A comparison of bulk metal nitride catalysts for pyridine hydrodenitrogenation

A comparison of various group IV–VIII bulk metal nitride catalysts identified Co₄N and Fe₃N as having higher pyridine hydrodenitrogenation activity per unit area than Mo₂N. Formation of the metal nitrides was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy, and all the nitrides were prepared from metal oxide precursors using the same temperature-programmed reaction technique. In general, the specific activity of the metal nitrides decreased with increased heat of formation of the metal nitride. This revised version was published online in July 2006 with corrections to the Cover Date.     

柴油非加氢脱氮技术研究进展

介绍了柴油非加氢脱氮技术的研究状况和近期发展动向,分析了酸碱精制、溶剂精制、吸附精制、加速老化、离子交换精制及组合脱氮、生物脱氮和微波脱氮等柴油脱氮方法的原理和特点,展望了柴油非加氢脱氮技术的应用前景。     

New technical challenges and recent advances in hydrotreatment catalysis. A critical updating review

The petroleum industry gets confronted with more stringent requirements with respect to transportation fuels: diminution by a factor of 10, or more, of the sulphur content, and a drastic diminution of the aromatic content. Besides, the quality of the crude oil supply keeps diminishing on an average. For this, the hydrotreating processes (HDS, HDN, HDM, hydrogenation, hydrocracking) will occupy a still increasing place in the refining processes. In a first part, we shall select some of the most important results published recently: use of new modifiers and supports (TiO₂, ZrO₂, mixed oxides), of metals not yet used in hydrotreating (Ru, Rh, Pd, Pt, possibly Nb, associations RuU, PdU, VU etc.), confirmation of the existence of distinct catalytic sites (hydrogenation and hydrogenolysis of the heteroatom-carbon bonds). Other new results should contribute to clarify the controversies and uncertainties concerning the origin of synergy between different elements and the changes of selectivity as a function of the experimental conditions. For this last topic, reference shall be made to the CoMoS model and the remote control theory. In a second part, we shall summarise the new constraints that the hydrotreating processes will face. It will be necessary to save still more energy. It will also be necessary to achieve a better balance of the various reactions taking place in a given process. The overall selectivity of catalysts and processes will have to be improved. In the third part, we shall try to emphasize directions of research which could help reach the objectives. We shall shortly outline the future contributions of chemical engineering. We shall examine with more details the problems concerning the genesis of adequate catalytic sites (underlining the enormous influence of the activation steps) and the modification of activity by means of the composition of the reacting medium. As the problem of synergy remains crucial for the future developments, we shall also present results with new synergetic systems (WS₂ + supported Rh or Pd; MoS₂ + supported Pt). The new results give hope that the mechanisms of synergy could get clarified in the near future.     

H2S和NH3对渣油杂原子加氢脱除反应的影响

以中东高硫渣油为原料,在4种工艺条件下分别进行了一段加氢流程和两段加氢流程的渣油加氢试验,考察H2S和NH3对渣油杂原子加氢脱除反应的影响。结果表明：H2S和NH3在催化剂活性位上的竞争吸附抑制了渣油加氢脱硫反应,加氢反应气氛中较高含量的H2S和NH3不利于渣油加氢脱硫反应;由于H2S促进C—N键加氢分解反应,H2S对加氢脱氮有促进作用,反应气氛中较高含量的H2S有利于渣油加氢脱氮反应;H2S对加氢脱金属有促进作用,反应气氛中较高含量的H2S有利于渣油加氢脱金属反应。     

催化裂化柴油氮化物分布及其加氢反应行为研究

选择不同来源的催化裂化柴油（LCO）,对其全馏分和窄馏分的氮化物进行深入分析,并研究其加氢脱氮（HDN）反应规律,深入探讨LCO中氮化物的分布规律及不同氮化物的加氢反应行为。结果表明：劣质LCO中的氮化物主要以吲哚类氮化物和咔唑类氮化物为主,苯胺类氮化物的含量比较小,且苯胺类氮化物和吲哚类氮化物主要分布在轻馏分段,咔唑类氮化物主要集中在重馏分段;当馏程大于320 ℃时,LCO中的氮化物含量剧增,且以咔唑类氮化物为主;不同LCO的氮化物分布有较好的一致性。LCO的HDN反应研究表明,咔唑类氮化物的HDN活性明显低于苯胺类氮化物和吲哚类氮化物的HDN活性,且碳数越多越难被脱除;劣质LCO经HDN反应后,产物中出现新的氮化物--苯基吲哚,而随着LCO终馏点的降低,原料中咔唑类氮化物的比例减小,HDN活性增强,产物中没有苯基吲哚生成。     

