Computational design applied to equilibrium-staged and rate-based absorption processes

Abstract

Simulators are of great interest in Chemical Engineering because they facilitate process optimization and help evaluate different solutions through the so-called “what-if” approach. They include the most advanced thermodynamical models and complete libraries for the calculation of physicochemical properties and estimation of phase equilibria data which are successfully integrated in the process design. Moreover, simulators allow addressing both stationary and batch operations. For this reason, their use in the design of Industrial Chemistry processes has gained much acceptance in the last decades. Even so, simulations should be accompanied by another computational tool which allows the professionals to implement specific algorithms which relate inputs and outputs, so as to get the most out of the computing power. We herein exemplify how Aspen Plus and Mathcad Prime software packages were successfully integrated in a case study on the removal of carbon disulphide by contact with a paraffinic oil in an absorption tower. This absorption operation was studied in both trayed and packed columns. Regarding the first contact type, i.e. trays, Mathcad's powerful programming tool and graphical interface enabled to corroborate and to better understand the effect of temperature on the number of theoretical stages previously observed with Aspen Plus.