BIOREFINERY: Much like a typical oil refinery, this demonstration facility will take raw plant material, treat it, turn it to oil and, ultimately, turn it into a full suite of transportation fuels. Image: Courtesy of Honeywell / UOP
On former pineapple fields outside of Honolulu, an industrial tube has been erected, ensconced in a steel scaffold. Dwarfed by the nearby oil refinery, the modest tube represents an attempt to one day wean Hawaii from imported oil. It is the nation's first dedicated biorefinery, employing high heat to turn plant matter into oil, followed by chemical catalysis to upgrade that oil into a useable fuel, just like the much larger refinery down the road.
The biorefinery "makes a fuel which is usable in generator sets, boilers and also possibly in marine engines," says chemical engineer Jim Rekoske, vice president of renewable energy and chemicals at Honeywell's UOP, the company responsible for building and operating the facility. By next year, UOP hopes to have the full biorefinery in place, which will be able to make almost any transportation fuel.
As the company has demonstrated elsewhere in the world, it is possible to make jet fuel from plant oils—whether they come from jatropha seeds, the flowering weed camelina or any other oil-producing plant. The same is true for other forms of transportation fuel, whether corn ethanol for cars or algal oil to power ships. The new facility in Hawaii will be the first integrated biorefinery dedicated to churning out bio-based versions of the full range of fuels more commonly made from petroleum.
Hawaii relies almost entirely on oil for its energy, whether it be gasoline for its cars, jet fuel for the planes that shuttle tourists in and out or even heavier oil to burn in its power plants. All of that oil comes in by supertanker, and even the island's most defensive inhabitant—the U.S. military—is nearly completely reliant on shipped-in fuel. All told, the state imports 45 million barrels of oil a year, nearly a third of which goes to run power plants.
The new biorefinery is a first step to changing that. It will take in biomass—the generic term for the leaves, stems and other bits of plants not typically used for food for humans and livestock. That will include inedible components of Hawaiian crops, such as macadamia nuts and sugarcane, as well as guinea grass and eucalyptus. The oil-rich jatropha plant and other so-called "energy crops" being grown on the island may also pass through the industrial plant, as long as growers are willing to part with it for free (though that may prove unlikely). "We're going to use whatever we can get our hands on," Rekoske says, in a bid to demonstrate the flexibility of the technology.
The biomass is ground into tiny bits and dried to drive out the water that can make up as much as half of the weight of fresh plant material. The plant flecks fly through the tube where ordinary sand heated to 500 degrees Celsius flashes them to an oil vapor in less than 800 milliseconds in a process called pyrolysis. What is left is the sand and the bits of biomass that cannot be vaporized, such as various salts and some residual char. The vapor exits and the solid bits drop to the bottom, where the char is burned to reheat the sand. "There is enough heat in the combustion of the char to heat the sand up to a high enough temperature to run the pyrolysis," Rekoske claims.
The oil vapor, meanwhile, is condensed into a liquid fuel, which is then further upgraded and processed to make a green fuel similar to the bunker fuel that is used in cargo ship engines and industrial boilers, for example, except it lacks the pollution-causing sulfur common to the bunker fuel refined from petroleum. Potential partners thus range from the U.S. Pacific Command (USPC), based in Honolulu, to local electricity cooperatives. And next year, when the full biorefinery is complete, UOP will be able to make everything from gasoline to jet fuel. "The idea is to make a whole barrel of product out of the biorefinery," Rekoske says.