Air permitting for biofuel has become easier recently. As long as a facility is permitted for heavy fuel oil, very little is required. Valley Proteins has partnered with Trigon Engineering Consulting, Inc. of Raleigh, North Carolina, on permitting. They should be able to easily assist you, as well. The North Carolina Department of Environment and Natural Resources provides a streamlined approach specific to biofuel permitting, and similar approaches are taken in other states.