Structured packing can be used in hydrogen peroxide concentration columns operating under vacuum because it provides effective vapor-liquid contact with relatively low pressure drop and liquid holdup. In this oxidizing service, packing selection must also consider approved material compatibility, strict contamination control, liquid distribution and drainage. Higher packing efficiency alone is not the objective; the complete contacting system should achieve the required separation without adding unnecessary temperature, pressure loss or retained liquid inventory.

Structured packing can be used in hydrochloric acid rectification and recovery columns, but the HCl-water azeotrope limits what ordinary single-pressure distillation can achieve. Higher acid concentrations may require dual-pressure or extractive rectification, while the packing must be selected for the actual pressure, liquid composition, impurities and highly corrosive environment. Packing efficiency cannot overcome the azeotrope; its role is to provide reliable mass transfer and hydraulic performance once the appropriate HCl recovery process has been defined.

Structured packing can be used in phenol recovery columns in nonylphenol production to separate recyclable unreacted phenol from heavier nonylphenol and dinonylphenol-containing streams. Reduced-pressure operation makes total column pressure drop important, while reflux distribution controls how effectively the packing is used. Packing selection should balance phenol recovery, recycle purity, heavy-product temperature, hydraulic capacity and fouling behavior rather than maximizing theoretical-stage density alone.

Structured packing is used in ethylene glycol purification columns because MEG, DEG and TEG separations commonly require vacuum distillation with good separation efficiency and controlled pressure drop. MEG-water separation, DEG purification and deep-vacuum TEG service present different hydraulic and fouling conditions, so one packing model should not automatically be applied throughout the purification train. Selection should consider absolute pressure, reflux and liquid load, heavy-glycol residue, distributor performance, product purity and total column pressure drop.

Structured packing is used in caprolactam purification for vacuum dehydration, light-end removal and heavy-end separation. Low pressure drop helps maintain the low column pressure needed to control bottoms temperature, while relatively low liquid holdup can reduce unnecessary thermal exposure. Because caprolactam can form oligomers under unfavorable hot conditions, packing selection should balance theoretical-stage efficiency with hydraulic openness, product residence time, heavy-residue behavior and total caprolactam recovery.