A comprehensive review on pyrolysis from the circular economy point of view and its environmental and social effects
Introduction
Today, the planet faces several grave concerns, including an ever-increasing world population and the resulting threats to water, energy, and food security (Amulya et al., 2016). Additionally, greenhouse gas (GHG) emissions and other contaminants pose a tremendous danger to humanity because of human-caused climate change (Ouda et al., 2016). Due to constrained funds, maintenance facilities, and infrastructure, sustainable waste management is still in its infancy in most developing nations (Tan et al., 2015). The actual rate of waste collection in the majority of cities in developing nations such as Pakistan, Bangladesh, and India is only around 60 percent, with the remaining waste accumulating on vacant lands, railway lines, street sides, sewers, and low-lying regions (Sadef et al., 2016). Hence, the gap between economic development and environmental sustainability is expanding (Nizami et al., 2017). The sustainable methods, policies, and legislation to overcome climate change and guarantee a consistent source of feed and energy have become essential to facilitating circular economies in developing nations (Guerrero et al., 2013).
Circular Economy (CE) became associated with offering an alternative to the current linear economic paradigm, often known as the “take, manufacture, and discard” model, during the past decade (Andersen, 2007). CE is projected to stimulate economic development by establishing new enterprises and employment opportunities, cutting the cost of products, reducing price volatility, and enhancing supply security while minimizing environmental consequences (Kalmykova et al., 2018). CE is based on the premise that the economy and environment might mutually reinforce environmental protection and develop and profit from new business models while offering creative employment prospects (Ghisellini et al., 2018).
Pyrolysis has recently received much attention from researchers. In this technique, organic molecules disintegrate thermochemically at temperatures between 300 and 1200 °C in an inert atmosphere (Foong et al., 2020). Pyrolysis, unlike combustion, is a thermochemical recycling process that allows for the recovery of energy and materials (Boateng, 2020). As a result, liquid and gaseous hydrocarbon compounds and a carbon-rich solid are produced. As will be discussed later, pyrolysis allows for separating the primary components of feedstock, creating ideal circumstances for a circular economy (Martínez, 2021). Furthermore, it can simultaneously address issues related to energy consumption, greenhouse gas (GHG) emissions, and waste management. When pyrolysis products are employed commercially as raw materials in other processes, ensuring social and environmental equality, pyrolysis is established as a tool for a CE. In this scenario, the waste cycle is closed, and natural resource consumption is reduced for the benefit of present and future generations (Kirchherr et al., 2017).
This review article first addresses the nature of pyrolysis. In the following, the pyrolysis of three types of waste, including biomass, plastic, and tire, is studied in depth from the CE perspective. Finally, in developed and developing countries, pyrolysis's environmental and social effects from the life cycle assessment (LCA) aspect are explored.
Section snippets
Literature review
A brief overview of pyrolysis and CE is required to pave the way for a more in-depth assessment. As a motivation, this article analyzes pertinent research on pyrolysis from the CE perspective during the previous years, in which the research on CE is extremely overgrowing. (Fig. 1). The expanding number of released papers illustrates that CE is becoming an increasingly important aspect of academic study and organizational practice. There are many review articles on CE or pyrolysis. For example,
Methodology
The current paper is conducted in line with the literature analysis results. The literature for this review article was chosen using Scopus scientific databases. The authors selected Research Gate, Web of Science, Google Scholar, and Scopus for citation. The keywords were selected by browsing papers for relevant phrases and jargon. A repetitive search was utilized to discover the best collection of inputs to provide the most precise results and, consequently, a credible analysis. The writers
An overview of the nature of the pyrolysis process
Pyrolysis is a thermochemical method and an applied technology for the treatment of various types of waste (Kim et al., 2020b), which is performed at a temperature between 300 and 1200 °C and in an oxygen-free environment or inert gas (Foong et al., 2020) (Fig. 4). Pyrolysis requires a lower temperature than conventional combustion. It emits fewer air pollutants and greenhouse gases (GHGs) (Wyrzykowska-Ceradini et al., 2011a). Scaling pyrolysis plants have more flexibility than incineration
Pyrolysis from the circular economy perspective
The scarcity of natural resources is one issue, and recycling the current intricate waste and converting it into useable resources is another. Existing policies are beneficial in minimizing the use of natural resources. Still, it should not be forgotten that vast amounts of various waste are already accumulated on the planet, and the volume of waste is increasing day by day. At best, it is counteracted by unsustainable methods that not only do not turn waste into useable resources but also
Environmental aspects of pyrolysis from the LCA point of view
Pyrolysis is a technology that has recently received much attention due to its variety of methods and unique properties. This section examines the environmental aspects of pyrolysis from the LCA perspective. Recently, pyrolysis procedures have been used for many waste recyclings, including biomass (Zhang et al., 2022), e-waste (Ali et al., 2022), antibiotic mycelial dreg (Chen et al., 2021), sewage sludge (Godlewska and Oleszczuk, 2022), and waste tires (Ye et al., 2022). Pyrolysis can decrease
Pyrolysis situation worldwide: the social and environmental aspects
Observing the performance of pyrolysis in a practical way requires a comprehensive assessment of its situation worldwide. Countries have tended to use recycling methods such as pyrolysis according to their conditions and challenges. Therefore, this section briefly evaluates the effect of using pyrolysis in waste recycling worldwide to identify the world's potential for using this process.
