Solution of material balances for flow sheets modeled with elementary modules: The constrained case
Article first published online: 17 JUN 2004
Copyright © 1979 American Institute of Chemical Engineers
Volume 25, Issue 2, pages 220–229, March 1979
How to Cite
Sood, M. K. and Reklaitis, G. V. (1979), Solution of material balances for flow sheets modeled with elementary modules: The constrained case. AIChE J., 25: 220–229. doi: 10.1002/aic.690250203
- Issue published online: 17 JUN 2004
- Article first published online: 17 JUN 2004
- Manuscript Accepted: 6 SEP 1978
- Manuscript Revised: 18 AUG 1978
- Manuscript Received: 21 DEC 1977
Flow sheet material balance calculations are greatly simplified if all process input streams, reaction stoichiometry, and conversions, as well as all stream and component split fractions, are specified. Yet in many applications, especially those arising in process design, the available material balance specifications can take on many alternate forms. Each of these additional specifications can readily be expressed as a linear or nonlinear constraint equation involving species or total flow rates.
In this paper, an approach is developed for incorporating such specifications within the computational framework for solving unconstrained material balance problems. The linear as well as the nonlinear constraints are accommodated by generating a parametric solution to the underlying unconstrained problem. The parameters are determined by solving simultaneously first the linear and then the nonlinear constraint equations. Only as many equations are solved iteratively as there are nonlinear constraints.