LOGIC: Towards green methanol from CO2 - Methanol synthesis from CO2, CO2 hydrogenation, reactor design, transport phenomena, heat transfer
Tim van Schagen is a PhD student in the Department Sustainable Process Technology. (Co)Promotors are prof.dr.ir. D.W.F. Brilman and prof.dr. S.R.A. Kersten from the Faculty of Science & Technology.
The thesis investigates a novel reactor concept for methanol synthesis from CO2. This LOGIC reactor integrates a reaction zone, heat integration zone and condenser section in a single pressure vessel, thereby bypassing the inherent equilibrium limitations of the reaction and allowing a near-100% yield of methanol over the reactor. Because of the temperature gradient in the reactor, the internal recycle is fully driven by free convection. Chapter 1 gives an overview of the research landscape of methanol synthesis and shows that methanol production from CO2 is already a century old. Chapter 2 discusses the experimental results obtained with the LOGIC 2.0 set-up and proves that the reactor concept works. The free convection flow works as expected, heat integration is demonstrated and space-time yields comparable to other CO2 to methanol processes are achieved. In chapter 3 a hot-wire flow sensor is successfully developed, characterized and modeled that is used in the space-constrained reactor. Chapter 4 investigates the performance of the LOGIC reactor in more detail by constructing a steady-state flowsheeting model. This model is then validated against experimental data and used to calculate the energy balance over the reactor. Furthermore, sensitivity analyses are performed and the feasible operating window of the set-up is determined. In Chapter 5 a 1D, dynamic CFD model is developed and used to investigate the dynamics of the reactor. It is shown that the set-up is very promising for intermittent operation (with green hydrogen). Chapter 6 investigates the fluid flow and heat transfer in the reactor in more detail with a 2D CFD model and it is determined that the flow inside the reactor is chaotic and highly complex. Engineering heat transfer correlations are also developed from the CFD results. The thesis ends with a conclusion and outlook.
