International Journal of Engineering

International Journal of Engineering

Valorization of Polypropylene Plastic Waste via Slow Pyrolysis: Pathways to Pyro-Oil Production

Document Type : Original Article

Authors
R. I. Mainil 1
J. J. Panjaitan 1
A. W. Sari 2
A. Susilawati 2
A. K. Mainil 3
O. Farobie 4
A. Amrullah 5
A. Aziz 1
1 Thermal Engineering Laboratory, Department of Mechanical Engineering, Universitas Riau, Kampus Bina Widya, Jl. HR. Soebrantas Km 12.5, Pekanbaru 28293, Riau, Indonesia
2 Department of Mechanical Engineering, Universitas Riau, Kampus Bina Widya, Jl. HR. Soebrantas Km 12.5, Pekanbaru 28293, Riau, Indonesia
3 Department of Mechanical Engineering, Universitas Bengkulu, Bengkulu, 38371A, Indonesia
4 Department of Mechanical and Biosystem Engineering, IPB University, IPB Darmaga Campus, Bogor, West Java 16002, Indonesia
5 Department of Mechanical Engineering, Lambung Mangkurat University, Banjarmasin, South Kalimantan, Indonesia
10.5829/ije.2026.39.10a.04
Abstract
This research examines the pyrolysis of polypropylene (PP) plastic waste as a feasible method for pyro-oil generation. The primary objective is to convert non-biodegradable polymer waste into value-added liquid fuel while addressing environmental concerns associated with plastic pollution. The pyrolysis of PP was conducted in a batch reactor at regulated temperatures of 300, 350, and 400 °C with reaction times of 30, 60, and 90 minutes to examine the thermal degradation behavior, product distribution, and quality of the obtained pyro-oil. The highest pyro-oil yield of 68% was achieved at 400 °C, indicating optimal thermal cracking of polypropylene chains. Under these conditions, the pyro-oil exhibited a hydrocarbon content of 49.3%, emphasizing its viability as an alternative energy source. The calorific value of the pyro-oil ranged from 48 MJ kg⁻¹ to nearly 49 MJ kg⁻¹. The possible reaction pathways were determined in this study, as indicated by the pre-exponential factor and activation energy derived from the Arrhenius equation. These findings demonstrate the feasibility of valorizing polypropylene waste through slow pyrolysis, offering a promising pathway for resource recovery, circular economy implementation, and reduction of the environmental impact of plastic waste.

Graphical Abstract

Valorization of Polypropylene Plastic Waste via Slow Pyrolysis: Pathways to Pyro-Oil Production
Keywords
Energy
Pyro-Oil
Pyrolisis
Polypropylen
Kinetics

Subjects

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International Journal of Engineering
Volume 39, Issue 10
TRANSACTIONS A: Basics
October 2026
Pages 2395-2406