碳化钼催化剂的喹啉加氢脱氮反应性能

用程序升温还原法在CH4/H2气氛中将MoO₃碳化制备了Mo₂C催化剂, 并对Mo₂C催化剂进行了XRD和BET表征。以喹啉/环己烷溶液为模型化合物, 通过高压微反评价实验考察了Mo2C催化剂的喹啉加氢脱氮活性。结果表明, MoO₃在CH₄/H₂气氛中程序升温至终点温度675 ℃,并在此终点温度下还原碳化150 min,可制得高纯度的β-Mo2C。当还原碳化温度高于675 ℃,随着还原碳化温度的升高,Mo₂C催化剂的比表面积降低, 表面积炭增多, 导致喹啉加氢脱氮活性下降。而当还原碳化时间少于150 min时,MoO₃未能充分转化为Mo2C,导致喹啉加氢脱氮活性较低。因此,较适宜的Mo2C催化剂的合成条件为：还原碳化温度675 ℃,还原碳化时间150 min。在反应压力3.0 MPa、 空速8 h-1、H₂与原料液体积比500∶1以及 氮含量为1 000 ng·μL^-1的喹啉/环己烷溶液中, Mo2C催化剂的喹啉加氢脱氮活性明显高于MoS₂和MoO₃催化剂。Mo₂C催化剂在反应温度360 ℃的喹啉加氢脱氮转化率达到58.69%,表现出较高的喹啉加氢脱氮活性。     

Identification of carbazoles and benzocarbazoles in a coker gas oil and influence of catalytic hydrotreatment on their distribution

Fractions highly enriched in pyrrole benzologues have been extracted from a coker gas oil before and after hydrotreatment under selected operating conditions. Carbazole, methyl- and dimethylcarbazoles and benzocarbazoles have been identified by means of g.c. coelutions with standards. The study of these compounds after catalytic hydrotreatment has shown that benzocarbazoles are more effectively removed than carbazoles in highly hydrogenating conditions (partial pressure of hydrogen, 10 MPa; temperature, 360 °C) whereas alkyl carbazoles and more particularly 1-methyl derivatives are more altered at a high temperature (380 °C, partial pressure of hydrogen, 5 MPa).     

FH-40系列轻质馏分油加氢精制催化剂研制及工业应用

成功开发出性能优异的FH-40A/FH-40B和FH-40C新一代轻质馏分油加氢精制催化剂，该系列催化剂具有孔容大、比表面积高、加氢活性好及堆积密度小等特点。在同等工艺条件下，达到相同精制效果，FH-40系列催化剂比国内外参比催化剂活性高［（10～15） ℃］。工业应用结果表明，FH-40系列催化剂对原料适应性强，具有优异的加氢脱硫和加氢脱氮活性，是加工轻质馏分油的理想催化剂。     

Hydrodenitrogenation of Quinoline Over a Dispersed Molybdenium Catalyst Using in situ Hydrogen

Hydrodenitrogenation (HDN) of quinoline using a Mo-based dispersed catalyst was studied in a batch reactor using H₂ generated in situ via the water gas shift reaction. In situ H₂ was found to be more active for HDN than externally supplied H₂. Both water and H₂S have an effect on HDN.     

Mechanism of carbon-nitrogen bond cleavage during amylamine hydrodenitrogenation over a sulphided NiMo/Al2O3 catalyst

By comparison of the hydrodenitrogenation rate of amylamine with those of neopentylamine and tert-amylamine over a conventional catalyst, it was evidenced that the hydrogen atoms of the carbon in the position with respect to the nitrogen atom participate in the C-N bond cleavage. A detailed mechanism including the interaction with the catalyst is proposed for this reaction.