A long unit train of tank cars moves through rural countryside from a Amason City, Iowa ethanol production facility, reflecting the central role rail transportation plays in moving the fuel. Photo via Getty Images.
Railroads across the United States are preparing for a new wave of ethanol demand as producers adjust to federal clean-fuel incentives that reward lower-carbon production pathways.
Ethanol is a renewable, plant-based alcohol produced by fermenting sugars and starches found in crops such as corn, sugarcane, and, increasingly, cellulosic biomass like crop residues and grasses. In the US, it is made primarily from field corn, which is milled, converted to sugars, fermented with yeast, and then distilled into a high-purity fuel.
Beyond its role as a gasoline blend stock, ethanol production also generates valuable co-products such as distillers grains for livestock feed and corn oil for biodiesel. Because it is derived from plants that absorb carbon during growth, ethanol offers a lower carbon-intensity profile than conventional petroleum fuels, making it a key component of North America’s clean-fuel and bioenergy strategies.
The Section 45Z Clean Fuel Production Credit—created under the Inflation Reduction Act in 2022 and taking effect in 2025—is already reshaping how ethanol producers plan for 2026 and beyond.
Ethanol production plants are evaluating carbon-intensity reductions, feedstock strategies, and logistics changes that will influence how the ethanol fuel moves from the Midwest to coastal and export markets.
Ethanol has long been one of the most rail-dependent commodities in the US energy sector. Between 60 and 70 percent of all ethanol produced in the country moves by rail, a share that has remained remarkably stable even as domestic consumption patterns shift.
Rail’s ability to move large volumes efficiently, safely, and cost-effectively makes it the preferred mode for connecting rural production hubs with major fuel-blending centers on the East Coast, Gulf Coast, and West Coast. As producers explore new opportunities in sustainable aviation fuel (SAF), renewable chemicals, and low-carbon export markets, rail’s strategic importance is expected to grow.
A major reason rail dominates ethanol logistics is simple chemistry: ethanol cannot be shipped through petroleum pipelines.
Why? Because ethanol is an alcohol, it is hygroscopic, meaning it absorbs water—and pipelines always contain trace moisture and condensation. Ethanol would pull that water into the fuel, degrading quality and making it unsuitable for blending.
Ethanol is also a solvent, capable of damaging pipeline seals, gaskets, and coatings, and it can dissolve residual petroleum products left in the line. These reactions create contamination and corrosion risks that pipeline systems were never engineered to handle.
As a result, ethanol must move by rail, truck, or barge, with rail providing the only scalable long-haul option.
Equipment selection continues to shape producer planning. Tank-car specifications, safety features, and commodity-specific design considerations influence how efficiently ethanol can be loaded, moved, and delivered. Manufacturers such as The Greenbrier Companies continue to refine tank-car engineering to improve durability, loading efficiency, and regulatory compliance.
For ethanol producers evaluating future logistics needs, understanding tank-car capacity, weight limits, and maintenance requirements is becoming increasingly important—especially as plants consider operational changes to qualify for 45Z credits.
The clean-fuel credit itself is driving significant operational adjustments.
To qualify for the incentive, ethanol plants must document carbon-intensity reductions through improved energy efficiency, carbon capture, renewable power sourcing, or feedstock changes.
These modifications can influence rail demand in several ways: plants may increase output to capitalize on the credit, diversify product streams, or expand shipments to new regions where low-carbon fuels command premium pricing.
In each scenario, railroads stand to play a central role in connecting producers with emerging markets.
Short-line and regional railroads are particularly important in this transition.
Roughly 15 to 20 percent of ethanol rail movements originate on short-line networks, which provide first-mile and last-mile service to rural plants not directly served by Class I railroads.
These smaller carriers handle switching, storage, and interchange operations that allow ethanol to reach the national rail system. Their ability to maintain reliable service, invest in track improvements, and coordinate with Class I partners will influence how smoothly ethanol producers can scale up or shift production strategies under the new incentive structure.
A railroad is Class I if it generates annual operating revenue above a federally set threshold, adjusted for inflation. For 2026, that threshold is roughly US$1.1 billion.
There are six Class I freight railroads operating in the United States as of this time:
- BNSF Railway;
- Union Pacific (UP);
- CSX;
- Norfolk Southern (NS);
- Canadian National (CN)—operates as a Class I in the US;
- Canadian Pacific Kansas City (CPKC)—also a US Class I.
Rail’s inherent fuel efficiency—moving one ton of freight nearly 500 miles per gallon of fuel—also positions it as a natural fit for low-carbon energy supply chains.
As ethanol producers pursue cleaner operations, the transportation sector supporting them is under similar pressure to demonstrate sustainability gains. Railroads have responded with locomotive upgrades, alternative-fuel pilot programs, and network-wide efficiency initiatives aimed at reducing emissions per ton-mile. These improvements further strengthen rail’s role in the evolving clean-fuel economy.
Looking ahead, ethanol’s next phase of growth will depend on how effectively producers can align plant operations, regulatory requirements, and transportation strategies.
Railroads—from major Class I carriers to rural short lines—are preparing for that shift by investing in infrastructure, equipment, and service models tailored to the needs of a changing biofuels sector.
As the clean-fuel credit accelerates innovation across the industry, rail is positioned to remain the essential link between US ethanol producers and the markets that depend on them.