Final Report Summary - SSRR (Smart Structured Rotating Reactors)
The ERC Grant research program “Smart Structured Rotating Reactors” aimed at the understanding, design and operation of two new types of multi-phase chemical reactors for intensification of synthesis and production of high-added value chemical products:
• A rotating foam reactor
• A multiple spinning disc reactor
Both reactors have the potential to radically improve mixing and to increase the rate and selectivity of multi-phase chemical conversions (e.g. gas/liquid or liquid/liquid systems), hereby creating opportunities for reducing production costs, e.g. by shorter processing cycles or by smaller reactors, and reducing waste, which lowers environmental impact but also will reduce purification costs. Current achievements will be highlighted.
Rotating foam reactor
A rotating foam reactor (RFR) is a reactor in which the stirrer is replaced by a foam structure that can be rotated. For the development of a RFR it is essential to attach catalyst, the enhancer of a chemical conversion, to the foam structure that serves as the stirrer. We developed a very controllable method, wash coating, to do so. The catalyst layers that we deposit can be fine-tuned dependent on the requirements of the chemical conversion. We tested the catalyst-containing foam in a particular reaction and showed that we can increase selectivity at comparable productivity as compared to a state of the art slurry reactor, due to better mixing. Other advantages of the RFR are i) better controllability as conversion can be stopped by stopping the stirring and ii) no costly catalyst recovery from the product. We developed and investigated three different RFRs:
• A single stage horizontally rotating foam reactor
• A single stage vertically rotating foam reactor
• A multi-stage vertical rotating foam reactor
The reactors were applied in hydrogenation reactions, specifically alkynes to alkenes and the hydrogenation of styrene, both gas-liquid type of reactions.
With the fundamental results obtained, we defined new projects in the application of RFR in bio-based chemical processes, the conversion of glucose to HMF in particular.
Multiple spinning disc reactor
A spinning disc reactor is a multi-phase reactor in which a disc rotates at high speed (can be >1000 rpm) in a (rotating) small slit. Due to the small distances (less than 5 mm) between disc and slit wall, and the high velocities, very good mixing can be obtained. This is beneficial for fast reactions, fast transfer of components between phases and for the removal of reaction heat from the reactor. Due to the centrifugal forces also very good separation of phases can be achieved, as the lighter phase will move to the axis, while the heavier phase will move to the outside. As many advantages are seen, mixing and transfer of components between different phases needs to be quantified and understood. From this knowledge a system in which multiple discs will be stacked can be designed, constructed, tested and applied to chemical conversions. We characterized the mixing behavior by establishing mixing times that can be as low as 0.1 millisecond, which is extremely fast. We also determined the rate at which components transfer between different phases at different rotational speeds. To complete this picture the interfacial area between the two phases was determined. Here we applied gamma and X-ray tomography to visualize hold up of the dispersed phase, which is impossible with a light microscope because of the extremely small droplet size.
Based on the research we developed and tested two multiple spinning disc reactors: (1) with co-current flow for a gas-liquid system, which means that both phases effectively flow in the same direction through the system, (2)
with counter-current flow for a liquid-liquid and gas-liquid system, where both phases flow in opposite direction through the device, which is not very obvious in a centrifugal field.
Due to the high potential of this technology, new, more applied projects were developed in collaboration with industry and the Dutch Institute for Sustainable Process Technology in which electrochemical processes and separation processes like distillation or extraction are explored.
• A rotating foam reactor
• A multiple spinning disc reactor
Both reactors have the potential to radically improve mixing and to increase the rate and selectivity of multi-phase chemical conversions (e.g. gas/liquid or liquid/liquid systems), hereby creating opportunities for reducing production costs, e.g. by shorter processing cycles or by smaller reactors, and reducing waste, which lowers environmental impact but also will reduce purification costs. Current achievements will be highlighted.
Rotating foam reactor
A rotating foam reactor (RFR) is a reactor in which the stirrer is replaced by a foam structure that can be rotated. For the development of a RFR it is essential to attach catalyst, the enhancer of a chemical conversion, to the foam structure that serves as the stirrer. We developed a very controllable method, wash coating, to do so. The catalyst layers that we deposit can be fine-tuned dependent on the requirements of the chemical conversion. We tested the catalyst-containing foam in a particular reaction and showed that we can increase selectivity at comparable productivity as compared to a state of the art slurry reactor, due to better mixing. Other advantages of the RFR are i) better controllability as conversion can be stopped by stopping the stirring and ii) no costly catalyst recovery from the product. We developed and investigated three different RFRs:
• A single stage horizontally rotating foam reactor
• A single stage vertically rotating foam reactor
• A multi-stage vertical rotating foam reactor
The reactors were applied in hydrogenation reactions, specifically alkynes to alkenes and the hydrogenation of styrene, both gas-liquid type of reactions.
With the fundamental results obtained, we defined new projects in the application of RFR in bio-based chemical processes, the conversion of glucose to HMF in particular.
Multiple spinning disc reactor
A spinning disc reactor is a multi-phase reactor in which a disc rotates at high speed (can be >1000 rpm) in a (rotating) small slit. Due to the small distances (less than 5 mm) between disc and slit wall, and the high velocities, very good mixing can be obtained. This is beneficial for fast reactions, fast transfer of components between phases and for the removal of reaction heat from the reactor. Due to the centrifugal forces also very good separation of phases can be achieved, as the lighter phase will move to the axis, while the heavier phase will move to the outside. As many advantages are seen, mixing and transfer of components between different phases needs to be quantified and understood. From this knowledge a system in which multiple discs will be stacked can be designed, constructed, tested and applied to chemical conversions. We characterized the mixing behavior by establishing mixing times that can be as low as 0.1 millisecond, which is extremely fast. We also determined the rate at which components transfer between different phases at different rotational speeds. To complete this picture the interfacial area between the two phases was determined. Here we applied gamma and X-ray tomography to visualize hold up of the dispersed phase, which is impossible with a light microscope because of the extremely small droplet size.
Based on the research we developed and tested two multiple spinning disc reactors: (1) with co-current flow for a gas-liquid system, which means that both phases effectively flow in the same direction through the system, (2)
with counter-current flow for a liquid-liquid and gas-liquid system, where both phases flow in opposite direction through the device, which is not very obvious in a centrifugal field.
Due to the high potential of this technology, new, more applied projects were developed in collaboration with industry and the Dutch Institute for Sustainable Process Technology in which electrochemical processes and separation processes like distillation or extraction are explored.