Flowsheet Level Units and Connectivities

Going one level up in aggregation we consider the structures of complete columns. Conventionally, RD columns are classified in hybrid and non-hybrid units, depending on the distribution of reactive trays inside the column. Thus, hybrid columns are distillation columns with a reactive core and nonreactive sections (rectifying and/or stripping sections). Non-hybrid RD columns denote columns where all trays including condenser and reboiler are reactive (Giittinger, 1998). Hybrid columns are commonly 

The recycle structures in RD may also vary depending on the physical properties of the reactive system and the kinetic regime of chemical reaction. For example, side stream reactors are in particular required for the case of rate-limited chemical reactions in heterogenous RD, whereas stirred vessels are needed in homogeneous RD. 

---