Selective Electrochemical Degradation of Lignosulfonate to Bio‐Based Aldehydes. Issue 8 (9th March 2023)

• Record Type: Journal Article
• Authors: Klein, Jana; Waldvogel, Siegfried R.
• Is Part Of: ChemSusChem. Volume 16:Issue 8(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-03-09
• Subjects: electrolysis -- electrochemistry -- lignin -- lignosulfonate -- oxidation; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202202300
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: A sustainable electrochemical pathway for degradation and thermal treatment of technical lignosulfonate is presented. This approach is an opportunity to produce remarkable quantities of low molecular weight compounds, such as vanillin and acetovanillone. For the electrochemical degradation, a simple two‐electrode arrangement in aqueous media is used, which is also easily scalable. The oxidation of the biopolymer occurs at the anode whereas hydrogen is evolved at the cathode. The subsequent thermal treatment supports the degradation of the robust chemical structure of lignosulfonates. With optimized electrolytic conditions, vanillin could be obtained in 9.7 wt% relative to the dry mass of lignosulfonate used. Aside from vanillin, by‐products such as acetovanillone or vanillic acid were observed in lower yields. A new and reliable one‐pot, two‐step degradation of different technically relevant lignosulfonates is established with the advantages of using electrons as an oxidizing agent, which results in low quantities of reagent waste. Abstract : Order from the chaos : An innovative electrochemical protocol for the degradation of lignosulfonate is presented. First lignosulfonate is oxidized electrochemically at planar nickel electrodes and then a thermal treatment at 170 °C follows. The complex polymer is degraded successfully into aldehydes such as vanillin and acetovanillone in good yields.