PROCESS DESIGN FOR THE OXIDATION OF FLUOROBENZENE TO FLUOROCATECHOL BY PSEUDOMONAS-PUTIDA

The characteristics of the conversion of fluorobenzene to fluorocatech ol by Pseudomonas putida have been determined. Three important constra ints on the design of an effective process were identified-reactant in hibition, product toxicity and reactant volatility. The first was over come by controlled feeding of fluorobenzene to the reactor. Product to xicity was minimised by the introduction of in situ product removal us ing a circulation loop from the reactor which contained a packed bed o f Norit pK13 onto which fluorocatechol adsorbed. At the end of fed-bat ch experiments the total amount of fluorocatechol produced was 70 time s greater than the minimum toxic level. A high loss of fluorobenzene f rom the reactor was eliminated by replacing air sparging by a membrane oxygenator installed in a second loop. The introduction of these two techniques allowed large step changes to be made in the productivity o f the biotransformation, making it a much more effective process. (C) 1997 Elsevier Science B.V.