Simulated Moving Bed (SMB) Systems
The basic principle of operation
With normal chromatography the mobile phase (the eluent) flows down the static, stationary phase (the column bed). However, it has been recognised for many years that it would be more efficient if the stationary phase could also move, in a counter-current to the mobile phase. But having a moving column bed is not practical, so to get around this a “simulated” moving bed system was developed which simulates the conditions of a moving bed through a circulating flow of feed, extract, eluent, and raffinate (the raffinate being what is left after the extract has been removed).
The bulk of the eluent is continuously circulated in the system, making it necessary to replace only that small amount which is removed in the extract and raffinate. This enables savings of up to 90% of the eluent in comparison to a batch process. Also, due to the simulated counter-current, the stationary phase is significantly better utilized with the SMB technique as compared to the batch process technique. The number of theoretical plates might be also less important, making it possible to use cost-effective larger particle size for the stationary phases.
Typically, the SMB process is used for mixtures of two components, like chiral separations or mixtures with a “leading” or a “trailing” key product peak in the chromatogram. But it is possible that each partial fraction can be separated into a further fraction by repeated use of the SMB process – down to binary substance mixtures.
Video: SMB theory for beginners
This is a 7:20 video from Knauer outlining the basic principles of Simulated Moving Bed chromatography
The KNAUER AZURA® SMB System Configuration
KNAUER has refined the SMB methodology further to produce a unique system that avoids the requirement for a large rotating multi-position valve, but instead utilizes seven smaller valves that gives the system greater efficiency and flexibility.
The AZURA® SMB systems consists of four pumps and seven multi-position valves. The devices are arranged as follows:
- Three pumps (Extract, Raffinate, Eluent) are placed inside the SMB cycle.
- The feed pump is placed outside the SMB cycle.
- Four valves are placed at the pump outlets.
- Three valves are placed at the pump inlets. The feed pump inlet is not connected to a multiposition valve.
Due to this configuration the SMB system can be used very flexible for many different separation modes. Additionally to the process stability AZURA® SMB systems are outperforming every other SMB system on the market regarding material and configuration flexibility as well usable pressure range.
The KNAUER AZURA® SMB Laboratory-Scale Models
The AZURA Lab SMB System is optimized for the multicolumn separation of binary mixtures of small molecules in gram-scale. The SMB System A29101 is the standard stainless steel configuration of our AZURA Lab SMB. It consists of seven 8-multiposition valves and four AZURA P 4.1S included in four Assitants ASM 2.2L. The high pressure range as well as the flexibility of the multiposition valves make this system the perfect solution for SMB chromatography.
The AZURA Lab SMB System is optimized for the multicolumn separation of binary mixtures of small or biomolecules in gram-scale. The SMB System A29100 is the standard configuration of our AZURA Lab SMB. It consists of seven 8-multiposition valves and four AZURA P 4.1S included in four Assitants ASM 2.2L. The high pressure range and the biocompatibility as well as the flexibility of the multiposition valves make this system the perfect solution for SMB chromatography.
The KNAUER AZURA® SMB Pilot-Scale
The AZURA Pilot SMB System is optimized for the separation of binary mixtures in gram to kilogram-scale. Its special emphasis is put on the continuous operation mode and high productivity.
A maximum pressure of 100 bar, eight columns and a flowrate of up to 500 ml/min allows you to do a separation on columns up to 50 mm ID, with output of up to 1000 kg per year.
Cannabis Producer: SMB Pilot System for continuous cannabinoid production
This AZURA SMB pilot system “Cannabis Producer” is dedicated for the continuous production of cannabinoids from cannabis. The Cannabis Producer allows the continuous separation of mixtures of substances and extraction into two fractions. High purities and simultaneous yields of up to 100% distinguish this process from conventional preparative LC methods.
For further details CLICK HERE or see the Knauer page at https://www.knauer.net/en/cannabis-producer-smb-pilot-system-for-continuous-cannabinoid-production/p38308