(71o) Modular Microreaction System - a Powerful Tool for Process Development and Production

Abstract

Microprocess technology opens new pathways for the development of economical and innovative processes. In the chemical and pharmaceutical industry, this technology plays an increasingly important role in research, development and production because of its decisive advantages over conventional technology. These include:

µ      very fast mixing

µ      efficient heat exchange

µ      narrow residence time distribution

µ      fast system response for efficient process control

µ      easy process control and automation

µ      high level of safety due to low hold-up

µ      easy scale-up

With the Modular Microreaction System, this work demonstrates a powerful development and production tool combining the advantages of microprocess technology with great flexibility and a wide scope of application for process development and intensification. The system comprises of individual (microstructure-equipped) modules that can be freely combined. These modules perform basic process operations such as mixing, dispersing, heat transfer, etc (Figure 1). The system can also be used for a wide range of process conditions including reactions in liquid phase, gas phase or heterogeneous gas-liquid reactions. Operating parameters include a temperature range of ?20 to 200 °C (?100 °C for the CryoReactor module); operating pressures up to 100 bar; and rated throughputs of up to 25 L/h for low-viscosity media.

In the presented work, the viability of the system for investigating various multiphase reactions will be displayed using specific examples. For example, a transesterification (Scheme 1) has been performed in the Modular Microreaction System and in a conventional laboratory equipment. Transesterifications are usually associated with moderate to slow reaction rate constants (Otera, 1993). The aim of this study was to elucidate whether microreaction technology offers advantages for these types of reactions.

Thomas.daszkowski.b@bayer.com; Ph: 281-383-7941; Fax:  281-383-5403

Fig. 2 shows a comparison of the yield obtained using conventional glassware reactor and the Modular Microreactor System. With conventional laboratory glass ware, the reaction temperature of 75 °C was limited by the boiling point of the reaction mixture. Under these conditions one observed a conversion of ~90% after ~ 9 hours (Fig. 2a). However, the Modular Microreaction System allows the measurement of an entire parameter space in that time. Due to the ability to work under elevated pressures and reaction temperature, the reaction rate can be increased. For example, at 150 °C and 10 bar, the conversion of 90% is achieved within 15 min (Fig. 2b). Due to the continuous operation mode and the small scale, the heat transfer from the reaction mixture become more efficient than in a corresponding batch process and possible thermal decomposition of the product or other unwanted losses can be avoided.

Reference

J. Otera, Transesterification, Chem. Rev. 93 (1993) 1449-1471

Figures

Scheme 1: Transesterification reaction scheme 

Figure 1: Example configuration of a Modular Microreaction System for heterogeneous reactions

                                    (a)                                                                               (b)

Figure 2: Comparison of yield measurements for a trans-esterification using (a) standard batch laboratory equipment at 1 bara and (b) the continuous flow Modular Microreaction System at 10 bara.