Mass transfer effects in the H2SO4 catalyzed pivalic acid synthesis

The synthesis of carboxylic acids from alkenes. carbon monoxide and water a ccording to the Koch process is usually carried out in a stirred gas-liquid -liquid multiphase reactor. Due to the complex reaction system with fast, e quilibrium reactions and fast, irreversible reactions the yield and product distribution depend on a number of process parameters. The effect of some of these parameters was studied for the production of pivalic acid, using s ulfuric acid as a catalyst. For the 96 wt.% sulfuric acid catalyst solution used the main reactions are relatively fast with respect to mass transfer and mixing. Therefore, aspects like the position of the injection point, in let concentration, agitation intensity and injection rate all influence the yield obtained. The presence of an inert organic liquid phase was found to be beneficial, due to a combined effect of enhanced gas-liquid mass transf er and a 'local supply' effect for carbon monoxide near the hydrocarbon rea ctant inlet. (C) 2001 Elsevier Science B.V. All rights reserved.