AbstractElectrosorption, or potential‐swing adsorption, appears well‐suited for recovery of dilute organic compounds from ionically conductive solutions.The feasibility of using electrosorption in an industrially difficult separation, removal of ethyleneamines from a brine stream, is assessed here. The assessment included lab‐scale measurements using the model compound ethylenediamine, paper design of a commercial‐scale process, and economic evaluation. Separation is achieved by periodically swinging the electrochemical potential on an adsorbent to achieve cycles of adsorption and desorption. Adsorption of ethylenediamine on activated carbon increased threefold following a change in potential of 1 volt.Adsorption increased at more negative potential, suggesting an acid/base‐type effect at the carbon surface. The key to scale‐up is use of relatively thin adsorbent beds to minimize time required to swing the potential. A design featuring stacked, 2‐cm‐thick layers of adsorbent separated by ion exchange membranes is proposed. The estimated cost of an electrosorption‐based process to reduce ethyleneamines concentration from 220 ppm to less than 60 ppm would be severalfold the value of recovered ethyleneamines.However, when employed for environmental reasons, cleanup by electrosorption would be economically attractive relative to alternate sepa
展开▼
