Abstract 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… Click to show full abstract
Abstract 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.
               
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