Optimization of Two-stage High-voltage Electrostatic Separation Parameters for Retired Passenger Vehicle Plastics by Response Surface Methodology

Abstract

Plastic parts in retired passenger vehicles are derived from non-renewable oil resources, and recycling them can conserve energy and reduce the burden on the environment. Effective separation is the premise of recycling vehicle plastics, and electrostatic separation is a clean and efficient method of plastic separation. On the basis of a self-developed, two-stage electrostatic separation equipment, this study investigated the high-voltage electrostatic separation of polyamide (PA), polyethylene (PE), and polypropylene (PP) mixtures. First, the single-factor experiment method was used to explore the influence of voltage, electrode spacing, and electrode inclination angle on the separation results. Second, the response surface methodology was employed to comprehensively analyze the effects of voltage, electrode spacing, and electrode inclination angle on the recovery rates of the three particles and their interactions. The optimum parameters for the secondary electrostatic separation of the three particles were determined to be 44 kV voltage, 156 mm electrode spacing, and 10� electrode inclination. Experimental verification showed that after the two-stage, electrostatic separation device was optimized through the response surface methodology, the purity of the PA particles reached 98.56%, and the recovery rate reached 96%. The purity of the PP particles reached 81.93%, and the recovery rate was 87.5%. Meanwhile, the purity of the PE particles reached 86.11%, and the recovery rate was 73%. This research provides a reference for the multi-stage, high-voltage, electrostatic separation of various automotive plastic particles.