Mixing and Chemical Reactions

The Effects of Mixing, Reaction Rates, and Stoichiometry on Yield for Mixing Sensitive Reactions—Part I: Model Development

“…There are several forms of the Damköhler number, with the mixing Damköhler number (Da) given by (Patterson et al [2]):…”

“…Since perfect instantaneous mixing is almost impossible to realise in practice, there have also been a number of investigations into the effect of imperfect mixing on the final yield of desired product (e.g., Patterson et al [2], Baldyga and Bourne [1,3], Baldyga et al [4], and Bhattacharya [11]). In the fine chemicals industry, reactions are frequently carried out in semi-batch stirred tanks.…”

“…Prediction of the yield for mixing sensitive reactions has been particularly difficult, as documented in Chapter 13 of the Handbook of Industrial Mixing [2], owing mostly to a lack of information about the reaction schemes, reaction rate ratios, mixing requirements, and so forth. Much of the work on mixing sensitive reactions is for specific known reactions, so the results are not directly transferable to a new reaction, and any general treatment has been restricted to specific stoichiometries, all with coefficients of one.…”

“…Therefore, for a perfectly homogeneous mixture of reactants present in a stoichiometric ratio of one (A : B = 1 : 1), the yield of by-product S should be very small. It is well established (Baldyga and Bourne [1], Patterson et al [2]) that the yield of byproduct can indeed be quite significant: an effect which is due to imperfect mixing. These classical stoichiometries have been extensively studied (Baldyga and Bourne [1,3], Baldyga et al [4], Cox et al [5], Clifford et al [6], Cox [7], and Patterson et al [2]).…”

“…It is well established (Baldyga and Bourne [1], Patterson et al [2]) that the yield of byproduct can indeed be quite significant: an effect which is due to imperfect mixing. These classical stoichiometries have been extensively studied (Baldyga and Bourne [1,3], Baldyga et al [4], Cox et al [5], Clifford et al [6], Cox [7], and Patterson et al [2]). The primary aim of this paper is to study the effect of a different overall reaction stoichiometry on the yield of desired product and the diffusive mass transfer limitations that are associated with this difference.…”