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Hu Y, Li M, Zhou N, Yuan H, Guo Q, Jiao L, Ma Z. Catalytic stepwise pyrolysis for dechlorination and chemical recycling of PVC-containing mixed plastic wastes: Influence of temperature, heating rate, and catalyst. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168344. [PMID: 37951271 DOI: 10.1016/j.scitotenv.2023.168344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/27/2023] [Accepted: 11/03/2023] [Indexed: 11/13/2023]
Abstract
The viability of pyrolysis technology for chemical recycling of plastics is challenged by the presence of PVC in real-world mixed plastic wastes. This study aims to investigate catalytic stepwise pyrolysis as a pretreatment step to remove chlorine from PVC-containing plastic wastes prior to further processing. TG-FTIR and Py-GCMS analysis as well as experiments on a lab-scale pyrolysis system were conducted to study the influence of key processing parameters on the pretreatment including temperature, heating rate, and catalysts. Py-GCMS results indicated 300 °C to be the best pretreatment temperature in terms of balancing Cl removal and avoidance of organochloride formation. Metal oxides, i.e., CaO and Fe2O3, mainly acted as adsorbents of HCl gases with little cracking effect, and their adsorption effects are positively correlated with alkalinity. ZSM-5 catalysts promoted the release of HCl, and the dechlorination effect was more pronounced with ZSM-5 of higher acidity. In contrast, in the lab-scale pyrolysis system, 350 °C pretreatment achieved the highest HCl generation ratio, i.e., 43.60 %. The addition of zeolite catalyst significantly reduced the content of organochloride in the pyrolysis oil in contrast to the performance of metal oxides, but also absorbed most HCl instead of promoting HCl release as in Py-GCMS tests. Mass balance analyses revealed that the majority of chlorine was retained in the solid residues following the catalytic stepwise pyrolysis process, with the notable exception of Fe2O3. ZSM-5(25) catalyst combined with 350 °C pretreatment temperature and 550 °C final pyrolysis achieved the lowest chlorine content in the pyrolysis oil, i.e., 20 ppm, among different process conditions.
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Affiliation(s)
- Yanjun Hu
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China; Zhejiang Carbon Neutral Innovation Institute, Zhejiang University of Technology, Chaowang Road 18#, 310024 Hangzhou, China
| | - Mingzhe Li
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Nan Zhou
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China.
| | - Hao Yuan
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Qianqian Guo
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Long Jiao
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Zengyi Ma
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, 310013 Hangzhou, China
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Meena P, Singh S, Sharma N, Saharan VK, George S, Bhoi R. Performance, combustion, and emission characteristics of bio-oil produced by in situ catalytic pyrolysis of polypropylene using spent FCC. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-30786-0. [PMID: 37950124 DOI: 10.1007/s11356-023-30786-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023]
Abstract
Plastic waste is a rich source of hydrocarbons that can be converted into bio-oil through pyrolysis. In this study, bio-oil was produced by pyrolysis of waste-polypropylene using spent FCC catalyst. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that catalytically produced oil has the majority of compounds in the hydrocarbon range of C6-C18. The catalytic pyrolysis oil was blended with conventional fuel (diesel) to extensively investigate its suitability as a fuel substitute in a single-cylinder, four-stroke, 3.5 kW, diesel internal combustion (IC) engine. Furthermore, four fuels, i.e., CF100PO00 (pure diesel), CF90PO10 (10% v/v pyrolysis oil blended with diesel), CF85PO15 (15% v/v pyrolysis oil blended with diesel), and CF80PO20 (20% v/v pyrolysis oil blended with diesel), were tested in IC diesel engine for performance, combustion, and exhaust emission analysis at 1500 rpm. The tests were carried out at five loads, i.e., 1, 5, 10, 15, and 20 Nm. It was found that CF90PO10 produced 6.61% higher brake thermal efficiency (BTE), whereas CO2 exhaust emission decreased by 20% for CF80PO20 with respect to the pure diesel. Diesel blends with plastic pyrolysis oil can be a promising biofuel to improve engine performance and combustion characteristics without any significant engine modification.
