Simulated Moving Bed Chromatographic Reactor Research Articles

Continuous Synthesis of Ethyl Esters from Triglycerides using Simulated Moving Bed Chromatographic Reactor Packed with Solid Acid Catalysts

Continuous Synthesis of Ethyl Esters from Triglycerides using Simulated Moving Bed Chromatographic Reactor Packed with Solid Acid Catalysts

Comparison between simulated moving bed and reverse flow chromatographic reactors for equilibrium limited reactions

A staged linear model, containing five parameters, is developed to compare equivalent simulated moving bed chromatographic reactors (SMBCR) and reverse flow chromatographic reactors (RFCR). A first order reversible reaction and linear adsorption equilibrium, with preferential adsorption of the reactant is assumed. The analysis uses simple, easily computable analytical solutions that rigorously represents the transients in the cyclic steady state for both the RFCR and the SMBR. A comparison between the two types of reactors is carried out to determine the maximum conversion attainable and the range of operation where these systems have advantages over conventional steady state reactors. It is found that the maximum conversion of both reactors is similar. The range of operation in terms of amount of catalyst and range of switching times favors the RFCR, while the conversion at low separation factors favors the SMBCR.

Comparing true countercurrent and simulated moving‐bed chromatographic reactors

AbstractSimulated Moving Bed reactors (SMBR) combine chemical reaction and adsorptive separation within one single continuous and countercurrent unit. This integration promises substantial improvements in process performance, especially when applied to equilibrium‐limited reactions involving such heat‐sensitive products as fine chemicals and pharmaceuticals. In this work, the interplay among the relevant process design parameters (dimensionless ratios of the fluid and solid flow rates, and the Damköhler numbers for each section of the unit) is investigated. For this, an analytical solution of differential mass‐balance equations for the corresponding true countercurrent process (TCC), using as a model system the reaction A⇌B+C with each species exhibiting linear adsorption behavior, was developed. Based on this solution, criteria were derived for the optimum process design with respect to productivity and solvent consumption. Comparing these results with numerical simulations of an SMBR unit shows that the TCC model does not apply to SMBR units with a finite number of columns per section, that is, units of practical relevance, because the two units exhibit different residence time distributions and, hence, lead to different degrees of conversion.

A new method supporting the design of simulated moving bed chromatographic reactors

In a chromatographic reactor, chemical or biochemical reactions are combined with a chromatographic separation. A conversion rate higher than chemical equilibrium as well as better yield or even an enhanced selectivity in comparison to conventional processes can be achieved by continuously removing the products from the reaction zone. Additionally, the combination of two unit operations in one apparatus leads to smaller capital expenditure. Due to the advantages of the Simulated Moving Bed concept recently, most of the work on chromatographic reactors has dealt with this process. In this paper a new method in order to estimate the effect of the reaction on the design of the reactor is introduced. Combined with the well-known triangle theory this allows a very good initial guess of the operating parameters that can be used for further process optimization based on dynamic simulation.

Optimal Design and Operation of Simulated Moving Bed Chromatographic Reactors

This paper presents a novel optimization and design strategy for simulated moving bed (SMB) chromatographic processes in general and SMB reactors in particular. A suitable computationally efficient...

Design and Layout of Simulated-Moving-Bed Chromatographic Reactors

In this work the Simulated-Moving-Bed chromatographic reactor (SMBCR) is considered. The design of this complex process cannot be done empirically. A concept, in order to design a SMBCR based on numerical simulation is presented.

Effect of process parameters on the performance of a simulated moving bed chromatographic reactor

The combination of a chemical reaction and a chromatographic separation process in a single unit-operation may improve the course of reaction as well as the separation efficiency. Higher conversion and better yields can be achieved by separating educts and products of an equilibrium reaction from each other. In this work the effect of the process parameters on the performance of a chromatographic SMB reactor for a reversible decomposition reaction of type A ↔ B + C has been examined. The considered parameters (adsorption coefficient of the educt, separation factor of the products and reaction kinetics) have been changed in a wide range with all the other parameters fixed. A lower limit of the product purity has been set and the process has been designed to meet the given product specifications. Afterwards the performance of the processes has been compared based on the maximum feed flow rate that can be used without falling short of the desired product purity. A second criterion that has been used is the specific desorbent demand. The results of these examinations allow to estimate in which case the use of chromatographic SMB reactors seems promising.

Dynamic simulation of simulated moving bed chromatographic reactors

The combination of a chemical reaction and a chromatographic separation process in a single unit-operation may improve the course of reaction as well as the separation efficiency. Higher conversions and better yields can be achieved by separating educts and products of an equilibrium reaction from each other. Other fields of application exist for the removal of inhibitors, poisons, or acceptor products to enhance reaction yields. Especially for a continuous process, based on a chromatographic simulated-moving-bed (SMB) unit, reactor design and layout is complicated by the integrated process. Dynamic simulation, however, is a powerful tool to assist reactor layout and optimization. This paper presents different types of chromatographic reactors and a simulation based strategy for the design and optimization of SMB chromatographic reactors. Also, dynamic simulation studies using a rigorous model of the SMB process illustrate the advantages of chromatographic reactors in comparison to conventional processes.