Statistical prediction and sensitivity analysis of kinetic rate constants for efficient thermal valorization of plastic waste into combustible oil and gases

Muhammad Irfan; Rao Adeel Un Nabi; Hammad Hussain; Muhammad Yasin Naz; Shazia Shukrullah; Hassan Abbas Khawaja; Saifur Rahman; Muhammad Usman Farid

doi:10.1016/j.heliyon.2023.e16049

Statistical prediction and sensitivity analysis of kinetic rate constants for efficient thermal valorization of plastic waste into combustible oil and gases

Heliyon. 2023 May 6;9(5):e16049. doi: 10.1016/j.heliyon.2023.e16049. eCollection 2023 May.

Authors

Muhammad Irfan¹, Rao Adeel Un Nabi², Hammad Hussain³, Muhammad Yasin Naz², Shazia Shukrullah², Hassan Abbas Khawaja⁴, Saifur Rahman¹, Muhammad Usman Farid⁵

Affiliations

¹ Electrical Engineering Department, College of Engineering, Najran University Saudi Arabia, Najran, 61441, Saudi Arabia.
² Department of Physics, University of Agriculture Faisalabad, 38040, Pakistan.
³ Department of Agricultural Engineering, Faculty of Agricultural Engineering & Technology, University of Agriculture Faisalabad, 38040, Pakistan.
⁴ Department of Automation and Process Engineering, UiT the Arctic University of Norway, Tromsø, Norway.
⁵ Department of Structures and Environmental Engineering, University of Agriculture Faisalabad, 38040, Pakistan.

Abstract

Sensitivity analyses of rate constants for chemical kinetics of the pyrolysis reaction are essential for the efficient valorization of plastic waste into combustible liquids and gases. Finding the role of individual rate constants can provide important information on the process conditions, quality, and quantity of the pyrolysis products. The reaction temperature and time can also be reduced through these analyses. For sensitivity analysis, one possible approach is to estimate the kinetic parameters using MLRM (multiple linear regression model) in SPSS. To date, no research reports on this research gap are documented in the published literature. In this study, MLRM is applied to kinetic rate constants, which slightly differ from experimental data. The experimental and statistically predicted rate constants varied up to 200% from their original values to perform sensitivity analysis using MATLAB software. The product yield was examined after 60 min of thermal pyrolysis at a fixed temperature of 420 °C. The predicted rate constant "k(8)" with a slight difference of 0.02 and 0.04 from the experiment revealed 85% oil yield and 40% light wax after 60 min of operation. The heavy wax was missing from the products under these conditions. This rate constant can be utilized to maximize the commercial-scale extraction of liquids and light waxes from thermal pyrolysis of plastics.

Keywords: Kinetic rate reactions; Polyethylene; SPSS; Sensitivity analysis; Thermal pyrolysis.