(374u) Energy Efficient Advanced Separation Process of Solvent Mixture (Xylene, Butyl Acetate and Methyl Ethyl Ketone) Recovery/Re-Processing for Paint Industry

Most of the OEM (Automotive sector) paints are solvent base, so the use of different types of solvents, resins, pigments and additives is essential for paint manufacturing. In manufacturing process, companies have to manufacture all types of color paints and in order to restart the next batch process they have to wash the machine and equipment every time to avoid color contamination of previous batch. This requires large quantity of solvents for cleaning purpose. The average consumption of these solvents is around 5-10 tons/month, majorly containing Xylene (C₈H₁₀), (MEK) Methyl Ethyl Ketone (C₄H₈O) and Butyl Acetate (C₆H₁₂O₂). (60%, 20% & 20 % weight respectively). In this study a novel method is investigated for the recycling and reuse of these solvents to reduce significant amount of cost and their hazardous effect on environment. Initially, Liquid- Liquid extraction (LLE) process is applied as the C₈H₁₀ is insoluble in water so its separation will be done by LLE using water as the pure solvent. Butyl acetate and MEK are slightly soluble in water so no. of stages of extractor and type of extractor are calculated.

Secondly the process involves membrane separation. Polysulfone (PS) membrane with different pore sizes were investigated to check the separation efficiencies. Finally, the binary distillation process to separate two component mixture C₆H₁₂O₂and C₄H₈O both solvents possibly forms azeotropic mixture. 85% to 88% efficiencies of this combined process were calculated, the mentioned process is most viable and cost effective process for the separation of above mention solvent solutions.