17 - Optimization Frameworks in Resource Management and Process Engineering

Abstract

This chapter presents the main advantages of using the design of experiments (DOE) method to optimize the conversion of polymers and plastics (also plastic waste) to liquid fuels, chemicals, and energy. The application of the DOE method to thermal and thermo-chemical process optimization, including the comparative design method, the response surface method, and the mixture design method, is primarily presented. This chapter includes information regarding the currently used methods of plastic waste management and plastic thermo-chemical conversion, such as thermal cracking, catalytic pyrolysis, and hydrocracking. In process optimization, determining which variables significantly affect the final products and the magnitude of their effects is important. For this reason, some critical issues were selected as examples: char, liquid, and gas yield optimization in a plastic-biomass copyrolysis process; analysis of the effect of the process conditions on the oil; and gas chemical composition and optimization of styrene recovery from waste polystyrene via pyrolysis. In this case, the use of the applied response surface method in the thermal process was found to be advantageous. As an example of the application of mixture design, the issue of selecting an optimal chemical composition for the catalyst used in the plastic thermal conversion process is presented.