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Old 11-14-2012, 09:27 PM   #18 (permalink)
redpoint5
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Quote:
Originally Posted by oil pan 4 View Post
A pound of wood holds about 10,000 BTUs of heat.
A gallon of gas packs at least 120,000 BTUs.

The process isn't 100% efficient and the process appears to leave a good portion of energy behind as "active charcoal" waste.

I'm thinking they would need at least 20 pounds of wood to produce each gallon of gasoline.
It would be helpful to use similar units when making BTU comparisons between wood and gasoline. A gallon of gasoline weighs roughly 6lbs, so according to your figures, it has twice the energy density of wood at 20,000 BTU per pound.

EDIT: from How Stuff Works

Quote:
Propane: 21,500 BTU per pound
Butane: 21,200 BTU per pound
Gasoline: 17,500 BTU per pound
Coal: 10,000 BTU per pound
Wood: 7,000 BTU per pound
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