Raceway materials have to be selected by more than just their cost or suitability for algae production. Depending on the species of algae and its intended final use, the liners and other materials used for constructing the pond may need to meet certain safety certifications. Even algae grown just for biofuel production must be pure and free of contaminants that could come from the materials used to build the raceway. As you design new raceways for algae cultivation, make your material selections with these concerns and limitations in mind.
Food Safety for Supplement and Food Production
First, any algae grown for pharmaceutical use, human consumption, or dietary supplement sales will need a food-grade liner and food-grade materials for all exposed equipment and parts. This can be harder to find than you may think on a commercial scale. Many pumps and paddlewheel systems available for the largest algaculture productions aren’t sealed to completely prevent any chance of oil or lubricant contaminating the water. This is unacceptable for food production, so you’ll need to source equipment that is designed to a higher safety standard for these purposes. This applies to liners as well. Look for NSF certification for potable water or food use to make sure a particular flexible liner product is appropriate for this kind of algaculture.
Fish and Animal Safety
If the algae will be used as a livestock or fish feed product instead, you’ll still need to look for liners rated for these uses. A liner rated for livestock drinking water supplies should be safe for algae production of feed, as will be a liner rated directly for contact with fish. These liners won’t leach out chemicals that could harm the animals or fish if they consume them through the final algae product. Algae is known for rapidly absorbing nearly anything mixed in with water, so that ability can backfire if it causes unsafe contamination of the final feed product. Make sure all the liners used for feedstock raceways and ponds are safe for the animals or fish that will eventually consume the algae.
Chemical Leaching
Chemical leaching from liners and other materials can be a major problem no matter the intended use for the algae. If chemical compounds are mixed into the final product, it may not be as suitable for fermentation into fuel or conversion into plastics. Many common plasticizers used to keep liners flexible can cause algae products to backfire since they also interfere with the processing of those finished products. Make sure to look for non-reactive and chemical resistant liners, that have been tested specifically in the algaculture environment, before assuming a particular product will work well for a commercial installation.
Reactivity from Liners
Reactivity can be an issue, specifically in algae production for biofuel or bioplastics, because these species tend to be high in lipid production. Lipids are natural oils that are chemically similar to petroleum products. In fact, petroleum formed from algae and other tiny lifeforms that were trapped and released their lipids as they decomposed under pressure. Unfortunately, this means that many liner materials and polymers generally used for algaculture equipment will react after long-term exposure to the water solution. Other macroalgae may aggressively root into the plastic liner of a raceway, damaging it physically rather than chemically. Either way, the result is a damaged liner that doesn’t last as long and that develops leaks that are hard to detect. Choose a liner that is both oil-resistant and reinforced against physical forms of damage, such as RPE.
Looking for a liner that can handle everything that the algaculture process can throw at it? You’ve found it here at BTL Liners. We have fish and food safe certified liners that can help you meet all the most stringent production requirements for edible and supplement algae products. Whether you want to produce biofuel, livestock feed, or cosmetic ingredients, our RPE liners are the right choice for your ponds and raceways.
