Component Selection of a 10 kg Reactor Pyrolysis System with a Three-Stage Condenser

Abstract

This study presents the design and testing of a High-Density Polyethylene (HDPE) waste plastic pyrolysis system with a 10 kg reactor and a three-stage condensation unit. The reactor was built from repurposed 12 kg LPG cylinders for their thermal strength and availability, while the condensers consisted of three spiral copper tubes (total length 7.80 m) designed to dissipate 35,625 W of heat. Experiments were conducted at 350–500 °C using LPG heating and an ice–water cooling medium. The process yielded 65 ml, 22 ml, and 13 ml of bio-oil from the first, second, and third condensers, respectively, equivalent to an overall conversion efficiency of ~0.01% of the initial plastic mass. The results highlight the critical role of condenser design and material selection in process efficiency, although the obtained yield remains low. This work provides a technical basis for improving small-scale pyrolysis systems through optimized condenser configuration, catalyst application, and better process control.