H. Lou et al., Parametric study on separation performance of air drying PSA and application of short cycle time approximation, J CHEM EN J, 33(2), 2000, pp. 205-210
The separation performance of air dehumidification is investigated over a w
ide range of experimental conditions by using an isothermal PSA apparatus.
Velocity ratio of purge to feed (gamma), half cycle time, column length (L)
, and particle size are round to have a great effect on the product concent
ration, while the independent effect of pressure ratio (beta) seems relativ
ely small with fixed values of the other parameters. A simplified analytica
l model proposed previously, short cycle time approximation, is extended to
the Langmuir isotherm to derive the following new algebraic equation which
identifies the combination of the operating and design parameters.
In[(1 - beta)(C-A1/C-A0)] - In(1 - 1/gamma) = -(N-0(1) - A)/r
in which N-0(1) is a combined number of mass transfer units given by
N-0(1) = (K(A)amL)/(1 + K-A/K-D)(1/u(A) -1/u(D)) and the parameter A in the
equation is a simple function given by the velocity ratio gamma and Langmu
ir coefficient r. Good agreement between the calculated results and the exp
erimental data show that the short cycle time approximation is suitable for
estimating the separation performance of the purification PSA process such
as the present air dehumidification system with a better understanding of
the role of each parameter on the separation performance.