Cationic membranes for phenols production.
Ionic Substitution by Electrodialysis is a good alternative to the industrial conversion of sodium salts of phenols into undissociated phenols, conventionally performed through acidification by strong acids. The acidification through electromembranes combines the possibility to achieve high conversion values with the advantage of keeping the process stream separated from the acid stream. The process is performed through cationic membranes; conversion can be obtained also in the absence of electric current, even if slightly better performances can be achieved by applying an electric field. Process feasibility as well as membrane resistance is tested, for the case of model solutions reproducing the main features of the real process streams. Maximum conversion and process rate are greatly affected by the ratio between protons in the acid solution and sodium ions in the process solution. Phenol losses into the acid stream and chloride contamination of the process stream can be reduced by working with diluted process and acid streams.
Bandini
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Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Facoltà di Ingegneria, Università di Bologna, Viale Risorgimento, 2 I-40136 Bologna. serena.bandini@mail.ing.unibo.it
D002412:Cations; D003956:Dialysis / Q000295:instrumentation / Q000379:methods; D004563:Electrochemistry; D006851:Hydrochloric Acid; D007220:Industrial Waste; D008567:Membranes, Artificial; D019800:Phenol / Q000737:chemistry / Q000302:isolation & purification; D012492:Salts; D012964:Sodium / Q000737:chemistry*; D014876:Water Pollution / Q000517:prevention & control
D002412:Cations; D007220:Industrial Waste; D008567:Membranes, Artificial; D012492:Salts; D019800:Phenol; D012964:Sodium; D006851:Hydrochloric Acid