Scientists from Wageningen Food & Biobased Research have reached the final stages of the Imagine Chemistry challenge in 2018 launched by AkzoNobel Specialty Chemicals. This challenge aims to help solving real-life chemistry-related challenges and uncover sustainable business opportunities.
Wageningen Food & Biobased Research submission is in the category 'Revolutionising chlorate production', which asked contestants to boost the sustainability of sodium chlorate production by finding new methods that are more energy-efficient and free of materials of concern. Sodium chlorate is a commercial product manufactured by AkzoNobel which is used to bleach paper pulp.
"In this specific challenge, we saw an opportunity to utilise our knowledge and expertise in the electrochemical production of hydrogen peroxide to meet AkzoNobel's objectives," explains Roel Bisselink, electrochemistry scientist at Wageningen Food & Biobased Research.
"AkzoNobel already produces hydrogen peroxide and supplies it mainly to the paper industry, just like sodium chlorate. Our proposal would allow the production of the two materials to be combined while mitigating the negative environmental effects related to the use of the hazardous substance hexavalent chromium (chromium(VI))."
"The huge potential of this solution to boost the sustainability and energy efficiency of chlorate production was acknowledged by AkzoNobel – ours was one of the 20 shortlisted ideas out of a total of 150 submitted across the different innovation platforms of the challenge. Our team will further develop their ideas and concepts to explore the potential cooperation during a three-day event at the end of May in Sweden."
Our approach and its advantages
As part of Wageningen University & Research's research into (decentralized) electrochemical hydrogen peroxide production, we propose exploring whether paired electrosynthesis of chlorate and hydrogen peroxide can enable chromium(VI)-free chlorate electrolysis.
Hydrogen peroxide is a chemical oxidant which can be produced electrochemically via the two electron reduction of oxygen. Using an innovative reactor concept WFBR has enabled the production of concentrated hydrogen peroxide (~10%) at current densities of ≤4 kA/m2, similar to what occurs in chlorate production. Anion exchange membranes which are in contact with alkaline hydrogen peroxide are incorporated in the electrochemical reactor concept.
These membranes have not shown deterioration during operation. The idea is therefore to use a membrane electrolyzer equipped with these anion exchange membranes (AEMs) for the production of chlorate. Placing an AEM between the electrodes would enable the reduction of chromium(VI) compounds or even chromium(VI)-free chlorate production.
Successful integration and strengthening of expertise
With the recent integration of the Functional Ingredients department of the Netherlands Organisation for Applied Scientific Research (TNO) into Wageningen Food & Biobased Research we now have a wide new field of expertise, which includes electrochemistry. The use of electrochemistry to drive chemical processes strengthens the sustainable chemistry portfolio technologies of Wageningen Food & Biobased Research.
"The fact that our idea was shortlisted for the 2018 Imagine Chemistry challenge exemplifies the renewed interest of the private sector in electrochemistry for the purposes of synthesis. Next to the development of the electrochemical production of hydrogen peroxide, we are currently working on electrosynthesis methods and electrodialysis-based separations for the valorisation of biomass and the conversion of chemicals derived from biobased processes. If you would like to know more about what electrochemistry can mean for you, do not hesitate to get in contact."