Use of Dimensional Analysis to Design Packed-Bed, Gas-Liquid Extraction Columns

The most reliable method for scaling a chemical process is to derive its governing or conservation equation(s), then non-dimensionalize that equation(s) and solve it, using a specified dimensionless initial condition and a set of dimensionless boundary conditions.  Following this procedure provides a result for upscaling or downscaling a given chemical process.  Unfortunately, most governing equations are too difficult to solve analytically without making a number of “reasonable” assumptions.  But, making such assumptions reduces the information content of the answer. 

            Dimensional Analysis provides us with a method for obtaining scaling information without making penalizing assumptions.  However, Dimensional Analysis does not yield a numerical answer; rather, it yields a functional answer that requires experimentation to achieve a graphical answer to the scaling problem.

            In this presentation, we demonstrate the use of Dimensional Analysis for obtaining scaling information about gas-liquid extraction in packed columns … a most complex chemical process indeed.