LanzaTech, a small company based in New Zealand, has developed a proprietary microbe that feasts on the carbon monoxide in waste gas from steel mills and converts it to pure ethanol. Last year the company launched a pilot facility at the New Zealand Steel plant near the city of Auckland, and its microbes have been happily churning out ethanol without the need for expensive pre-conditioning to remove contaminants.
LanzaTech has found that the same low-cost technology can be applied to biomass syngas, but the real excitement is in the success of this first-ever attempt to capture and convert steel mill waste gas into a clean, sustainable fuel.
LanzaTech and Steel Mill Waste Gas
LanzaTech was founded in 2005 specifically to develop a microbe-based process for harvesting ethanol from steel waste gas. Steel mill waste gas has some ideal properties for microbial fermentation, namely a high concentration of carbon monoxide with little or no hydrogen, but according to company co-founder Dr. Sean Simpson the attempt had never been made due to concerns that contaminants would disable the microbes. In the New Zealand Steel pilot project, LanzaTech’s microbes are actually thriving in the toxic soup, demonstrating that when you have the right microbe for the job, the expensive infrastructure required to pre-condition waste gas is not needed.
LanzaTech and Biomass Syngas
LanzaTech’s propriety microbe is “feedstock agnostic,” meaning that it can also work on practically any biomass syngas, which is carbon monoxide and hydrogen gas produced through the breakdown of organic matter. That includes municipal waste and other next-generation biofuel sources such as woody biomass and other non-food plants. According to LanzaTech, gassification makes over 90% of the energy in biomass available for fermentation, giving it a clear advantage over other technologies. After scrubbing and cooling, the gas is sent to a bioreactor where it becomes food for the microbes. According to Dr. Simpson, because LanzaTech’s microbes eat only carbon monoxide the resulting ethanol is a high octane premium fuel.
Microbes and Sustainability
A similar waste gas-to-ethanol experiment is progressing at Coskata Inc. and this is only the first ripple ahead of a new wave of energy-harvesting microbes in our future. Researchers are also developing microbes that can generate electricity from mud and wastewater, as well as microbes that can generate methane from an electrical current, potentially creating efficient, low-cost storage for electricity produced by solar and wind farms. In the sci-fi classic War of the Worlds, author H.G. Wells positioned microorganisms as humankind’s sole defense against planet-destroying aliens. In an odd twist of fate, companies like LanzaTech are bringing fiction to life, using microbes to create sustainable energy that will eventually replace planet-destroying practices such as mountaintop coal mining.
Image: Flag of New Zealand by Takuta on flickr.com.
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.