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Affiliation(s)
- Prathwiraj Meena
- Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India
| | - Surabhi Singh
- Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India
| | - Nikhil Sharma
- Department of Mechanical Engineering, Malaviya National Institute of Technology, Jaipur, 302017, India
| | - Virendra Kumar Saharan
- Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India
| | - Suja George
- Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India
| | - Rohidas Bhoi
- Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
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Chang SH. Plastic waste as pyrolysis feedstock for plastic oil production: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162719. [PMID: 36933741 DOI: 10.1016/j.scitotenv.2023.162719] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/15/2023] [Accepted: 03/04/2023] [Indexed: 05/06/2023]
Abstract
Turning plastic waste into plastic oil by pyrolysis is one of the promising techniques to eradicate plastic waste pollution and accelerate the circular economy of plastic materials. Plastic waste is an attractive pyrolysis feedstock for plastic oil production owing to its favorable chemical properties of proximate analysis, ultimate analysis, and heating value other than its abundant availability. Despite the exponential growth of scientific output from 2015 to 2022, a vast majority of the current review articles cover the pyrolysis of plastic waste into a series of fuels and value-added products, and up-to-date reviews exclusively on plastic oil production from pyrolysis are relatively scarce. In light of this void in the current review articles, this review attempts to provide an up-to-date overview of plastic waste as pyrolysis feedstock for plastic oil production. A particular emphasis is placed on the common types of plastic as primary sources of plastic pollution, the characteristics (proximate analysis, ultimate analysis, hydrogen/carbon ratio, heating value, and degradation temperature) of various plastic wastes and their potential as pyrolysis feedstock, and the pyrolysis systems (reactor type and heating method) and conditions (temperature, heating rate, residence time, pressure, particle size, reaction atmosphere, catalyst and its operation modes, and single and mixed plastic wastes) used in plastic waste pyrolysis for plastic oil production. The characteristics of plastic oil from pyrolysis in terms of physical properties and chemical composition are also outlined and discussed. The major challenges and future prospects for the large-scale production of plastic oil from pyrolysis are also addressed.
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Affiliation(s)
- Siu Hua Chang
- Waste Management and Resource Recovery (WeResCue) Group, Chemical Engineering Studies, College of Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, 13500 Permatang Pauh, Penang, Malaysia.
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Lu L, Li W, Cheng Y, Liu M. Chemical recycling technologies for PVC waste and PVC-containing plastic waste: A review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 166:245-258. [PMID: 37196390 DOI: 10.1016/j.wasman.2023.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/29/2023] [Accepted: 05/07/2023] [Indexed: 05/19/2023]
Abstract
The extensive production and consumption of plastics has resulted in significant plastic waste and plastic pollution. Polyvinyl chloride (PVC) waste has a high chlorine content and is the primary source of chlorine in the plastic waste stream, potentially generating hazardous chlorinated organic pollutants if treated improperly. This review discusses PVC synthesis, applications, and the current types and challenges of PVC waste management. Dechlorination is vital for the chemical recycling of PVC waste and PVC-containing plastic waste. We review dehydrochlorination and dechlorination mechanisms of PVC using thermal degradation and wet treatments, and summarize the recent progress in chemical treatments and dechlorination principles. This review provides readers with a comprehensive analysis of chemical recycling technologies for PVC waste and PVC-containing plastic waste to transform them into chemicals, fuels, feedstock, and value-added polymers.
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Affiliation(s)
- Lihui Lu
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Weiming Li
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Ying Cheng
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Meng Liu
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China.
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Liu X, Tian K, Chen Z, Wei W, Xu B, Ni BJ. Online TG-FTIR-MS analysis of the catalytic pyrolysis of polyethylene and polyvinyl chloride microplastics. JOURNAL OF HAZARDOUS MATERIALS 2023; 441:129881. [PMID: 36063710 DOI: 10.1016/j.jhazmat.2022.129881] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/25/2022] [Accepted: 08/28/2022] [Indexed: 06/15/2023]
Abstract
Microplastics (MPs) are frequently detected in urban waters, which would pose a threat to human health through the food chain. Thus, efficient approaches to the elimination of MPs are urgently required. Pyrolysis is a powerful technique for the potential treatment of MPs. The online thermogravimetry-Fourier transform infrared reflection-Mass spectrometry (TG-FTIR-MS) is applied for tracking the pyrolysis process of representative polyethylene (PE) and polyvinyl chloride (PVC) MPs in urban waters, together with or without the FeAlOx catalyst. TG could quantitatively determine the decomposition behavior and kinetics of MPs while FTIR and MS spectra would be capable of characterizing the pyrolysis products. The results revealed that FeAlOx is an excellent carbon support, and the deposited carbon can be gasified to CO at higher pyrolysis temperatures. Moreover, more aromatic compounds were generated from the pyrolysis of PE MPs with the catalyzation of FeAlOx. Large quantities of benzene were also produced in the PVC MPs pyrolysis with or without FeAlOx. Also, FeAlOx largely decreased the concentrations of chlorine-containing compounds in the liquid products of PVC MPs pyrolysis. This study provides a efficient technique for the online observation of the MPs' catalytic pyrolysis process, which would guide future upcycling of MPs into value-added products.
