Monoxide Fischer-Tropsch reaction

Fischer-Tropsch reaction The catalytic reaction of hydrogen and carbon monoxide (synthesis gas ) to produce high-molecular weight hydrocarbons. 

Fischer-Tropsch. Caibon monoxide is catalyticaily hydrogenated to a mixtuie of straight-chain aliphatic, olefinic, and oxygenated hydrocarbon molecules in the Fischer-Tropsch reaction (eq. 11) (see Fuels, synthetic). 

Wesner, D. A., Linden, G., and Bonzel, H. P. 1986. Alkali promotion on cobalt Surface analysis of the effects of potassium on carbon monoxide adsorption and Fischer-Tropsch reaction. Appl. Surf. Sci. 26 335-56. 

Formally, at least, there is some mechanistic similarity between the water gas-shift and the Fischer-Tropsch reactions in that both can be considered in terms of an initial nucleophilic attack at the carbon atom of a coordinated carbon monoxide, OH- or H20 being the nucleophile in the gas-shift reaction and H that in the Fischer-Tropsch reaction. 

Lanthanum rhodate catalysts, carbon monoxide hydrogenation, 36 296-297 Fischer-Tropsch reaction, temperature effect, 36 297-298... 

After World War II, direct liquefaction of coal became uneconomical as the use of lower-cost petroleum products became more widespread. However, the German process of indirect coal liquefaction, the Fischer-Tropsch process, continued to hold some interest. The Fischer-Tropsch process first involved production of a carbon monoxide and hydrogen-rich synthesis gas by the controlled gasification of coal followed by a catalytic reaction process to yield a valuable mixture of hydrocarbon products. Simplified Fischer-Tropsch reactions are shown by the following equations ... 

The rapid development of the chemistry of transition metal complexes containing terminal carbene (A) or carbyne (B) ligands (7) has been followed more recently by much research centered on bridged methylene compounds (C) (2). The importance of /t-methylidyne complexes, whether in recently established binuclear examples (D), the well-known trinuclear derivatives (E), or the unusual complexes (F), has also become apparent. All are based on one-carbon (C,) fragments, and considerable interest is centered on their possible significance as models for intermediates in surface-catalyzed reactions between carbon monoxide and hydrogen (Fischer -Tropsch reactions) and related processes. These topics have been extensively ... 

Hydroformylation is a precious metal-catalyzed reaction of synthesis gas, a 1 1 mixture of hydrogen and carbon monoxide, and an olefinic organic compound to form aldehydes. The reaction was discovered by Otto Roelen in 1938 in experiments for the Fischer-Tropsch reaction [8]. In Scheme 3, hydroformylation of a terminal olefin is shown in which the addition of carbon monoxide can be conducted at both carbon atoms of the double bond, thus yielding linear (n) and branched (iso) aldehydes. 

Another important association reaction is hydrocarbon formation by carbon-carbon bond closure. This occurs with hydrocarbon fragments in the presence of hydrogen or from carbon monoxide (Fischer-Tropsch process). The surface reaction... 

The Reduction of Carbon Monoxide by Hydrogen the Fischer-Tropsch Reaction... 

Earl L. Mnetterties et al. Metal clusters as homogeneous catalysts for reduction of carbon monoxide in Fischer-Tropsch reaction... 

Synthesis gas contains a mixture of carbon monoxide and hydrogen and can be obtained from the combusfion of coa) or natural gas. This gas can be used to produce synthetic crude by the Fischer-Tropsch reaction. Describe two industrial reactors used to convert synthesis gas to a mixture of hydrocarbons by the Fischer-Tropsch process. 

These processes for obtaining synthetic fuels were used by a number of countries during World War II. They are, however, uneconomical in most cases, because hydrogen and carbon monoxide in sufficient quantities must be obtained from coal or petroleum sources. Currently, South Africa, which has large coal reserves, makes the greatest use of Fischer-Tropsch reactions in the synthesis of fuels in its Sasol plants. 

The two philosophies are typically exemplified by hydroformylation (eq. (1)) [26] on the one hand and the Fischer-Tropsch reaction (eq. (2)) [7] on the other. They both represent catalytic carbon monoxide chemistry in the first case the molecular structure of the homogeneous catalyst (Structures 1 and 2) is precisely known to be trigonal-bipyramidal,... 

The main argument in favor of this possibility is that in metal-organic complexes containing alkyl groups and carbon monoxide, cis insertion has been observed. Application of this mechanism to Fischer-Tropsch reactions is therefore essentially reasoning by analogy. Since these views have been reviewed properly, we can confine ourselves to referring to the relevant literature (20). 

Reduction of Ta(silox)3Cl2 with Na/Hg leads to a three-coordinate alkoxide complex Ta(silox)3. The coordinatively unsaturated tantalum complex is capable of cleaving H2 and O2 bonds resulting in the hydride and 0x0 complexes as illustrated in Scheme 7.14. Carbon monoxide is also split upon carbonylation of Ta(silox)3 generating the 0x0 and p-dicarbide complexes. This reaction models the C—O bond cleavage and C—C bond formation believed to occur in the Fischer-Tropsch reaction, and the ketenylidene complex Ta(silox)3(=C=C=0) was postulated as the key intermediate. On the other hand, when Ta(silox)3 was treated with pyridine and benzene, remarkable T -coordinated complexes were formed. 

Slurry reactors are also used in other situations, such as the polymerization of ethylene or propylene. Here the slurry consists of catalyst particles and a solvent, such as cyclohexane, into which the ethylene or propylene is bubbled and dissolved. Another illustration is the Fischer-Tropsch reaction between hydrogen and carbon monoxide, where these gases are dissolved in a slurry of hydrocarbon oil and catalyst (iron) particles. Catalysis by colloidal metal particles and colloidal enzyme particles are other examples, although not always is one reactant a gas. 

Carbon monoxide has three major industrial uses. The first is in the synthesis of a large variety of organic compounds. For example, it takes part in a group of reactions known as the Fischer-Tropsch reactions in which carbon monoxide is first reduced with hydrogen gas and then converted to any number of organic compounds that contain oxygen. The gas is also used to make acetic acid, a major industrial chemical used in the synthesis of polymers and other organic products. 

Carbon monoxide may be hydrogenated to produce either alcohols or hydrocarbons, depending on the catalysts used and the reaction conditions. Temperatures ranging from 100-400°C and pressures as high as 1,000 atm have been studied. Different catalysts yield radically different types of products. Important processes for uch reactions consist of the methanol synthesis, the higher-alcohol synthesis (or the variation termed the iso synthesis), the Fischer-Tropsch reaction (or the version called hydrocarbon synthesis), and the methanation reaction. These syntheses were discovered in the period 1920-1925, at which time the methanol and higher-alcohol syntheses developed rapidly. A brief summary of processes and conditions used for the hydrogenation of carbon monoxide is presented in Table 10-17. 

Production of Synthesis Gas. Synthesis gas for the Fischer-Tropsch reaction consists of mixtures of hydrogen and carbon monoxide in ratios of from O.7H2 ICO to 2.5H2 ICO. Mixtures of hydrogen and carbon monoxide have been made in the past by water-gas generators operated cyclically, usually using coke as a fuel. The coke is first heated by an air blow (1) to heat the bed, and then, during the make cycle, steam is blown through the hot coke bed (2) to produce hydrogen and carbon monoxide ... 

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