In honor of the National Biodiesel Conference & Expo, we’re taking a look at how mineral filter aids can be used for renewable fuels, like biodiesel. Biodiesel is an alternative fuel source that can be used as a replacement for conventional, fossil diesel. Some feedstock choices include pure vegetable oil, animal oil, animal fats, and waste oils. Before these oils can be used as fuel, they need to be processed appropriately, and minerals like diatomaceous earth can help.

The Importance of Biodiesel Filtration

A Change in Standards

In the mid-2000s, many of the biofuels sold did not meet quality specifications because solids found in oils clogged fuel filters and stopped the flow of fuel to the engine. To solve this problem, the Vehicle Technologies Office partnered with the National Biodiesel Board to improve specifications and find ways to manage standards. The solution? A more thorough filtration process.

Impurities Targeted for Removal

Phosphorous and soaps are two main impurities targeted for removal. These impurities are created during the process of neutralizing free fatty acids.

When biodiesel is made, soap is produced as a by-product when free fatty acids in the oils mix with water and catalyst. Generally, the higher the free fatty acid level, the higher the soap content. It is considered a contaminant and congeals in the filter fibers, reduces throughput, causes clogs, and increases the time it takes for producing. Also, when soap burns, it leaves behind an ash residue in your engine.

Phosphorus can be found in plant oils when a phosphorus-containing fertilizer was used. Phosphorus also needs to be filtered because the phospholipid compounds can greatly impair the effectiveness of emission control systems. The effects are cumulative, so over time, even trace levels can cause severe damage.

Filtration Methods

Oil can be filtered in different ways, depending on the clarity you desire for the final product and the ease of use versus productivity you require. Some common methods include:

• Settling
• Bag filters
• Cartridge filters
• Leaf filters
• Filter presses utilizing diatomaceous earth

How Diatomaceous Earth Is Used for Filtering Biodiesel Fuels

The Bleaching Phase in Biodiesel Fuel Processing

There are many steps in the physical refining process for biodiesel production, including extracting, degumming, bleaching, and deodorizing. During the bleaching phase, the oil is filtered through a diatomaceous earth filter to remove potential peroxides, peroxide former, and residual impurities.

Improvements of Palm Oil Biodiesel Filterability

Palm oil biodiesel has a high cold soak filtration time, which places the acceptability of the biofuel at risk. When diatomaceous earth is used as an adsorbent, there are decreased levels of precipitate, glycerin, and moisture content.

A Theory: Diatomaceous Earth Can Continue to Contribute to the Environment after Filtration

Pacific Biodiesel’s pretreatment system features a filter press with diatomaceous earth to filter out impurities from highly degraded feedstock. After the oil is filtered through and the DE captures the poly materials, a dry filter cake is left behind. Rather than throwing it away, Pacific biodiesel is looking into whether the filter cakes can be repurposed after use and converted to a soil amendment or fertilizer.

Learn even more about how to use diatomaceous earth for biodiesel production.

We’ll See You at the National Biodiesel Conference & Expo

Come visit our team at the 2020 National Biodiesel Conference & Expo in Tampa, Florida to learn more about diatomaceous earth’s role in renewable fuel refining. If you can’t come to meet us in person, our customer service representatives located at our plants are standing by, and our technical experts are anticipating your call. Call us today at 866-728-3303 for your free sample and to see for yourself what makes Dicalite Management Group a customer-first industrial minerals company.

If you’d like to learn more about using minerals for filtration, download our free e-book A World of Filtration Experience today.