What’s That – HEFA Renewable Diesel

Did you know that the refining process behind renewable diesel not only defines its unique qualities but also makes it nearly indistinguishable from traditional petroleum diesel? Renewable diesel, crafted from renewable resources like vegetable oils, animal fats, and even used cooking oil, undergoes a fascinating transformation through a method called hydrotreating. In this week’s “What’s That Wednesday” article, we’re exploring the science of hydrotreating and revealing how this process sets renewable diesel apart from other biofuels. Get ready to discover the innovation fueling the future of sustainable energy!

What is Hydrotreating?

Most renewable diesel is hydro-processed esters and fatty acids (HEFA) created through hydrotreating. Hydrotreating is a refining process long used to de-sulfurize petroleum diesel biomass-based. It can also convert biomass-based feedstocks into high-quality biofuels, such as renewable diesel and sustainable aviation fuel. Unlike renewable diesel, biodiesel relies on a separate, distinct method known as transesterification to transform feedstocks into fuel. The hydrotreating process involves reacting a wide variety of feedstocks with hydrogen gas at high temperatures and pressures in the presence of a catalyst.

This chemical transformation removes impurities like oxygen, sulfur, and nitrogen, resulting in a cleaner, more stable fuel than conventional petroleum fuels that performs well in modern diesel engines and aligns with existing fuel infrastructure.

Hydrotreating Process

The hydrotreating process begins with feedstock pre-treatment to eliminate impurities like particulates, metals, and water. These contaminants can otherwise damage equipment or deactivate catalysts used in later stages. Once cleaned, the feedstock undergoes hydrodeoxygenation (HDO), where oxygen is removed through a reaction with hydrogen to form water. This step improves the fuel’s energy density and stability, making it more comparable to traditional petroleum diesel.

Next, the feedstock is subjected to hydrodesulfurization (HDS) and hydrodenitrogenation (HDN), processes that remove sulfur and nitrogen by converting them into hydrogen sulfide (H₂S) and ammonia (NH₃), respectively. These steps ensure that the fuel meets stringent environmental regulations, reducing the potential for harmful emissions during combustion. Additionally, hydrocracking and isomerization processes break down long hydrocarbon chains into shorter, branched ones. This not only improves the fuel’s cold-flow properties but also enhances its cetane number, a key measure of diesel fuel quality.

Benefits and Challenges of Hydrotreating

Hydrotreating offers several benefits for biofuel production. It produces renewable diesel that is chemically identical to petroleum diesel, allowing it to be used as a direct replacement without blending limitations. The fuel exhibits superior properties, including better oxidation stability, higher cetane numbers, and improved performance in cold weather. The overall process reduces sulfur and nitrogen content, leading to cleaner combustion and lower emissions of sulfur oxides (SOₓ) and nitrogen oxides (NOₓ).

However, hydrotreating also presents challenges. The process consumes large amounts of hydrogen, which can impact both the carbon footprint and the cost of production. Impurities in the feedstock can deactivate catalysts, requiring rigorous pre-treatment steps and ongoing catalyst management. The presence of corrosive compounds in bio-oils can also cause equipment wear, necessitating the use of advanced materials and process controls. Despite these challenges, advancements in catalyst technology and process optimization are continuously improving the efficiency and viability of hydrotreating for producing high-quality renewable fuels.

Advantages and Applications of Hydrotreating

Hydrotreating offers several advantages, including the efficient conversion of biomass into hydrocarbons similar to conventional fossil fuels, achieving high conversion yields. The resulting biofuel, renewable diesel, features high heating values, better oxidation stability, and higher cetane numbers, making it compatible with existing engines and infrastructure. This process also enables the production of byproducts such as renewable naphtha and renewable propane, fuels that can be utilized across multiple sectors. In transportation, hydrotreated biofuels act as substitutes for gasoline, diesel, and jet fuel. Furthermore, the marine industry benefits from low-sulfur marine fuels derived from this process. Hydrotreated biofuels help reduce greenhouse gas emissions and reliance on fossil fuels, contributing to a more sustainable future.

Take advantage of the sustainable solutions Mansfield offers for your business. From renewable diesel to kerosene, Mansfield is your one-stop shop for all fuel distribution needs. Stay on top of environmental regulations and initiatives and discover how renewable diesel can elevate your business’s sustainability efforts while ensuring seamless operations.