Design and control aspects of hybrid reactive distillation for the synthesis of the gasoline oxygenates, ETBE and MTBE, have been studied via steady state and dynamic simulation and experimentation. An accurate and efficient simulation of the reactive distillation process was successfully developed for the steady state case using the equilibrium stage model, and then extended to the dynamic case. These models were used to demonstrate the design and optimisation of various ETBE processes utilising reactive distillation and to investigate the effect of operating variables on the product compositions and yields. A generalised design method for hybrid reactive distillation columns was developed using a combination of residue curve diagrams and simulations.
The steady state and dynamic simulations were also used to investigate multiple steady states (output multiplicity) in reactive distillation and to identify the causes for this phenomenon. Input multiplicity was also investigated with respect to the operation and control of reactive distillation processes. A range of control schemes were implemented via simulation and assessed for their effectiveness and appropriateness for reactive distillation. Open-loop, one-point composition control and two-point composition control were considered.
Simulation results were used to design a reactive distillation pilot plant for the synthesis of ETBE from ethanol and C4 hydrocarbon from the local oil refinery (BP, Kwinana). The pilot plant was designed to operate at industrially significant pressures and temperatures, and to produce a high ether purity and a high conversion of isobutene to ETBE. It was constructed and commissioned at Curtin University using novel structured and reactive packings. A fully automatic control system was subsequently installed on the pilot plant in order to implement and test a range of advanced control applications. AU aspects of the equipment were tested and found to operate according to design.
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