Methane fuel processing

Kus, S Taniewski, M. The effect of some impurities on the basicity of MgO tested by the transformation of 2-butanol and on its catalytic performance in oxidative coupling of methane. Fuel Processing Technology, 2002 76, 41-49. 

Hagh [13] has derived a general formula for the fuel processor efficiency. Thus, by describing the fuel processing reactions with the following general and simplified formula (by-products such as methane are not taken into consideration, the same applies for unconverted methane in case of methane fuel processing) ... 

Khodadadian, M., Taghizadeh, M., and Hamidzadeh, M. (2011) Effects of various barium precursors and promoters on catalytic activity of Ba-Ti perovskite catalysts for oxidative coupling of methane. Fuel Process. Technol, 92 (6), 1164-1168. 

X 10 GJ (436 x 10 BTU) of methane was processed into 15, 200 x 10 kg of ammonia (9) and 924 X 10 kg of methanol (3) in the United States in 1990. Natural gas prices generally foUow cmde oil prices in the United States because they compete in energy markets, but natural gas prices exhibit less volatiHty and have been lower in cost on a fuel basis. Historical natural gas and cmde oil prices are shown in Eigure 4. 

NASA conducted studies on the development of the catalysts for methane decomposition process for space life-support systems [94], A special catalytic reactor with a rotating magnetic field to support Co catalyst at 850°C was designed. In the 1970s, a U.S. Army researcher M. Callahan [95] developed a fuel processor to catalytically convert different hydrocarbon fuels to hydrogen, which was used to feed a 1.5 kW FC. He screened a number of metals for the catalytic activity in the methane decomposition reaction including Ni, Co, Fe, Pt, and Cr. Alumina-supported Ni catalyst was selected as the most suitable for the process. The following rate equation for methane decomposition was reported ... 

Figure 4.2 presents a simplified flow diagram of the ENCOAL Liquid from Coal (LFC) process. The process upgrades low-rank coals to two fuels, Process-Derived Coal (PDF ) and Coal-Derived Liquid (CDL ). Coal is first crushed and screened to about 50 mm by 3 mm and conveyed to a rotary grate dryer, where it is heated and dried by a hot gas stream under controlled conditions. The gas temperature and solids residence time are controlled so that the moisture content of the coal is reduced but pyrolysis reactions are not initiated. Under the drier operating conditions most of the coal moisture content is released however, releases of methane, carbon dioxide, and monoxide are minimal. The dried coal is then transferred to a pyrolysis reactor, where hot recycled gas heats the coal to about 540°C. The solids residence time... 

The fact that reaction (3.82) may not proceed as written at high temperatures may explain why methane oxidation is slow relative to that of other hydrocarbon fuels and why substantial concentrations of ethane are found [4] during the methane oxidation process. The processes consuming methyl radicals are apparently slow, so the methyl concentration builds up and ethane forms through simple recombination ... 

The necessary fuel processing of natural gas or other hydrocarbons and coal before its use in the SOFC changes the system design. The following investigations have been done for methane as the main component of natural gas to keep the calculations simple. A common type of fuel processing for hydrocarbons is the endothermic steam reforming process as shown for methane in Equation (2.105) with the heat demand Equation (2.106)... 

The hydrogen fuel for the PAFC is produced from hydrocarbons by fuel processing. It is worthwhile describing the gas-phase catalytic processes used to generate the hydrogen for the PAFC since the product compositions will determine how the PAFC anode operates. Methane or methanol are the easiest fuels to process, since reforming does not require breaking of a carbon-carbon bond. 

SERP. See adsorption, pressure swing SE-SMR. See sorption-enhanced steam methane reforming process Shanxi New Style Fuel and Stove Company, 520... 

The production of higher hydrocarbons directly from methane by catalytic oxidative coupling is a novel methane conversion process which warrants further study. When combined with an ethylene oligomerisation step it is a potential alternative to conventional processes, based on synthesis gas, for producing liquid fuels from methane. However, further research is necessary to provide the information required to assess the commercial prospects for this route. 

S.-Y. Lee and G.D. Holder (2001) Fuel Processing Technology, vol. 71, p. 181 - Methane hydrates potential as a future energy source . 

Thus, each molecule of methane gives rise to four molecules of hydrogen, of which two molecules originate from the steam. In reality, the practical yield of hydrogen is less than this because, as already mentioned, some of the methane is burnt externally to provide the heat needed for reaction (2.1). A schematic representation of the overall steam—methane reforming process is shown in Figure 2.2. To improve overall efficiency, unreacted fuel and steam are recycled to the reformer. 

A 1 kW SOFC prototype based on tubular cells was designed, manufactured and tested in 1989. The cell had a working surface of 63 cm2 and a mean power 12.5 W or 0.2 W/cm2 at 900°C. 16 cells were assembled into a stack. The prototype consisted of 6 stacks. The prototype was fed with methane internal partial oxidation was used for fuel processing. The prototype worked at fuel utilization of 0.9 and had efficiency about 40%. 

---