Reactors without a catalyst bed

The reactor types introduced in Sections 1.2 and 1.3 depend on the existence of a catalyst bed, either fixed or moving, for the operation. However, there are multiphase reactions, such as the gas-liquid type, which do not involve the use of a solid catalyst. Gas deaning/purification applications, such as removal of 

In stirred-tank reactors, the possibility of regulating the agitation speed and the selection of various impeller types and diameters allow control over the degree of mixing of different fluids, which is quantified by the impeller Reynolds number Re = D Sp/f D, impeller diameter S, speed of agitation p, fluid 

In addition to processes involving gas-liquid reactions, stirred-tank reactors can also be used for single (liquid)-phase reactions. Moreover, their operation is not limited to the continuous mode, and they can be easily adapted for use in semibatch and batch modes. The absence of a gas phase does not pose important structural and operational differences from those stated earlier for multiphase systems. However, in the case of single-phase operation, the aspect ratio is usually kept lower ( 1) to ensure well mixing of the reactive liquid. Regardless of the number of phases involved, stirred-tank reactors can approach their ideal states if perfect mixing is established. Under such conditions, it is assumed that reaction takes place immediately just 

1 Onsan ZI, Avci AK. Reactor design for fuel processing. In Shekhawat D, Spivey JJ, Berry DA, editors. Fuel cells technologies for fuel processing. Amsterdam Elsevier Science 2011. p. 451-516. 

2 Dybkjaer I. Tubular reforming and autothermal reforming of natural gas - an overview of available processes. Fuel Processing Technology 1995 42 85-107. 

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