The power of sludge

Interesting. Sewage into ethanol.

It's that dream come true - turning waste into something valuable. There has been a lot of talk about, and work toward, harnessing methane produced at landfills, manure pits and wastewater at slaughter houses, but now an e-mail has arrived touting the use of the solids in municipal wastewater to create energy.

Applied Cleantech and Qteros are announcing their “breakthrough Q Microbe technology” to turn a substance produced from municipal wastewater solids into cellulosic ethanol. That might disappoint researchers who have been focused on cellulosic feedstocks like waste wood chips, switch grass and stuff like sorghum that can grows like it's on steroids.

If you’ve ever wondered what to do with your city’s sewage sludge, this is apparently it.
The companies claim a yield of 120-135 gallons of ethanol for every ton of Recyllose, the feedstock they create from sludge.

There is, however, a problem of scale. The companies say a wastewater plant that handles the sewage of about 2 million people can supply a “smaller-scale” ethanol plant. So don’t be looking for any of this alchemy in the Panhandle, or a lot of places that don’t have a concentration of at least 2 million people.

Meanwhile, if people insist on ethanol as the best next-generation fuel to act as a bridge to some dreamed about solution to oil addiction, don’t stop growing that corn and grain sorghum.

Slime sublime

The National Biodiesel Board is pushing research to turn slime respectable.


The NBB is supporting scientists in their work to make algae an efficient source of oil to make biodiesel. Research topics include developing a non-destructive oil extraction process. That means there would be a lot fewer algae bodies to dispose of or find a good use for after squishing them to get the oil out. Continuously removing oil from living algae is called, “milking the algae,” according to the NBB.

I get a real fuzzy picture of what that entails, but the potential result sounds good. Besides, you can grow algae in tanks of yucky water on land where crops like corn for ethanol or soybeans for biodiesel can’t grow.

The enthusiasm at a recent summit covering the topic almost sweeps you away.

“Ted Abernathy with the Southern Growth Policies Board captured the as yet unknown potential for algae in his welcome address.,” according to the NBB Web site. "When this started, it seemed interesting," he said. "Now it seems really interesting."

Really or really-really interesting?

Okay, he’s not a motivational speaker but the results could be helpful, especially if algae can be contained and not become an invasive species like kuzu or johnson grass.

The New York Times recently ran a cautionary story about some of the crops under consideration for farmers to grow to make cellulosic ethanol. The story cites giant reed, a scary grass that grows in dense clumps up to 20 feet tall, that researchers want to plant in Florida.

We probably don't have to worry about it here, since it grows in damp spots, but it crowds out native plants, forms a dense root mat that blogs water seeping into the ground, chokes water ways and, oh boy, is easily ignitable.

Giant reed photo courtesy of the National Park Service. Hmmmm.