The increasing need to decarbonize the transport sector is accelerating the adoption of renewable fuels, particularly biofuels, as sustainable alternatives to conventional diesel. For compression ignition engines, Hydrotreated Vegetable Oil (HVO) represents a promising solution due to its clean combustion profile and high-quality fuel properties. HVO is a paraffinic fuel obtained via hydrotreatment of renewable lipids. It is characterized by a high cetane number (>70), very low particulate emissions, and excellent oxidative stability. However, the absence of polar molecules results in poor lubricity, which raises durability concerns for high-pressure fuel systems.
Biodiesel, composed of fatty acid methyl esters (FAME) derived from vegetable oils or used cooking oil, is known for its renewable origin and favorable lubricity. Its ester content enhances lubricity and contributes to reductions in carbon monoxide (CO), unburned hydrocarbons (HC), and particulate matter. Nonetheless, biodiesel can present lower oxidative stability, material compatibility issues, and increased NOx emissions under certain engine conditions.
Recent studies show that mid-level blends , when properly formulated and metal-controlled, can reduce well-to-wheel GHG emissions by up to 13% while maintaining compatibility with diesel particulate filters (DPFs). Combining HVO and biodiesel offers the potential to balance oxidation stability, lubricity, and emission performance.
This paper investigates the impact viability of HVO–biodiesel blends, using B20 as a case study due to its practicality and regulatory acceptance. The methodology includes literature analysis and engine bench trials, aiming to assess the performance and emissions of fossil and renewable fuel blends.