We destroy perhaps as many as 7 units of free energy in the environment and human economy to produce 1 unit of free energy as corn ethanol
And yet they still make a profit, and it is still highly rational to do so. Because it turns out 1 Joule of liquid hydrocarbons is more valuable than 7 Joules of methane or coal or sunshine.
This is why a tax on carbon is better than subsidies. Then that 7 fossile fuel Joules to 1 biofuel Joule would be a huge loss. Incentivize what you actually want to optimize.
A comment below mentions subsidies - that's certainly part of the answer. In addition, for mobile applications, not all energy sources are equal. Transportability (stability, energy density, etc.) also contribute to liquid hydrocarbon Joules being more valuable than methane, coal or sunshine.
Tangent- we have LPG, and from what I understand it's actually very successful in niche applications. Have we tried liquefied methane gas? We have many more sources of methane than propane.
Generally, it hasn't been very economical to do so, although I wonder what the numbers are now that we've got so much natural gas production in the US.
Comments
We destroy perhaps as many as 7 units of free energy in the environment and human economy to produce 1 unit of free energy as corn ethanol
And yet they still make a profit, and it is still highly rational to do so. Because it turns out 1 Joule of liquid hydrocarbons is more valuable than 7 Joules of methane or coal or sunshine.
But would they make a profit without government subsidies and set-asides for corn-derived fuels? That's what is at issue.
This is why a tax on carbon is better than subsidies. Then that 7 fossile fuel Joules to 1 biofuel Joule would be a huge loss. Incentivize what you actually want to optimize.
A comment below mentions subsidies - that's certainly part of the answer. In addition, for mobile applications, not all energy sources are equal. Transportability (stability, energy density, etc.) also contribute to liquid hydrocarbon Joules being more valuable than methane, coal or sunshine.
Tangent- we have LPG, and from what I understand it's actually very successful in niche applications. Have we tried liquefied methane gas? We have many more sources of methane than propane.
Natural gas is increasingly being shipped on the oceans:
http://en.m.wikipedia.org/wiki/LNG_carrier
When used as a portable fuel it is usually just compressed.
Methane has a much lower boiling point (-182 C) than propane (-42 C), so liquefying methane (and keeping it liquid) is substantially harder.
Can you not simply roughly double the pressure you store it at? Or is LPG already stored at borderline risky pressures.
Vapor pressure is exponentially related to temperature; you really need to keep it cold.
If you really want to produce a liquid transportation fuel from methane, the usual approach is F-T synthesis:
http://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process
Generally, it hasn't been very economical to do so, although I wonder what the numbers are now that we've got so much natural gas production in the US.