A wastewater plant treating 30 million gallons a day generates sufficient digester gas to fuel a one-megawatt fuel cell power plant using carbonate technology. King County s wastewater plants in Renton and West Point treat three to four times that amount. Fuel cell technology may also provide the benefit of cleaner air. Executive Sims said the technology will help the county do its part to reduce greenhouse gas and air pollution associated with electricity generation. This project will demonstrate the versatility of fuel use with the Direct Fuel Cell, as well as its capability to produce more electricity than other technologies using the same quantity of fuel.
Fuel cells are an emerging technology for efficient, clean generation of electrical power.
In addition, the heat produced by the chemical reaction that occurs in a fuel cell can be captured and used within the treatment plant for digester and space heating. Fuel cells can operate on a range of fuels, including methane or natural gas, and offer enormous potential for the wastewater treatment industry. Similar to a battery, a fuel cell is composed of a number of individual cells, each consisting of an anode, cathode and electrolyte. Hydrogen, oxygen and carbon dioxide react with the electrolyte to produce electric current. The byproducts of the reaction are heat, carbon dioxide and water.