A new continuous chromatographic process is presented. This is in contrast
to the known simulated moving bed (SMB) process which employs a synchronous
shift of inlet/outlet lines. The basic principle of the new VARICOL proces
s is based on a nonsynchronous shift of the inlet/outlet valves in a multic
olumn system. A numerical example compares the performances of the new VARI
COL process to the well-known SMB process. This study shows that the VARICO
L performances can be better than those of the SMB process. For example, a
5-columns VARICOL permits the same purities to be reached as a 6-columns SM
B with the same productivity. Interest in the process is also validated exp
erimentally. Both SMB and VARICOL are optimized to reach the highest achiev
able productivity for given outlet purities. The productivity of a 5-column
s system can be improved 18.5% by using the VARICOL process.