The cost could be much lower if plants eliminated biomass and used only coal and natural gas to run the process, Floudas said, but that would eliminate most of the environmental benefit.
"If you want to have a 50 percent reduction in emissions, you need to have the biomass," he said.
In many ways, synthetic fuels are cleaner than petroleum fuels. The heavy metal and sulfur contaminants of petroleum fuels can be captured in the synthetic plants before the fuel is shipped out. Synthetic fuels also can be used in gasoline and diesel engines with no need for modifications, unlike many biofuels. The biofuel ethanol, for example, is commonly mixed with gasoline, but high levels of ethanol require modifications to car engines and pose special challenges for starting at low temperatures.
Floudas said that synthetic fuels also would allow carbon reduction with the fleet of cars currently on the road. Even if the country immediately converted to zero-emitting electric or fuel cell vehicles, millions of internal combustion vehicles would still be driving. By switching to synthetic fuels, he said, the country would have the opportunity to reduce those emissions, even if it they would not be completely eliminated.
"This is an opportunity to create a new economy," Floudas said. "The amount of petroleum the U.S. imports is very high. What is the price of that? What other resources to do we have? And what can we do about it?"
|Contact: John Sullivan|
Princeton University, Engineering School