Amends the Clean Air Act to: (1) extend the duration of credits for renewable fuel and biodiesel to 36 months (currently, 12 months) after the date of generation; (2) extend the temporary exemption for small refineries from renewable fuel program requirements until 2013 (currently, they are exempted until 2011); and (3) apply the authorization of funding for the cost of loan guarantees to carry out commercial demonstration projects to demonstration projects for celluosic biomass ethanol and ethanol (currently, for celluosic biomass ethanol and sucrose-derived ethanol).