1. Residence Time Distribution: Unlike plug flow reactors (PFRs), CSTRs have a broad residence time distribution, which can lead to incomplete conversion of reactants. 2. Large Volume: CSTRs often require larger volumes to achieve the same conversion as PFRs, which can be a drawback in terms of space and cost. 3. Mixing Limitations: While CSTRs provide good mixing, there can still be issues with achieving perfect mixing, especially in large-scale reactors.