Supplier news

Impact Bioenergy expands product offering

Seattle-based Impact Bioenergy has expanded its model 185 digester design for facility operators interested in generating energy from their own food scraps and paper products. The company has taken the model AD185 and expanded it to include the AD185-2 model.

This larger unit has five times the daily capacity (5,000 pounds per day versus 1,000 pounds per day) in comparison to the AD185, the company says. The technology uses anaerobic digestion (AD) to generate biogas. Nutrient-rich organic matter is the end product after the biogas has been extracted, Impact Bioenergy says.

The manufacturer says the AD185 offers an output of 111,000 British thermal units (Btu) per hour and requires 450 square feet of ground space. The new AD185-2 has a 555,000-Btu-per-hour output and requires 900 square feet, according to the company. Energy storage systems of 320 square feet for AD185 and 1,200 square feet for the AD185-2 can be added for peak demand cycling, the company adds.

The equipment can be used in an urban setting with features like gas lighting to visually engage passers-by with an illustration of the energy value of food scraps, according to Impact Bioenergy. The system is prefabricated and can be installed in a single day with simple connections to building wiring, water and sewage systems, the company adds. Aspects of the design include a skid-mounted food waste recycling and preparation system, digester and power production unit. The company also says the portable bioenergy plant can be configured for electrical output or biogas supply to an existing furnace or boiler.

Electrical output on a baseload 24/7 basis starts at 11.7 kilowatts (kW), with peak output at 35.1 kW. Odor is captured and treated with odor control technology including biofiltration, carbon filtration and atomizing in a fully enclosed system.

Impact Bioenergy has offices in British Columbia, Washington and Oregon. More information on Impact Bioenergy’s products and services is available at www.impactbioenergy.com.

Composting expert authors book on heat recovery

Gaelan Brown, the founder of CompostPower.org has written a book about what is described as “a revolutionary approach for space heating and generating hot water.” Brown has worked with engineers and compost scientists for years to refine methods of composting that can heat greenhouses, barns, buildings and hot water, all without combustion.

The book, The Compost-Powered Water Heater, provides detailed plans for constructing small do-it-yourself systems with wood chips and sawdust, step-by-step illustrations and photos to guide readers through the process and calculations to help estimate the heating capabilities of various approaches. The book includes an overview of a large engineered system that can be scaled to suit any heating need, according to the publisher, The Countryman Press, Woodstock, Vermont.

According to the CompostPower.org, the book aims to be a valuable resource on compost heat recovery. It includes reports on projects from Norway, Chile, Siberia, Canada and the United States. The Compost-Powered Water Heater is available on Amazon.com.

California AD system in use for 25 years

The city of Tulare, California, is celebrating 25 years using anaerobic digestion technology as well as its 25-year partnership with equipment provider Geomembrane Technologies Inc. (GTI), headquartered in the Canadian province of New Brunswick, with U.S. offices in Denver.

Tulare is home to six large-scale cheese and dairy producers, including Nestlé-Dreyer’s, Saputo Cheese and Kraft USA, which together produce large volumes of high-strength industrial wastewater that is treated by the city. In 1989 the city installed an ADI-BVF anaerobic digester (AD) with a four-acre gas-tight cover manufactured by GTI. The same system, with an updated cover, continues to operate today, says Darrin Evans, vice president of product management for GTI.

“That AD unit has been the heart of their industrial wastewater treatment for a continuous period of 25 years,” Evans says. “In a lot of other cases you wouldn’t have that continuity and the one tank doing all that work for so many years.” Further, Evans adds, “the cover is a vital step in the conversion of the waste to energy.”

The AD unit was designed to treat the city’s industrial wastewater, comply with discharge limits and also allow for the conversion of wastes to energy. The GTI cover expands over the entire surface of the digester to contain and collect biogas generated by the reactor so it can be used to power plant operations.

GTI says the cover collects up to 600,000 cubic feet of biogas per day, which is enough to generate a significant portion of the plant’s power.