Gas-Liquid-Solid Fluidized-Bed Adsorber for Continuous Solvent Recovery: From Intrinsic Parameters to Continuous-Flow Validation

This work proposes a continuous gas-liquid-solid fluidized bed adsorber for solvent recovery. Using a methylene blue-water model, batch and continuous experiments were conducted. An amended pseudo-first-order kinetic model revealed two stages. Phase I: the initial adsorption capacity (q0) remained constant (∼0.851 mg·g–1) across superficial gas velocities (3.33 × 10–3 – 2.50 × 10–2 m·s–1), indicating negligible external liquid-film resistance. Phase II: the rate constant (k) increased monotonically with superficial gas velocity (from 0.133 min–1 at 3.33 × 10–3 m·s–1 to 0.339 min–1 at 2.50 × 10–2 m·s–1), enhancing surface renewal and intraparticle mass transfer under stronger bubble-induced mixing. Empirical power-law equations correlated operating parameters with q0 and k. A numerical continuous-flow model, validated against effluent data (R2 > 0.90) and a 7 h test, confirmed its predictive capability. Contour maps for ≥99.5% adsorption efficiency optimized energy and adsorbent usage. These findings demonstrate the feasibility of the proposed experimental and modeling framework for continuous adsorption.