Biotech breakthrough could end biodiesel's glycerin glut

June 26, 2007

With U.S. biodiesel production at an all-time high and a record number of new biodiesel plants under construction, the industry is facing an impending crisis over waste glycerin, the major byproduct of biodiesel production. New findings from Rice University suggest a possible answer in the form of a bacterium that ferments glycerin and produces ethanol, another popular biofuel.

"We identified the metabolic processes and conditions that allow a known strain of E. coli to convert glycerin into ethanol," said chemical engineer Ramon Gonzalez. "It's also very efficient. We estimate the operational costs to be about 40 percent less that those of producing ethanol from corn."

Gonzalez said the biodiesel industry's rapid growth has created a glycerin glut. The glut has forced glycerin producers like Dow Chemical and Procter and Gamble to shutter plants, and Gonzalez said some biodiesel producers are already unable to sell glycerin and instead must pay to dispose of it.

"One pound of glycerin is produced for every 10 pounds of biodiesel," said Gonzalez, Rice's William Akers Assistant Professor in Chemical and Biomolecular Engineering. "The biodiesel business has tight margins, and until recently, glycerin was a valuable commodity, one that producers counted on selling to ensure profitability."

Researchers across the globe are racing to find ways to turn waste glycerin into profit. While some are looking at traditional chemical processing -- finding a way to catalyze reactions that break glycerin into other chemicals -- others, including Gonzalez, are focused on biological conversion. In biological conversion, researchers engineer a microorganism that can eat a specific chemical feedstock and excrete something useful. Many drugs are made this way, and the chemical processing industry is increasingly finding bioprocessing to be a "greener," and sometimes cheaper, alternative to chemical processing.

In a review article in the June issue of Current Opinion in Biotechnology, Gonzalez points out that very few microorganisms are capable of digesting glycerin in an oxygen-free environment. This oxygen-free process -- known as anaerobic fermentation -- is the most economical and widely used process for biological conversion.

"We are confident that our findings will enable the use of E. coli to anaerobically produce ethanol and other products from glycerin with higher yields and lower costs than can be obtained using common sugar-based feedstocks like glucose and xylose," Gonzalez said.

Source: Rice University

Explore further: Ethanol and heterogeneous catalysts for biodiesel production

Related Stories

Ethanol and heterogeneous catalysts for biodiesel production

November 12, 2014

Biodiesel is an alternative fuel to conventional fossil ones. The EU policies of boosting biodiesel have achieved its implementation in the transport fuels market and increasingly its sustainable nature is being taken into ...

Ultrasound 'making waves' for enhancing biofuel production

May 31, 2013

All chefs know that "you have to break some eggs to make an omelet," and that includes engineers at Iowa State University who are using high-frequency sound waves to break down plant materials in order to cook up a better ...

Research yields pricey chemicals from biodiesel waste

June 30, 2008

In a move that promises to change the economics of biodiesel refining, chemical engineers at Rice University have unveiled a set of techniques for cleanly converting problematic biofuels waste into chemicals that fetch a ...

Recommended for you

How to curb emissions? Put a price on carbon

September 3, 2015

Literally putting a price on carbon pollution and other greenhouse gasses is the best approach for nurturing the rapid growth of renewable energy and reducing emissions.

Magnetic fields provide a new way to communicate wirelessly

September 1, 2015

Electrical engineers at the University of California, San Diego demonstrated a new wireless communication technique that works by sending magnetic signals through the human body. The new technology could offer a lower power ...

For these 'cyborgs', keys are so yesterday

September 4, 2015

Punching in security codes to deactivate the alarm at his store became a thing of the past for Jowan Oesterlund when he implanted a chip into his hand about 18 months ago.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.