In news that was somewhat overshadowed during his Midwest tour last week, EPA Administrator Scott Pruitt announced the registration of isobutanol as a fuel additive for blending into gasoline at levels up to 16 volume percent from the previous 12.5 percent blend level.

Pruitt issued a letter of notification on June 12 to Butamax Advanced Biofuels LLC registering isobutanol “after all applicable Clean Air Act requirements were met and after careful review of the numerous comments received.” Isobutanol or biobutanol is considered to be a second generation biofuel that can be made from biomass.

Butamax is a joint venture between BP and DuPont that was locked in a legal battle over the technology with Gevo Inc. for many years until the two companies came to an agreement in August 2015. Shares of Gevo skyrocketed over 300 percent this week on news of the EPA decision.