Decomposition products methane

Methane Decomposition Production of Hydrogen and Carbon Filaments... 

Alkaline earth metal alkoxides decompose to carbonates, olefins, hydrogen, and methane calcium alkoxides give ketones (65). For aluminum alkoxides, thermal stability decreases as follows primary > secondary > tertiary the respective decomposition temperatures are ca 320°C, 250°C, and 140°C. Decomposition products are ethers, alcohols, and olefins. 

It could be concluded that thermal plasma process for methane decomposition is very effective for the production of high purity of the hydrogen as well as synthesis of the carbon black. 

Subsequent admission of oxygen in pulses indicated that carbon deposited by methane decomposition could be removed quantitatively by oxidation. The carbon remaining on the catalysts could also be quantitatively removed in the presence of Pt by CO2 CO was the only reaction product... 

Figure 2.19 provides the thermodynamic equilibrium data for methane decomposition reaction. At temperatures above 800°C, molar fractions of hydrogen and carbon products approach their maximum equilibrium value. The effect of pressure on the molar fraction of H2 at different temperatures is shown in Figure 2.20. It is evident that the H2 production yield is favored by low pressure. The energy requirement per mole of hydrogen produced (37.8 kj/mol H2) is significantly less than that for the SMR reaction (68.7 kj/mol H2). Owing to a relatively low endothermicity of the process, <10% of the heat of methane combustion is needed to drive the process. In addition to hydrogen as a major product, the process produces a very important by-product clean carbon. Because no CO is formed in the reaction, there is no need for the WGS reaction and energy-intensive gas separation stages.

Ermakova, M. and Ermakov, D., Ni/SiOz and Fe/Si02 catalysts for production of hydrogen and filamentous carbon via methane decomposition, Catal. Today, 77, 225, 2002. 

Consider, for example, the decomposition of t-butylperoxybenzoate (TBPB). Based on the set of small molecules described above, it could be assumed that methane, carbon, and water would be the main reaction products. However, a variety of decomposition products, including a significant amount of tar, have been determined experimentally, as shown in Table 2.8. 

During decomposition, organic matter is broken down into smaller and smaller organic molecules until it is completely converted into carbon dioxide, water, and humus.2 The same is true for anaerobic decomposition except that one of the final decomposition products is methane. Thus, at any given time, intermediate decomposition products can be found in the soil solution. 

The major fossil fuels are coal and petroleum. Marine organisms were typically deposited in mud and under water, where anaerobic decay occurred. The major decomposition products are hydrocarbons, carbon dioxide, water, and ammonium. These deposits form much of the basis for our petroleum resources. Many of these deposits are situated so that the evaporation of the more volatile products such as water and ammonia occurred, giving petroleum resources with little nitrogen- or oxygen-containing products. By comparison, coal is formed from plant material that has decayed to graphite carbon and methane. 

The decomposition of methane is an important process since it can produce two valuable products hydrogen and carbon filaments. Wayne Goodman (Texas A M University) and Tushar Choudhary (ConocoPhillips) show that methane decomposition may be a viable alternative to conventional steam reforming as a source of hydrogen, without the formation of COx as a byproduct. The authors examine the effects of catalyst support and promoters, as well as the inevitable regeneration of the catalyst. The formation of carbon fibers, under certain conditions, makes this process an attractive one. 

Production of Carbon Filaments by Catalytic Methane Decomposition 176... 

Recent studies have shown that unreduced Ni catalysts/ depending on the synthesis procedure, are also efficient for the hydrogen production reaction. Since most fundamental studies have been undertaken on reduced Ni catalysts (Ni°), it will be interesting to investigate methane decomposition fundamentals on unreduced Ni catalysts. 

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