Study of feed temperature control of chromatography using computional fluid dynamics simulation

Recently preparative high-performance liquid chromatography (HPLC) has been used more and more frequently to separate drugs and natural substances. However, large-scale HPLC easily tends to reduce the yield and purity of the product. Hydrodynamic and heat factors play an important roles. Generally, in a large-scale HPLC column, the tracer profile inside column will take on a parabolic shape because of the distributor, which will impact the separation performance of the column. With the inlet temperature suitably lower than the wall temperature, this situation could be improved to some extent. In this work, some experiments were conducted using HPLC, with a column 10 cm in diameter to determine the optimal temperature difference between wall and inlet temperatures. The wall temperature was fixed at about 30 degrees C and the inlet temperature varied from 15 to 30 degrees C. The flow-rate of the eluent, methanol, was 300 ml/min. The experimental result was simulated using CFD software FLUENT 4.4.4. The simulated temperature field fitted the experimental one very well and the simulated flow, temperature and tracer distribution inside column could provide good explanation of separation performance under different conditions. In addition, the simulation could at least approximately predict the optimal temperature difference.