Distillers’ grains carbon for high-performance capacitive deionization

• Published in: Separation and purification technology 2025-06, Vol.359, p.130882, Article 130882
• Main Authors: Chen, Mingyang, Liu, Weifeng, Yu, Tianchao, Liu, Bingbing, Wang, Meiling, Fu, Dongju, Xue, Jinbo, Wen, Hairong, Liu, Xuguang
• Format: Article
• Language: English
• Subjects: Capacitive deionization; Distillers’ grains carbon; Electro-adsorption mechanism; Thermodynamic kinetics
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2024.130882

Because of its abundant supply and long-term availability, biomass-based activated carbon is one of the first porous carbon electrode materials recommended for capacitive deionization. This work describes the preparation of biomass distillers’ grains-based porous carbon materials with high capacity and quick desalination rates by a sequence of thermal carbonization, chemical activation, and de-ashing from waste distillers’ grains of Shanxi Fenjiu Liquor. Compared to other carbon materials, the optimum material had a high salt adsorption capacity of 41.85 mg∙g−1 at 1.2 V with a starting concentration of 500 ppm NaCl. Following acidification during the ash removal process, the material’s surface became rich in oxygen-containing functional groups such as carboxyl, as well as a huge number of active sites exposed by the ultra-high specific surface area and profound pore structures. The material had a substantially higher average salt adsorption rate of 17.67 mg∙g−1∙min−1, compared with other carbon materials. After cycles, it maintained 75 % of its maximum capacity in cycle 25. These positive results highlight the potential of biomass distillers’ grains-based carbon materials in desalination. This work introduces new ways to treating waste distillers’ grains from the Fenjiu liquor production process.