Renewable Diesel vs Biodiesel - how are they different?
In the quest for cleaner and more sustainable fuel options, both Hydrotreated Vegetable Oil (HVO) and biodiesel have emerged as popular alternatives to traditional fossil fuels. While they share the common goal of reducing carbon emissions and reliance on non-renewable resources, there are significant differences between the two.
1. Production Process
The primary difference between HVO and biodiesel lies in their production processes. HVO is produced through a process called hydrotreatment, where vegetable oils or animal fats are treated with hydrogen at high temperatures and pressures. This process removes impurities and saturates the oil, resulting in a high-quality, stable fuel that is chemically similar to conventional diesel.
On the other hand, biodiesel is produced through a process called transesterification. In this process, vegetable oils or animal fats react with an alcohol in the presence of a catalyst, to produce fatty acid methyl esters (FAME) and glycerin. The FAME is then separated and purified to create biodiesel.
2. Chemical Composition
Due to the differences in their production processes, HVO and biodiesel have distinct chemical compositions.
HVO is a pure hydrocarbon, similar to conventional diesel, which means it does not contain oxygen. This lack of oxygen makes HVO more stable and less prone to oxidation, resulting in a longer shelf life and better performance in cold temperatures.
Biodiesel, on the other hand, contains oxygen due to the presence of fatty acid methyl esters. This oxygen content can lead to higher NOx emissions and lower oxidative stability, which can affect the fuel's performance and storage life.
3. Performance and Compatibility
HVO's chemical similarity to conventional diesel gives it an edge in terms of performance and compatibility. It can be used in existing diesel engines without any modifications. RD2Go's HVO also meets both international standard EN15940 and the Australian Fuel Quality Standards (Paraffinic Diesel) Determination 2025 for paraffinic diesel fuels. This makes HVO a drop-in replacement for conventional diesel, offering a seamless transition for users.
Biodiesel, while also compatible with most diesel engines, may require some modifications or blending with conventional diesel to ensure optimal performance. It should meet its own standards for biodiesel (e.g. EN14214), but its higher oxygen content and different chemical properties can affect engine performance and emissions.
4. Environmental Impact
Both HVO and biodiesel offer significant environmental benefits compared to conventional diesel. They are both produced from renewable resources which helps reduce greenhouse gas emissions and reliance on fossil fuels.
However, HVO has an advantage in terms of its overall environmental impact. The hydrotreatment process used to produce HVO results in a cleaner-burning fuel with lower emissions of particulate matter, NOx, and other pollutants. Additionally, HVO's longer shelf life and better cold-weather performance reduce the need for additives and improve fuel efficiency.
Conclusion
In summary, while both HVO and biodiesel are valuable alternatives to conventional diesel, they have distinct differences in their production processes, chemical compositions, performance, and environmental impacts. HVO's superior stability, compatibility, and cleaner-burning properties make it an attractive option for those looking to reduce their carbon footprint and transition to more sustainable fuel sources.