Design of heat integrated and control structures of butane isomerization plant for reversible reaction case

Abstract

To use plantwide control strategies to develop the control structures for the butane isomerization plant for reversible reaction case with energy integration schemes that are designed to achieve the control objective. The butane isomerization process is a complex plant consisting of many unit operations converting normal butane (nC4) into isobutane (iC4). In this work presents 4 alternatives of heat integrated (RHEN1-3 and Base case) with 4 alternatives of the control structure (CS1-4) for butane isomerization plant for reversible reaction are simulated using Luyben's heuristics method and Fixture point theorem (Wongsri, 2008). Various heat pathways throughout the network designed using Wongsri's disturbance propagation method to achieve dynamic maximum energy recovery. They are evaluated energy saving compared to Base case (Luyben, 1998), the energy saved is 15.11-22.09 %. Because of control difficulties associated with heat integration, the suitable control structure is necessary to process operation. We found that CS2 and CS3 are proper control structures with heat-integrated process when change in thermal disturbance and change in material flow disturbance and RHEN-1 have a performance control better than RHEN-2 and RHEN-3. The performances of the plants using software HYSYS for heat exchanger networks and control structures.