Fixed-bed column adsorption of the coffee aroma compound benzaldehyde from aqueous solution onto granular activated carbon from coconut husk

Abstract

This paper evaluated the performance of fixed-bed columns with activated carbon as the adsorbent for the removal of benzaldehyde present in an aqueous solution. The effects of the following parameters were evaluated: inlet concentration (91.9 mg L−1 – 440.0 mg L−1), feed flow rate (3.9 mL min−1 – 11.8 mL min−1), bed depth (30 mm–90 mm) and column inner diameter (6.2 mm–12.2 mm). All of the experiments were performed at 293.15 K. The results showed that the bed capacity, total bed capacity and saturation time decreased as the feed flow rate was increased. The opposite effect was observed with an increase in bed depth. Increasing the inlet concentration resulted in higher aroma adsorption. An increase in the inner diameter without changing the feed flow rate resulted in better aroma recovery. The results showed that the column performed well at all of the analyzed parameter values. Data obtained from the analysis of the effects of feed flow rate and bed depth were used for a scale-up study using the bed depth service time model, which showed good results with errors of less than 12%. The experimental data obtained in this study will be useful for further applications involving coffee aroma recovery.