Catalysts alumina-based hydrotreating

Influence of Phosphorus on the Properties of Alumina-Based Hydrotreating Catalysts... 

Ml. Preparation of Alumina-Based Hydrotreating Catalysts Containing Phosphorus, Molybdenum, and Cobalt or Nickel... 

Fig. 13. Procedures for the preparation of alumina-based hydrotreating catalysts containing phosphorus, molybdenum, and cobalt or nickel, a. Impregnation or equilibrium adsorption method (coimpregnation) b, impregnation or equilibrium adsorption method (sequential impregnation) c, precipitation or hydrogel method d, sol-gel method [adapted from Iwamoto and Grimblot 40). ...

Hydrotreating catalysts are usually alumina supported molybdenum based catalysts with cobalt or nickel promotors. By 1990, the demand for hydrotreating catalysts is expected to reach 80,000,000 pounds annually (1). The increased demand for these catalysts and the limitations on the availability and supply of the active metals increase the urgency to develop effective catalyst regeneration techniques. 

Following Section 11. J, which reported some characteristic vibrational and NMR data representing phosphorus-based reference compounds (Tables VI-Vlll), it is interesting to propose similar compilations concerning phosphorus-containing alumina catalysts in the dried and calcined forms. These vibrational and NMR data (Tables IX-XII) are more informative in characterizing hydrotreating catalysts than are XRD data because the catalysts are amorphous. 

Aluminas are used in various catalytic applications, a-, y-, and -aluminas are all used as support materials, the first one in applications where low surface areas are desired, as in partial oxidation reactions. The latter two, and especially y-alumina, in applications where high surface areas and high thermal and mechanical stability are required. One of the most prominent applications of y-alumina as support is the catalytic converter for pollution control, where an alumina washcoat covers a monolithic support. The washcoat is impregnated with the catalytically active noble metals. Another major application area of high-surface aluminas as support is in the petrochemical industry in hydrotreating plants. Alumina-supported catalysts with Co, Ni, and/or Mo are used for this purpose. Also, all noble metals are available as supported catalysts based on aluminas. Such catalysts are used for hydrogenation reactions or sometimes oxidation reactions. If high... 

Ni-Mo or NAt present, industrial hydrotreating processes are based on alumina supported Co-Mo or Ni-W sulfide catalysts (2,3). We expect that transition metal containing molecular... 

Recently, the hydrogenation a mixture of toluene, styrene and 1-octene, representing a model feed for hydrotreating in the refining industry, was performed in monolith reactors [37]. One is a y-alumina monolith of diameter 1 cm and 15 or 30 cm long and the other is a more conventional cordierite monolith with a wall-coated layer of y-alumina. In both monoliths, the channels size is 1-2 mm and the catalyst is based on Ni. Substantial alkene conversions of more than 50% were observed in the small-channel reactors, which was attributed to the intensified mass-transfer rate generally measured in monolith reactors [16]. 

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