Distillation studies in a two-stage counter-current rotating packed bed

Based on the advantages and disadvantages of the conventional rotating packed bed (RPB) and the rotating zigzag bed (RZB), a novel two-stage counter-current rotating packed bed (TSCC-RPB) was developed for the continuous distillation. The present research conducted continuous distillation experiments in the TSCC-RPB using the methanol–water binary system. Experimental results show that the packing plays a significant role in enhancing the separation efficiency. To achieve a high number of theoretical trays (NT), the optimum rotational speed of the TSCC-RPB was about 700–800 r/min. Compared with the conventional RPB, the TSCC-RPB shows almost equivalent mass transfer efficiency and the same optimal rotational speed but can easily achieve the intermediate feed of continuous distillation. Compared with the RZB, the HETP of the TSCC-RPB, ranged from 31.16 to 47.21 mm, was smaller than that of the RZB ranged from 50.00 to 66.67 mm. The optimal rotational speed of the TSCC-RPB was also much lower than that of the RZB of 1000 r/min.

► TSCC-RPB was specially designed for continuous distillation with novel rotors.
► The HETP of TSCC-RPB was ranged from 31.16 to 47.21 mm.
► The optimum rotational speed of TSCC-RPB was determined at about 700–800 rpm.
► The results showed that TSCC-RPB has a potential for continuous distillation.