Ethanol-to-jet (ETJ) is projected to soon catch up to hydroprocessed esters and fatty acids (HEFA) in supplying growing demand for sustainable aviation fuel (SAF). But questions have quickly arisen: How much ethanol is available near- and long-term? And what’s the likelihood that corn ethanol will be able to reduce its carbon intensity enough to qualify as a SAF feedstock?The revised Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET) model will address how corn ethanol’s carbon intensity (CI) is to be measured, although it had not yet been released at press time in mid-March. The revised model will be used to evaluate greenhouse gas (GHG) reductions to qualify for Inflation Reduction Act incentives. Another big unknown is how the regulatory process will play out for proposed pipelines to transfer ethanol CO2 to suitable sequestration sites—the quickest and most cost-effective means to slash ethanol’s GHG footprint. The outcome on both fronts will either accelerate or slow ETJ’s prospects, but ethanol industry spokesmen express confidence that ethanol’s SAF potential will be realized regardless.Net-Zero Ethanol Goal&nbsp; Initially responding to California’s Low Carbon Fuel Standard, the ethanol industry has embraced CI reduction. The spreading adoption of low carbon fuel standards, plus the buzz surrounding corporate net-zero pledges, prompted ethanol producers to up the ante. In 2021, ethanol producer members of the Renewable Fuels Association adopted a goal of 70% GHG reduction relative to gasoline by 2030 and net zero by 2050. Other industry groups soon announced their own pledges.The net-zero goal was enthusiastically embraced by RFA members, says Geoff Cooper, CEO of the Washington-based ethanol association. In 2022, RFA released a study, “Pathways to Net-Zero Ethanol,” which was commissioned to support the decarbonization effort. The study evaluated more than two dozen potential GHG reduction actions, prioritizing them by technical feasibility, scale of reduction and cost. Conducted by Informed Sustainability Consulting, the study found that an ethanol producer who optimizes multiple plant efficiencies and is located in a region with high adoption rates of climate-smart farming practices could meet RFA’s 2030 target of 70% GHG reduction without carbon capture and sequestration (CCS). &nbsp;In addition to modeling the impact of widespread adoption of plant efficiency improvements already implemented by industry leaders, the study looked at wider adoption of advanced fermentation technologies, increased renewable electricity and biomethane, among other technologies.The RFA followed that study with a survey last year. “Nearly eight out of 10 member facilities are on track to achieve net zero by 2050 or sooner,” Cooper says. &nbsp;All producer members have adopted at least one, and most more than one, of the carbon-reduction technologies identified in the pathways paper, reporting a 12% reduction in average CI since 2016. Over a third already capture biogenic CO2 and more than three-quarters intend to adopt sequestration technologies.”Cooper points out that with an industry capacity of 18 billion gallons, “the ethanol and feedstock assets are already in place to support to the first billion gallons of ethanol-to-jet fuel.”Not only is ethanol capacity greater than current utilization, but it’s also greater than projected demand from existing markets. The USDA Economic Research Service projects that 2021’s domestic ethanol use of 13.9 billion gallons will grow to just 14.7 billion gallons by 2030. Current exports of around 1.4 billion gallons annually are projected to grow to 2.1 billion gallons by 2030.A billion gallons of ETJ will bring the nation one-third of the way to the Biden administration’s goal of 3 billion gallons of SAF from all sources by 2030. The 2050 goal of 35 billion gallons is a bigger challenge. For the country to achieve 100% SAF by 2050, all feedstock pathways will be needed—ethanol, HEFA, municipal solid waste and wood chips—says David Miller, analyst with Decision Innovation Solutions. &nbsp;“We need it all.”In January, the Iowa Renewable Fuels Association released Miller’s analysis, “Sustainable Aviation Fuel for the Future: What Does the Midwest Have to Gain?”Miller projects that HEFA-based SAF and ethanol-to-jet will be the two most prominent, cost-effective pathways for SAF production for the next 20 years. In his analysis, the ETJ pathway begins with 21 million gallons coming online in the near term, ramping up to 623 million gallons in 2030, and rising through the remaining period to 5.59 billion gallons of ETJ-SAF by 2050.LanzaJet lays claim to bringing the first ethanol-to-SAF plant online in January at Soperton, Georgia. Its Freedom Pines Fuels plant will produce 9 MMgy SAF and 1 MMgy renewable diesel—the first commercial-scale unit of the technology it plans to quickly scale, expecting to reach 1 billion gallons of global capacity by 2030. One project announced in 2022 proposes a 120 MMgy SAF facility in Hennepin, Illinois, where Marquis Energy operates a 350 MMgy corn ethanol plant. The news release announcing the memorandum of understanding says the plant will employ on-site CCS and renewable energy to produce SAF with a lifecycle GHG reduction of more than 70% compared to conventional jet fuel.Corn Availability&nbsp; Long-term projections for the corn ethanol supply are based on the expected size of the corn crop. Miller uses the 40-year trend line for corn production and subtracts the 10-year trend line volume of nonethanol use (exports, feed and food use for starch and high-fructose corn syrup) to project that by 2050, an extra 5 billion bushels of corn will be available for ethanol production—nearly double the roughly 5.4 billion bushels used today. In Miller’s modeling, corn production will increase, on average, 210 million bushels a year, while nonethanol demand increases 55 million bushels a year for feed and food use.Midwest farmers need SAF demand for ethanol to maintain the ag economy, Miller says. “We’re back into a period where we’re going to grow ending corn stocks without new demand.” In past cycles when supply outpaced demand for corn, farm prices declined, he says, which suggested that the downward cycle had begun again. “In the past 18 months, we’ve gone from $6 to $4 corn, and ending stocks have gone from 1 billion to 2 billion bushels.”The only thing helping further price decline, he says, is