Membrane microreactors fluid flow

A distinctive feature of microreactors is the microchannels for fluid flow. MMRs are mainly characteristic of such microchannels with anchored catalysts for reactions and miniature membranes to perform separation, which are formed on the porous ceramic or metal supports. Based on the configuration and architecture of the reactor, MMRs can be classified into two categories plate type and tubular type. 

When the membrane tube is reduced in diameter to a certain level, that is, ID < 1 mm, it becomes a hollow fiber and the fiber lumen may take on the effect of a microchannel on the fluid flow. The catalyst can be coated on the inner surface of the hollow fiber or impregnated inside the porous wall, while the separation is achieved by the porous hollow fiber itself or by the membrane formed on the outer surface of the hollow fiber, as shown in Figure 8.5. Such catalytic hollow fiber membranes can easily be fabricated into MMRs, called hollow fiber membrane microreactors (HFMMRs). 

Any notable accumulation of gas was unlikely since the two fans inside the chassis create a flow rate of approximately 180 CFM of air through the system. This corresponded to more than 95 complete air changes or turnovers every minute (Heck and Manning, 2000). The most likely zone of gas escape would be above the microreactor due to a membrane failure. If this occurs, the control system should have interlocked and shutoff the flow of combustible gas to that reaction channel. The flammable gas that does escape would have been immediately diluted by air flowing over the microreactor at an estimated rate of 120 ft min (Heck and Manning, 2000). To provide a more detailed analysis of gas mixing in the immediate vicinity of a microreactor die, a computational fluid dynamics (CFD) model was constructed to simulate the gas flow hydrodynamics. This simulation quantifies that there is a recirculation zone above the reactor with an airflow rate... 

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