Methane oxidation states

The carbon m methane has the lowest oxidation number (—4) of any of the com pounds m Table 2 4 Methane contains carbon m its most reduced form Carbon dioxide and carbonic acid have the highest oxidation numbers (+4) for carbon corresponding to Its most oxidized state When methane or any alkane undergoes combustion to form carbon dioxide carbon is oxidized and oxygen is reduced A useful generalization from Table 2 4 is the following... 

Oxidation of carbon corresponds to an increase in the number of bonds between carbon and oxygen or to a decrease in the number of carbon-hydrogen bonds Conversely reduction corresponds to an increase in the number of carbon-hydrogen bonds or to a decrease in the number of carbon-oxygen bonds From Table 2 4 it can be seen that each successive increase m oxidation state increases the number of bonds between carbon and oxygen and decreases the number of carbon-hydrogen bonds Methane has four C—H bonds and no C—O bonds car bon dioxide has four C—O bonds and no C—H bonds... 

Metal oxide-mediated oxidation of methane using air as a primary oxidant is an alternative way to produce N2-free syngas. The concept is based on the oxidation of methane by transition metal oxides in high-oxidation state yielding syngas and corresponding metal oxide in a low-oxidation state ... 

For a couple of centuries, scientists have been making an analogy between human metabolism and the burning of a candle. The analogy is really pretty good. A candle is basically lipid in nature and most of its carbon atoms are attached to hydrogen atoms. This is a low oxidation state, similar to that of methane. Much of our food is as well we call it fat. When a candle bums, it converts the candle wax into carbon... 

In this paper, we summarize results from a small scale methane direct oxidation reactor for residence times between lO and lO seconds. For this work, methane oxidation (using air or oxygen) was studied over Pt-10% Rh gauze catalysts and Pt- and Rh-coated foam and extruded monoliths at atmospheric pressure, and the reactor was operated autothermally rather than at thermostatically controlled catalyst temperatures. By comparing the steady-state performance of these different catalysts at such short contact times, tiie direct oxidation of methane to synthesis gas can be examined independent of the slower reforming reactions. 

First you need to balance a reaction in which some of the carbons in benzene (redox state -I) are oxidized to bicarbonate carbons (redox state +IV) and the rest are reduced to methane (redox state -IV) ... 

Calculate the steady-state output trichloroethene concentration (/tM) after the methanotrophs have increased their biomass to a steady state level (cell-m-3) assuming a tank with a volume of either V= 10 m3 or 50 m3. Assume you have a waste water flow, Q, of 5 m3 d l, a microbial inoculum with growth properties like those shown in Table 17.6 for the landfill-derived methane oxidizers, and a die-off coefficient b of 0.1 d . 

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