Solving a separation-network synthesis problem by interval global optimization technique

1

Solving a separation-network synthesis problem by interval global optimization technique

A. Szlama

, K. Kalauz

, I. Heckl

, B. Bertok

1

Department of Computer Science and Systems Technology, University of Pannonia, Egyetem utca 10, Veszprem, H-8200, Hungary

szlama@dcs.uni-pannon.hu, kalauz@dcs.uni-pannon.hu, heckl@dcs.uni-pannon.hu, bertok@dcs.uni-pannon.hu

2013

Abstract

A novel method is presented here for solving certain classes of separation-network synthesis (SNS) problems, which are inherently non-linear, using branch-and-bound framework and linear programming.

The proposed method determines effectively the structure and flowrates of the optimal separation network.

The examined problem contains simple and sharp separators, mixers, and dividers; its aim is to produce three pure product streams from two three-component feed streams with minimal cost. The cost of the network is the sum of the costs of the separators and the cost of a separator is a concave function of its mass load. The mathematical programming model generated from the rigorous super- structure is non-linear.

The goal of our work is to determine the optimum of the aforementioned model effectively. The splitting ratios of the dividers are handled as intervals. A B&B method operates on them. The cost functions of the separators are approximated with lower estimating functions.

Keywords: separation synthesis, interval method, global optimization, branch-and-bound framework