shortonoil wrote:First: you can not have a negative ERoEI. ERoEI is a ratio; ER/EI, neither energy returned, or energy invested can be negative, there is no negative energy (outside of theoretical discussions in physics and Star Trek movies).
Well, do excuse my sloppy wording. What I meant was of course an EROI below 1.
shortonoil wrote:Second: if you have a situation where you extract oil at an energy loss to provide liquid fuel, you are inputting energy into the process. Such as converting hydro, NG, nuclear or coal into oil by subsidizing the process with energy from those sources. This is impractical as you loose energy in the process (The Second Law). It would be more efficient, therefore more economical, to produce synfuel directly from the coal or NG. If you were insistent on pursuing such a program you would soon be out of business as your competitors could always under price you. Of course we have examples of energy loosing products being produced, like ethanol, where the government subsides the farmers and producers. This is only possible because the funds originate from (still) energy delivering oil.
No, this is wrong.
Consider that you have an oil well with an EROI at 0.9.
You must add energy to the process to get it too work. Sure. You can still make money because liquid energy can be sold at a premium.
Consider CTL. The process has large capital costs, far larger than just adding some nodding donkeys to a depleted old oil field.
It's also energy negative. Just like you have to add energy to a depleted oil field to get out liquid energy, you must do the same to a CTL factory.
That's why enhanced oil recovery is pursued much more vigourusly than CTL is.