Adsorption dynamics of toluene in composite bed with microfibrous entrapped activated carbon

Stainless steel microfibrous entrapped activated carbon composites were prepared by wet layup papermaking and sintering process. The composite beds were filled with granular activated carbons and microfibrous composites in the inlet and outlet of the fixed bed, respectively. The adsorption breakthrough curves of toluene in the composite bed were measured, and compared with that in the fixed bed with granular activated carbons (GAC) alone. The effects of different operation parameters such as flow rate, bed height and inlet concentration on the breakthrough curves of toluene in the composite bed were investigated. The length of unused bed (LUB) was determined by analysis of the breakthrough curves. The experimental results showed that the breakthrough time of toluene in the composite bed increased 15 min compared with that in the individual GAC bed at the same volume. The breakthrough time increased with decrease in both flow rate and inlet concentration but increased with increase in bed height. The LUB values were 1.59 and 1.14 cm for 5 cm individual GAC bed and composite bed, respectively. The LUB values increased with increase in both flow rate and inlet concentration. The experimental data were fitted to two fixed bed adsorption models namely, Yoon–Nelson and Bed Depth Service Time (BDST) models. The results fitted well to Yoon–Nelson model and the rate constant (k′) values computed using Yoon–Nelson model were 0.1 and 0.151 for the individual GAC bed and composite bed, respectively. Also BDST model was found to show good agreement with the experimental results and the adsorption capacity (N0) values calculated using BDST model were 175.47 and 182.19 g/L for the individual GAC bed and composite bed, respectively.

► The microfibrous entrapped activated carbon composites with high adsorption rate were prepared.
► The breakthrough time of toluene in the composite bed clearly increased compared with that of the fixed bed.
► The adsorption rate constant of the composite bed increased compared with that of the fixed bed.
► The length of unused bed (LUB) of the composite bed significantly decreased compared with that of the fixed bed.