A Comparative Study of Thermal Behavior and Kinetics of the Rice Husk, Low-Density Polyethylene (LDPE) and Polyethylene Terephthalate (PET) for Pyrolysis

Abstract

Recently, waste materials have garnered attention for their potential in providing clean and affordable energy through thermochemical conversion techniques. They play a significant role in transforming waste into eco-friendly energy, but the proper selection of materials is crucial for successful thermochemical conversion. The primary objective of this study is to assess combustion efficiency based on activation energy, utilizing TGA and DTG analysis. Rice husk (RH), low-density polyethylene (LDPE), and polyethylene terephthalate (PET) waste materials were chosen for investigation. Experiments were conducted at temperatures ranging from 25 °C to 600 °C, with varying heating rates of 10, 20, 30, and 40 °C min-1. The apparent activation energy of the feedstocks was determined using five different iso-conversional model-free approaches, namely Kissinger Akahira Sunose (KAS), Friedman, Flynn Wall Ozawa (FWO), Starink, and Tang methods. The apparent activation energy for rice husk, LDPE, and PET fell within the range of 113-123 kJ mol-1, 101-101 kJ mol-1and105-117kJmol-1, respectively This research also contributes to establishing Comprehensive Pyrolysis Index (CPI) values to identify suitable sources for pyrolysis and gasification. According to CPI results, temperatures between 500 to 600 °C are optimal for pyrolysis, and an increase in heating rate enhances the output of pyrolysis products. A higher CPI index is favorable for achieving both a high calorific value and increased hydrocarbon contents.

Keywords

• rice husk
• ldpe
• pet
• kinetics
• iso - conversion
• activation energy