Stumptown Coffee Roasters and Energy Trust of Oregon are teaming up for one of the largest gas-savings projects the trust has ever funded.
Stumptown, which is preparing to move from its original home to modern quarters in the Central Eastside (Portland Business Journal subscribers can read all about the move here), will retire the high-temperature afterburner it uses to burn off particulates in the emissions from its coffee roaster.
Oregon law requires manufacturers to scrub air before releasing it to the environment. It is an energy-intensive process.
Matt Dawson, a roaster at Stumptown, demonstrated how the current system works during a recent tour of the company's existing plant in Southeast Portland.
The afterburner works in tandem with Stumptown’s roaster, which can process up to 100 pounds of coffee beans at a time.
As the roaster heats up and the green beans turn to brown, the temperature in the gas-fired afterburner rises to the 1,300 degrees needed to incinerate the organic particles coming off the beans.
It takes a lot of gas to reach those high temperatures. Stumptown buys and roasts more than 2 million pounds of green coffee beans annually and runs its roasting equipment seven days a week. Gas is a major expense.
Matt Lounsbury, operations director, told the Portland Business Journal he expects the new system will curb its demand by at least 25 percent.
When it moves, Stumptown will retire the afterburner in favor of a “regenerative thermal oxidizer” or RTO. Energy Trust is contributing about $200,000 toward the cost. Stumptown officials expect the new system to cut its gas bill by a quarter and to pay for itself within three years.
RTO systems are widely used in manufacturing and save energy by capturing heat from the industrial process — roasting coffee in Stumptown’s case — to generate heat to burn off particulate matter. That cuts down on the amount of energy needed to combust particulates.
The project is funded in part by Energy Trust’s Production Efficiency Program, available to all industrial customers of Portland General Electric, Northwest Natural, Cascade Natural and Pacific Power.
Susan Jowaiszas, marketing manager, said hundreds of businesses turn to the trust each year for help identifying ways to save energy. The program provides technical assistance and cash incentives for projects that qualify.
Stumptown’s RTO project is one of the largest natural gas projects it has ever done.
The results are good for both the environment and cut energy bills, she said.
“They can use dollars in their core business,” she said.
The Energy Trust program is funded by a 3 percent public purpose charge paid by customers of Portland General Electric and Pacific Power. The money also pays for energy conservation projects in schools, low-income energy assistance.
Stumptown will consolidate its operations, including warehouse, labs, administrative offices and roasting plant, in the Central Eastside district this summer. The business has outgrown its current home — three buildings along a 10-block stretch of Southeast Division Street.