The intensive use of fossil fuels caused the raise of atmospheric CO2 levels. High (>400 ppm) CO2 concentrations in the atmosphere are resulting in environmental problems including global warming, and in an increased frequency and severity of extreme weather event. To counteract these issues, EU committed to cut by 40% its greenhouse gas emissions by 2030. The achievement of such ambitious target is linked to a switch from fossil fuels to renewable sources of energy and chemicals. This is driving carbon-intensive industries such as paper, food, energy, cement, and oil refining industries, towards the circular economy concept, in which side- and waste-streams, including CO2 streams, are a feedstock for fuel and/or chemical production. Indeed, CO2 is a building block for synthesising a wide array of chemical and energy-rich products through (bio)technological routes. Biological processes, in which enzymes or microorganisms are employed to convert CO2 into products, are inherently circular, enable carbon-neutral or even carbon-negative balance, and demand less energy than chemical processes. Among these biological processes, microbial electrosynthesis (MES), in which specific bacteria convert CO2 and renewable electricity to green chemicals and fuels, is a promising technology to contribute reducing industrial CO2 emissions, and at the same time enable circular economy. However, to date, the adoption of MES in industry is hindered by sub-optimal production rates, yields and product purity. The ATMESPHERE project aimed to develop a novel, multi-step process for the production, extraction and purification of caproic acid, a platform chemical that finds application in the food and chemical industry, from CO2.
Overall, the ATMESPHERE project reached the planned objective by developing (i) a bioelectrochemical platform for CO2 capture and utilization, (ii) a fermentation platform for further upgrading MES products such as ethanol and acetic acid to caproic acid, and (iii) a downstream processing method to concentrate and purify the final products. Technologies such as those developed in ATMESPHERE will contribute to the paradigm shift towards resource recovery and circular economy, leading the way towards a “green” industrial revolution. This will drastically reduce waste generation and pollution in comparison with the traditional, linear economic model, with clear benefits for the well-being of the whole society.
