A patented process for converting alcohol from renewable or industrial waste gases into aircraft fuel or diesel is being extended to the U.S. Department of Energy’s Pacific Northwest National Laboratory with assistance from partners from Oregon State University and carbon recycling experts from LanzaTech.
One-step chemical conversion streamlines what is currently a multi-step process. The new patented PNNL catalyst converts biofuel (ethanol) directly into n-butene, a versatile platform chemical. A new microchannel reactor design further reduces costs while providing a scalable modular processing system.
The new process would provide a more efficient route to convert renewable and waste-derived ethanol into useful chemicals. Currently, n-butene is produced from raw materials of fossil origin using the energy-intensive cracking – or decomposition – of large molecules. The new technology reduces carbon dioxide emissions by using renewable or recycled carbon raw materials.
Using sustainably derived n-butene as a starting point, existing processes can further refine the chemical for multiple commercial uses, including diesel and aviation fuels, and industrial lubricants.
In a leap to commercialization, PNNL partners with longtime collaborators at Oregon State University to integrate the patented chemical conversion process into microchannel reactors built using new 3D printing technology . 3D printing allows the research team to create a pleated honeycomb of mini-reactors that dramatically increases the effective surface area to volume ratio available for the reaction.
The possibility of using new multi-material additive manufacturing technologies to combine microchannel manufacturing with large area catalyst supports in a single process step, has the potential to significantly reduce the costs of these reactors.
âOSU Principal Researcher, Brian Paul
3D printed microchannel mini-reactors dramatically increase the efficiency of chemical conversion of biofuels. (Image: Oregon State University)
Due to recent advances in microchannel fabrication methods and associated cost reductions, we believe the time has come to adapt this technology to new commercial bioconversion applications.
âRobert Dagle, Co-Principal Investigator of the Research
Microchannel technology would make it possible to build commercial-scale bioreactors near agricultural centers where most of the biomass is produced. One of the main obstacles to the use of biomass as fuel is the need to transport it over long distances to large centralized production plants.
The quarter of the commercial scale test reactor will be produced by 3D printing using methods developed in partnership with OSU and will be operated at PNNL’s Richland, Wash. Campus.
Once the test reactor is complete, PNNL’s business partner, LanzaTech, will supply ethanol to fuel the process. LanzaTech’s patented process converts carbon-rich wastes and residues produced by industries, such as steelmaking, petroleum refining and chemical production, as well as gases generated from the gasification of forestry and agricultural residues and municipal waste into ethanol.
The test reactor will consume ethanol equivalent to up to half a ton of dry biomass per day. LanzaTech has already extended the first generation of PNNL technology for the production of jet fuel from ethanol and formed a new company, LanzaJet, to market LanzaJet Alcohol-to-Jet. The current project represents the next step in streamlining this process while providing additional product streams from n-butene.
PNNL has been a strong partner in the development of the ethanol-jet technology that LanzaTech’s spin-off company, LanzaJet, uses at several plants under development. Ethanol can come from a variety of sustainable sources and, as such, is an increasingly important feedstock for sustainable aviation fuel. This project holds great promise for an alternative reactor technology that could have benefits for this key route to decarbonization of the aviation sector.
âJennifer Holmgren, CEO of LanzaTech
Since their first experiences, the team has continued to perfect the process. When the ethanol is passed over a solid silver-zirconia catalyst supported on silica, it performs the essential chemical reactions which convert the ethanol to n-butene or, with some changes in reaction conditions, to butadiene.
But more importantly, after long-term studies, the catalyst remains stable. In a follow-up study, the research team showed that if the catalyst loses its activity, it can be regenerated with a simple procedure to remove coke, a hard carbon-based coating that can build up over time. An even more efficient and updated catalyst formulation will be used for scale-up.
We discovered the concept of this highly active, selective and stable catalyzed system. By adjusting the pressure and other variables, we can also tune the system to generate either butadiene, a building block for synthetic plastic or rubber, or n-butene, which is suitable for making jet fuels or products. such as synthetic lubricants. Since our initial discovery, other research institutions have also started to explore this new process.
âVanessa Dagle, Co-Principal Investigator of the Initial Research Study
Research on chemical conversation was supported by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, within the Chemical Catalysis for Bioenergy (ChemCatBio) Consortium sponsored by the Bioenergy Technology Office (BETO). ChemCatBio is a research and development consortium led by a national DOE laboratory and dedicated to identifying and solving catalysis problems for the conversion of biomass and waste into fuels, chemicals and materials. The scale-up public-private partnership is supported by DOE-BETO and the Oregon State University Innovation Research Fund.
Vanessa Lebarbier Dagle, Austin D. Winkelman, Nicholas R. Jaegers, Johnny Saavedra-Lopez, Jianzhi Hu, Mark H. Engelhard, Susan E. Habas, Sneha A. Akhade, Libor Kovarik, Vassilliki-Alexandra Glezakou, Roger Rousseau, Yong Wang , and Robert A. Dagle (2020) ACS catalysis 10 (18), 10602-10613 doi: 10.1021 / acscatal.0c02235
F. Lin, VL Dagle, AD Winkelman, M. Engelhard, L. Kovarik, Y. Wang, Y. Wang, R. Dagle, H. Wang (2021) âUnderstanding the deactivation of Ag â ZrO2/ SiO2 Catalysts for the single-step conversion of ethanol to butenes’ChemCatChem 13,999 doi: 10.1002 / cctc.202001488