The company is in the process of raising the funding to build one of its ECOsystems in Pasa Robles, California, said Darren Eng, CEO of Greenbelt Resources. The “local-scale” waste-to-energy system is focusing on using waste products from regional breweries, wineries and other ag businesses to generate bioethanol and ingredients for animal feed.
“The value of a Greenbelt system being utilized this way is because it’s a waste product on their product, like beer or wine, but we’re actually producing it as a product,” he told FeedNavigator. “We standardize what it looks like – we have a certain amount of control over what the product is and improve it so it will be appropriate for whatever [producer] is buying it.”
The company started working with breweries and wineries to test their by-products for use in an ethanol and feed producing system as a way to address industry by-products, he said.
The pattern appears to be that a small brewery is able to find an outlet for generated by-products like trub, sometimes with producers feeding cattle, he said. However, as the brewery expands it starts to make more of the by-product than can be used in feed and the waste becomes an expense.
That’s how the company started working with breweries like Firestone Brewery and Barrelhouse Brewing Company he said. “We’ve been testing the different trubs – what’s the energy cost and labor cost of processing the different types of trub? And how does that affect our economics?”
Setting up PRECO (Paso Robles ECOSystem project)
Greenbelt currently has a small-scale research and development facility in Paso Robles, California, where it has the ability to test different materials for the generation of ethanol and feed ingredients, said Eng.
However, it is in the process of gathering funding to establish a full-scale facility, he said. That facility will use the tested brewery by-products and waste from multiple area wineries.
Establishing the funding for the project is expected to take the next two to three quarters followed by the building period, he said.
When completed, the project is expected to produce at least 500,000 gallons of bioethanol along with feed ingredients, bioproducts and water.
Feed focus and chemistry
The feed ingredient generated by the bioethanol facility is removed from the brewery waste products like trub and red wine pumice, said Eng.
The brewery waste is comprised of brewers’ yeast and solids involved in the brewing process, he said. Similarly, the red wine pumice is material removed from the wine.
“That’s one of the three different types of waste in a winery."
Those facilities also can generate waste wine, and vapor, which also can be used in the bioethanol generation process.
The potential feed ingredient would be generated in a proportion to the ethanol collected, said Eng. “We’re not generating millions of tons of DDGS, we’re looking at small amounts,” he added.
“There’s a certain amount of animal feed produced,” he said. “It is not in a large volume, but are there niche markets where we can find a higher value – so we’re starting to look at the chemistry of the feed.”
The ingredient contains a high concentration of protein, he said. Other nutrient levels can vary depending on the type of the yeasts used.
The product is commercially of interest when sold as bulk commodity, said Eng. However, the company is assessing it for potential use in other areas like as a protein ingredient for aquafeed or niche swine or animal production.
There also is work being done to evaluate the interaction of different ethanol sources on resulting feed ingredient quality, he said.
The target market for the feed ingredient will be in a range around the ethanol facility, he added.