PhD research carried out as part of the PROVIDES project has recently resulted in promising new sustainable hydrophobic Deep Eutectic Solvents (DESs). These hydrophobic DESs could successfully replace chemical solvents in the paper recycling process in order to remove transition metal ions such as iron and manganese from paper pulp. Coordinated by ISPT, the industry-driven PROVIDES project focuses on developing environmentally friendly alternatives to chemical solvents in the European pulp and paper industry. It is financially supported by 20 industrial partners.
“We first discovered hydrophobic DESs in 2015,” explains PhD student Dannie van Osch. “Until then, all known DESs had been hydrophilic, which means they dissolve in water, making them unsuitable for removing contaminants from paper pulp, which consists of 95% to 99% water. The discovery of hydrophobic DESs was therefore a crucial breakthrough in my research.”
The hydrophobic DESs currently consist of various ratios of decanoic acid and lidocaine. “Decanoic acid is a plant-based substance, which makes it very suitable for use in an environmentally friendly solvent,” says Dannie. “We have now proven that these sustainable DESs successfully extract transition metal ions, significant contaminants in used paper, from water. And it only takes five seconds! Another major advantage is that these DESs are extremely easy to prepare. Furthermore, tests have shown that it is highly likely that the DESs can be reused, which will make them even more economical. The project will now focus on using this ground-breaking discovery for the main challenge in environmentally friendly recycling: removing inks and stickies.”