CUTTINGBUBBLES · Bubbles on the Cutting Edge

Many processes in the chemical, petrochemical and/or biological industries involve three phase gas-liquidsolid flows, where the solid material acts as a catalyst carrier, the gas phase supplies the reactants for the (bio-)chemical transformations and the liquid phase carries the product. In these processes the performance and operation of the reactor is mostly constrained by the interfacial mass transfer rate and the achievable insitu heat removal rate. A micro-structured bubble column reactor that significantly improves these crucial properties is proposed in this project. This novel type of reactor takes advantage of micro-structuring of the catalyst carrier in the form of a wire-mesh (see Figure 1).The aim of the wire-mesh is i) to cut bubbles into smaller pieces leading to a larger interfacial area, ii) to enhance the bubble interface dynamics and mass transfer due to the interaction between the bubbles and the wires, and iii) to save costs in practical operation due to the smaller required reactor volume and the fact thatthere is no need for an external filtration unit.Cutting edge three-phase direct numerical simulation (DNS) tools and novel non-invasive optical (highspeed camera) techniques are used to study the micro-scale interaction between bubbles and a wire-mesh to gain understanding of the splitting and merging of bubbles and associated mass transfer characteristics. Furthermore, a proof-of-principle of the micro-structured reactor will be given through lab-scale experiments and macroscopic Euler-Lagrange numerical simulations, employing bubble-wire interaction closures based on the DNS simulations.In addition to the novel reactor type, the project will generate a broad set of fundamental numerical and experimental research tools that can be used for the improvement of various gas-liquid-solid processes.Several large companies (AkzoNobel, DSM, Sabic and Shell) have indicated their interest in the proposedproject and would like to be involved in a users committee.