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Li C, Liu C, Xia H, Zhang L, Liu D, Shu B. Catalytic pyrolysis of waste printed circuit boards to organic bromine: reaction mechanism and comprehensive recovery. Environ Sci Pollut Res Int 2023; 30:108288-108300. [PMID: 37743446 DOI: 10.1007/s11356-023-29944-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 09/13/2023] [Indexed: 09/26/2023]
Abstract
The production of waste printed circuit boards (WPCBs) is increasing, and its complex composition makes recycling difficult. In addition, the presence of heavy metals and brominated flame retardants makes it a hazardous waste. Therefore, its recycling is a necessary way for resource recycling and green sustainable development. The purpose of this study is to propose a green, efficient, and pollution-free recycling process as an alternative to recycle WPCBs. In this work, an alkaline metal oxide catalytic pyrolysis process was used to recover WPCBs. In the presence of alkali metal oxides (such as Ca(OH)2) and coexisting copper, Ca(OH)2 and coexisting copper are transformed into CaBr2 and Cu Br by reacting with organic bromine in WPCBs and remaining in the solid phase product. The bromine content and the proportion of inorganic bromine in the solid phase products were 87.68% and 87.56%, respectively. In addition, the content of organic bromine in the pyrolysis oil obtained by co-pyrolysis was significantly reduced. This study demonstrated the feasibility of Ca(OH)2 catalytic pyrolysis for WPCB recovery.
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Affiliation(s)
- Chunyu Li
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
| | - Chengfei Liu
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Copper Co., Ltd., Kunming, 650000, China
| | - Hongying Xia
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China.
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
| | - Libo Zhang
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
| | - Dafang Liu
- Yunnan Copper Co., Ltd., Kunming, 650000, China
| | - Bo Shu
- Chuxiong Dianzhong Nonferrous Metals Co., Ltd., Chuxiong, 675000, China
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Hadi P, Ning C, Ouyang W, Xu M, Lin CSK, McKay G. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor. Waste Manag 2015; 35:236-246. [PMID: 25445263 DOI: 10.1016/j.wasman.2014.09.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced.
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Affiliation(s)
- Pejman Hadi
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Chao Ning
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Weiyi Ouyang
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Meng Xu
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Carol S K Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong Special Administrative Region
| | - Gordon McKay
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region; Division of Sustainable Development, College of Science, Engineering and Technology, Hamad bin Khalifa University, Doha, Qatar.
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Hadi P, Xu M, Lin CSK, Hui CW, McKay G. Waste printed circuit board recycling techniques and product utilization. J Hazard Mater 2014; 283:234-243. [PMID: 25285997 DOI: 10.1016/j.jhazmat.2014.09.032] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 09/02/2014] [Accepted: 09/08/2014] [Indexed: 06/03/2023]
Abstract
E-waste, in particular waste PCBs, represents a rapidly growing disposal problem worldwide. The vast diversity of highly toxic materials for landfill disposal and the potential of heavy metal vapors and brominated dioxin emissions in the case of incineration render these two waste management technologies inappropriate. Also, the shipment of these toxic wastes to certain areas of the world for eco-unfriendly "recycling" has recently generated a major public outcry. Consequently, waste PCB recycling should be adopted by the environmental communities as an ultimate goal. This article reviews the recent trends and developments in PCB waste recycling techniques, including both physical and chemical recycling. It is concluded that the physical recycling techniques, which efficiently separate the metallic and nonmetallic fractions of waste PCBs, offer the most promising gateways for the environmentally-benign recycling of this waste. Moreover, although the reclaimed metallic fraction has gained more attention due to its high value, the application of the nonmetallic fraction has been neglected in most cases. Hence, several proposed applications of this fraction have been comprehensively examined.
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Affiliation(s)
- Pejman Hadi
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Meng Xu
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Carol S K Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region
| | - Chi-Wai Hui
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Gordon McKay
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region; Division of Sustainable Development, College of Science, Engineering and Technology, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
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