In the next few years, Mason City will be home to one of the most advanced biofuel and biochemical production facilities in the U.S., thanks to a plant now in development by Pennsylvania-based New Energy Blue.

The facility — dubbed New Energy Freedom — will produce about 20 million gallons of second-generation ethanol from renewable agricultural residue, specifically corn stover, the leftover part of the stalk after a field is harvested. 

Products developed at the facility will go not only into traditional consumer-level ethanol, but also renewable jet fuel and numerous other so-called “green”...