What Is Renewable Diesel?
Can renewable diesel go into the trucks and tanks a fleet already runs? In California, state regulators have answered that question. The California Air Resources Board and the State Water Resources Control Board have stated that renewable diesel meeting the required fuel standards should be treated the same as conventional CARB diesel for all purposes, including storage in underground tanks.
That is a major reason California fleets have adopted renewable diesel. It can lower lifecycle greenhouse gas emissions without changes to existing engines or storage tanks.
What You'll Learn
- Whether it works in existing diesel trucks and tanks
- What renewable diesel is, in plain language
- How it is made through the HVO process
- How it differs from biodiesel
- The main benefits and tradeoffs, including emissions and compatibility
- How to get current pricing in California
Renewable Diesel Definition and Why It Matters
Renewable diesel is a hydrocarbon fuel made from biological feedstocks, such as used cooking oil, animal fats, and vegetable oils, that are hydrotreated to be chemically similar to petroleum diesel. It meets ASTM D975, the same specification that applies to petroleum diesel, and can be used on its own or blended with petroleum diesel in any amount. It can significantly reduce lifecycle greenhouse gas emissions depending on feedstock and production pathway.
That definition matters because the phrase drop-in is literal. Renewable diesel can generally be stored, transported, blended, and used like conventional diesel. No special storage tanks are required. No blending is required before use. No separate fueling process is needed for day to day fleet operations. The difference is in the feedstock and production method, not in the way the fuel is handled in normal diesel use.
The term renewable refers to the biological feedstocks used to make the fuel, unlike finite petroleum reserves. The resulting fuel, however, is not experimental chemistry. It is a diesel range hydrocarbon fuel that fits the same ASTM D975 specification used for conventional diesel. That is the main reason renewable diesel is treated differently from biodiesel in both operations and engine compatibility.
How Renewable Diesel Is Made
The production process is usually called hydrotreating, and the finished fuel is often referred to as HVO, short for hydrotreated vegetable oil. In practical terms, the process converts fats and oils into diesel-range hydrocarbons.
Here is the process in five steps:
- Feedstock collection
Used cooking oil, animal fats such as tallow, and vegetable oils are collected and pretreated to remove water, metals, and other impurities. - Hydrotreating
The feedstock is combined with hydrogen under heat and pressure. This removes oxygen, sulfur, and nitrogen from the original material. - Hydrocracking
Larger molecules are broken into shorter hydrocarbon chains in the diesel range. - Isomerization
The carbon chains are rearranged to improve cold-flow properties, which improves how the fuel performs at lower temperatures. The degree of isomerization varies by producer, so cold-weather properties vary by product grade. - Finishing and testing
The final product is tested to confirm that it meets ASTM D975 before entering the fuel supply system.
The key point is that hydrotreating removes oxygen from the original fat or oil molecule. What comes out is a hydrocarbon fuel, not an ester fuel. That difference is what separates renewable diesel from biodiesel.
Renewable Diesel vs. Biodiesel
Renewable diesel and biodiesel are both made from biological feedstocks, but they are not the same fuel. The U.S. Department of Energy distinguishes them clearly, noting that renewable diesel is chemically similar to petroleum diesel, while biodiesel is a separate fuel type with different properties.
The short version is simple: biodiesel is a different molecule, while renewable diesel is a diesel hydrocarbon. That difference affects storage, blending, engine compatibility, and cold-weather performance.
Benefits and Tradeoffs of Renewable Diesel
Renewable diesel has real advantages, but those benefits are easiest to evaluate when the tradeoffs are shown alongside them.
Feedstock quality matters here. A waste oil pathway can have a much lower lifecycle carbon intensity than a crop-based pathway. That is why buyers often evaluate renewable diesel by both product type and carbon intensity score, not by name alone.
Renewable Diesel Pricing in California
Renewable diesel pricing moves with feedstock costs, supply, and market conditions, so it changes often. The most reliable way to compare renewable diesel with conventional diesel for a specific operation is a current delivered quote. Double AA Corporation provides delivered quotes for renewable diesel across California.
Why Renewable Diesel Has Grown in California
Renewable diesel has grown in California because it lets fleets reduce lifecycle emissions while keeping their existing engines and tanks. Many fleets want lower carbon fuels but cannot rapidly electrify every diesel asset.
California's Low Carbon Fuel Standard, which rewards fuels with lower carbon intensity, has supported renewable diesel supply in the state.
That does not mean renewable diesel is a universal answer for every decarbonization goal. It does mean it has become a practical transitional fuel for fleets that need lower carbon performance without a full equipment transition.
Frequently Asked Questions
Is renewable diesel cheaper than regular diesel?
Pricing depends on market conditions, location, and volume, so it changes often. A current delivered quote is the best way to compare renewable diesel with conventional diesel. Double AA Corporation provides delivered quotes for customers in California.
What's the difference between renewable diesel and biodiesel?
Renewable diesel is a hydrocarbon fuel chemically similar to petroleum diesel. Biodiesel is a fatty acid methyl ester fuel with different chemistry, different standards, and different blend practices. That is why the two fuels behave differently in storage, blending, and cold-weather performance.
Can any diesel engine use renewable diesel?
In California, regulators treat renewable diesel that meets conventional CARB diesel and ASTM D975 requirements the same as conventional CARB diesel, including for storage in existing tanks. Fleet operators still often verify OEM guidance for specific equipment classes, but the fuel is designed to function within existing diesel systems.
How clean is renewable diesel?
Lifecycle greenhouse gas reductions vary by feedstock and pathway, but renewable diesel can reduce emissions substantially relative to petroleum diesel. CARB LCFS carbon intensity data is commonly used in California to assess those differences. These figures measure lifecycle emissions, from feedstock through fuel use, rather than tailpipe emissions. The U.S. Department of Energy reports an average 65% reduction in carbon intensity.
Does renewable diesel work in cold weather?
Renewable diesel generally handles cold weather better than higher biodiesel blends because isomerization improves its cold-flow properties. Performance varies by product grade, so operators in colder areas should confirm the fuel's cloud point with their supplier.
Is renewable diesel the same as regular petroleum diesel?
It is made from different feedstocks, but renewable diesel produced to ASTM D975 meets the same fuel standard as petroleum diesel, and California regulators treat compliant renewable diesel the same as conventional CARB diesel.
Can renewable diesel be used in a diesel truck?
Yes. Renewable diesel is designed as a drop-in fuel for diesel engines, which means a diesel truck can generally use it without a modified fueling routine or dedicated infrastructure.
Can renewable diesel be mixed with petroleum diesel?
Yes. Renewable diesel can generally be blended with petroleum diesel in any ratio because the fuels are chemically compatible as diesel hydrocarbons. California regulators have confirmed it can be blended with conventional CARB diesel in any amount.
Does Double AA Corporation offer renewable diesel?
Double AA Corporation provides renewable diesel, biodiesel, and other fuel products for fleets, fuel retailers, and commercial operations in California. The company also supports organizations looking for lower-carbon fuel options that align with operational needs. Contact Double AA Corporation for a current delivered quote.