Gevo Inc., which produces an alternative alcohol in a former ethanol plant in Luverne, Minn., said Monday that the Army has successfully flown a Black Hawk helicopter using a 50-50 blend of jet fuel and the company's biofuel.

The fuel, isobutanol, was produced at the Luverne plant and converted to jet fuel at Gevo's hydrocarbon processing plant in Silsbee, Texas. The test flight took place in Alabama last month, but its announcement was delayed while Gevo completed a $23 million secondary stock ­offering, the company's general counsel, Brett Lund, said in an interview.

The military, which has long supported biofuel development, is among the early customers of Gevo as it ramps up commercial production of isobutanol at its Luverne plant. Gevo also has contracts to sell jet fuel to the Navy and Air Force. In 2012, the Air Force flew an A-10 fighter jet using the same biofuel blend.

In a statement, Gevo CEO Patrick Gruber said the bio-based jet fuel "is truly the same as petroleum jet fuel" and the company hopes to deliver it at a competitive price. The ­pricing was not disclosed, however.

Gevo, based in Englewood, Colo., also expects to sell ­isobutanol as a renewable chemical for a range of products including pop bottles and as a motor fuel. In a separate announcement, Gevo said Monday that Underwriters Laboratories approved existing gasoline fuel pumps to ­dispense isobutanol blends.

The company has worked for more than a year to overcome problems with commercial isobutanol fermentation at Luverne. Lund said two of three production "trains" in the plant are operating.

"We are selling product from those two, and once that third one is online, we'll be all the way up," he said.