固定床雷尼金属催化剂研究进展

雷尼金属催化剂具有价格低廉、工艺可控性强、技术成熟等优势,广泛用于各种有机合成加氢反应。但是雷尼型粉末催化剂存在容易粉化流失而活性降低、反应完毕后需要过滤分离催化剂等固有的缺点,仅能应用于小批量生产。固定床雷尼金属催化剂在工业装置上的应用进展较快,但现有文献散见于专利技术和新闻报道。本文介绍了固定床雷尼金属催化剂国内外的应用进展,总结了固定床雷尼金属催化剂的制备方法,主要有块状雷尼金属破碎、雷尼合金粉成型和热喷射镀层方法。分析了各种固定床雷尼金属催化剂制备方法的特点和创新点,指出国内外固定床雷尼金属催化剂已经取得一定进展,正在逐渐取代基于传统釜式工艺的粉末雷尼镍催化剂。     

雷尼镍双氧水装置工作液发泡问题的解决

0引言目前双氧水生产都是采用有机物自动氧化法,其中蒽醌法使用最多。国内双氧水生产主要采用镍催化剂悬浮床加氢和钯催化剂固定床加氢两种工艺。蒽醌法生产双氧水过程中,氢化工序所用催化剂分为镍催化剂和钯催化剂两种,前者主要为雷尼镍(RaneyNi),又称之为骨架镍,用于液相悬浮氢化;后者主要为以Al2O3为载体的钯催化剂,粗颗粒用于固定床氢化,细颗粒用于悬浮氢化。雷尼镍是由铝镍合金粉(镍含量>47%)经过烧碱溶液浸提处理和用重芳烃脱水后制得的,具有遇空气自燃的特点。采用雷尼镍催化剂时,氢化反应是在内部装有高速搅拌器、液体导流筒和多…     

雷尼镍催化剂活性简易测定及改性方法

我国生产的金属催化剂主要是Al-Ni二元合金的雷尼镍催化剂,它广泛用于加氢过程。Al-Ni二元合金通常含有4种金属化合物,雷尼镍催化剂的活性常受浸取温度、碱浓度,时间及洗涤过程的影响,甘露糖法是测定雷尼镍催化剂活性简易而准确的方法。雷尼镍催化剂改性方法包括合金熔合法与雷尼镍反应法。     

钼改性雷尼镍催化剂的葡萄糖加氢性能

Mo改性雷尼镍是葡萄糖加氢制备山梨醇工业中重要的催化剂。考察了不同Mo含量雷尼镍催化剂的葡萄糖加氢性能。结果表明,Mo改性雷尼镍催化剂的活性和稳定性得到大幅提高,探讨了Mo改性雷尼镍催化剂活性和稳定性提高的原因。Mo改性雷尼镍催化剂活性和稳定性提高的原因是改性催化剂中氧化态的Mo可以作为L酸吸附中心,有利于葡萄糖在催化剂上的吸附,从而提高催化剂活性;Mo的存在,减少了雷尼镍催化剂在反应过程中Al的流失量,是催化剂稳定性提高的主要原因。     

己二腈加氢用雷尼镍催化剂的开发研究

简单介绍了雷尼镍催化剂的理化性质，国内外雷尼镍催化剂在己二腈加氢反应中的使用状况及存在的差距，国产己二腈加氢用雷尼镍催化剂的开发研究过程，并对其工业化应用进行简单评价。     

改性雷尼镍在合成间苯二甲胺反应中的性能研究

考察了间苯二甲腈加氢制间苯二甲胺的雷尼镍催化剂改性前后的活性和使用寿命,发现适量添加Fe的雷尼镍在显著提高间苯二甲胺收率的同时,却降低了使用寿命。但是,经过简单再生后,完全可以恢复含Fe雷尼镍催化剂的初始活性。     

苯加氢钝化型骨架镍催化剂的研制

一、前言骨架镍催化剂——又名雷尼镍催化剂,它主要应用于有机化合物的加氢和脱氢反应。一九二七年雷尼(Raney)用苛性钠处理Ni-Al合金,制得了高活性的镍催化剂。后来,以此得名将这类催化剂称为雷尼镍催化剂。骨架镍催化剂的制备方法比较简单。先把铝加热熔融,在900～1200℃下投入一定量的镍块。随即发生强烈的放热反应,温度迅速升到1700～1900℃,经成型冷却后,加以粉碎即得合金粉,将合金粉用苛性碱溶液处理(将铝溶解除掉),然后用水洗净,得到骨架镍催化剂。在碱处理反应过程中,铝和碱反应产生了大量氢气,骨架镍催化剂不但吸附了氢,同时     

Raney-Ni催化剂的制备

Raney-Ni催化剂是一种十分重要的骨架型催化剂,由于其具有的高活性及高选择性,被广泛应用于有机反应,本文将介绍雷尼镍催化剂的比较新的制备方法及其主要的加工剂型.     

