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Zhang Y, Zhou C, Liu Y, Qu J, Ali Siyal A, Yao B, Dai J, Liu C, Chao L, Chen L, Wang L. The fate of bromine during microwave-assisted pyrolysis of waste printed circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 173:160-171. [PMID: 37992535 DOI: 10.1016/j.wasman.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 10/20/2023] [Accepted: 11/13/2023] [Indexed: 11/24/2023]
Abstract
Bromine control is imperative for efficient treatment and products utilization during pyrolysis of waste printed circuit boards (WPCBs). This study investigated Br-species in products from microwave-assisted auger pyrolysis of WPCBs, and discussed synergetic evolution mechanisms, release kinetics and thermodynamics of Br-containing pollutants with different kinds of mineral species (alkaline earth, alkali, and transition metals). Results indicated that heavy Br-containing volatiles release (e.g., brominated phenols) was dominated at 320-520 °C. Brominated phenols released Br* to react with small-molecule groups to form light Br-containing products (e.g., HBr, CH3Br, and CH3CH2Br) at >520 °C. K2CO3 efficiently suppressed Br-containing pollutants emissions (∼50% reduction) and promoted bromine fixation in char (∼33.49% increase). With K2CO3 addition, bromine evolution mechanism is largely dehydrobromination and neutralization reactions when bromine bonds with aliphatic carbon with an adjacent aliphatic hydrogen. Negatively charged oxygen of K2CO3 attacks bromine and causes C-Br scission when bromine bonds with CH3* or aromatic carbon. The chemical reaction models (CRM3-CRM5) are best fitted with bromine evolution and the activation energy of WPCBs-KC reached the lowest (149.83-192.19 kJ/mol). Furthermore, bromine control strategy in WPCBs pyrolysis products toward environmental and economic sustainability were suggested, which created less environmental impact and maximum resource recovery.
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Affiliation(s)
- Yingwen Zhang
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Chunbao Zhou
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Yang Liu
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Junshen Qu
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Asif Ali Siyal
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Bang Yao
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jianjun Dai
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Chenglong Liu
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Li Chao
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Lei Chen
- State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Long Wang
- Systematic Engineering Center, JIHUA Group Co., Ltd., Beijing 100070, China
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Liu J, Zhan L, Xu Z. Debromination with Bromine Recovery from Pyrolysis of Waste Printed Circuit Boards Offers Economic and Environmental Benefits. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3496-3504. [PMID: 36794988 DOI: 10.1021/acs.est.2c06448] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Bromine is an important resource that is widely used in medical, automotive, and electronic industries. Waste electronic products containing brominated flame retardants can cause serious secondary pollution, which is why catalytic cracking, adsorption, fixation, separation, and purification have gained significant attention. However, the bromine resources have not been effectively reutilized. The application of advanced pyrolysis technology could help solve this problem via converting bromine pollution into bromine resources. Coupled debromination and bromide reutilization during pyrolysis is an important field of research in the future. This prospective paper presents new insights in terms of the reorganization of different elements and adjustment of bromine phase transition. Furthermore, we proposed some research directions for efficient and environmentally friendly debromination and reutilization of bromine: 1) precise synergistic pyrolysis should be further explored for efficient debromination, such as using persistent free radicals in biomass, polymer hydrogen supply, and metal catalysis, 2) rematching of Br elements and nonmetal elements (C/H/O) will be a promising direction for synthesizing functionalized adsorption materials, 3) oriented control of the bromide migration path should be further studied to obtain different forms of bromine resources, and 4) advanced pyrolysis equipment should be well developed.
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Affiliation(s)
- Jiangshan Liu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lu Zhan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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3
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Ali L, Shafi Kuttiyathil M, Altarawneh M. Oxidative and pyrolytic decomposition of an evaporated stream of 2,4,6-tribromophenol over hematite: A prevailing scenario during thermal recycling of e-waste. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 154:283-292. [PMID: 36308795 DOI: 10.1016/j.wasman.2022.10.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 10/08/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Brominated flame retardants (BFRs) constitute a major load in the polymeric fraction of e-waste. Degradation of BFRs-laden plastics over transition metal oxides is currently deployed as a mainstream strategy in the disposal and treatment of the non-metallic segment of e-waste. However, interaction of pyrolysis's products of BFRs with transition metal oxides is well-known to facilitate the formation of notorious pollutants. Despite recent progress to comprehend the germane chemistry of this interaction, several important pertinent aspects remain to be addressed. To fill in this gap, an integrated experimental and simulation account of the pyrolytic and oxidative decomposition of a gaseous stream of 2,4,6-tribromophenol (TBP) over hematite (Fe2O3) has been reported herein. TBP is utilized as a model compounds of BFRs as their most common formulations include brominated phenolic rings. Overall, hematite entails a rather low cracking capacity under pyrolytic conditions. Analysis of condensate products indicates that oxidative degradation of a gaseous stream of TBP results mainly in the formation of brominated alkanes such as bromoethane and bromo-pentane. Likewise, Ion chromatography (IC) measurements disclosed a noticeable reduction in the concentrations of escaped HBr. Transformation of iron oxides into iron bromides (possibly in the form of FeBr2) during pyrolysis and combustion operations is evident through XRD measurements. Density functional theory (DFT) calculations map out important reactions pathways that operate in the initial degradation of the TBP molecule. From a broader perspective, outlined results shall be instrumental to precisely assess the effectiveness of using iron oxides in thermal catalytic recycling of e-waste and the likely emission of brominated toxicants.