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Affiliation(s)
- Xiaoqing Liu
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Ke Tian
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Zhijie Chen
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Wei Wei
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Bentuo Xu
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
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Hu Y, Mu S, Zhang J, Li Q. Regional distribution, properties, treatment technologies, and resource utilization of oil-based drilling cuttings: A review. CHEMOSPHERE 2022; 308:136145. [PMID: 36029858 DOI: 10.1016/j.chemosphere.2022.136145] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/07/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Oil-based drilling cuttings (OBDC) are hazardous wastes produced during the extensive use of oil-based drilling mud in oil and gas exploration and development. They have strong mutagenic, carcinogenic, and teratogenic effects and need to be properly disposed of to avoid damaging the natural environment. This paper reviews the recent research progress on the regional distribution, properties, treatment technologies, and resource utilization of OBDC. The advantages and disadvantages of different technologies for removing petroleum pollutants from OBDC were comprehensively analyzed, and required future developments in treatment technologies were proposed.
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Affiliation(s)
- Yuansi Hu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Shiqi Mu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Jingjing Zhang
- Sichuan Solid Waste and Chemicals Management Center, Chengdu, 610036, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
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A Brief Review of Poly(Vinyl Chloride) (PVC) Recycling. Polymers (Basel) 2022; 14:polym14153035. [PMID: 35893999 PMCID: PMC9332854 DOI: 10.3390/polym14153035] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/14/2022] [Accepted: 07/22/2022] [Indexed: 02/01/2023] Open
Abstract
Bearing in mind the aspiration of the world economy to create as complete a closed loop of raw materials and energy as possible, it is important to know the individual links in such a system and to systematise the knowledge. Polymer materials, especially poly(vinyl chloride) (PVC), are considered harmful to the environment by a large part of society. The work presents a literature review on mechanical and feedstock recycling. The advantages and disadvantages of various recycling methods and their development perspectives are presented. The general characteristics of PVC are also described. In conclusion, it is stated that there are currently high recycling possibilities for PVC material and that intensive work is underway on the development of feedstock recycling. Based on the literature review, it was found that PVC certainly meets the requirements for materials involved in the circular economy.
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Abstract
With the increase in demand for plastic use, waste plastic (WP) management remains a challenge in the contemporary world due to the lack of sustainable efforts to tackle it. The increment in WPs is proportional to man’s demand and use of plastics, and these come along with environmental challenges. This increase in WPs, and the resulting environmental consequences are mainly due to the characteristic biodegradation properties of plastics. Landfilling, pollution, groundwater contamination, incineration, and blockage of drainages are common environmental challenges associated with WPs. The bulk of these WPs constitutes polyethene (PE), polyethene terephthalate (PET) and polystyrene (PS). Pyrolysis is an eco-friendly thermo-chemical waste plastic treatment solution for valuable product recovery, preferred over landfilling and incineration solutions. In this extensive review, a critical investigation on waste plastic catalytic pyrolysis (WPCP) is performed, including catalyst and non-catalyst applications to sustainably tackle WP management. Current catalysis techniques are revealed, and some comparisons are made where necessary. Common pyrolytic products and common shortcomings and errors related to WP catalysis were also identified. The benefits of catalysts and their applications to augment and optimise thermal pyrolysis are emphasised. With all these findings, and more, this paper provides reassurance on the significance of catalysis to industrial-scale applications and products and supports related WPCP research work concerning the environment and other beneficiaries.
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