Stocker11: that was an interesting link, but it looks like that product is for cleaning heat transfer fluid systems rather than being a HTF itself.

The link Rawnoc provided gives a good description of HTF:

http://www.therminol.com/pages/application/oil.asp

It is not clear how JBI employs HTF's. But it seems that the used HTF's are to be included with the plastic for distillation into additional fuel.