Purification and Regeneration of Organic Solvents: Modern Approaches and Development Prospects

Organic solvents are essential across various industrial sectors, including pharmaceuticals, petrochemicals, and polymer manufacturing, but they gradually accumulate contaminants during technological processes. Direct disposal of spent solvents leads to substantial economic losses and environmental degradation through the formation of volatile organic compounds. Consequently, developing efficient purification and regeneration technologies is crucial for sustainable industrial operations. This work reviews key physical, chemical, and combined solvent recovery methods, evaluating their operating principles, benefits, and limitations. Standard techniques such as distillation and rectification enable high-volume processing but demand high energy, whereas membrane separation, extraction, and vacuum technologies offer energy-efficient solutions suitable for azeotropic or heat-sensitive mixtures. Adsorption is particularly effective for removing trace impurities, with increasing emphasis on biomass-derived adsorbents. Special attention is paid to lignin, whose functional group diversity, high porosity, and chemical modifiability enable the creation of low-cost, highly effective, and ecologically safe adsorbents. Furthermore, integrated processes—such as combining distillation with adsorption or membrane technologies—are increasingly implemented to achieve superior solvent purity while optimizing energy use. Overall, advancing energy-saving technologies and natural adsorbents supports green chemistry principles and promotes sustainable resource reuse.