When using of solid-phase catalysts or adsorbents in reactors, the physical degradation of the materials is a common problem. The traditional stirred tank reactor inflicts mechanical damage to the particles, which causes attrition, fines that are difficult to separate, and loss of the functionality of the solid-phase.
By protecting the solid phase inside the rotating bed reactor, the lifetime of the catalyst or adsorbent is greatly increased. The mechanical damage associated with the stirred tank reactor is completely removed, enabling the use of conventionally impractical materials, such as:
This picture illustrates how much damage a stirred tank reactor can inflict on molecular sieves (left) and compares it with the rotating bed reactor (right). Both photos were taken after 24 hours of operation at a rotational speed of 500 RPM.
The wide range of compatible materials enable industrial usage of rotating bed reactors for many applications, such as:
Further reading:
Details
Conditions: Molecular sieve (3 Å, rods 3-5 mm, 15 g), placed either into a SpinChem® S2 rotating bed reactor (RBR) or free in solution agitated by a 3-blade stainless steel propeller (5 cm), both operated at 500 rpm within a SpinChem® V2 flower-baffled reaction vessel containing isopropanol (130 mL). Photos were taken after 24 hours of operation with the RBR and stirrer in place, respectively. The theoretical calculation assumed an RBR with space for 20 g molecular sieve with a 20% (w/w) water adsorption capacity, a synthesis yield of 99%, a product weight of 450 g/mol, and an organic solvent with a density of 0.8 kg/L and an initial moisture content of 200 ppm; data partly taken from literature; J. Org. Chem. 2010 (75) 8351-8354.