Application of tribo-electrostatic separation in the recycling of plastic wastes

• Published in: Process safety and environmental protection Vol. 114; pp. 219 - 228
• Main Authors: Silveira, A.V.M., Cella, M., Tanabe, E.H., Bertuol, D.A.
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier B.V 01.02.2018; Elsevier Science Ltd
• Subjects: Comminution; Drying; High density polyethylenes; Industrial development; Industrial wastes; Mechanical processing; Plastic; Plastics; Plastics recycling; Polymers; Polyvinyl chloride; Purity; Recycling; Separation; Solid wastes; Tribo charging; Tribo-electrostatic separation; Tribology; Waste materials; Wastes; Plastic; Recycling; Mechanical processing; Tribo-electrostatic separation; Solid wastes; Tribo-charging
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2017.12.019

•Application of a roll-type electrostatic separator in plastics recycling.•Determination of the best parameters for tribo-electrostatic separation.•Use of plastics particles from the selective collection of urban solid waste.•Alternative process to separate different types of plastic waste.•Efficient recovery of different types of plastics from a mixture of polymeric waste. In the last decades, increasing industrial development has led to huge consumption of plastic materials, due to their versatility and low cost. Therefore, the implementation of efficient and environmentally friendly recycling technologies is of great importance. This study proposes an alternative separation process for recycling mixtures of plastic wastes, using a tribo-electrostatic separation process. The methodology adopted in this work was firstly characterization of the polymeric wastes, followed by preparation of the wastes using different unit operation processes (washing, drying, and comminution), tribo-charging, and electrostatic separation of different combinations of plastics (HDPE/PP, LDPE/PP, and PET/PVC). Various parameters were evaluated in the tribo-charging process and the electrostatic deflection. Separation of a mixture of HDPE and PP achieved PP recovery of 92.8% (purity of 95.7%) and HDPE recovery of 95.9% (purity of 93.1%). Recovery and purity values higher than 90.2% and 95.9% were obtained for PP/LDPE and PET/PVC mixtures, respectively. These results demonstrated that tribo-electrostatic separation is a promising and efficient method for use in the recycling of plastic wastes. The process studied enabled significant recoveries of the components at high levels of purity.