The World's #1 Renewable Energy Network for News, Information, and Companies.

Microbes Treat Waste and Produce Power

Microbes have been evolving for millions of years to efficiently digest organic material. Now researchers are tapping these natural processes to maximize energy output from the breakdown and use it to power farms and even waste facilities.

One process, developed by researchers at Michigan State University, mimics the natural mechanism of waste digestion and generates 20 times more energy than existing processes by creating ethanol and hydrogen for fuel cells.

Two Bacteria Are Better than One

Instead of using one microbe to break down cellulose in a fermenter, Gemma Reguera, an associate professor of Microbiology and Molecular Genetics from Michigan State University, is using two bacteria.

The process recreates a symbiotic relationship between bacteria and fungi – the same relationship responsible for breaking down organic material in nature.

The technology goes by many names, including microbial electrolysis cells, and microbial electrochemical cells, but the guiding principle remains the same: using microbes to digest waste and produce a usable by-product. These by-products include hydrogen and ethanol.

A chemical pretreatment on the organic matter synthetically reproduces the fungi’s role in the process. The researchers then screened bacteria to find the two that could work together to efficiently degrade the feedstock.

Using two bacteria instead of one is unique, but extremely useful: in the device, one bacterium creates ethanol and non-ethanol fermentation products, and the other converts these products into electricity. The electrons are removed to produce hydrogen, which is stored in a fuel cell to create electricity.

The fermentation process alone recovered around 50 percent of the energy as ethanol. Add in the production of hydrogen, and the energy recovery reaches 73 percent.

Once scaled up and further optimized, Reguera sees this research allowing farmers to process their agricultural wastes into ethanol and hydrogen, which can be stored and used as a household or transportation fuel.

Waste Powered Waste Treatment

Meanwhile, in Arizona, Cesar Torres, an assistant professor of Chemical Engineering from Arizona State University, and his team envision a future where the energy from our waste is used to power the facilities that treat it.

His research is focused on identifying and solving problems that limit electrical output in microbial electrochemical cells. The paper published by his team in the journal ChemSusChem outlines and provides some solutions to the problem of losing voltage at the cathode in microbial fuel cells.

Torres expects more fundamental knowledge about microbial fuel cells to lead to solutions that increase power outputs to economically attractive levels. Many companies are currently investing in commercializing these technologies for various applications, says Torres. For example, his team is working with a company seeking to commercialize a technology that turns food and beverage waste into hydrogen.

But Torres also sees a future for this technology at a city-wide scale. The result, researchers hope, could be municipal wastewater treatment plants that are energy neutral, or even energy positive.

“A big step now is the path towards commercialization,” says Torres. “Hopefully, through more fundamental research, we can get to the point where we can design a good microbial fuel cell that can be used commercially.”

Top image: Cells of the bacteria Shewanella putrefaciens CN32Courtesy Department of Energy.

This article was originally published on ecomagination and was republished with permission.

RELATED ARTICLES

Wind turbines

Why It's Time To Get Real About Energy Security

Hannah Smith, Contributor Energy is Europe’s quiet crisis. While the clamour of failing economies, desperate migrants and political clashes grabs the headlines, energy policy is rarely front-page news, but it should be — the statistics are shocking.

A Closer Look at Fossil and Renewable Energy Subsidies

Susan Kraemer, Contrubutor A new study by the International Monetary Fund puts the total cost of fossil fuel subsidies at approximately $10 million a minute globally, when health costs and environmental degradation are included, never mind the effect...

How to Win Planning Permission for Renewable Energy Projects (and Influence People)

Tildy Bayar, Contributor At Tuesday afternoon’s POWER-GEN Europe and Renewable Energy World Europe conference session in Amsterdam, Paul Davison of PR firm Proteus discussed how to best communicate with the public regarding renewable ener...
Egypt flag

Egypt's Renewable Energy Drive Gains Steam

Andrew Burger, Correspondent There's a lot of action in Egypt's rapidly developing solar and renewable energy market space. Nearly 5 GW worth of solar power development agreements have been signed so far this year, while Egypt 's New and Renewable Ener...

CURRENT MAGAZINE ISSUE

Volume 18, Issue 3
1505REW_C11

STAY CONNECTED

To register for our free
e-Newsletters, subscribe today:

SOCIAL ACTIVITY

Tweet the Editors! @megcichon @jennrunyon

FEATURED PARTNERS



EVENTS

Mastering RETScreen® 4 for Clean Energy Project Analysis

Hands-on modeling class using RETScreen 4. Michael Ross designed this co...

CIREC WEEK

Chile is still considered to be one of the world’s hottest m...

Renewables and Mining Summit and Exhibition

African mining leaders are seriously exploring new energy solutions to s...

COMPANY BLOGS

Substrate Feeder for Biogas Facilities

RUD manufactures complete, ready-to-use conveyor systems for transportin...

US Energy Grid Review Finds Needed Upgrades Would Allow More Solar,...

Yesterday (April 21) the U.S. Department of Energy released the first Qu...

Clean Energy Patents Rise in 2014, Solar Tops others, Toyota and GM...

U.S. patents for Clean Energy technologies in 2014 were again at an all ...

NEWSLETTERS

Renewable Energy: Subscribe Now

Solar Energy: Subscribe Now

Wind Energy: Subscribe Now

Geothermal Energy: Subscribe Now

Bioenergy: Subscribe Now  

 

FEATURED PARTNERS