1
|
Moussa K, Awad S, Krawczak P, Al Takash A, Faraj J, Khaled M. An Overview of the Non-Energetic Valorization Possibilities of Plastic Waste via Thermochemical Processes. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1460. [PMID: 38611975 PMCID: PMC11012670 DOI: 10.3390/ma17071460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 03/11/2024] [Accepted: 03/15/2024] [Indexed: 04/14/2024]
Abstract
The recovery and recycling/upcycling of plastics and polymer-based materials is needed in order to reduce plastic waste accumulated over decades. Mechanical recycling processes have made a great contribution to the circularity of plastic materials, contributing to 99% of recycled thermoplastics. Challenges facing this family of processes limit its outreach to 30% of plastic waste. Complementary pathways are needed to increase recycling rates. Chemical processes have the advantage of decomposing plastics into a variety of hydrocarbons that can cover a wide range of applications, such as monomers, lubricants, phase change materials, solvents, BTX (benzene, toluene, xylene), etc. The aim of the present work is to shed light on different chemical recycling pathways, with a special focus on thermochemicals. The study will cover the effects of feedstock, operating conditions, and processes used on the final products. Then, it will attempt to correlate these final products to some petrochemical feedstock being used today on a large scale.
Collapse
Affiliation(s)
- Kazem Moussa
- Energy and Thermo-Fluid Group, Lebanese International University, LIU, Bekaa P.O. Box 146404, Lebanon; (K.M.); (A.A.T.); (J.F.); (M.K.)
| | - Sary Awad
- IMT Atlantique, GEPEA, UMR CNRS 6144, 4 Rue Alfred Kastler, F-44000 Nantes, France
| | - Patricia Krawczak
- IMT Nord Europe, Institut Mines-Télécom, University of Lille, Centre for Materials and Processes, 941 rue Charles Bourseul, CS 10838, F-59508 Douai, France;
| | - Ahmad Al Takash
- Energy and Thermo-Fluid Group, Lebanese International University, LIU, Bekaa P.O. Box 146404, Lebanon; (K.M.); (A.A.T.); (J.F.); (M.K.)
- Energy and Thermo-Fluid Group, The International University of Beirut BIU, Beirut P.O. Box 146404, Lebanon
| | - Jalal Faraj
- Energy and Thermo-Fluid Group, Lebanese International University, LIU, Bekaa P.O. Box 146404, Lebanon; (K.M.); (A.A.T.); (J.F.); (M.K.)
- Energy and Thermo-Fluid Group, The International University of Beirut BIU, Beirut P.O. Box 146404, Lebanon
| | - Mahmoud Khaled
- Energy and Thermo-Fluid Group, Lebanese International University, LIU, Bekaa P.O. Box 146404, Lebanon; (K.M.); (A.A.T.); (J.F.); (M.K.)
- Center for Sustainable Energy & Economic Development (SEED), Gulf University for Science & Technology, Hawally P.O. Box 7207, Kuwait
| |
Collapse
|
2
|
Albor G, Mirkouei A, McDonald AG, Struhs E, Sotoudehnia F. Fixed Bed Batch Slow Pyrolysis Process for Polystyrene Waste Recycling. Processes (Basel) 2023. [DOI: 10.3390/pr11041126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023] Open
Abstract
This study evaluates the potential of recycling polystyrene (PS) plastic wastes via a fixed bed (batch) slow pyrolysis reactor. The novelty lies in examining the reactor design, conversion parameters, and reaction kinetics to improve the process yield, activation energy, and chemical composition. PS samples were pyrolyzed at 475–575 °C for 30 min under 10–15 psi. Process yield and product attributes were evaluated using different methods to understand PS thermal degradation characteristics better. The results show that PS decomposition started within 2 min from all temperatures, and the total decomposition point of 97% at 475 °C at approximately 5 min. Additionally, analytical results indicate that the average necessary activation energy is 191 kJ/mol. Pyrolysis oil from PS was characterized by gas chromatography–mass spectrometry. The results show that styrene was produced 57–60% from all leading oil compounds (i.e., 2,4-diphenyl-1-butene, 2,4,6-triphenyl-1-hexene, and toluene), and 475 °C has the major average of conversion effectiveness of 91.3%. The results show that the reactor temperature remains the main conversion parameter to achieve the high process yield for oil production from PS. It is concluded that pyrolysis provides a sustainable pathway for PS waste recycling and conversion to value-added products, such as resins and polymers. The proposed method and analytical results are compared with earlier studies to identify directions for future studies.
