The U.S. Air Force proposes to spend between $1 to 4 billion to build a synthetic fuel plant at Malmstrom Air Force Base in Great Falls Montana. The Air Force has a goal of using 50% synthetic jet fuel within 8 years. Assistant Air Force Sec. William Anderson said that whoever builds the plant would need to be able to capture the CO2 given off. Companies interested in building the plant include Chevron, Shell, Rentech, ConocoPhilips and Sasol, a South African company. Only 3 synthetic fuels plants are in operation worldwide, and all are in South Africa, although a plant is under construction in China.