By Cecilia Baldwin
SACRAMENTO, Calif. – American River College takes a step towards environmental stewardship with a tour of the nation’s first commercial anaerobic biodigester that will begin processing the campus’s compostable material next spring.
Ruihong Zhang, a UC Davis professor of biological and agricultural engineering, has been working on the biodigester system for a decade with a pilot stage that began in 2006 on the UC Davis campus and went commercial in 2012 after CleanWorld Partners obtained exclusive licensing of the technology from UC Davis.
Zhang’s anaerobic digester technology uses natural microbes to break down organic waste and in the process generates biogas and other forms of renewable energy such as heat, electricity, natural gas, and fertilizer.
The ARC Sustainability Committee has been working with Atlas Disposal and CleanWorld Partners to arrange for the compostable material from campus to be converted into clean renewable energy at the Sacramento South Area Transfer Station.
The station’s biodigester provides clean fuel to the adjacent CNG Fueling Station operated by Atlas Disposal; the fuel is then used to power waste disposal vehicles, school buses and other fleet vehicles.
Both the Student Center servery and the culinary arts program will be contributing organic waste to be collected and hauled to the biodigester beginning early next semester.
“We need to raise awareness of the environmental efforts being done on campus and to rally together people that can teach others about what can and can’t be composted so that when the program begins we will be ready,” said Don Reid, ARC’s Green Office Program chair and Sustainability Committee representative.
“ARC must meet regulations set by AB341 which requires that the campus divert 75 percent of its waste stream from land fills by 2020 … this partnership with CleanWorld Partners is the final piece of the puzzle,” said Don.
According to Don, the campus will be adding three more tri-bin waste receptacles to the Student Services building with signage designating each bin as either recyclable, compostable or landfill with hopes to eventually expand the program throughout the rest of campus.
“We are hoping to have the program up and running by Earth Day,” said Don.
The Transfer Station’s biodigester processes an average of 25 tons a day of mixed corrugated and food waste product from the surrounding Sacramento area and has an expansion planned for the system that would quadruple the waste processed daily and prevent 100 tons of food waste a day from going into local landfills and reducing greenhouse gas emissions in the area according to Katie Oliver, an environmental engineer for CleanWorld Partners.
Once the system is upgraded, “the biodigester will produce 700,000 diesel gallons per year of renewable CNG and prevent the release of 18,000 tons of CO2 into the atmosphere,” said the CEO of CleanWorld Partners, Michele Wong in a press release.
The station also “produces 8 million gallons a year of organic soils and fertilizer products for Sacramento area farms and agriculture and generates 1 million kilowatts of electricity to be used to power the facility and the adjacent Fueling Station,” said Michele.
“The fueling station produces the only commercially available fuel that has negative carbon intensity in the US, meaning it destroys more carbon than it creates,” said Katie.
According to Katie, the City of Sacramento is saving $1 million a year by switching from diesel to the biodigester’s transportation quality methane fuel and the remaining solid waste from the system is separated out and shipped to Davis where it becomes fertilizer sold under the brand name Ecoscraps.
cillyglue 