出改进生产工艺的意见。     

含微量元素铜焊锡丝的研制

在６０／４０的锡铅焊料中加入０．２％左右的铜，凝固后具有均匀细小的共晶组织，其熔点为１８３℃，焊点强度和扩展率均高于未加铜的６０／４０锡铅焊料，并且含铜的锡铅焊料在焊接时，对铜烙铁头和微细铜线了小的熔蚀性。     

提高气门弹簧钢丝质量的途径

指出了影响气门弹簧钢丝疲劳性能的主要因素是冶金因素，介绍了国外先进的气门弹簧钢丝生产的冶炼、轧制和拉拔新工艺，提出了提高国产气门弹簧钢丝质量应采取的措施。