Impact Bioenergy’s Microdigester Testing Waste at Seattle Brewery

by Katie Fletcher (Biomass Magazine) Seattle-based Impact Bioenergy, a small startup focused on distributed energy with its portable, prefabricated anaerobic digestion (AD) technology, deployed its first microdigester at the Fremont Brewery Co. in Seattle this April.

The company manufactures and sells bioenergy systems that convert organic waste materials into renewable natural gas and fertilizer with zero waste. Impact Bioenergy has two systems: The HORSE 25 series with the capacity to divert 135 pounds of waste per day from waste generators and the NAUTILUS 185 series with the capacity to process 1,000 to 5,000 pounds per day.

At Fremont Brewery, it’s the HORSE bioenergy system that is currently being deployed. The system’s footprint takes up approximately 160 square feet of ground space and arrives completely built. The only setup required is to make a water and a power connection and the plant is up and running, according to Impact Bioenergy president Jan Allen. “We have made it simple and easy to operate this system—about as complicated as operating a fish aquarium,” Allen said.

The process begins with the collection of food waste, edible liquids, or fats, oils and grease in an oversized sink for inspection and pre-grinding. This breaks things like chicken, fish, cabbage and pineapples down to bite-sized pieces. The system has a blending and feeding system that runs automatically so labor cost is minimal, Allen said. You simply look at the temperature, mixing, liquid level, pressure, gas storage and battery status when feeding the system.

The installation at the Fermont Brewery Co. was made possible through a grant from the city of Seattle to do a one-year demonstration project of nonresidential onsite organics recycling. Impact Bioenergy is first demonstrating the brewery waste and then the plan is to bring in restaurant waste within the 12-month time period. “Our intention is to just keep it going after the 12-month demonstration,” Allen added.

Once the company begins collecting food waste they plan to deploy a Community Supported Biocycling initiative to cut down on emissions from the trucking of wastes. The company is designing a net-negative carbon collection system that will use an electric cargo tricycle with electric motor hubs. “We’re going to collect within a 2-mile radius of all of the commercial organics,” Allen said.

In addition to the city grant, another way the project raised funding was through a crowdfunding campaign launched last fall. The campaign raised over $36,000 with over 300 backers.

Impact Bioenergy was initially just looking at North America and the Caribbean, but with the global response is now looking at ways to license and serve a global market. “We have about 13 distributors and we have about 20 collaboration agreements with other companies, so what we’re trying to do is collaborate and partner with other companies to deliver these plants and get them on the ground,” Allen said. READ MORE