Lignin biorefinery: Separation of vanillin, vanillic acid and acetovanillone by adsorption

• Published in: Separation and purification technology 2019-06, Vol.216, p.92-101
• Main Authors: Gomes, E.D., Rodrigues, A.E.
• Format: Article
• Language: English
• Subjects: Acetovanillone; Biorefinery; Oxidized lignin; SP700; Vanillic acid; Vanillin
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2019.01.071

[Display omitted] •Indulin AT alkaline solution oxidized and phenolic compounds produced recovered.•Ultrafiltration and nanofiltration reduced the organic solids content.•Two-step elution process fractionates vanillin, vanillic acid and acetovanillone.•Cyclic operation of the chromatographic column.•All separation steps performed at alkaline pH (>13), without acidification. Vanillin (V), acetovanillone (VO) and vanillic acid (VA) were fractionated after alkaline depolymerization of lignin. The feed solution had an initial pH of 13.7 and the work was performed always under alkaline pH, reducing chemical waste. The organic charge of the solution was reduced from the initial 58.8 (±0.4) g/L to 31.0 (±1.3) g/L by membrane filtration. Permeate from the last membrane, was fed to the chromatographic column, resulting in fractions with different composition. From the total amounts fed to the column, 3.21(±0.25) g of V, 1.48(±0.10) g of VA and 0.35(±0.04) g of VO, it was possible to recover 94.1% of VA in the first eluted fraction, 96.2% of V and 43.4% of VO in the second fraction by water desorption and, the remaining VO, 52.7%, in the third fraction by ethanol desorption. Cyclic operation can be implemented without deep regeneration of the adsorbent as the 4 cycles performed revealed.