U.S. ethanol exports jumped 26 percent in 2016, exceeding 1 billion gallons for just the second time in history, and are expected to remain an important outlet for ethanol refiners again this year despite uncertainty in key world markets.

"U.S. ethanol exports are responding to increased demand for clean, high-octane ethanol to blend into transportation fuel," said Mike Dwyer, U.S. Grains Council chief economist, who oversees the organization’s ethanol programs. "U.S. exports [through late February] are up 65 percent from last year’s pace and on target to comfortably exceed 1 billion gallons by year’s end."

U.S. ethanol exports last year were valued at $2.018 billion, up 15.3 percent from the previous year, according to the U.S. Department of Agriculture. Ethanol producers exported the fuel to 34 different countries in 2016, with nearly 70 percent of...