三甲基氢醌的合成

本文研究了氧化催化剂和雷尼镍催化剂的制备,以间甲酚为起始原料,使用这两种催化剂合成三甲基氢醌,收率达75％以上。     

二硝基甲苯加氢制甲苯二胺催化剂的研究进展

综述了二硝基甲苯液相加氢合成甲苯二胺催化剂的研究进展,并介绍了(Pd+Pt)/C等贵金属催化剂、雷尼镍催化剂、负载型镍基催化剂、非晶态镍催化剂和漆原镍催化剂的最新研究成果。通过对比上述各催化剂在生产成本、制备工艺及催化二硝基甲苯加氢性能等方面的优缺点,发现非晶态镍催化剂不但价格低廉,而且在1 MPa低压二硝基甲苯液相加氢的反应中表现出与(Pd+Pt)/C工业催化剂相似的活性和选择性,是替代二硝基甲苯液相加氢贵金属和雷尼镍工业催化剂的首要选择;漆原镍催化剂制备工艺简单,价格低廉,且在众多的加氢反应中表现出与骨架镍催化剂相似的催化性能,也具有较大的工业化潜质。     

Stationary catalysts for the continuous hydrogenation of fats

Hydrogenation characteristics of a wide variety of stationary catalysts were studied with an aim to explore their possible use in the continuous hydrogenation of fats. Refined soybean oil was hydrogenated continuously in a vertical flow-through reactor over a fixed bed of catalyst. Catalysts investigated were pelleted products containing Raney nickel, reduced nickel, reduced palladium, and copper chromite, as well as granulated alloys of the Raney type, such as Ni-Al, Cu-Al, Pd-Al, and Cu-Cr-Al, which were activated with alkali. These catalysts offered a wide choice of activity, selectivity, and ability to form geometrical isomers. Pelleted copper chromite and granular Raney copper-chromium were found to be highly selective toward the linolenate moiety of soybean oil, whereas pelleted palladium on carrier, as well as granular Raney nickel, Raney copper, and Raney palladium, though moderately selective, exhibited very high activity even at relatively low temperatures. A unique feature of most of the stationary catalysts was the remarkably high rate of hydrogenation. With most catalysts, the iodine value of soybean oil was reduced by 40–60 units within a reaction period of 2–4 min. The hydrogenated fat was practically free of catalyst particles.     

Structured Raney Nickel Catalysts for Liquid‐Phase Hydrogenation

Structured catalysts consisting of metal sheets on which Raney nickel was deposited by the thermal spraying method were tested for the liquid‐phase hydrogenation of glucose to sorbitol and 2‐nitrotoluene to 2‐methylaniline, used as model reactions. Catalytic tests performed in a bench‐scale (1 L) reactor showed that the catalytic activity of Raney Ni sheets is significantly higher than the one of the pellets used for fixed‐bed applications, but lower than the activity of the powder catalyst used in slurry mode. The activity could be significantly improved when applying a two‐phase co‐current flow through a monolith. In this case, the activity was superior to the one obtained with the slurry catalyst. These results confirm the potential of Raney Ni monoliths as structured catalysts.     

Die katalytische Herstellung von Zuckeralkoholen und deren Verwendung

Catalytic production of sugar alcohols (polyols) and their application . The article surveys the numerous applications of the principal sugar alcohols sorbitol and xylitol and their world production in 1978. Nowadays, the industrial production of sugar alcohols is almost exclusively by catalytic hydrogenation of the corresponding sugars; thus sorbitol is manufactured by hydrogenation of D-glucose, xylitol by hydrogenation of xylose, and mannitol by hydrogenation of invert sugar or fructose. Some 80% of the world production of sugar alcohols are manufactured in batch suspension processes using Raney nickel catalysts. Apart from the Atlas Powder continuous suspension process employing nickel-carrier catalysts, continuous processes have recently been developed which use Raney nickel and prove more economical owing to the lower catalyst costs. Trickling processes with fixed catalyst continue to play a minor role. Available production capacity based on batch suspension processes can be expanded by process optimization and new catalyst developments. A newly developed special Raney nickel catalyst reduces the specific catalyst consumption by about 50%.     

