This work aims to study the citric acid recovery from an aqueous mixture by an adsorption process using a Reillex (R) 425 resin as adsorbent and methanol as desorbent. A theoretical model has been developed to describe the aqueous citric acid adsorption on Reillex (R) 425 and its desorption with methanol. An SMB process for recovering citric acid from a citric acid/water mixture containing 10% w/w of citric acid using methanol as desorbent has been designed and optimized, with purity above 99% and recovery above 95%. An evaporation-crystallization method is designed to recover citric acid and methanol from the extract.