Mahin, Z.K.; Kühn, S.; Minceva, M. Adsorptive recovery of beer-relevant aroma compounds from ethanol-water mixtures: Toward process integration in beer dealcoholization. Separation and Purification Technology, 2026, 404, 138777. doi.org/10.1016/j.seppur.2026.138777

Abstract

Membrane-based dealcoholization of beer results in the loss of key volatile aroma compounds, leading to a non-alcoholic beer (NAB) with reduced sensory quality. To address this limitation, an integrated process combining membrane dealcoholization with selective recovery of aroma compounds via adsorption and desorption was investigated. Representative esters and higher alcohols were chosen based on their concentration in beer and their sensory relevance. Adsorption equilibrium of these compounds was determined in ethanol–water mixtures (5–30 % v/v) on six adsorbents at temperatures ranging from 15°C to 35°C. Among the tested adsorbents, XAD-4, SP-700, and F300 exhibited the highest adsorption capacity and affinity toward the aroma compounds. The adsorption capacity decreased with increasing ethanol concentration, while the effects of temperature remained negligible. Fixed-bed adsorption experiments were conducted to assess continuous adsorption and to identify suitable desorption media for aroma compound recovery. Recoveries exceeding 97 % were achieved with 30 % v/v ethanol aqueous solution. Adsorption–desorption cycles were modeled using the Equilibrium Dispersive model with a modifier-dependent multi-component Langmuir isotherm where ethanol is the modifier. The isotherm model considers Langmuir parameters q_max and b, where is dependent on the ethanol concentration. The model successfully reproduced the experimental concentration profiles of aroma compounds during adsorption and desorption steps.

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