Production of commercial dyes via impingement-sheet mixing Part II. Results of laboratory experiments

Abstract

Three commercial azo dyes of Ciba-Geigy AG were produced using the industrial impingement-sheet mixer discussed in Part 1 ( Chem. Eng. Process., 29 (1991) 173–177) of this paper. Relative to conventional technology, yield increases of 7%–14% were obtained for two of the dyes. Impingement-sheet mixing of the third dye, however, produced small explosions in the mixed liquid sheet that decreased the observed yield. Inability to remove heat from the liquid sheets resulted in an adiabatic temperature rise that, coupled with a high reaction, pH, led to strong decomposition of the relatively unstable diazo reactant.