Methane-hydrogen environment

In continually submerged soils, there is no oxygen. Thus, the entire environment is anaerobic and reducing. Under these conditions, there will be a predominance of the reduced forms mentioned earlier, namely, methane, hydrogen sulfide, ferrous iron, and so on. 

A newly-reclaimed peat bog is usually an unsatisfactory medium in which to grow cultivated crops. The reasons include lack of aeration and oxidation, especially of the lower layers. Peat bogs have been under anaerobic conditions for centuries, and the roots of cultivated plants do not thrive in, or even penetrate, such an environment. This is due in part to lack of adequate oxygen, but often also to the presence of toxic amounts of such substances as ferrous iron, manganese compounds, sulfuric acid, and possibly soluble aluminum. Methane, hydrogen and sulfides are also likely to be present at least in traces initially, but are no longer formed when oxygen is abundant. 

If the production of vinyl chloride could be reduced to a single step, such as dkect chlorine substitution for hydrogen in ethylene or oxychlorination/cracking of ethylene to vinyl chloride, a major improvement over the traditional balanced process would be realized. The Hterature is filled with a variety of catalysts and processes for single-step manufacture of vinyl chloride (136—138). None has been commercialized because of the high temperatures, corrosive environments, and insufficient reaction selectivities so far encountered. Substitution of lower cost ethane or methane for ethylene in the manufacture of vinyl chloride has also been investigated. The Lummus-Transcat process (139), for instance, proposes a molten oxychlorination catalyst at 450—500°C to react ethane with chlorine to make vinyl chloride dkecfly. However, ethane conversion and selectivity to vinyl chloride are too low (30% and less than 40%, respectively) to make this process competitive. Numerous other catalysts and processes have been patented as weU, but none has been commercialized owing to problems with temperature, corrosion, and/or product selectivity (140—144). Because of the potential payback, however, this is a very active area of research. 

Methanogens, may be the Earth s oldest organisms, produce methane from carbon dioxide and hydrogen. They can survive only in an anaerobic (i.e., oxygen-free) environment and have been found in ocean trenches, in mud, in sewage, and in cow s stomachs. 

Carbon monoxide (CO) and hydrocarbons such as methane (CH4) can be used as fuels in SOFCs. It is feasible that the water gas shift involving CO (CO + H2O H2 + CO2) and the steam reforming of CH4 (CH4 + H2O 3H2 + CO) occur at the high temperature environment of SOFCs to produce H2 that is easily oxidized at the anode. The direct oxidation of CO in fuel cells also is well established. It appears that the reforming of CH4 to hydrogen predominates in... 

---