Fluidized bed membrane reactors FBMRs

Comparison of performance of fluidized bed membrane reactor (FBMR), fluidized bed reactor (FBR) and continuous stirred tank reactor (CSTR)... 

Recently, the fluidized bed membrane reactor (FBMR) has also been examined from the scale-up and practical points of view. Key factors affecting the performance of a commercial FBMR were analysed and compared to corresponding factors in the PBMR. Challenges to the commercial viability of the FBMR were identified. A very important design parameter was determined to be the distribution of membrane area between the dense bed and the dilute phase. Key areas for commercial viability were mechanical stability of reactor internals, the durability of the membrane material, and the effect of gas withdrawal on fluidization. Thermal uniformity was identified as an advantageous property of the FBMR. 

Different types of membrane reactors for hydrogen production have been proposed in the literature. Most of the previous work has been performed in packed bed membrane reactors (PBMRs) however, there is an increasing interest in novel configurations such as fluidized bed membrane reactors (FBMRs) and membrane micro-reactors (MMRs), especially because better heat management and decreased mass transfer limitations can be obtained in these novel reactor configurations. 

The so-called fluidized bed membrane reactor (FBMR) is obtained by immersing bundles of hydrogen-selective membranes into a gas—solid fluidized suspension (see Figure 3.7) (Gallucci et al., 2008a, 2008b). 

By far the most commonly referred to reactor is the packed bed membrane reactor (PBMR), in which the reaction function is provided by a packed bed of catalysts in contact with the membrane. The membrane itself is not catalytic or at least not intentionally so, but is used to add or remove certain species from the reactor. If the membrane is highly perm-selective, this configuration appears ideal for situations where two complementary reactions take place on either side of the membrane - the product of the reaction on one side acting as a reactant on the other side, while the endothermicity of one reaction is compensated by the exothermicity of the other. When the catalysts at work are present in a fluidized mode, the reactor is then called a fluidized bed membrane reactor (FBMR). 

In this case two different reactor configurations are usually distinguished the packed-bed membrane reactor (PBMR), and the fluidized-bed membrane reactor FBMR). 

---