Former Renova plant digester to produce biogas from ethanol syrup

By Holly Jessen | March 02, 2011

The site of a partially constructed ethanol plant in Heyburn, Idaho, may never produce ethanol but that doesn’t mean the renewable fuel won’t be an important part of its future operations.

The new owner, Natural Chem Holdings LLC, plans to upgrade the on-site anaerobic digester and produce biogas from an ethanol byproduct. The digester, which is 98 percent completed, will be fed with thick stillage, or syrup, from ethanol production, as well as cheese waste from the dairy industry. The biogas produced by the digester will then be sold into the natural gas market. “Everybody is always looking for better value-added proposition related to the ethanol industry, and this is one idea that has never been commercialized,” said Natural Chem CEO Bob Salazar.

In addition, the Texas-based company will utilize an underground tank farm at the site to develop an Eco-Fuels Terminal for blending gasoline and diesel, both with and without ethanol or biodiesel. The site currently has 17 underground tanks with piping and the company plans to add above-ground facilities such as truck receiving and loading as well as computerized systems for 24/7 operations.

Construction on Renova Energy Idaho LLC, a 20 MMgy plant, was suspended in late 2007 after the project's price tag reportedly grew from $45 million to $60 million. The goal was to feed the digester with syrup from the plant and use the resulting biogas to power the facility. “In a sense we’re still implementing that aspect of the Renova plan,” Salazar told EPM.

For $2.4 million Natural Chem now has control of the entire ethanol plant site, including the anaerobic digester and the underground tank farm. Other pieces of property, such as plant equipment, some still in crates, were auctioned off to the highest bidder in November.

If the concept proves itself in Heyburn, the company is interested in taking the idea to other areas with several relatively close ethanol plants. For example, one area of interest is the Texas Panhandle, the location of several large dry-mill ethanol plants. The company could build digesters to consume syrup from the plants and produce biogas in many areas around the country. “We would seek to commercialize this concept on a much broader scale, maybe taking it to 20 or 30 additional ethanol plants in the future,” he said.