Waste plastic pyrolysis process control method based on morphological characteristics

During pyrolysis process reaction state of waste plastics cannot be easily observed and controlled, which makes it is difficult to control the process precisely. In this paper, a new process control method is proposed based on some special morphological characteristics of plastic wastes during their pyrolysis process. These characteristics' quantitative values can be obtained by sampling photograph images in sequence and analyzing the characteristics after digital image processing. Wastes polypropylene(PP) film was chosen as plastic waste for pyrolysis experiment here, and the morphological image during the pyrolysis process were obtained by a IR Camera. The result show that identified objects' area and bubble ratio from digital processed images can quantify morphological characteristics of waste plastic (PP) pyrolysis steps and reaction extent. It can be an effective way to describe pyrolysis behaviour of waste plastics and thus used for process control. To set up the control system, first a process observer is designed based on these characteristic parameters; then combined with other thermal process parameters, the control strategy can be realized for a special control target such as oil production.