Abstract

Stacking the Stirred Tanks for Efficient Mixing and Solids Handling

Nikolay Cherkasov, Managing Director, Stoli Chem

Continuous chemical manufacturing provides just-in-time manufacturing at lower labour costs with ample sustainability benefits. Yet, there are major adoption barriers such as limited expertise of process chemists and significant capital costs. Compared to multipurpose batch plants, continuous reactors are often narrow in scope, bespoke, and expensive. A series of stirred tanks (CSTRs) is multifunctional, scalable and uses a lot of batch knowledge. That is why we developed a novel reactor that contains 10 CSTRs in a single vessel. In the talk, we discuss several case studies that benefit from CSTR-in-series continuous operation. For example, a sulphur insertion liquid-liquid reaction involved a reaction between an aqueous salt, a sulphur source, and a small amount of solid by-products. A significant amount of heat (about 200 kJ/mol) is released and it must be quickly dissipated to maintain the temperature below 10C. The CSTR operation provides rapid mixing and quick transfer with good scalability and ton-scale production. Such exothermic chemistry is a typical process that could reduce or eliminate solvents, maximise process throughput, reduce costs. CSTRs are particularly beneficial for processes with solids or viscous materials, and where rapid scale-up is required.