Synthesis gas, production from methane

Synthesis gas production. Alqahtany et al.92 have studied synthesis gas production from methane over an iron/iron oxide electrode-catalyst. Although the study was essentially devoted to fuel cell operation, for purposes of comparison some potentiometric work was performed at 950°C. It was found that under reaction conditions Fe, FeO or Fe304 could be the stable catalyst phase. Hysteresis in the rates of methane conversion were observed with much greater rates over a pre-reduced surface than over a pre-oxidised surface possibly due to the formation of an oxide. 

INVESTIGATION OF SYNTHESIS GAS PRODUCTION FROM METHANE BY PARTIAL OXIDATION OVER SELECTED STEAM REFORMING COMMERCIAL CATALYSTS... 

Alqahtany H, Eng D, Stoukides M (1993) Synthesis gas production from methane over an iron electrode in a solid electrolyte cell. J Electrochem Soc 140 1677-1681... 

In principle biomass is a useful fuel for fuel cells many of the technologies discussed above for using biomass as a fuel produce either methane or hydrogen directly and as highlighted below synthesis gas production from biomass for conversion to methanol is an attractive option. Cellulose-based material may be converted to a mixture of hydrogen (70% hydrogen content recovered), CO2 and methane by high-temperature treatment with a nickel catalyst. 

Of all the oxygenates, methyl-t-butyl ether (MTBE) is attractive for a variety of technical reasons. It has a low vapor pressure, can be blended with other fuels without phase separation, and has the desirable octane characteristics. If oxygenates achieve recognition as vehicle fuels, the biggest contributor will probably be methanol, the production of which is mostly from synthesis gas derived from methane. 

In steam reforming for synthesis gas production from natural gas on a Ni/alumina catalyst, coke is mainly formed by tiie cracking of hydrocarbons. For a methane feed the main reactions and the coking reactions can be represented by ... 

Synthesis gas production from combined CO2 reforming and partial oxidation of natural gas Maximization of both methane conversion and carbon monoxide selectivity while maintaining tiie hydrogen to carbon monoxide ratio close to 1. Real-coded NSGA with blend crossover Empirical models were used for optimization. Mohanty (2006)... 

Propane and butane are transformed on the corresponding olefin using a catalyst comprising alumina-chromia on supported and promoted platinum or tin. CJ-C4 olefins can also be obtained fi om methanol on ZSM-5 zeolites. Methanol intum could be obtained fi-om synthesis gas produced from methane, or in the future may be produced directly from methane. When olefins are produced they can easily be used for petrochemicals or reacted on zeolites to produce aromatics, foels, or fine chemicals and commodity products (123). 

According to another important and promising technology, hydrocarbons are produced from methanol, which, in turn, is synthesized from synthesis gas. Called the methanol-to-gasoline process, it was practiced on a commercial scale and its practical feasibility was demonstrated. Alternative routes to eliminate the costly step of synthesis gas production may use direct methane conversion through intermediate monosubstituted methane derivatives. An economic evaluation of different methane transformation processes can be found in a 1993 review.1... 

Methanation, that is, the transformation of CO to methane222 270-272 [Eq. (3.1), reverse process], was developed in the 1950s as a purification method in ammonia synthesis. To prevent poisoning of the catalyst, even low levels of residual CO must be removed from hydrogen. This is done by methanation combined with the water-gas shift reaction.214,273,274 In the 1970s the oil crises spurred research efforts to develop methods for substitute natural-gas production from petroleum or coal via the methanation of synthesis gas. ... 

Whatever the source of synthesis gas, it is the starting point for many industrial chemicals. Some examples to be discussed are the hydroformylation process for converting alkenes to aldehydes and alcohols, the Monsanto process for the production of acetic acid from methanol, the synthesis of methanol from methane, and the preparation of gasoline by the Mobil and Fischer-Tropsch methods. 

If the rich gas from the CRG reactor is passed over another bed of high-nickel catalyst at a lower temperature, the equilibrium of the five components is reestablished. Carbon oxides react with hydrogen to form methane and the calorific value of the gas is increased. It should be noted that this methanation step differs from that encountered in ammonia synthesis gas production because of the high steam content the temperature rise is reduced and there is no possibility of temperature runaway as the... 

It is fair to state that by and large the most important application of structured reactors is in environmental catalysis. The major applications are in automotive emission reduction. For diesel exhaust gases a complication is that it is overall oxidizing and contains soot. The three-way catalyst does not work under the conditions of the diesel exhaust gas. The cleaning of exhaust gas from stationary sources is also done in structured catalytic reactors. Important areas are reduction of NOv from power plants and the oxidation of volatile organic compounds (VOCs). Structured reactors also suggest themselves in synthesis gas production, for instance, in catalytic partial oxidation (CPO) of methane. 

Aside from the synthesis pattern shown in Fig. 19, carbon dioxide was found to cause amounts of methane to be formed at concentrations of C02 exceeding 10% in (CO + C02)/H2 = 30/70 synthesis gas (55, 56). Methane production increased with increasing concentration of C02 and with de-... 

---