Industry Market Trends

Sludge Crawls Out of the Sewers and Into Sustainability Spotlight

Sep 29, 2010

Not too long ago, we talked about the merits of algae becoming a viable source of renewable energy in the blog post, Is Alage Poised for Renewable Energy Superstardom? Guess what? Now it's sludge's turn! Sure, turning wastewater sludge into sustainable energy isn't a new concept, but a recent "cost-effective" process developed by University of Nevada researchers has brought sludge out of the sewers and into the sustainable spotlight again. The end result of this process could lead to the mass-production of a cheap source of renewable energy.

Here's how the process works, according to the article "Researchers Turn Sludge Into Sustainable Energy" from International Business Times:

Led by University of Nevada at Reno associate professor of chemical engineering, Chuck Coronella, the team has created a process where wet sludge is dried at relatively low temperatures in a fluidized bed of sand and salts. This produces a humid air and a dry fuel, the latter of which is burnable for a gasification process.

"You end up with something that is essentially like wood," Coronella, who is also the project's principal investigator, said. "It has similar content and volatility to wood. Anywhere wood is used for fuel, it can basically be used."

The article makes some very good points about the benefits of wet sludge. For one, it's a lot more renewable and environmentally friendly to use as a fuel source than wood. And since every city in the developed world produces sludge on a daily basis, there's plenty to go around. As far as its effectiveness is concerned, microscopic research indicates that 140 tons of wet sludge is enough dry fuel to produce 1 megawatt of renewable electricity.

Oftentimes, sustainable projects like sludge get caught up in the first phase of research and development. So what's next for the crafty team of researchers at the University of Nevada? How do they plan to mass-produce their sludge concept? Here's a glimpse:

The team now looks to perform the drying process on a much larger scale. Coronella says by producing it 100 times larger, they hope to convince investors and plant operators that their process is a viable way to turn sludge into energy. If all goes right, Coronella says the completed product could be on the market within five years.

What do you think? Could something as unseemly as wastewater sludge help the cause for global adoption of sustainable best practices?