Collapse
Affiliation(s)
- Galo Albor
- Environmental Science Program, University of Idaho, Idaho Falls, ID 83402, USA
| | - Amin Mirkouei
- Environmental Science Program, University of Idaho, Idaho Falls, ID 83402, USA
- Department of Mechanical Engineering, University of Idaho, Idaho Falls, ID 83402, USA
| | - Armando G. McDonald
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Ethan Struhs
- Department of Mechanical Engineering, University of Idaho, Idaho Falls, ID 83402, USA
| | - Farid Sotoudehnia
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844, USA
| |
Collapse
|
3
|
Gonzalez-Aguilar AM, Pérez-García V, Riesco-Ávila JM. A Thermo-Catalytic Pyrolysis of Polystyrene Waste Review: A Systematic, Statistical, and Bibliometric Approach. Polymers (Basel) 2023; 15:polym15061582. [PMID: 36987361 PMCID: PMC10054604 DOI: 10.3390/polym15061582] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/15/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Global polystyrene (PS) production has been influenced by the lightness and heat resistance this material offers in different applications, such as construction and packaging. However, population growth and the lack of PS recycling lead to a large waste generation, affecting the environment. Pyrolysis has been recognized as an effective recycling method, converting PS waste into valuable products in the chemical industry. The present work addresses a systematic, bibliometric, and statistical analysis of results carried out from 2015 to 2022, making an extensive critique of the most influential operation parameters in the thermo-catalytic pyrolysis of PS and its waste. The systematic study showed that the conversion of PS into a liquid with high aromatic content (84.75% of styrene) can be achieved by pyrolysis. Discussion of PS as fuel is described compared to commercial fuels. In addition, PS favors the production of liquid fuel when subjected to co-pyrolysis with biomass, improving its properties such as viscosity and energy content. A statistical analysis of the data compilation was also discussed, evaluating the influence of temperature, reactor design, and catalysts on product yield.
Collapse
Affiliation(s)
- Arantxa M Gonzalez-Aguilar
- Mechanical Engineering Department, Engineering Division, Campus Irapuato-Salamanca, University of Guanajuato, Salamanca Gto. 36885, Mexico
| | - Vicente Pérez-García
- Mechanical Engineering Department, Engineering Division, Campus Irapuato-Salamanca, University of Guanajuato, Salamanca Gto. 36885, Mexico
| | - José M Riesco-Ávila
- Mechanical Engineering Department, Engineering Division, Campus Irapuato-Salamanca, University of Guanajuato, Salamanca Gto. 36885, Mexico
| |
Collapse
|
4
|
Gonzalez-Aguilar AM, Cabrera-Madera VP, Vera-Rozo JR, Riesco-Ávila JM. Effects of Heating Rate and Temperature on the Thermal Pyrolysis of Expanded Polystyrene Post-Industrial Waste. Polymers (Basel) 2022; 14:polym14224957. [PMID: 36433086 PMCID: PMC9699519 DOI: 10.3390/polym14224957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
The use of plastic as material in various applications has been essential in the evolution of the technology industry and human society since 1950. Therefore, their production and waste generation are high due to population growth. Pyrolysis is an effective recycling method for treating plastic waste because it can recover valuable products for the chemical and petrochemical industry. This work addresses the thermal pyrolysis of expanded polystyrene (EPS) post-industrial waste in a semi-batch reactor. The influence of reaction temperature (350-500 °C) and heating rate (4-40 °C min-1) on the liquid conversion yields and physicochemical properties was studied based on a multilevel factorial statistical analysis. In addition, the analysis of the obtaining of mono-aromatics such as styrene, toluene, benzene, ethylbenzene, and α-methyl styrene was performed. Hydrocarbon liquid yields of 76.5-93% were achieved at reaction temperatures between 350 and 450 °C, respectively. Styrene yields reached up to 72% at 450 °C and a heating rate of 25 °C min-1. Finally, the potential application of the products obtained is discussed by proposing the minimization of EPS waste via pyrolysis.
