An-Najah Staff

The classic experiments of Paul and Treybal (1971) on the competitive/ consecutive iodination of L—tyrosine exhibit mixing affected yields of the mono—iodo intermediate product. The network of backmixed zones model has been applied to provide a comprehensive simulation of Paul’s semi—batch experiments which showed yields in the 50% to 70% range. It is shown that the reactions are fast relative to internal impeller generated mixing rates, so that iodine concentrations show strong partial segregation. A localised excess of iodine leads to a loss of yield of the intermediate relative to perfect mixing. The intensity of this partial segregation changes markedly with stirrer speed and so therefore does the yield. Details of the internal concentration fields in space and time are presented as sectional image reconstructions.