Nickel catalyst hydrogenation processing technologies

The manufacture of gas mixtures of carbon monoxide and hydrogen has been an important part of chemical technology for about a century. Originally, such mixtures were obtained by the reaction of steam with incandescent coke and were known as water gas. Eventually, steam reforming processes, in which steam is reacted with natural gas (methane) or petroleum naphtha over a nickel catalyst, found wide application for the production of synthesis gas. 

While the first commercial installation of a unit employing the t5q)e of technology in use today was started up in Chevron s Richmond, California refinery in 1960, hydrocracking is one of the oldest hydrocarbon conversion processes. Its origin is the work done by Sabatier and Senderens, who in 1897 published the discovery that unsaturated hydrocarbons could be hydrogenated in the vapor phase over a nickel catalyst. In 1904, Ipatieff extended the range of feasible hydrogenation reactions by the introduction of... 

The foremost licensors of these processes and of palladium catalysts are Amoco American Oil Co. BASF Badische Anilin itnd Soda Fabrik Bayer-lurgi, Engelhard (HPN), IFP, Lummus (DPG Hydrotreating), Mitsubishi, UOP Universal Oil Products etc. The industrial unit scheme is substant ly the same as for selective hydrogenation in the presence of nickel. However, the technology selected by Bayer differs in so far as the fee tock is cooled and the temperature maintained at the desired level by meaas of a refrigerant fluid or water. 

Due to the new developments [5] in fuel cell technology—the manufacture of carbon supported platinum catalysts and the use of the Nafion membrane—the cost of bipolar electrolyzers has been reduced a lot, and therefore almost all commercial devices are of this type. In this case, stainless steel or nickel cathodes are used together with nickel anodes in 25%-35% of potassium hydroxide at temperatures between 65°C and 90°C. The hydrogen current density reaches 100-300 mA/cm2 at cell potentials of 1.9-2.2 V, denoting a faradaic efficiency of 80% (losses in peripheries). Usually, a pressurized cell is employed to increase their performance and to reduce the size of the bubbles, thus lowering the overpotential associated with the process. This can be done with appropriate membranes and insulators and by using temperatures near 100°C. 

The state-of-the-art technology in free fatty acid hydrogenation is characterized by discontinuous operation and the use of powdered nickel on silica catalysts. Known disadvantages of this process are discontinuous operation, low... 

Two types of water-based processes were initially studied. The first of these, based on Bergstrom s earlier work (1), employed sodium carbonate as a soluble catalyst and carbon monoxide as a reducing gas (2). The second technology, also based on earlier work, used nickel metal catalysts and hydrogen (3). In all cases the substrate was powdered wood slurried in water. In both processes the role of the added chemicals was not clear. Sodium carbonate would initially dissolve any phenolic and other acidic products. However, its major role was assumed to be an aid for the addition of carbon monoxide via the formate ion. As we have shown, wood will liquefy without the addition of sodium carbonate and carbon monoxide. Researchers at the University of Saskatchewan also noted that removal... 

---