Collapse
|
5
|
Oh S, Stache EE. Chemical Upcycling of Commercial Polystyrene via Catalyst-Controlled Photooxidation. J Am Chem Soc 2022; 144:5745-5749. [PMID: 35319868 DOI: 10.1021/jacs.2c01411] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemical upcycling of polystyrene into targeted small molecules is desirable to reduce plastic pollution. Herein, we report the upcycling of polystyrene to benzoyl products, primarily benzoic acid, using a catalyst-controlled photooxidative degradation method. FeCl3 undergoes a homolytic cleavage upon irradiation with white light to generate a chlorine radical, abstracting an electron-rich hydrogen atom on the polymer backbone. Under the oxygen-rich environment, high MW polystyrene (>90 kg/mol) degrades down to <1 kg/mol and produces up to 23 mol % benzoyl products. A series of mechanistic studies showed that chlorine radicals promoted the degradation via hydrogen-atom abstraction. Commercial polystyrene degrades efficiently in our method, showing the compatibility of our system with polymer fillers. Finally, we demonstrated the potential of scaling up our approach in a photoflow process to convert gram quantities of PS to benzoic acid.
Collapse
Affiliation(s)
- Sewon Oh
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Erin E Stache
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| |
Collapse
|
6
|
Thiyagarajan S, Maaskant-Reilink E, Ewing TA, Julsing MK, van Haveren J. Back-to-monomer recycling of polycondensation polymers: opportunities for chemicals and enzymes. RSC Adv 2021; 12:947-970. [PMID: 35425100 PMCID: PMC8978869 DOI: 10.1039/d1ra08217e] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/21/2021] [Indexed: 12/29/2022] Open
Abstract
The use of plastics in a wide range of applications has grown substantially over recent decades, resulting in enormous growth in production volumes to meet demand. Though a wide range of biomass-derived chemicals and materials are available on the market, the production volumes of such renewable alternatives are currently not sufficient to replace their fossil-based analogues due to various factors, in particular cost-effectiveness. Hence, the majority of plastics are still industrially produced from fossil-based feedstocks. Moreover, various reports have clearly raised concern about the plastics that are not recycled at their end-of-life and instead end up in landfills or the oceans. To avoid further pollution of our planet, it is highly desirable to develop recycling processes that use plastic waste as feedstock. Chemical recycling processes could potentially offer a solution, since they afford monomers from which new polymers can be produced, with the same performance as virgin plastics. In this manuscript, the opportunities for using either chemical or biochemical (i.e., enzymatic) approaches in the depolymerization of polycondensation polymers for recycling purposes are reviewed. Our aim is to highlight the strategies that have been developed so far to break down plastic waste into monomers, providing the first step in the development of chemical recycling processes for plastic waste, and to create a renewed awareness of the need to valorize plastic waste by efficiently transforming it into virgin plastics.
Collapse
Affiliation(s)
| | | | - Tom A Ewing
- Wageningen Food & Biobased Research Wageningen P. O. Box 17 6700 AA The Netherlands
| | - Mattijs K Julsing
- Wageningen Food & Biobased Research Wageningen P. O. Box 17 6700 AA The Netherlands
| | - Jacco van Haveren
- Wageningen Food & Biobased Research Wageningen P. O. Box 17 6700 AA The Netherlands
| |
Collapse
|