Carbon-negative acetone and isopropanol possible through gas fermentation, LanzaTech research finds

22 Feb 2022 --- LanzaTech’s fermentation scale-up and life-cycle analysis (LCA) is carbon negative as it removes 1.17 kg to 1.79 kg of CO2 from the atmosphere per kg of generated acetone or isopropanol. In contrast, conventional routes emit 1.85 kg to 2.55 kg CO2 per kilogram output.

This is according to a LanzaTech study (in collaboration with several US universities) that found gas fermentation produces carbon-negative acetone and isopropanol at an industrial pilot size.

Isopropanol can be used in cosmetics and personal care items such as aftershave lotions, bath products, eye and other makeup products and nail, hair and skincare products.

Meanwhile, acetone can be used in cosmetics and skin creams. It is also one of the main chemicals found in nail paint remover.

Perks of using fermentation
According to the researchers, many industrial compounds made from fossil fuels might be made more sustainable using fermentation.

The invention of a carbon-negative fermentation pathway to produce the industrially essential chemicals acetone and isopropanol from abundant, low-cost waste gas feedstocks, such as industrial emissions and syngas, is possible.

The researchers obtained an industrial strain collection for improved enzymes, which was used to construct the Clostridium autoethanogenum bacteria using a combinatorial pathway library technique.

This bacteria is then utilized to produce ethanol from carbon monoxide during fermentation.Acetone is one of the main chemicals found in nail paint remover.

“Unlike typical manufacturing processes, which emit greenhouse gasses, our method fixes carbon. These findings reveal that tailored microorganisms can produce chemicals in a sustainable, high-efficiency, high-selectivity manner,” researchers explain.

Synthesis of ethanol and isopropanol
The study used a three-pronged route, strain and process optimization approach that enabled efficient acetone and isopropanol synthesis.

The researchers first selected the best sets of heterologous pathway enzymes (enzymes transplanted from foreign organisms) to carry out the needed molecular transformations. Then, for improved flow to the product, they adjusted strains. Finally, process optimization, scale-up and life-cycle analysis were performed.

The GHG emissions of acetone and isopropanol produced utilizing the scaled-up gas fermentation process were compared to current fresh fossil-based production using propane and the cumene process using LCA.

Pilot-scale data was combined with design data from industrial-scale ethanol production, which employs steel mill off-gas feedstock with utilities, to evaluate chemical and energy inputs and product yield. 

Previous partnership, fermentation efforts and CCU
This study follows Coty and LanzaTech’s partnership that utilized the latter’s fermentation process to produce the “first internationally disseminated” carbon-captured ethanol fragrances.

Yesterday, fermentation was pegged to provide cleaner, ecological and inexpensive ingredients to the beauty and personal care industry.

Previously, carbon capture and utilization (CCU) was showcased as a new technology that can change the way businesses and governments pursue climate goals. Manufacturers can use CCU to produce packaging for cosmetics and perfumes.

By Nicole Kerr