DMF recovery from synthetic leather wastewater is complicated because water-containing DMF can hydrolyze during heating to form formic acid and dimethylamine. Vacuum distillation reduces the required temperature and helps suppress this decomposition, while low-pressure-drop structured packing helps preserve the vacuum through the rectification section. Industrial DMF recovery and retrofit projects have directly used structured packing to improve separation and capacity. Packing selection should nevertheless consider high-boiling residues, solids, deacidification requirements, feed variability and the complete heat-integrated recovery system rather than treating the service as a clean DMF-water binary distillation.

N-methyl-2-pyrrolidone recovered from lithium-ion battery electrode manufacturing contains water together with low- and high-boiling impurities, so industrial NMP recycling requires more than simple solvent dehydration. Published battery-recovery systems use packed or tray columns to first remove water and light components and then reject high-boiling contaminants, producing NMP of 99.9 wt% or higher. Single-column side-cut designs can place high-purity NMP between the light-impurity zone above and heavy-impurity zone below. Structured packing is attractive because its high stage density and low pressure drop support reduced-pressure operation, but packing grade, liquid distribution, side-draw position and turndown must be evaluated against the actual battery recovery duty.

1,4-Butanediol purification commonly uses vacuum distillation because BDO is high boiling and excessive thermal exposure can promote decomposition, including formation of tetrahydrofuran and water. The column must remove water and lower-boiling impurities overhead while rejecting heavy diols, tars and salts toward the bottom. High-purity BDO can be recovered from an intermediate product zone, making side-draw location and bed staging important. Modern industrial BDO technology directly uses high-efficiency structured packing such as Sulzer BXPlus under deep vacuum. Packing selection should therefore balance theoretical-stage efficiency, pressure drop, impurity profile, heavy-end tolerance and product side-draw location rather than HETP alone.

Isopropyl alcohol and water form a minimum-boiling azeotrope near 87–88 wt% IPA at atmospheric pressure, so conventional distillation cannot directly produce anhydrous IPA simply by adding more theoretical stages. Industrial purification may use extractive distillation, pervaporation, adsorption or other dehydration technologies to move beyond the azeotropic limitation. Structured packing becomes particularly valuable in high-efficiency and final polishing sections, where low pressure drop, high stage density and uniform liquid distribution help remove residual water and trace organic impurities. For semiconductor-grade IPA, packing cleanliness and contamination control become part of the equipment specification alongside normal hydraulic performance.

Tetrahydrofuran purification is complicated by the THF-water minimum-boiling azeotrope, so ordinary single-pressure distillation cannot directly produce dry THF from an azeotropic mixture simply by adding more stages. Industrial processes use pressure changes, extractive solvents or other dehydration methods before final high-purity polishing. Structured packing is particularly valuable in the polishing stage, where many effective stages and low pressure drop may be required to remove trace impurities such as methanol and other ethers. Packing selection should therefore follow the exact column duty, pressure level, extractive-solvent circulation and trace impurity specification rather than THF concentration alone.