During the research conducted in North Carolina in the USA, it was observed that in 2011, 9,467,045 tons of
Discussion and future recommendations
This article examines pyrolysis from the circular economy point of view worldwide. In this section, at first, it is discussed to what extent pyrolysis is a closed-loop recycling process. Next, the environmental and social aspects of pyrolysis are examined. Finally, challenges and suggestions for future research are provided.
Conclusions
Humanity has maximized the exploitation of non-renewable resources to meet its demands. This over-exploitation has resulted in the generation of vast quantities of various wastes and limited the share of future generations of non-renewable resources. If hazardous materials are removed, wastes become valuable resources that can re-enter the production cycle. Pyrolysis is a promising technological process that converts waste into materials and energy to reduce pressure on non-renewable sources.
CRediT authorship contribution statement
Amirhossein Andooz: Conceptualization, Resources, Writing – original draft, Writing – review & editing. Mohammad Eqbalpour: Conceptualization, Resources, Writing – original draft, Writing – review & editing. Elaheh Kowsari: Conceptualization, Writing – review & editing, Project administration, Supervision, Funding acquisition. Seeram Ramakrishna: Conceptualization, Writing – review & editing, Project administration, Funding acquisition. Zahra Ansari Cheshmeh: Writing – review & editing.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
The authors are grateful for the financial and spiritual support provided by AmirKabir University of Technology (AUT) in Tehran, Iran. Author Seeram Ramakrishna acknowledges (Sustainable Tropical Data Centre Test Bed: A-0009465-01-00) awarded by the National Research Foundation of Singapore.
References (254)
- et al.
Microwave vacuum co-pyrolysis of waste plastic and seaweeds for enhanced crude bio-oil recovery: experimental and feasibility study towards industrialization
Renew. Sustain. Energy Rev.
(2021) Valorisation of end of life tyres (ELTs) in a newly developed pyrolysis fixed-bed batch process
Process Saf. Environ. Protect.
(2020)- et al.
Fast pyrolysis of agroindustrial wastes blends: hydrocarbon production enhancement
J. Anal. Appl. Pyrol.
(2021) - et al.
Gasification versus fast pyrolysis bio-oil production: a life cycle assessment
J. Clean. Prod.
(2022) - et al.
Removal of Bromine from the non-metallic fraction in printed circuit board via its Co-pyrolysis with alumina
Waste Manag.
(2022) - et al.
Effect of heating power on the scrap tires pyrolysis derived oil
J. Anal. Appl. Pyrol.
(2015) - et al.
Fast co-pyrolysis of sewage sludge and lignocellulosic biomass in a conical spouted bed reactor
Fuel
(2015) - et al.
Chapter 19 - building a bio-based economy through waste remediation: innovation towards sustainable future
- et al.
A comprehensive review on pyrolysis of E-waste and its sustainability
J. Clean. Prod.
(2022) - et al.
Experimental proof of concept for a sustainable End of Life Tyres pyrolysis with energy and porous materials production
J. Clean. Prod.
(2015)
Re-designing a viable ELTs depolymerization in circular economy: pyrolysis prototype demonstration at TRL 7, with energy optimization and carbonaceous materials production
J. Clean. Prod.
Quality protocol and procedure development to define end-of-waste criteria for tire pyrolysis oil in the framework of circular economy strategy
Waste Manag.
Sustainable mobility: the route of tires through the circular economy model
Waste Manag.
Carbon black as an outstanding and affordable nanomaterial for electrochemical (bio)sensor design
Biosens. Bioelectron.
Supplying renewable energy for Canadian cement production: life cycle assessment of bioenergy from forest harvest residues using mobile fast pyrolysis units
J. Clean. Prod.
Pyrolysis as an economical and ecological treatment option for municipal sewage sludge
Biomass Bioenergy
Addressing temporal considerations in life cycle assessment
Sci. Total Environ.
