Adsorption of butanol from aqueous solution onto a new type of macroporous adsorption resin: Studies of adsorption isotherms and kinetics simulation

Background: Owing to the rapid depletion of petroleum fuel, the production of bio-butanol has attracted much attention. However, low butanol productivity severely limits its potential industrial application. It is important to establish an approach for recovering low-concentration butanol from fermentation broth. Experiments were conducted using batch adsorption mode under different conditions of initial butanol concentration and temperature. Batch adsorption data were fitted to Langmuir and Freundlich isotherms and the macropore diffusion, pseudo-first- and second-order models for kinetic study. Results: The maximum adsorption capacity of butanol onto KA-I resin increase with increasing temperature, ranged from 139.836 to 304.397 mg g ^-1. The equilibrium adsorption data were well fitted by the Langmuir isotherm. The adsorption kinetics was more accurately represented by the macropore diffusion model, which also clearly predicted the intraparticle distribution of the concentration. The effective pore diffusivity (D _p) was dependent upon temperature, but independent of initial butanol concentration, and was 0.251 × 10 ^-10, 0.73 × 10 ^-10, 1.32 × 10 ^-10 and 4.31 × 10 ^-10 m ² s ^-1 at 283.13, 293.13, 303.13 and 310.13 K, respectively. Conclusion: This work demonstrates that KA-I resin is an efficient adsorbent for the removal of butanol from aqueous solutions and available for practical applications for future in situ product recovery of butanol from ABE fermentation broth.