The U.S. Environmental Protection Agency has approved the registration and use of a renewable gasoline blendstock developed by Vertimass LLC and the Department of Energy’s Oak Ridge National Laboratory that can significantly reduce the emissions profile of vehicles when added to conventional fuels.
EPA approved the blending of up to 20% of the VertiGas20 green gasoline product with conventional gasoline. The low-cost, biomass-derived product is made from renewable ethanol produced by a method called Conventional Alcohol Deoxygenation and Oligomerization, or CADO, a technology originally invented at ORNL.
Ethanol is a familiar biofuel made from plants such as corn and sugar cane. It has been blended with gasoline since the 1970s to reduce reliance on imported oil and lower vehicle greenhouse gas emissions, but is currently limited to blending at 10% to 15% without vehicle modifications. Upgrading ethanol using the ORNL technology resulted in a more energy-dense hydrocarbon product that can be blended at higher quantities without changes to car and truck engines.
While ethanol’s chemical makeup includes oxygen, VertiGas20 is composed of only hydrogen and carbon, giving it properties similar to, and compatible with, petroleum-based fuels. Blending 20% of this hydrocarbon product with 10% bioethanol results in a 30% drop-in renewable gasoline. A variant of the Vertimass product currently under development could be used to help decarbonize planes, tractor-trailers and locomotive engines — heavy-duty applications where electrification options are currently limited.
In its announcement regarding the EPA approval, Vertimass indicated that use of the blendstock could eliminate 560 billion pounds of new carbon dioxide accumulation in the atmosphere as it replaces a portion of the fossil fuels required for conventional gasoline production.
The technology was licensed exclusively to Vertimass LLC in 2014, and the company then worked to scale up the process. Vertimass collaborated with ORNL, Technip Energies and DOE to optimize CADO and its novel catalyst, test it under varying conditions, analyze the technoeconomic and life-cycle sustainability of the process, and develop data for commercialization. The results demonstrated the new blendstock retains its sustainability benefits as it was scaled for commercial deployment.
Key to the conversion method is an ORNL-developed catalyst made from lower-cost metals and zeolite, a porous, absorbent mineral. Together, the new catalyst directly produces longer hydrocarbon chains from the original alcohol, in this case ethanol. ORNL replaced a traditional multi-step process with a highly efficient single-step method that requires no added hydrogen and less energy during production.