Chemical Reaction Simulation

The Colorful Fluid Mixing Gallery

This series of images shows the flow and progression of a pair of competitive chemical reactions in a stirred vessel equipped with a Rushton turbine. The first image shows the radial flow pattern created by the impeller by means of velocity vectors. The other images show concentration fields of the chemicals after 0, 1, 2, 4, 10 and 20 seconds respectively. The following chemical reactions occur:

A + B --> R

R + B --> S

The world's most commonly used reactants A and B combine to form the extremely popular chemical products R and S. The first reaction is very fast, which means that the actual reaction rate is limited by the degree of mixing. The second reaction is slow, and only occurs in regions where reactant A has been depleted. Thus the final product composition, the amount of R and S produced, depends on the mixing process. The occurrence of such side reactions, that can form undesired by-products, is very common and being able to simulate the effect of mixing on the productivity of a chemical reactor is extremely useful.

The flow field in the reaction vessel.

These images show the concentration fields of A, R, and S at various instants in time. At time 0 the vessel is filled with reactant A (shown in red), and a certain amount of reactant B (shown in blue) is added above the impeller. The images show the concentration field in one half of the vessel only, because the flow and scalar fields are symmetrical around the shaft. After about 20 seconds the reaction is completed and almost seven times as much R as S has formed.

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Last Updated March 14, 1998 by André Bakker
© André Bakker 1998