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Affiliation(s)
- Labeeb Ali
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Sheikh Khalifa bin Zayed Street, Al-Ain 15551, United Arab Emirates
| | - Mohamed Shafi Kuttiyathil
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Sheikh Khalifa bin Zayed Street, Al-Ain 15551, United Arab Emirates
| | - Mohammednoor Altarawneh
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Sheikh Khalifa bin Zayed Street, Al-Ain 15551, United Arab Emirates.
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Peng Z, Wang J, Zhang X, Yan J, Shang W, Yu J, Zhu G, Rao M, Li G, Jiang T. Enrichment of heavy metals from spent printed circuit boards by microwave pyrolysis. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 145:112-120. [PMID: 35537320 DOI: 10.1016/j.wasman.2022.04.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 03/02/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
This study reports the enrichment behaviors of heavy metals, including copper, tin, lead and zinc, in the process of microwave pyrolysis of spent printed circuit boards (SPCBs). The SPCB had good microwave absorptivity. Under the optimal conditions of microwave power of 700 W, pyrolysis temperature of 400 °C, dwell time of 5 min, N2 gas flow rate of 1.2 L/min, and load mass of 5 g, the yield of pyrolyzed SPCB was 79.16%. The contents of copper, tin, lead, and zinc in the pyrolyzed SPCB were increased to 28.52 wt%, 7.15 wt%, 1.31 wt%, and 1.13 wt%, respectively, with the corresponding retention percentages of 99.98%, 85.89%, 92.59% and 82.06%. The loss of metals was attributed to volatilization of the elements, which was affected by metal discharge due to excitation of electrons in the metals under microwave irradiation. Little copper loss was found because of the difficult reaction between copper and hydrogen bromide and the very high temperature required by the volatilization of copper. Tin, lead and zinc were mainly volatilized in the form of their metal bromides, including SnBr4, ZnBr2, and PbBr2. By controlling the pyrolysis conditions and metal discharge induced in the microwave field, the metals could be effectively enriched for subsequent treatment with high efficiency.
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Affiliation(s)
- Zhiwei Peng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Jie Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Xin Zhang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China.
| | - Jiaxing Yan
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Wenxing Shang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Jingfeng Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Guangyan Zhu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Mingjun Rao
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Guanghui Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
| | - Tao Jiang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Changsha, Hunan 410083, China
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Joo J, Kwon EE, Lee J. Achievements in pyrolysis process in E-waste management sector. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 287:117621. [PMID: 34171724 DOI: 10.1016/j.envpol.2021.117621] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/29/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
Many aspects of modern life of our civilization are associated with using electrical and electronic devices (EEE). Ever-increasing demand for high-performance EEE and accelerated technological development make the replacement of EEE become frequent. This leads to the generation of a tremendous amount of electronic waste (E-waste). Challenges of the management of E-waste have recently arisen out of a dearth of proper technologies to treat E-waste. Pyrolysis process can thermochemically treat waste materials that have a complicated nature and inhomogeneity. This article gives a systematic review as an effort to tackle the challenges in the context of achievements in pyrolysis process in E-waste management sector. Pyrolysis mechanism and types of pyrolysis processes and pyrolysis reactors are first discussed. Various pyrolysis technologies applied to the E-waste treatment are then summarized and compared to each other. Points to be considered for further research and pending challenges of E-waste pyrolysis are also discussed. The pyrolysis treatment of E-waste is not yet fully industrialized mostly because of high costs. However, there should be much room for further developing the E-waste pyrolysis; hence, its industrialization and commercialization is just a matter of time.
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Affiliation(s)
- Junghee Joo
- Department of Energy Systems Research, Ajou University, 206 World Cup-ro, Suwon, 16499, Republic of Korea
| | - Eilhann E Kwon
- Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Seou, 05006, Republic of Korea
| | - Jechan Lee
- Department of Energy Systems Research, Ajou University, 206 World Cup-ro, Suwon, 16499, Republic of Korea; Department of Environmental and Safety Engineering, Ajou University, 206 World Cup-ro, Suwon, 16499, Republic of Korea.
