Ceramic microreactors for heterogeneously catalysed gas-phase reactions

Abstract

The high surface to volume ratio of microchannel components offers many advantages in micro chemical engineering. It is obvious, however, that the reactor material and corrosion phenomena play an important role when applying these components. For chemical reactions at very high temperatures or/and with corrosive reactants involved, microchannel components made of metals or polymers are not suited. Hence, a modular microreactor system made of alumina was developed and fabricated using a rapid prototyping process chain. With exchangeable inserts the system can be adapted to the requirements of various reactions. Two heterogeneously catalysed gas-phase reactions (oxidative coupling of methane, isoprene selective oxidation to citraconic anhydride) were investigated to check the suitability of the system at temperatures of up to 1000 degrees C. Apart from the high thermal and chemical resistance, the lack of any blind activity was found to be another advantage of ceramic components.

Hermetic Gas‐tight Ceramic Microreactors

“…Among the reasons for this is the fact that it is difficult to form complex structures on a micrometer scale due to the high hardness of ceramics. However, remarkable progress has been achieved with certain casting techniques, including microinjection molding, low-pressure injection molding, and others [7,8]. It still remains difficult to manufacture hermetic, gas-tight microreactor systems with zero leakage without the use of seals or brazed joints, particularly when high pressures or high temperatures are applied.…”

A new technology for microfluidic structures preparation based on a photoimageable ceramic

“…The most important parameters in fabrication of microfluidic systems are chemical resistance, optical properties, well-known surface chemistry, ability to electroosmotic flow and many others. The most often applied materials in micromechanical engineering are glass, quartz, silicon (Tiggelaar et al 2005;Kikutani et al 2002;Ratner et al 2005;Huber et al 2003), various polymers (Duffy et al 1998;Becker et al 2002;Mello 2002) and ceramic (Henry et al 1999;Knitter et al 2001Knitter et al , 2002Mengeaud et al 2002;Knitter and Liauw 2004;Golonka et al 2005). Transparence, good optical properties and chemical resistance are the main features of glass and quartz.…”

Determination of Residence Time Distribution in Gas‐Phase Microreactors using Light Emitting (Quasi‐)Continuous Plasma Discharges

“…Two essential prerequisites for such promising microreactor concepts are the use of a large amount of catalyst and uniform flow distribution in the constituent microchannels. The use of ceramic microreactor materials [9][10][11] facilitates the adhesion of the thicker catalyst coats required to ensure the desired high catalyst loadings, with little deterioration in thermal performance. However, the characterization of the flow distribution in microreactors for gas-phase reactions has not yet been resolved satisfactorily, since many conventional techniques are unsuitable for measurements at the microscale.…”