University of Tulsa chemical engineering professors have succeeded in producing renewable 91-octane gasoline made from “green crude,” a crude oil equivalent derived from algae via renewable processes.
The idea is totally different from other alternative fuel projects because it isn’t biodiesel or ethanol or so-called third generation biofuels, and it’s not an alternative to gasoline which requires a huge investment in infrastructure. It is gasoline, just made from another source.
The process takes four inputs — sunlight, carbon dioxide (CO2), water and photosynthetic microorganisms – algae – to produce a chemically rich component that can be refined to replace petroleum-based products. Additionally, the process does not require fertilizer, farmland or large amounts of fresh water.
“Algae can grow almost anywhere. The exciting thing about this project is that we aren’t using any cropland to produce the algae, and the process can use non-potable water and non-arable land,” said Daniel Crunkleton, assistant professor of chemical engineering and director of TU’s Alternative Energy Institute.
In the wake of higher food prices, fuels like biodiesel and ethanol have been criticized because they rely on food crops, like corn and soybeans, to produce fuel. Criticism has also been focused on the energy-intensive processes used to grow, harvest and refine ethanol and biodiesel. Crunkleton said green crude addresses those concerns while reducing U.S. dependence on imported crude oil.
Crunkleton collaborates with Geoffrey Price, professor and chairman of TU’s Russell School of Chemical Engineering to develop a patent-pending refining process owned by TU. The system refines green crude into 91-octane gas that meets ASTM standards. According to Sapphire Energy, TU’s depth of experience in benchmark-setting technology for the oil industry made the university an ideal partner.
The green crude is compatible with the existing petroleum infrastructure, from refinement through distribution and the retail supply chain. That downstream compatibility is one of the many advantages that caught Price’s attention. After more than 25 years researching important processes in the oil refining industry, Price knew that alternative fuels could more easily become mainstream if they conformed to the distribution system already in place. Green crude can be refined at existing refineries, transported in pipelines, sold at gas stations and used in existing cars. That’s one of the keys to bridging the gap between fossil and renewable fuels.
In addition to green crude’s possibilities as a renewable fuel and its independence from using food crops or agricultural land, algae uses large quantities of CO2, removing greenhouse gases from the atmosphere.
“The process is essentially carbon neutral,” Crunkleton said. “Vehicles running on green crude do emit CO2, but those emissions are then reabsorbed by the algae, resulting in a closed chemical loop.”