Very promising biobased alternatives exist for controversial solvents that are harmful to health. This was revealed by a report by Wageningen Food & Biobased Research.
The Wageningen researchers made an overview of possible biobased alternatives for the polar aprotic solvents N-methylpyrrolidone (NMP), dimethylacetamide (DMAc) and dimethylformamide (DMF). The research was commissioned by the Netherlands National Institute for Public Health and the Environment (RIVM) and the Ministry of Infrastructure and Environment. The solvents are used in industry around the world in the production of paint, coatings, drugs, batteries and more. ‘These solvents are very harmful to the health of those working with them, as they can affect reproductive capacity’, says project leader Daan van Es of Wageningen Food & Biobased Research. For example, the solvent DMAc was brought to negative attention last year (link in Dutch), as it is suspected to have caused fertility issues in female employees of the chemical company DuPont.
DMAc and other polar aprotic solvents have been included in RIVM’s list of Substances of Very High Concern (in Dutch), whose use should be restricted in the future. ‘Possible alternatives have been searched for in traditional chemistry for some time, but it is still very difficult’, Van Es explains. ‘Hence the demand for biobased alternatives.’ In the report, he mentions 19 biobased substances, such as Cyrene, that could possibly replace the current undesirable solvents. These substances are produced from residual waste that is rich in carbohydrates, like beet pulp or straw. He emphasises that additional research is required to determine which alternatives are most likely to succeed. ‘This project is just the first step on a long journey. We have found several possible alternatives, but these currently aren’t produced for that purpose.’
In the follow-up studies, Van Es wants to produce and extensively test a number of biobased replacements with the help of industry. In addition, Wageningen Food & Biobased Research is already developing safe alternatives for the solvents NMP and toluene within the EU project RESOLVE.
The biobased alternatives will first be tested on a pilot scale. This will also confirm whether the production of these solvents is technically and economically viable. Furthermore, the researchers must also determine whether these substances are not harmful too, Van Es says. ‘One should not assume something is safe just because it is biobased. There are very toxic substances among those as well.’