by MarkR » Thu 23 Jun 2005, 18:04:28
$this->bbcode_second_pass_quote('', 'D')oes anyone actually know the EROEI of this whole process--from liquifying the gas, loading it into the tanker, transporting it across the ocean, then re-expanding (do you need energy for this, or will it re-expand at room temp?)?
My understanding is it takes about 25-30% of the energy content of the gas in order to chill and liquify it.
Shipping it uses relatively little energy (a fraction of 1%), given the enormous volume. The older tankers which are powered by the LNG itself, use very inefficient gas turbines for propulsion and to power the refrigeration. More modern designs are revisiting diesels for their higher efficiency.
Regasification does need energy but there are several ways to get it. The most expensive way is to burn the gas - in which case you need about 10% of the gas for energy. However, all you really need is heat - so if you have a fast flowing tropical ocean, that will do. Or, if you have a power station, then the LNG terminal can act as a heatsink for the powerstation instead of cooling towers - if the power plant demand is about 30-50% of the LNG terminal capacity, then this can be done with virtually no loss of energy.