How to Decarbonize Transportation with Bioethanol
Bioethanol has already offset millions of tons of carbon emissions. New research shows how it could do even more.
The Energy Futures Initiative Foundation (EFIF), led by Ernest J. Moniz, the 13th U.S. Secretary of Energy, recently released a new study detailing pathways to further decarbonize bioethanol to reach near net-zero carbon intensity by 2035 and negative carbon intensity by 2050.
The research, sponsored by Growth Energy, included months of research by EFIF staff to analyze the carbon reduction potential, feasibility, and cost-effectiveness of a total of 21 different measures taking place on farms and at biorefineries across the U.S.
Bioethanol's Impact to Date
544
Millions of tons of CO2 that didn't enter the atmosphere thanks to bioethanol.23%
How much bioethanol's carbon intensity has decreased since 2005.42%
How much lower bioethanol's CI is compared to unblended gasoline
Bioethanol Today
The U.S. bioethanol industry’s emissions intensity has continuously decreased the last few decades, primarily due to increasing corn grain and bioethanol yields and decreased energy use in bioethanol production. For example, from 2005 to 2019, corn bioethanol’s carbon intensity (CI) decreased by 23%. Currently, the corn-to-bioethanol industry produces an estimated 64.9 million metric tons per year of carbon dioxide (CO2) emissions over its lifecycle, accounting for about 1% of total U.S. net CO2 emissions in 2022.
As a baseline, researchers estimate that bioethanol’s carbon intensity was 53.6 grams of CO2 equivalent per megajoule of bioethanol produced (gCO2e/MJ) throughout the lifecycle. This includes corn farming, bioethanol production, and end-use (mainly in light-duty vehicle engines).
“Low-carbon liquid fuels will be essential for decarbonizing transportation, and ethanol has been the leader in the move to affordable low-carbon fuels.”
-Prof. Ernest J. Moniz, Former U.S. Energy Secretary and President and CEO of the EFI Foundation
How Bioethanol Gets to Net-Zero
The research found nine currently available and affordable pathways, which together could help renewable vehicle fuels achieve its emissions reductions goals, including:
- Carbon Capture, Utilization, and Storage (CCUS) of the fermentation process;
- Low-carbon energy use at biorefineries including using combined heat and power generation with biomass power and installing carbon-free electricity;
- Sequestering Soil Organic Carbon (SOC) through cover crops and no-till farming;
- Precision fertilizing practices and renewable energy on farms.
While carbon capture is the quickest, most effective means for lowering bioethanol’s lifecycle emissions, there are many other changes farms and biorefineries can make to lower their CI even further.
The Report's Recommendations
Congress should preserve the existing IRA funds for conservation programs so the USDA can proceed with the full multiyear funding allocations to accelerate the implementation of CSA practices.
The USDA should provide farmers with a comprehensive information package, including grants, loan programs, technical support, tools, and contracts, which can be used to invest in CSA practices.
The USDA should accelerate collecting field-based data on CSA practices, develop an MMRV framework for CSA practices, and disseminate the data and framework to stakeholders, including federal agencies designing incentive programs, GREET modelers, farmers, and the bioethanol industry.
The IRS should not require the bundling of CSA practices to qualify for the 45Z credit—as has been done with the current SAF tax credit (40B). Rather, the credit qualification should reflect the emissions reductions measured by the GREET model.
In collaboration with the USDA, the IRS should consider ways to help bioethanol producers share the value of these credits with corn growers who contributed to reducing the carbon intensity of bioethanol by adopting CSA practices.
Congress should modify the 45Z clean fuels production tax credit in a manner similar to other IRA incentives, i.e., extend it for 10 years to facilities producing qualified transportation fuels before Dec. 31, 2027.
In collaboration with the USDA, DOE should continue improving the GREET model to reflect a broader range of emissions-reduction practices. These practices should be incorporated into the IRS 45Z guidance.
Bioethanol producers should seek opportunities to increase carbon-free sources of electricity for use at biorefineries—including electricity from renewables, hydrogen, nuclear, hydropower, and others—in cases where the grid is not being decarbonized fast enough.
Bioethanol producers should consider forming a cooperative to facilitate demand aggregation for purchasing RNG or RNG certificates, which can help incentivize increased supply while mitigating financial risks.
DOE’s hydrogen hubs program and the Hydrogen Demand Initiative should consider making clean ammonia one of their early targets for financial support.
The USDA should reopen and repurpose its domestic fertilizer production program, focusing on retrofitting existing facilities to produce low-carbon fertilizers using funds from the Commodity Credit Corporation (CCC). Congress should not use the upcoming farm bill to restrict the USDA’s authority to use CCC funds for this purpose.
The administration should launch an interagency study of the feasibility of a national clean fuel standard (CFS), including a process for broad public engagement.
Apart from the CFS, the U.S. Environmental Protection Agency should consider the feasibility of higher blending requirements in establishing RFS standards, and states should consider requirements for E15 and higher blends in gasoline.