Off-gases from the production of iron and steel contain significant amounts of carbon monoxide (CO) and carbon dioxide (CO₂). Globally, the iron and steel industry contributes 6.7% to the worldwide CO₂ emissions. To produce one metric ton of steel, an average of 1.8 metric tons of carbon dioxide (CO₂) is emitted. Up to now, these gases have been flared or used to create process heat and electrical energy within the plant.

LanzaTech’s innovative technology instead re-uses the off-gases from converter, coking plant or blast furnace processes as nutrients and a source of energy. The patented biological fermentation process allows steel plant operators to make use of the chemical energy contained in off-gases in the form of CO, CO₂ and hydrogen for the production of bioethanol or other basic chemicals such as acetic acid, acetone, isopropanol, n-butanol or 2,3-butanediol.

The global market for ethanol alone is estimated to amount to an annual volume of more than 80 million metric tons, of which 75 million metric tons is used as biofuel. Unlike the bioethanol produced through agriculture, LanzaTech’s fermentation process does not compete with food production.

Another major benefit of this technology is that the CO₂ emissions are between 50 to 70% lower than petroleum-based fuels and around one-third lower than when steel plant off-gases are converted into electricity.

LanzaTech has been operating a pilot plant in Auckland, New Zealand since 2008 utilizing raw steel mill gases. In 2012, LanzaTech became the first company ever to scale gas fermentation technology to a pre-commercial level, developing and successfully operating two facilities converting flue gas from Baosteel and Shougang steel plants into ethanol, each at an annualized capacity of 300 tons.

LanzaTech is now planning to begin construction on two commercial facilities in China in 2013 with production expected in 2014. Siemens and LanzaTech are already pursuing several commercial gas fermentation project opportunities around the world.