Supreme Court justices appeared skeptical of small oil refiners' arguments to extend previously expired exemptions from federal biofuel requirements, a position opposed by biofuel producers and the Biden administration.

The refinery companies want the high court to undo the Tenth Circuit's voiding of their small-refinery economic hardship exemptions from renewable fuel blending requirements handed out by the U.S. Environmental Protection Agency, exemptions that were challenged by biofuel industry groups.

However, during oral arguments, several justices questioned the refiners' assertion that the Clean Air Act provisions covering Renewable Fuel Standard allows the EPA to extend small refinery exemptions even if they have lapsed.

Pillsbury partner Matt Morrison, representing the biofuel groups that had successfully challenged the small refinery exemptions, said that the Tenth Circuit got it right and that giving small refiners "a permanent safety valve to excuse them from their compliance obligations is belied by the text and structure of the statute, and is antithetical to Congress's goal of increasing the volume of renewable fuel in the nation's transportation system."

"All small refineries have every incentive in the world to apply for an exemption in a timely fashion because otherwise, they would have to comply," Morrison told the justices.

Read more on the arguments here.