Economical Biodiesel From Sewage Sludge
According to a recent article in ACS’ Energy and Fuels, today’s technology is capable of producing biodiesel fuel from sewage sludge that is just a few cents away from being competitive with the costs of producing diesel from petroleum. Sludge is the solid material that remains after sewage is treated at wastewater treatment plants.
The high demand for biodiesel has led researchers to look for most cost efficient ways to produce the green fuel. Sunflower seeds, soybeans and several other food crops have been used, but they are too expensive to be economical. Sewage sludge makes the perfect alternative. Each year, the United States produces around seven million tons of sludge.
To boost the production of biodiesel, treatment plants could make use of microorganisms that will produce higher amounts of oil. That one step could boost the production of biodiesel to 10 billion gallons. However, the report also warns that there are some huge challenges that still exist. Gathering the sludge, separating the biodiesel from the other materials, maintaining quality and regulatory concerns still need to be addressed.
“Biodiesel production from sludge could be very profitable in the long run,” the report states. “Currently the estimated cost of production is $3.11 per gallon of biodiesel. To be competitive, this cost should be reduced to levels that are at or below the recent costs of $3.00 per gallon.”