Oxygenates, synthesis methanol

In the synthesis of the boron-capped cobalt(II) tris-dioximates, ferrocenylboronic acid was also used as a capping agent [43], Reaction of this Lewis acid with anhydrous C0CI2 and dioximes in oxygen-free methanol gave clathrochelate CoNx3(BFc)2 and CoDm3(BFc)2 complexes ... 

In summary, cluster-derived catalysts have been widely used in various types of CO-based reactions such as Fischer-Tropsch synthesis, methanol synthesis, hydroformylation, carbonylation, and water-gas shift reactions. The catalytic performances of cluster-derived species are evaluated in terms of higher activities and selectivities for lower olefins and oxygenates in CO hydrogenation, compared with those of metal complexes in solution and conventional metal catalysts (Table XIII). 

Nitrite and nitrate are reduced to gaseous nitrogen by a variety of facultative heterotrophs in an anoxic environment. An organic source, such as acetic acid, sewage, acetone, ethanol, methanol, or sugar is needed to act as hydrogen donor (oxygen acceptor) and to supply carbon for synthesis. Methanol is used, as it is frequently the least expensive. The basic reactions take the form ... 

CeHsC-O-OHj. Ethylene oxide will react with two moles of methanol, with an acid catalyst, to produce the desired product. The electron rich oxygen of methanol attacks a carbon of ethylene oxide to form methyl cellosolve. The hydroxyl group becomes protonated and reacts with a second molecule of methanol. The synthesis is ... 

Comparatively the synthesis of long-chain oxygenated from methanol has attracted relatively low attention because very low selectivity was obtained in previous work, but more recent studies, using decomposed hydrotalcite (MgO/AlgOg mixed oxides) and ZnO promoted Cu as catalysts, concluded that a mixture of alcohols, ketones, aldehydes, esters and ethers, with two to nine carbon atoms (79% of the total oxygenates products) can be obtained. In addition, in this study it is proposed that the first C-C carbon bond formation goes via formyl and formaldehyde intermediates. 

Development up to the pilot scale (5 1/h) of the direct synthesis of hydrogen peroxide from hydrogen and oxygen in methanol, carried out in very safe conditions, has been reported in patent applications" " " and presented at international congresses. ... 

Wang Yu, Liu C. Oxygenates synthesis using methanol plasmas. Prepr Pap Am Chem Soc Div Fuel Chem 2005 50(2) 641. 

Lietti L, Tronconi E, Forzatti P. Synthesis of C2+ oxygenates from methanol at atmospheric pressure over alkali-promoted zinc-chromium oxide catalysts. Appl Catal 1991 70 73—86. 

Oxygen enrichment of steel blast furnaces accounts for the greatest use of the gas. Large quantities are also used in making synthesis gas for ammonia and methanol, ethylene oxide, and for oxy-acetylene welding. 

By selection of appropriate operating conditions, the proportion of coproduced methanol and dimethyl ether can be varied over a wide range. The process is attractive as a method to enhance production of Hquid fuel from CO-rich synthesis gas. Dimethyl ether potentially can be used as a starting material for oxygenated hydrocarbons such as methyl acetate and higher ethers suitable for use in reformulated gasoline. Also, dimethyl ether is an intermediate in the Mobil MTG process for production of gasoline from methanol. 

The Texaco process was first utilized for the production of ammonia synthesis gas from natural gas and oxygen. It was later (1957) appHed to the partial oxidation of heavy fuel oils. This appHcation has had the widest use because it has made possible the production of ammonia and methanol synthesis gases, as well as pure hydrogen, at locations where the lighter hydrocarbons have been unavailable or expensive such as in Maine, Puerto Rico, Brazil, Norway, and Japan. 

High temperature steam reforming of natural gas accounts for 97% of the hydrogen used for ammonia synthesis in the United States. Hydrogen requirement for ammonia synthesis is about 336 m /t of ammonia produced for a typical 1000 t/d ammonia plant. The near-term demand for ammonia remains stagnant. Methanol production requires 560 m of hydrogen for each ton produced, based on a 2500-t/d methanol plant. Methanol demand is expected to increase in response to an increased use of the fuel—oxygenate methyl /-butyl ether (MTBE). 

Because the synthesis reactions are exothermic with a net decrease in molar volume, equiUbrium conversions of the carbon oxides to methanol by reactions 1 and 2 are favored by high pressure and low temperature, as shown for the indicated reformed natural gas composition in Figure 1. The mechanism of methanol synthesis on the copper—zinc—alumina catalyst was elucidated as recentiy as 1990 (7). For a pure H2—CO mixture, carbon monoxide is adsorbed on the copper surface where it is hydrogenated to methanol. When CO2 is added to the reacting mixture, the copper surface becomes partially covered by adsorbed oxygen by the reaction C02 CO + O (ads). This results in a change in mechanism where CO reacts with the adsorbed oxygen to form CO2, which becomes the primary source of carbon for methanol. 

Synthesis Gas Generation Routes. Any hydrocarbon that can be converted into a synthesis gas by either reforming with steam (eq. 4) or gasification with oxygen (eq. 5) is a potential feedstock for methanol. 

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