Raney Ni催化剂的制备及应用研究

Raney-Ni催化剂是一种十分重要的骨架型催化剂,由于其具有的高活性及高选择性,被广泛应用于有机反应。本文简述了Raney Ni催化剂的制备方法,阐述了铝镍合金晶体结构、第三金属、残余铝、活化条件和催化剂粒度对活性的影响,并对Raney Ni催化剂在氢化反应、脱硫、脱卤反应、硝基加氢反应、氨解反应等方面的应用作了概括说明。     

Hydrogenation of heptaldehyde to heptyl alcohol with nickel catalysts

Hydrogenation of heptaldehyde to heptyl alcohol was studied with W2 Raney nickel catalyst, prepared in the laboratory, commercial Raney nickel catalyst and Rufert nickel catalyst by varying temperature, catalyst concentration, hydrogen pressure and reaction time. The products were analyzed by gas-liquid chromatography on SE-30 column. The optimum conditions found for quantitative conversion (99.6%) of heptaldehyde to heptyl alcohol were: temperature, 100°C, W2 Raney nickel catalyst concentration, 2% based on heptaldehyde (w/w), hydrogen pressure, 145 psig and reaction time, 1 h. IICT Communication No. 3085.     

钼助剂对二硝基苯加氢催化剂的改性研究

采用猝冷法制备了Mo修饰的骨架镍催化剂,通过BET、XRD和SEM等手段对催化剂进行表征,研究助剂Mo对骨架镍催化剂组成和结构的影响,确定催化剂制备条件为:催化剂与氢氧化钠质量分数为20%的碱溶液质量比为0.6,80℃投加合金粉,催化剂在二硝基苯加氢反应中选择性和转化率近100%。     

采用骨架钴和骨架镍催化剂加氢还原制备糠醇的研究

从钼、铬、铜和铁中筛选金属铬和铁作为助催化剂加入骨架钴或骨架镍催化剂，铬和铁的量分别为催化剂质量的３％和１％。在１００～１２０℃、１０～１２ＭＰａ条件下，用上述骨架钴或骨架镍催化剂在乙醇溶剂中，氢化还原糠醛制备糠醇。用骨架镍催化剂，反应产物含有７８５％的糠醇和１９６％的四氢糠醇；用骨架钴催化剂，反应产物含有９８８％的糠醇和０８％的四氢糠醇，收率９４％。在无乙醇溶剂条件下，反应产物含有９０５％的糠醇、０３％的四氢糠醇和９２％的糠醛。在１８０℃条件下，反应产物含有９０８％的糠醇和８９％的四氢糠醇。     

癸二睛加氢制癸二胺骨架镍催化剂的研究

本文介绍了癸二脯加氢制癸二胺用骨架镍催化剂的制备方法、活化条件,以及反应温度、压力、接触时间等因素对转化率的影响,揭示了骨架镍催化剂的反应特性和用于癸二脑加氮的最佳操作条件。     

Raney-Ni催化剂甘油蒸气重整制氢研究

采用管式固定床流动反应器,以Raney-Ni为催化剂,对甘油蒸气重整制氢进行了研究,考察了常压下不同温度、料液浓度和催化剂装载量对催化活性和氢气选择性的影响。结果表明:当进料浓度合适,催化剂Raney-Ni可在较低温度下呈现出对蒸气重整制氢反应较好的催化活性和选择性。当温度为280℃、料液浓度为5%(质量分数)、流量为0.5 mL/min时,碳转化率和H_2产率分别可达99.9%和93.21%,H_2和CO选择性分别为80.70%和0.20%。     

陶瓷膜微滤骨架镍催化剂的膜污染机理分析

用孔径为0.2μm的陶瓷膜过滤骨架镍催化剂悬浮液,研究膜污染机理。结果表明,膜污染主要是骨架镍催化剂在膜表面上形成的滤饼层,当操作压力循环变化时滤饼层表现出不可逆性。工业上用过的污染膜和滤饼层的组分分析表明,污染物主要是骨架镍催化剂。应用结果也表明了膜污染原因是骨架镍催化剂在膜表面形成了不可逆性滤饼层。