Biofuel in paradise

The islands of Hawaii, which obviously have to import virtually all of their energy, are taking a small step toward archipelagic energy independence.  They're building a refinery to brew biofuels from agricultural biomass.

Hawaii plans biorefinery

"At the facility, biomass -- including components of Hawaiian crops, such as macadamia nuts and sugarcane -- will be ground into small pieces and dried. The small bits will then go through a process called pyrolysis, which uses sand heated to 500 degrees Celsius that transforms the material to an oil vapor in less than 800 milliseconds, Honeywell's UOP says.

The residue, or char, is used to reheat the sand.

The oil vapor, meanwhile, is condensed into a liquid fuel that can be upgraded and processed to make fuel used for transportation and industrial boilers, without the sulfur pollution associated with petroleum-refined products."

OK, but first question:  what keeps the sand heated, because we know that any process that outputs energy needs more energy as input.  That is, if the laws of thermodynamics are to be believed.