Lab Innovations 2023: sustainable solvent selection

Climate change is arguably the most pressing issue of our time, with many scientists warning that, if significant progress is not made towards becoming a more sustainable society, damage to the planet will become irreversible. The UK Government has committed in legislation to achieve net-zero carbon emissions by 2050, but this is unlikely to happen unless there are substantial changes across industrial sectors such as the lab industry.

University College London’s sustainability report for 2021 reported that roughly half of the university’s emissions came from its laboratories. The findings of this report, and others like it, indicate that laboratories must do more. Ultimately, this means the lab industry will significantly impact the likelihood of meeting the net-zero by 2050 goal. Therefore, laboratories must address problems such energy consumption as well as chemical and solvent selection. 

Going green

Organic solvents, such as hexane, are commonly used in various chemical processes, such as separations and extractions, but are quite environmentally harmful. Therefore, a key goal for the lab industry is to reduce their use in favour of green solvent alternatives.

Hexane is widely used for extracting oil contaminants from water and soil for analysis and for extracting edible oils from seeds and vegetables because of its efficiency in these experiments, which could not traditionally be matched by alternatives. However, supercritical CO₂ systems now allow comparable results to be achieved without using such a harmful chemical.

The lab industry will significantly impact the likelihood of meeting the net-zero by 2050 goal. Therefore, laboratories must address problems such energy consumption as well as chemical and solvent selection

For example, supercritical liquid CO₂ is non-flammable, non-toxic, not environmentally harmful, easy to prepare and does not contribute to global warming because any process CO₂ is recycled back into the system. Supercritical fluid extraction (SFE) is an area of growing interest and CO₂ is the most common supercritical fluid used in SFE procedures as a replacement for traditional hexane use. 

SFE is performed by pumping supercritical CO₂ through a fixed bed of substrate where the CO₂ flows through the substrate and dissolves soluble components until they are depleted. The loaded solvent is then passed through a separator where the soluble components are precipitated by adjusting the temperature and pressure before the CO₂ is condensed and recirculated.

By controlling the density of supercritical CO₂ fluids, they can replicate the performance of various organic solvents whose polarities range from n-pentane, at the lowest density, to pyridine, at the highest. This feature allows selective extraction, purification and fractionation procedures to be performed.

This just one of many examples of ways the lab industry can improve chemical and solvent selection in experimentation to improve sustainability without negatively impacting results. At this year’s Lab Innovations, visitors will be able to see many of these methods first hand and speak to the industry’s leading experts about how they can improve sustainability in their labs.

The Sustainable Laboratory will return to Lab Innovations in 2023, hosted by Andy Evans, director of Green Light Laboratories, and offer insight into ways labs can become more sustainable and share some data-driven case studies. Furthermore, the show will once again host the sustainability trail, which was new to Lab Innovations in 2022, to give visitors a guided tour of some of the key exhibitors making a positive impact on lab sustainability.

Lab Innovations 2023 takes place on 1-2 November at the NEC, Birmingham. Visit the website and register here. And for more about sustainable lab practices, visit SciMed on stand E70.

Paul Vanden Branden is Director at SciMed, and a member of the Lab innovation showadvisory board