Dioxins (Score 1)

Based on the fuss there was in Ireland when the wrong type of oil was used when milling animal feed http://www.rte.ie/news/2008/1207/pork.html, I can't imagine this is a good idea. Combustion is exactly the process that generates dioxins, and they build up in animals that cosume them, so if these crops end up used for plant feed, or the process becomes more widespread, eventully even traces of dioxins in the fumes would cause problems.