Spinning Band Distillation Column–Rotating Element Design and Vacuum Operation

To lower the barriers to entry into modular production, applicable, flexible modules that can be integrated into modular plants are needed already in the laboratory environment for reaction and separation processes. Such a module with the continuous operated spinning band column for distillation is presented here. Modifications from the classical batch spinning band column extending the operating window and making the column more flexible are described. Particularly the variation of the slope of the spinning band as well as a flexible feeding system are investigated, where the height of the feeding position can be adjusted within the column. Furthermore, a vacuum unit is added to the column allowing for the separation of temperature-sensitive materials. The column achieves HETP values between 4 cm for vacuum operation and very low throughput of 3 g min^–1 and 8 cm for ambient pressure and moderate throughputs of up to 8 g min^–1. The operation range is limited by flooding effects to the gas factor range of 0.9 to 2.3 Pa^0.5 and a liquid load between 3 and 10 m³ m^–2 h^–1. By changing the slope of the spinning band, it is possible to operate the column with higher separation performance but lower throughputs or, in contrary, with lower separation performance but higher throughputs. By adapting the feeding height, the separation can be moved either to the heavy or to the light key component. In combination with a modular automation and sensor system, the spinning band column represents a versatile and robust distillation tool.