At Amar Stirred Pressure Reactors form a key part of our product portfolio. These Stirred pressure reactors (often also referred to as Stirred autoclaves) are our oldest product line at Amar and still growing strong. For applications such as Hydrogenation reactors or similar unit processes Stirred autoclaves are the workhorse of the chemical industry. Here are some links to past topics from our blogs on stirred reactors. (Selecting best heating cooling solutions for stirred reactors, Agitator/impeller selection for stirred reactor)
In this blog post we reiterate some of the key factors that influence the performance of stirred pressure reactors in chemical synthesis. The goal is to serve as a checklist or cheat sheet for our end users whenever they are purchasing their next pressure reactor:
- RPM: Mass Transfer limited reactions will benefit from a high rpm reactor but only to a certain point. There is no point stirring any faster. That’s wasted effort and money. Any good reactor should have a variable rpm feature to help you find this optimal operating rpm.
- Agitator type selection: Agitators (impellers) for stirred autoclaves come in several different types (shapes) e.g. Rushton turbines, propellors, pitched blade turbines, anchors etc. Use the right agitator for the right fluid. E.g. No point using a high rpm propeller for a high viscosity system where an anchor may fit best.
- Operating pressure: Resist the temptation of only running reactions at atmospheric pressure. Higher pressures will often allow higher temperatures. This increases reaction rates. This approach should be a key strategy for Process Intensification and hence smaller reactors. Remember: most of the Amar stirred autoclaves are rated for 50 or 100 bars of pressure. Why waste this ability? (Of course, scale up constraints must be kept in mind)
- Heat Transfer: It is highly likely that you have an exothermic or endothermic reaction. Too often time is wasted waiting for reaction T to be attained or dosing has to be intentionally slowed down (for exothermic reactions). Remember to add generous heating and cooling surfaces. Coils, limpets and jackets are all there for good reason.
- Geometric Similarity: Always have scale up in mind. Try to design lab reactors similar in geometry to avoid surprises. Always have baffles in ratios identical to the plant reactor you intend to use.
Stay tuned for Part 2 of this blog post for more such tips on remembering the key factors that influence the performance of stirred pressure reactors in chemical synthesis
