Historically, it has been the petroleum industry griping about ethanol, but now some supporters of advanced biofuels contend that the conventional part of the RFS inhibits their opportunities given the blend wall and infrastructure issues.The Renewable Fuel Standard (RFS) and its ethanol mandate are safe from any near-term undoing. However, like any special interest program, it confronts numerous critics. The mandate levels for this year and next are pending at the Office of Management and Budget, and they will assuredly be lower than those in the 2007 Energy Act. Historically, it has been the petroleum industry griping about ethanol, but now some supporters of advanced biofuels contend that the conventional part of the RFS inhibits their o...