A Central Valley huller has found a way to rid themselves of a growing pile of agriculture waste with an incinerating unit called an “air curtain burner.” The device is well known in the forestry field and may be the answer to disposing of a large amount of sticks and twigs that are an increasing problem with fewer cogeneration options available.
Minturn Hulling Cooperative, with the help of Western Agricultural Processors Association (WAPA), went through the rigorous process of permitting the burner for use on the huller grounds in Le Grand. Minturn General Manager Jeff Hamilton said he was looking for an answer to a two-year stockpile of sticks and twigs that are piling up behind his office. He describes what the unit does in the video below.
The unit is relatively simple in both looks and how it works. “It looks just like a roll-off trash bin,” Hamilton said. Tree debris is loaded into the burner and manually set on fire. A small fan is attached to back of the burner, and it pushes air across the top of the open unit. The “curtain” of air across the top pushes the particulate matter from the fire back into the blaze. “It’s very clean, and if it weren’t for the flames and the heat waves you can see off in the distance, you wouldn’t even know it was running,” Hamilton said.
WAPA President Roger Isom said the project was a challenge. “It wasn’t easy to get through the process. There are two major hurdles you have to cross with the air district,” Isom said. Minturn Hulling sits on a large, open plot of land. The burner is in the middle of the lot, a less than ideal location so that it could clear drift restrictions to surrounding properties. Isom added that they also had to place limits on how much debris the facility could process, even though it isn’t exceeding those limits at this point.
Because of those restrictions, this will not be an option for any facility, and there is still more to do. “We still have to go out and get a federal Title V permit from the Environmental Protection Agency,” Isom said. CAL Fire currently uses several of the burners and Isom said that has likely paved the way for them to get the Title V permit for the Minturn Hulling unit.
The burner may not be the ultimate answer the industry. However, Isom said it’s a much-needed tool right now. “The air curtain burner is not the silver bullet, but it is one option,” Isom said. “It looks like a promising option that can get us by in the short-term until we can find long-term solutions like the biogas plants.”