What is Green Diesel? In this month’s newsletter we will explore the world of renewable green diesel by looking into the process of transforming animal fats, plant-based oils, and yellow grease into a sustainable fuel source from the feedstocks to the finished product.

1. Feedstock Acquisition: All Aboard the Rail Car

Renewable green diesel starts with the acquisition of feedstocks, which are sourced from various origins. Animal fats, such as beef tallow and poultry fat, are obtained from meat processing plants, while plant-based oils, like soybean oil and canola oil, come from agricultural crops. Yellow grease, which is primarily used cooking oil, is collected from restaurants, food processors, and other foodservice establishments.

These diverse feedstocks are transported to green diesel production facilities via rail cars. Rail transportation offers a cost-effective and efficient method for large-scale feedstock delivery, enabling producers to acquire substantial quantities required for continuous production.

2. Pretreatment: Getting the Feedstocks Ready

Upon arrival at the production facility, the feedstocks undergo a pretreatment process. Pretreatment involves removing impurities, such as water, free fatty acids, and solid contaminants, from the feedstocks. The removal of these impurities helps ensure the quality and efficiency of the subsequent conversion process.

3. Hydrogenation: The Conversion Magic Begins

The pretreated feedstocks then enter the hydroprocessing unit, where the magic of conversion takes place. Hydrogenation, the core process, involves the reaction of feedstocks with hydrogen gas in the presence of a catalyst, typically a metal sulfide. This reaction occurs at high temperatures and pressures.

During hydrogenation, triglycerides present in the feedstocks are broken down into fatty acids and glycerol. The fatty acids further undergo a series of reactions, including decarboxylation and isomerization, to produce hydrocarbons similar to those found in traditional petroleum diesel. The hydrogenation process also helps remove impurities, such as sulfur and nitrogen compounds, resulting in a cleaner fuel.

4. Product Refining: Polishing for Perfection

After the hydroprocessing stage, the resulting product, known as green diesel, undergoes further refining to meet the desired specifications. This refining process typically involves distillation, where various hydrocarbon fractions are separated based on their boiling points. Distillation helps remove any remaining impurities and ensures the final product complies with the required standards.

5. Distribution and Utilization: Fueling a Sustainable Future

Once the refining process is complete, the green diesel is ready for distribution. It can be transported via pipelines, tank trucks, or rail cars to fueling stations or other end-users. Green diesel can be seamlessly integrated into existing diesel infrastructure and used in diesel engines without any modifications.

Renewable green diesel offers numerous environmental benefits compared to conventional diesel. It reduces greenhouse gas emissions, decreases air pollutants such as particulate matter, and contributes to a cleaner and more sustainable energy future.

S&S Technical Solutions:

Need help with proven solutions to offload feed stocks from railcars and trucks to complete loading rack packages to load green diesel with custody transfer metering, meter provers, loading arms, controls – give us a call to explore.