- #1
Jorge Stolfi
- 279
- 0
Methane from natural gas could be a great source of energy (eg. in thermoelectric plants), but the need to curb CO2 emissions stands in the way.
I wonder whether one could get useful energy from some partial combustion reaction of CH4, that yields H2O plus some carbon-containing solid that could be safely buried or stored. While that would fail to recover the full energy content of methane, it might be better than nothing.
The question has two parts: (1) find a reaction that is theoretically possible, exothermic, and carbon-trapping; and (2) figure out whether it could be achieved in practice.
The simplest answer to (1) may be
I suppose that it would be exothermic, but not very much. Correct?
The solid C-containing product could also be any of a large number of CxHyOz compounds, such as oxalic acid C2H2O4, mellitic anhydride C12O9, ... With these partly oxidized end-products one may perhaps recover a large fraction of the heat yielded by full combustion.
Part (2) of the question seems harder, as the carbon seems easier to oxidize than the hydrogens. It seems that attempt at partial combustion with 1:1 methane oxigen ratio usually gives syngas:
However it seems that at high pressure the reaction is shifted to
This reaction seems to be a commercially interesting synthesis route for methanol, but could it be also a useful source of heat? (Note that additional processing would be needed to convert the methanol into a safely disposable solid.)
I wonder whether one could get useful energy from some partial combustion reaction of CH4, that yields H2O plus some carbon-containing solid that could be safely buried or stored. While that would fail to recover the full energy content of methane, it might be better than nothing.
The question has two parts: (1) find a reaction that is theoretically possible, exothermic, and carbon-trapping; and (2) figure out whether it could be achieved in practice.
The simplest answer to (1) may be
CH4 + O2 → C + 2H2O
I suppose that it would be exothermic, but not very much. Correct?
The solid C-containing product could also be any of a large number of CxHyOz compounds, such as oxalic acid C2H2O4, mellitic anhydride C12O9, ... With these partly oxidized end-products one may perhaps recover a large fraction of the heat yielded by full combustion.
Part (2) of the question seems harder, as the carbon seems easier to oxidize than the hydrogens. It seems that attempt at partial combustion with 1:1 methane oxigen ratio usually gives syngas:
CH4 + O2 → CO + H2O + H2
However it seems that at high pressure the reaction is shifted to
CH4 + 0.5O2 → H3COH
This reaction seems to be a commercially interesting synthesis route for methanol, but could it be also a useful source of heat? (Note that additional processing would be needed to convert the methanol into a safely disposable solid.)