Structured packing can be used in PTA acetic acid dehydration towers to recover valuable acetic acid while removing reaction water from the solvent loop. The separation may involve heterogeneous azeotropic distillation with an entrainer, condenser and decanter, making reflux composition and liquid distribution important to packing performance. PTA service can also require specialty metallurgy because acetic acid, bromide-containing catalyst species and temperature may create severe corrosion conditions. Packing selection should therefore consider solvent recovery, entrainer balance, hydraulic capacity, pressure drop and approved materials as one integrated system.

Structured packing is widely used in ethylbenzene/styrene splitters because the separation combines low relative volatility, high reflux, deep vacuum and styrene polymerization risk. Low packing pressure drop helps maintain low bottom temperature, while reduced liquid holdup limits hot styrene residence time. Packing selection should balance stage efficiency, hydraulic capacity, reflux distribution, polymer fouling and the performance limits of the vacuum, reboiler and condenser systems rather than choosing the highest specific surface area by default.

Structured packing can be highly effective in Sulfolane solvent recovery columns used in benzene and toluene aromatics-recovery units. Vacuum operation helps limit sulfolane temperature, making total column pressure drop important because excessive resistance increases bottom pressure and thermal stress on the recycled solvent. Packing selection should consider solvent degradation, steam stripping, liquid distribution, sulfolane carryover, lean-solvent quality and the capacity of the reboiler and vacuum system rather than separation efficiency alone.

1,3-Butadiene recovery from crude C4 streams commonly relies on extractive distillation using selective solvents such as NMP, DMF or ACN because the C4 components have difficult relative volatilities. Structured packing can be used in selected extraction, rectification and recovery sections, but the high solvent-to-vapor ratio, solvent distribution, acetylene impurities, polymerization tendency and solvent-recovery system must be considered together. The packing should support the licensed extraction process rather than being selected from nominal surface area alone.

Structured packing can be used in acrylonitrile absorbers where efficient mass transfer and low pressure drop are required, but polymerization and fouling make long-term reliability a central selection criterion. Documented industrial practice uses smooth-surface structured packing to reduce absorber pressure drop and potentially lower gas inlet temperature, helping reduce polymerization risk. Packing geometry, liquid distribution, upstream quench carryover and fouling severity should be evaluated together, and severe fouling may justify more open grid-type internals rather than progressively finer structured packing.