The fuel known as propane, or liquefied petroleum gas (LPG), has traditionally been a co-product of two fossil fuel processes: the refining of crude oil and the processing of natural gas. This conventional propane is a hydrocarbon molecule with the chemical formula C3H8. Renewable propane, by contrast, is chemically identical to its conventional counterpart, but it is derived entirely from sustainable, non-fossil sources. This shift in origin allows the fuel to retain all of its physical properties while significantly reducing its overall carbon intensity. The method by which this common molecule is generated from diverse organic matter represents a significant pathway toward decarbonizing heating and transportation sectors.
Renewable Feedstocks
The production of renewable propane relies on a variety of organic materials, primarily waste products from other industries. This focus on waste-derived sources ensures a much lower carbon footprint than fossil fuels. Primary feedstocks include used cooking oil (UCO) and various waste greases collected from restaurants and food processing facilities.
Another significant source is animal fats, specifically rendered tallow, a byproduct of the meat packing industry. Utilizing these fats and oils ensures the feedstock does not compete with the human food supply chain, a common concern with first-generation biofuels. Certain non-food grade plant oils, such as those from the camelina plant, are also gaining traction as dedicated energy crops.
Camelina is a hardy, drought-resistant oilseed that can be grown on marginal land, further enhancing the fuel’s sustainability profile. Future feedstocks are expected to broaden the supply base, potentially including cellulosic biomass and municipal solid waste. Research is exploring how to convert the organic content of these waste streams into the necessary oils and fatty acids for processing into renewable propane.
Conversion Technologies
The conversion of feedstocks into renewable propane is primarily achieved through hydrotreating, a technology widely used in facilities producing renewable diesel and sustainable aviation fuel (SAF). The hydrotreated vegetable oil (HVO) pathway is the dominant commercial method today.
Feedstocks, such as triglycerides in animal fats or plant oils, are long-chain molecules composed of fatty acid groups attached to a glycerol backbone. During hydrotreating, the feedstock is exposed to high temperatures and pressure in the presence of a catalyst and hydrogen gas. This environment causes chemical reactions, including hydrogenation and hydrodeoxygenation.
Hydrogenation saturates the double bonds in the fatty acid chains, while hydrodeoxygenation removes oxygen atoms, typically as water. Propane generation occurs when the glycerol backbone, a three-carbon chain, is cleaved from the fatty acids. This C3 component is then saturated with hydrogen, forming the propane molecule (C3H8).
Renewable propane is a co-product of the main renewable diesel production process; the longer fatty acid chains are converted into the paraffinic hydrocarbons that make up renewable diesel. While HVO is the most established method, other emerging technologies include the gasification of biomass followed by Fischer-Tropsch synthesis. Advanced processes, such as the electro-catalytic conversion of carbon dioxide into propane, are also being developed to create new, carbon-recycled pathways.
Practical Applications and Compatibility
A major benefit of renewable propane is its “drop-in” compatibility, meaning it is ready for immediate use in all existing infrastructure and appliances. Because the finished molecule is chemically indistinguishable from conventional propane, no modifications are required for storage tanks, distribution pipelines, or end-use equipment. This includes residential heating systems, commercial cooking appliances, and vehicles powered by propane autogas.
This seamless integration significantly lowers the barrier to adoption for consumers and businesses seeking to reduce their carbon footprint. Renewable propane can be used on its own or blended with traditional propane in any proportion, allowing for a flexible transition for fuel providers and customers.
Current market adoption is largely driven by regulatory incentives, such as the Low Carbon Fuel Standard programs in states like California, Oregon, and Washington. These policies assign a low carbon intensity score to the fuel, making it an attractive option for fleets and industries aiming to meet emission reduction targets. As production capacity for the HVO process—and its primary products, renewable diesel and SAF—continues to expand globally, the co-product renewable propane will naturally scale up alongside it.