Biodiesel and Renewable Diesel in the North American Rail Industry Q & A


The rail industry continues to advance lower carbon targets to help reduce lifecycle carbon emissions using bio-based diesel fuel solutions in locomotives. For insights on how biodiesel and renewable diesel play a role, we’ve turned to Rajani Modiyani (RM), Senior Manager, Emerging Markets at Chevron.

Q: What is driving lifecycle carbon emissions reduction initiatives for the North American rail industry? 

RM: There are several factors that are driving the North American rail industry to plan and helping them implement lower carbon targets at various levels.

One important factor is establishing voluntary lifecycle carbon emission reduction targets. Class 1 railroads such as Canadian National, Union Pacific and others have established mid-term and long-term targets for their Scope 1, Scope 2 and Scope 3 

Stakeholder groups including investors, customers, employees and communities where railroads operate are some of the driving forces behind how these voluntary targets are being established by the railroads.   

National, state and local regulatory agencies are further pushing the urgency on carbon reduction by introducing policies. These policies typically take the form of incentives such as tax credits that enable higher biofuels adoptions, lowering carbon emissions footprint. 

One additional factor that is discussed less frequently but is important for competitiveness of the rail industry is that rail freight carbon reduction targets must be equal to, if not lower than, other modes of freight transportation to ensure they are in the best position to serve the Scope 3 emissions needs for end customers.  

Chevron Rajani Modiyani

Rajani Modiyani, Chevron Senior Manager, Emerging Markets

Q: How common is the use of biodiesel and renewable diesel in the rail sector today? 

RM: Biodiesel blended with conventional diesel at varying levels has become commonplace in the rail industry for nearly a decade, driven by its ability to be a drop-in solution.

Several key locomotive and engine manufacturers have already approved varying levels of biodiesel blends, and many OEMs approve the use of 100% renewable diesel (RD100) and blends of up to 20% biodiesel (B20) in their locomotive engines. With these approvals, we have continued to see increasing amounts of biodiesel utilized across rail networks to drive lifecycle carbon emission reduction while also benefitting from incentives and market blend economics.

Railroads, national labs and OEMs are making significant progress with biofuels to gain confidence in performance aspects such as supply chain reliability, cold weather operability and transparency in handling under current infrastructure and operating procedures.

Q: How much do renewable diesel and biodiesel reduce lifecycle carbon emissions compared to other fuels? 

RM: Compared to conventional diesel, renewable diesel may reduce engine emissions by up to 100% for fossil carbon.Biodiesel also reduces total hydrocarbon by up to 70% and renewable diesel does so by up to 40%.2 The carbon intensity (CI) scores of both biodiesel and renewable diesel have also been consistently lower than LNG and hydrogen.Compared to electric, biodiesel may be about 56% more effective at reducing carbon when taking the power grid into consideration.4

Q: What are storage and handling differences with biodiesel and renewable diesel compared to petroleum diesel? 

RM: Biodiesel can be used in existing diesel tanks, generally without any modifications. Rail operations regularly consume significant quantities of fuel, so the fuel in storage tanks turns over very quickly. Because of this, there isn’t much difference between storage and handling of biodiesel versus petroleum diesel. 

The one exception is cold weather extremes. The cloud point of biodiesel and renewable diesel is different from that of conventional diesel. For distilled biodiesel, storing at least a few degrees above the fuel’s cloud point is important. For biodiesel blends up to B30, heated or insulated tanks aren’t typically needed depending on some aspects of fuel handling prior to delivery to the storage tanks.

Q: Does a transition to biodiesel require any modifications to operational infrastructure or engines? 

RM: One of the biggest advantages of biofuels as a lower carbon fuel solution is that it can be implemented today with virtually any existing equipment and infrastructure, with little to no impact on operations. In fact, biodiesel can provide some engine performance benefits, including improved lubricity and combustion, which helps to reduce diesel particulate filter (DPF) clogging and regenerations when compared to petroleum diesel.

Biodiesel fuel blends can help reduce particulate matter which can have a positive impact on local air quality. Many rail yards and rail tracks are located near residential areas, so an additional noteworthy benefit.

Q: What advice would you give to someone in the rail industry that may be skeptical of integrating biodiesel? 

RM: When evaluating various lower carbon fuel solutions, take a more holistic approach and evaluate a number of specific criteria, including: technology readiness, operational impact, economic viability and fuel availability. You may find that biodiesel and renewable diesel check all those boxes — including usability in virtually any existing equipment, maintaining operations, being easy to implement and readily available. 

Two of the most significant benefits of bio-based fuel solutions are the ability to use existing infrastructure, typically without changes and maintaining interoperability that is critical to the operations of the railroad industry.

As bio-based fuels see increased adoption, lower carbon fuel producers such as Chevron are investing to enhance the availability of these renewable fuels to market. One such example is the improvement and expansion of our Geismar biorefinery that will take production site capacity from 90 million gallons of renewable diesel production per year to 340 million gallons per year by 2030.

Another relevant aspect is the availability of feedstocks that go into making lower carbon fuels. Chevron has a diversified strategy to source feedstocks reliably. Our feedstock flexibility helps ensure more predictable pricing, greater availability and lower carbon intensity. 

Lower carbon solutions for the rail industry are already being demonstrated with key Class 1 railroads successfully deploying biodiesel and renewable diesel in their operations. Chevron has partnered with Union Pacific (UP) and Canadian National Railways (CN) to implement lower carbon fuel solutions.

Learn More

Through Union Pacific’s partnership with Chevron, they are making progress toward their lower carbon targets. See how using UltraClean BlenD™, a proprietary renewable fuel combination, benefits engine performance.

Read UP Case Study


Canadian National Railway Company (CN) is testing high-level blends of renewable fuel to help them work toward lower carbon targets. Learn why CN and other railway companies are turning to Chevron for high-quality, lower carbon fuel solutions.

Read CN Case Study