Characterization of pyrolytic light naphtha from vacuum pyrolysis of used tyres comparison with petroleum naphtha
Fuel
A review on the susceptor assisted microwave processing of materials
Energy
Framework for consequential life cycle assessment of pyrolysis biorefineries: a case study for the conversion of primary forestry residues
Renew. Sustain. Energy Rev.
Review of fast pyrolysis of biomass and product upgrading
Biomass Bioenergy
Insecticidal properties of pyrolysis bio-oil from greenhouse tomato residue biomass
J. Anal. Appl. Pyrol.
On the distillation of waste tire pyrolysis oil: a structural characterization of the derived fractions
Fuel
Vacuum pyrolysis of automobile shredder residues: use of the pyrolytic oil as a modifier for road bitumen
Resour. Conserv. Recycl.
Impact of COVID-19 lockdown on routine immunisation in Karachi, Pakistan
Lancet Global Health
Pyrolysis technologies for municipal solid waste: a review
Waste Manag.
Synergistic effect on thermal behavior and char morphology analysis during co-pyrolysis of paulownia wood blended with different plastics waste
Appl. Therm. Eng.
Pyrolysis of antibiotic mycelial dreg and characterization of obtained gas, liquid and biochar
J. Hazard Mater.
Slow pyrolysis as a platform for negative emissions technology: an integration of machine learning models, life cycle assessment, and economic analysis
Energy Convers. Manag.
Optimization of microwave-assisted accelerated transesterification of inedible olive oil for biodiesel production
Renew. Energy
Experimental investigation of performance, emission and combustion characteristics of waste plastic pyrolysis oil blended with diethyl ether used as fuel for diesel engine
Energy
A comprehensive review on the pyrolysis of lignocellulosic biomass
Renew. Energy
Hydrotreatment of pyrolysis oil from waste tire in tetralin for production of high-quality hydrocarbon rich fuel
Fuel
Experimental and economic study of small-scale CHP installation equipped with downdraft gasifier and internal combustion engine
Appl. Energy
Athermal microwave effects for enhancing digestibility of waste activated sludge
Water Res.
Performance analysis and fate of bromine in a single screw reactor for pyrolysis of waste electrical and electronic equipment (WEEE)
Process Saf. Environ. Protect.
Production of liquid fuels and activated carbons from fish waste
Fuel
Life cycle assessment of electricity generation using fast pyrolysis bio-oil
Renew. Energy
Environmental remediation in circular economy: end of life tyre magnetic pyrochars for adsorptive removal of pharmaceuticals from aqueous solution
Sci. Total Environ.
Recent developments in life cycle assessment
J. Environ. Manag.
Sewage sludge pyrolysis for liquid production: a review
Renew. Sustain. Energy Rev.
Valorization of biomass waste to engineered activated biochar by microwave pyrolysis: progress, challenges, and future directions
Chem. Eng. J.
Vacuum pyrolysis incorporating microwave heating and base mixture modification: an integrated approach to transform biowaste into eco-friendly bioenergy products
Renew. Sustain. Energy Rev.
Exploring environmental and economic costs and benefits of a circular economy approach to the construction and demolition sector. A literature review
J. Clean. Prod.
Effect of biomass addition before sewage sludge pyrolysis on the persistence and bioavailability of polycyclic aromatic hydrocarbons in biochar-amended soil
Chem. Eng. J.
Thermal plasma technology for the treatment of wastes: a critical review
J. Hazard Mater.
Solid waste management challenges for cities in developing countries
Waste Manag.
Life cycle analysis of fuel production from fast pyrolysis of biomass
Bioresour. Technol.
Energy-carbon-water footprint of sugarcane bioenergy: a district-level life cycle assessment in the state of Maharashtra, India
Renew. Sustain. Energy Rev.
Opportunities and barriers for producing high quality fuels from the pyrolysis of scrap tires
Renew. Sustain. Energy Rev.
Cited by (24)
Life cycle assessment of electricity generation by tire pyrolysis oil
2024, Process Safety and Environmental ProtectionA review on the pyrolytic conversion of plastic waste into fuels and chemicals
2024, Journal of Analytical and Applied PyrolysisAdvancing environmental assessment of the circular economy: Challenges and opportunities
2024, Resources, Conservation and Recycling AdvancesOptimizing capacitance performance: Solar pyrolysis of lignocellulosic biomass for homogeneous porosity in carbon production
2024, Journal of Cleaner ProductionInvestigation of gasoline-like transportation fuel obtained by plastic waste pyrolysis and distillation
2024, Journal of Cleaner Production