Solvent recovery system enables 95% reuse

The process reduces the amount of solvent Promethean uses, as well as the amount of solvent to be disposed of.

This generates cost savings along the supply chain and significantly enhances the company’s eco-credentials in its move towards creating a manufacturing workflow that is wholly sustainable.

Promethean manufactures nanomaterials for current and next-generation applications in a variety of market sectors, via a unique, market-disrupting continuous-flow production process.

The nanoparticles manufactured are reproducible on a large scale, without affecting performance and quality.

The process enables thousands of litres of output to be generated, achieving important economies of scale, in comparison to the batch processes typically employed by other nanomaterial manufacturers. 

Batch processing means only small volumes can be produced at any one time, making it energy intensive and costly in comparison.

Lewis Neve, Engineering Manager at Promethean Particles, said: “At Promethean, where the chemistry allows, we always aim to manufacture and process our products using water, rather than organic solvents, to minimise our environmental impact. However, in some instances, the chemistry isn’t compatible or there is no other option but to use organic solvents to achieve the final desired outcome. For example, when activating our Metal Organic Frameworks (MOFs) to achieve greater surface area and adsorption potential, organic solvents are a must.

“Our new solvent recovery system operates on a single batch distillation principle. The boiler drum is loaded with the solvent to be recovered before being heated to above the solvent’s boiling point. The vapour produced is then condensed and collected. Ultimately, the solvent is recovered and re-used throughout a production campaign, from synthesis to post-synthesis, thereby removing the need to add more solvent to the process.”

The cost of recovering the solvent in-house is less than 10p per litre and with more than 95% of solvent being recovered and re-used, CO₂ emissions linked to solvent use, transportation and licensed disposal, are greatly reduced.

In addition to increasing the sustainability of nanomaterial processing at Promethean, the new system means smaller volumes of organic solvents are required to be stored on site, improving safety for employees at the Nottingham-based site. It is home to the largest reactor system of its kind in the world, with manufacturing capacities in excess of 1,000 tonnes of nanomaterials per year.

Lewis added: “Sustainability is one of the pillars of our technology and something we continually consider when producing and developing new nanomaterials. This new solvent recovery system is another step in our manufacturing workflow that significantly improves our commitment and approach to producing dispersions and materials with the environment front of mind in our thinking.”