|Centia biofuels process. Click to enlarge.|
A new biofuels technology developed by North Carolina State University engineers has the potential to turn virtually any lipidic compound—e.g., vegetable oils, oils from animal fat and oils from algae—into aviation fuel or other high-value fuels.
The technology, called Centia, which is derived from “crudus potentia,” or “green power” in Latin integrates a sequence of three thermocatalytic-reforming processes that are either extensions of current commercial processes or based on recent laboratory breakthroughs. Centia can also be used to make additives for cold-weather biodiesel fuels and holds the potential to fuel automobiles that currently run on gasoline.
NC State received provisional patents to use the process to convert fats into jet fuel or additives for cold-weather biodiesel fuels. The technology has been licensed by Diversified Energy Corp., a privately held Arizona company specializing in the development of advanced alternative and renewable energy technologies and projects.
Dr. William Roberts, professor of mechanical and aerospace engineering and director of the Applied Energy Research Laboratory at NC State, developed the biofuels process with NC State’s Dr. Henry Lamb, associate professor of chemical and biomolecular engineering; Dr. Larry Stikeleather, professor of biological and agricultural engineering; and Tim Turner of Turner Engineering in Carrboro, N.C.
We can take virtually any lipid-based feedstock, or raw material with a fat source—including what is perceived as low-quality feedstock like cooking grease—and turn it into virtually any fuel. Using low-quality feedstock is typically 30% less costly than using corn or canola oils to make fuel. And we’re not competing directly with the food supply, like ethanol-based fuels that are made from corn.—William Roberts
Centia is based on a three-step thermal, catalytic, and reforming process:
Hydrolytic conversion. The feedstock is heated under pressure to separate free fatty acids from glycerol in the triglycerides in the feedstock. Centia accomodates any lipidic compound without modification to the production process.
Decarboxylation. The free fatty acids and solvent are heated, pressurized, and passed through a catalyst in a reactor.
Reforming long-chain alkanes. The resulting alkanes—straight-chain hydrocarbons of 15-17 carbon atoms—are reformed into branched alkanes and ring structures. The process is optimized to maximize C10 through C14 iso-alkanes.
The fuel output is capable of meeting strict aviation specifications and acting as a biodiesel additive for cold weather operations, according to NCSU. In addition, the basic process may also be extendable to produce any other hydrocarbon fuel, including conventional gasoline.
The developers claim an end-to-end energy efficiency for the process of up to 85%, with roughly one-half the external energy of other conventional biofuel processes. This translates into higher yields and lower costs.
Centia does not require the addition of any form of fossil fuel as a component of the biofuel produced, and the production process itself can be designed to operate without consuming fossil fuels as a heat source.
Steps one and three are direct extensions from the commercial marketplace, step two builds upon recent NCSU-DEC laboratory results validating the science. Centia is ready for an end-to-end demonstration and commercialization.