Iron-containing catalysts

KAAP [Kellogg advanced ammonia process] The first high-pressure process developed for synthesizing ammonia from its elements which does not use an iron-containing catalyst. The reformer gas for this process is provided by the KRES process. The catalyst was developed by BP it contains ruthenium supported on carbon. Developed by MW Kellogg Company in 1990 and first installed by the Ocelot Ammonia Company (now Pacific Ammonia) at Kitimat, British Columbia, from 1991 to 1992. Another plant was installed at Ampro Fertilizers in Donaldsonville, LA, in 1996. 

Figure 5.5 The four most common types of Mossbauer spectra observed in iron-containing catalysts along with the corresponding nuclear transitions. Also indicated is how the Mossbauer parameters are derived from the spectra.

With the aim of becoming independent of the individual origins and compositions of the various materials, we attempted to prepare, synthetically, an iron-containing catalyst equivalent in structure and in composition to the Magnetite of Gallivare (Sweden) which had proved, in repeated tests, to be an efficient and dependable catalyst. 

Warburg and Christian showed that the color of this old yellow enzyme came from a flavin and proposed that its cyclic reduction and reoxidation played a role in cellular oxidation. When NADP+ was isolated the proposal was extended to encompass a respiratory chain. The two hydrogen carriers NADP+ and flavin would work in sequence to link dehydrogenation of glucose to the iron-containing catalyst that interacted with oxygen. While we still do not know the physiological function of the old yellow enzyme,b the concept of respiratory chain was correct. 

The KAAP (Kellogg Advanced Ammonia process) process is the first high-pressure ammonia synthesis process that makes ammonia from nitrogen and hydrogen without the aid of an iron-containing catalyst.1 It is described in References 22-25. 

Series of zeolite-supported iron-containing catalysts with weight percent iron (% Fe) varying from 1 to 17% Fe have been prepared from Fe3(CO) 2 and the synthetic zeolites ZSM-5, mordenite and 13X by an extraction technique. The zeolites ZSM-5 and mordenite were used in the acid form, 13X in the sodium form. 

Where there are very strong M—C interactions, carbide formation can occur. For example, reduced iron is converted into Fe Cy under the Fischer-Tropsch conditions. The carbide is characterized by a lower M—C bond energy than pure metallic iron. The high chain-growth probability observed with iron-containing catalysts is a result of the relatively weak M—C bond on the iron carbide surface. 

Lunin V.V., Sichov N.N., Kruglova M.A., Grigoryan E.H., Nayborodenko Y.S., Effect of Method of Starting Alloies Preparation on Physicochemical Properties of Iron-Containing Catalysts for Ammonia Synthesis, Zhum. Phiz. Khim.,69, No. 6 (1995) 987 (Rus). 

The activity of catalysts was strongly influenced by the copper content of the parent alloy, the specific copper surface area, and addition of a second metal. Contrary to that only minor changes were observed in the M/S ratio. The highest M/S values were obtained over boron and iron containing catalysts. 

A Japanese patent issued to Watanabe and Okamoto [301] describes preparation and illustrates an iron containing catalyst for polyethylene preparation. It is shown here as an illustration ... 

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