Growing algae in sewage - a fuelish idea 6
June 10, 2011
Growing algae in sewage - a fuelish idea
An experiment in making "bio-fuel" is slated to get under way this summer at Baltimore's Back River wastewater treatment plant.
The city's Board of Estimates approved Wednesday a $255,000 contract with a small Maryland company to grow algae at the plant and convert it to fuel. The project is underwritten with federal economic stimulus funds the city receved last year.
Under the one-year agreement, Hytek Bio LLC of Dayton will install "bioreactors" to cultivate algae, using the nutrients in the treatment plant's wastewater as food.
"The water's still fairly high in nitrogen and phosphorus, and it's low in dissolved oxygen, which is not good in the (Chesapeake Bay)," said Bob Mroz, Hytek president and CEO. "The algae will consume the balance of the nitrogen and phosphorus and put oxygen back in the water."
In another kind of virtuous circle, the algae's growth will be boosted by feeding it carbon dioxide. The source - the flue gas given off by the generator that's burning methane from the sewage to help power the treatment plant.
City officials are looking to see the algae harvested and converted to biofuel, which might be burned one day in city boilers or used to run city vehicles. Mroz, a retired federal official, says this one-year project is a "small-scale demonstration of the technology." But he's bullish on the prospects for making fuel, oil, cosmetics and even "bioplastics" from the algae while capturing climate-warming greenhouse gases and helping reduce nutrient pollution of the bay.
The biomass-to-biofuel pilot is one of more than 18 initiatives the city's Department of General Services has launched with federal aid to see about reducing the municipal government's energy bills through greater efficiency and conversion to alternative fuels.
(Sludge digester domes at Baltlimore's Back River treatment plant. Photo special to the Sun by Colby Ware)