weather problems in Argentina and elsewhere in the global market.With no evidence of corn yields declining or even leveling off, Miller says, new SAF demand is not only critical to maintain Midwest agriculture, but it could spark impressive economic impacts. As corn production increases, one to two ethanol plants could be built each year for 20 years, he says. “Our numbers said we need 68 new plants by 2050. So we will have a construction effect for a long time. We modeled that, in 2050 with 68 new plants operating, it’s $79 billion a year of output on the ethanol side.”Adding the impact of SAF plants and HEFA, he says, “SAF becomes a $100 billion industry that is ag-driven. That’s huge. That rivals the kind of economics we’re getting from the whole livestock industry.”Reducing Corn’s CI&nbsp; Although the volume of corn necessary to support a doubling of production will be available, ethanol’s carbon intensity must be drastically cut to qualify for the new incentives under the Inflation Reduction Act. SAF needs a CI under 45, Miller points out, and with SAF conversion adding about 12 points, the ethanol feedstock has to have a CI score of 32 or less. Currently, Miller says, Midwestern dry mill ethanol plant scores range between 52 and 58 CI points, depending on the plant and electrical mix. The average is 55.Plants could cut 20 points by converting to all renewables for electricity and thermal energy, combined with farm-level CI reductions through climate-smart farming practices and green ammonia-based nitrogen fertilizers, he says. “You have to do all [of that] to get 20 points off, but they’re all way more expensive than getting 30 points off with carbon sequestration.”The lengthy and contentious CO2 pipeline permitting process introduces uncertainty regarding how quickly and widely CCS will be deployed in the ethanol industry. Most plants aren’t located on geologic formations suitable for on-site sequestration and will require access to a pipeline. However, Miller estimates that if all current ethanol plants with the potential to do on-site sequestration build out CCS, it would account for 42% of the ethanol needed for SAF by 2050.Brian Jennings, CEO of the American Coalition for Ethanol, agrees with Miller on the advantage of CCS. “Without question, carbon capture and sequestration is the single most important step that could be taken to reduce the carbon intensity of corn ethanol.”ACE, however, is focusing on a different component of corn ethanol’s CI—the corn feedstock itself. Corn production at 27 CI points accounts for roughly half of ethanol’s CI score, Jennings says. The 2023 GREET updates, released in December, lower corn's CI from 29 points, he points out, plus assign a value for two climate-smart farming practices. “The GREET model suggests that the implementation of continuous no-till corn could shave 10 points off corn’s CI,” Jennings says. “Another three points could be subtracted if farmers adopt 4R nitrogen management—right time, right place, right form, right rate. You can get down to 14-CI-point corn.”When asked about the pending announcement of the GREET revisions to be used for determining eligibility for the SAF incentives in the Inflation Reduction Act, Jennings reports mixed feelings. “When looking at the 2023 GREET, it does make one very optimistic that GREET is accounting for modern day farming practices,” Jennings says. If included, it would be the first program to accept farm-level CI reductions in carbon scores. “I do feel optimistic, but there are a lot of forces trying to box corn ethanol out of being able to qualify as a feedstock for SAF.”A major point of contention surrounds land use. “Direct land use change is easier to measure and determine,” Jennings says, “but international indirect land use has always been more abstract. EPA still claims a 29-CI-point penalty for corn ethanol when it comes to indirect land use change. The GREET model says it’s in the seven or eight gram neighborhood.”How that 20-point difference settles out in the Department of the Treasury guidance, developed by an interagency task force involving treasury, DOE, EPA and USDA, will play a big role in how difficult it will be for ethanol to meet CI reduction requirements.Another issue surrounds the challenge of measuring and verifying on-farm practices to satisfy regulators, policymakers and environmentalists that the claimed GHG reductions are accurate and auditable. Since verification and auditing could potentially be cumbersome and expensive for facilities buying corn from hundreds of farmers, there are several groups working with farmers and ethanol producers on automated systems tapping into technologies such as block-chain, satellite imagery and farm implement GPS data.ACE is leading an effort to demonstrate a different approach to use existing ag models that quantify carbon and GHG emissions based on precipitation, temperature, climate, soil type and specific farming practices. A cover crop in Missouri, for example, would earn more credits for sequestering carbon than a cover crop in Minnesota where the growing season is shorter, Jennings says. The concept would facilitate replacing the national averages currently used to determine corn’s CI with region or county average CI scores.The research collaboration to demonstrate and validate the concept is funded with a USDA grant. South Dakota State University is conducting research on 15,000 acres in the seven counties surrounding ethanol producer Dakota Ethanol at Wentworth, South Dakota. The five-year program pays farmers to introduce no-till cover crops or 4R nutrient management and allow SDSU researchers to closely monitor and measure the resulting GHG benefits. In turn, that data will be used to pressure-test the models used to determine corn’s GHG emissions. Funding to expand the project to include farmers surrounding 13 ethanol plants in 10 states was announced in late February.“The long-term goal is to empower farmers and ethanol producers to increase the value of their corn and corn ethanol, whether selling to an SAF producer, getting a greater tax credit or marketing fuel in low-carbon fuel markets,” Jennings adds. Author: Susanne Retka Schill&nbsp; Contributing Writer, SAF Magazine&nbsp;

SAF Magazine Issue 1 2024.css-7jxktu{position:absolute;bottom:0px;left:0px;right:0px;height:3px;border-radius:3px;background-color:var(--chakra-colors-brandBlack);}

SAF Magazine Issue 1 2024