(586d) Reactive Dividing Wall Column: Experimental and Simulative Studies about Process Control and Dynamic Behaviour

Egger, L., Hamburg University of Technology
Fieg, G., Hamburg University of Technology
Process integration is an important method to increase process efficiency in chemical industry. A highly integrated process is represented by the reactive dividing wall column (RDWC), which combines a chemical reaction and several separation steps in one column shell. This integration can lead to major savings in investment costs and energy demand in comparison to conventional reaction and separation sequences. However, the high degree of integration also causes a very complex process behaviour. Hence chemical industry is reluctant to build and operate RDWCs. In order to assure constant product purities and a stable continuous operation a good understanding of dynamic effects as well as reliable process control strategies are required. To date various papers have been published about design and steady state operation of RDWCs but there are only few papers about the control and dynamic operation. Experimental studies about the control of RDWCs are still pending.

Our work aims to contribute to the research about RDWC process control. In our research we systematically develop and examine decentralized process control concepts for the RDWC. For the first time we conduct comprehensive experimental studies with focus on the dynamic behaviour and the control of RDWCs with an enzymatically catalysed RDWC in pilot scale. By comparison of data obtained experimentally and by simulation studies (all employed simulation models were developed at the Institute of Process and Plant Engineering, Hamburg University of Technology, and provide high reliability due to extensive experimental validation [1]) we are able to validate the developed control structures. Our studies allow deep insights about important dynamic effects of the apparatus and provide thus a basis for stable and safe process operation.

In the poster a suited decentralized process control strategy is shown, analysed and evaluated. Based on steady state simulations an optimal structure is established, while dynamic simulations are employed to adjust the controllers. Afterwards the control structure is tested in simulation studies in order to analyse the dynamic behaviour in different disturbance scenarios. In the next step the control structures are verified in experimental tests on our RDWC in pilot scale. Therefore, experimental data of the RDWC pilot plant will be shown. The dynamic behaviour under the influence of disturbances will be analysed in detail. Based on the results further developments for the control structure will be derived.

[1] Egger, T.; Fieg, G. (2016): Enzymatic Catalyzed Reactive Dividing Wall Column. Experiments and Model Validation. In AIChE J. DOI: 10.1002/aic.15598.