Making vinegar from excess carbon dioxide could reduce emissions

Monash University’s chemical engineers have developed an industrial process to produce acetic acid that uses the excess carbon dioxide (CO₂) in the atmosphere, potentially creating negative carbon emissions.

Acetic acid is used in several industrial processes and is an ingredient in household vinegar, vinyl paints and some glues. There is an estimated worldwide industrial demand of 6.5 million tonnes per year.

The research, published in Nature Communications, shows that acetic acid can be made from captured CO₂ using an economical solid catalyst to replace the liquid rhodium or iridium based catalysts currently used.

Liquid catalysts require additional separation and purification processes. Using a solid catalyst made from a production method that doesn’t require further processing also reduces emissions.

Akshat Tanksale, lead researcher, said CO₂ is the main cause of global warming and climate change, and there is an urgent need to actively remove it from the atmosphere and convert it into products that do not release the captured CO₂ back into the atmosphere.

The researchers first created a class of material called the metal organic framework (MOF), which is a highly crystalline substance made of repeating units of iron atoms connected with organic bridges. They then heated the MOF to break those bridges, allowing iron atoms to come together and form particles a few nanometres in size. The iron nanoparticles are then embedded into a porous carbon layer, making them highly active while remaining stable in harsh reaction conditions.

The process will be more efficient and cost-effective from an industrial point of view. From an environmental perspective, it offers an opportunity to significantly improve current manufacturing processes that pollute the environment.

In collaboration with the Australian Research Council (ARC) Research Hub for Carbon Utilisation and Recycling, the researchers are currently developing the process for commercialisation.

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