4 ms·
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 m
by uvdiv 14y ago
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.
- alsocasey 14y agoA 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.
- sliverstorm 14y agoTangent- 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.
- surrealize 14y agoMethane has a much lower boiling point (-182 C) than propane (-42 C), so liquefying methane (and keeping it liquid) is substantially harder.
- sliverstorm 14y agoCan you not simply roughly double the pressure you store it at? Or is LPG already stored at borderline risky pressures.
- DaniFong 14y agoVapor pressure is exponentially related to temperature; you really need to keep it cold.
- surrealize 14y agoIf 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 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.
- maxerickson 14y agoNatural gas is increasingly being shipped on the oceans: http://en.m.wikipedia.org/wiki/LNG_carrier http://en.m.wikipedia.org/wiki/LNG_carrier When used as a portable fuel it is usually just compressed.
- gojomo 14y agoBut would they make a profit without government subsidies and set-asides for corn-derived fuels? That's what is at issue.
- jules 14y agoThis 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.