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Das P, Gabriel JCP, Tay CY, Lee JM. Value-added products from thermochemical treatments of contaminated e-waste plastics. CHEMOSPHERE 2021; 269:129409. [PMID: 33388566 DOI: 10.1016/j.chemosphere.2020.129409] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 12/14/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
The rise of electronic waste (e-waste) generation around the globe has become a major concern in recent times and its recycling is mostly focused on the recovery of valuable metals, such as gold, silver, and copper, etc. However, e-waste consists of a significant weight fraction of plastics (25-30%) which are either discarded or incinerated. There is a growing need for recycling of these e-waste plastics. The majority of them are made from high-quality polymers (composites), such as acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), polycarbonate (PC), polyamide (PA), polypropylene (PP) and epoxies. These plastics are often contaminated with hazardous materials, such as brominated flame retardants (BFRs) and heavy metals (such as Pb and Hg). Under any thermal stress (thermal degradation), the Br present in the e-waste plastics produces environmentally hazardous pollutants, such as hydrogen bromide or polybrominated diphenyl ethers/furans (PBDE/Fs). The discarded plastics can lead to the leaching of toxins into the environment. It is important to remove the toxins from the e-waste plastics before recycling. This review article gives a detailed account of e-waste plastics recycling and recovery using thermochemical processes, such as extraction (at elevated temperature), incineration (combustion), hydrolysis, and pyrolysis (catalytic/non catalytic). A basic framework of the existing processes has been established by reviewing the most interesting findings in recent times and the prospects that they open in the field recycling of e-waste plastics.
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Affiliation(s)
- Pallab Das
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
| | | | - Chor Yong Tay
- School of Materials Science and Engineering, Nanyang Technological University, N4.1, 50 Nanyang Avenue, Singapore, 639798, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Jong-Min Lee
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
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Zhang T, Mao X, Qu J, Liu Y, Siyal AA, Ao W, Fu J, Dai J, Jiang Z, Deng Z, Song Y, Wang D, Polina C. Microwave-assisted catalytic pyrolysis of waste printed circuit boards, and migration and distribution of bromine. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123749. [PMID: 33254771 DOI: 10.1016/j.jhazmat.2020.123749] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 06/12/2023]
Abstract
Microwave-assisted pyrolysis (MAP) of waste printed circuit boards (WPCB) was performed to investigate the characteristics of pyrolysis product and Br fixation. Pyrolysis conversion increased with increasing temperature, reaching 93.3 % at 650 °C. However, increasing heating time did not exhibit remarkable influence on pyrolysis conversion. At 350 °C, phenols were main compounds in the oil accounting for 91.15 %. As the temperature increased to 650 °C, polycyclic aromatic hydrocarbons and monocyclic aromatic hydrocarbons (except phenols) increased to 20.55 % and 19.03 %, respectively. Meanwhile, the total content of CO2, CO, CH4 and H2 in the non-condensable gases increased significantly. Addition of ZSM-5 and kaolin promoted the recombination reaction of pyrolysis products, increased the relative percentage of monocyclic aromatic hydrocarbons (except phenols) and C11-C20 compounds in the oil, and reduced non-condensable gases. The oxygen bomb-ion chromatography was used to evaluate the Br content of pyrolysis residues. Higher pyrolysis temperature enhanced transfer of Br to pyrolysis gas. K2CO3, Na2CO3 and NaOH reacted with hydrogen bromide to generate KBr and NaBr, which significantly improved the Br fixation efficiency of pyrolysis residues (i.e. from 29.11%-99.80%, 96.39 % and 86.69 %, respectively) and reduced Br content in pyrolysis gas.
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Affiliation(s)
- Tianhao Zhang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Xiao Mao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Juanshen Qu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Yang Liu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Asif Ali Siyal
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Wenya Ao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Jie Fu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Jianjun Dai
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China.
| | - Zhihui Jiang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Zeyu Deng
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Yongmeng Song
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Daiying Wang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Chtaeva Polina
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
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Qin B, Lin M, Yao Z, Zhu J, Ruan J, Tang Y, Qiu R. A novel approach of accurately rationing adsorbent for capturing pollutants via chemistry calculation: Rationing the mass of CaCO 3 to capture Br-containing substances in the pyrolysis of nonmetallic particles of waste printed circuit boards. JOURNAL OF HAZARDOUS MATERIALS 2020; 393:122410. [PMID: 32120221 DOI: 10.1016/j.jhazmat.2020.122410] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/07/2020] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
Pyrolysis technology is advised to dispose nonmetallic particles of waste printed circuit boards to produce oils and gases. During pyrolysis, brominated flame retardants in nonmetallic particles are converted into small-molecular Br-containing substances. They disperse into oil and gas so as to cause secondary pollution. Then, CaCO3 is suggested to be employed to capture the small-molecular Br-containing substances. However, too much CaCO3 will produce over solid wastes. Less CaCO3 might not capture the total Br-containing substances. How to ration the mass of adsorbent for capturing pollutant has not been detailed investigated. This paper found HBr was the main Br-containing substances during high temperature pyrolysis of nonmetallic particles. The capture process of HBr was detailed investigated by the method of computational chemistry. At the condition of 973 K and 100 Pa, HBr was captured by chemical reaction and physical absorption of CaCO3. Unit cell of CaCO3 reacted with two HBr to form CaBr2, and the generated unit cell of CaBr2 can adsorb 0.011 HBr. 0.0106 g CaCO3 can absorb all HBr produced by high temperature vacuum pyrolysis of 1 g nonmetallic particles. This paper contributes a novel approach to accurately ration the mass of adsorbents employed for capturing pollutants.
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Affiliation(s)
- Baojia Qin
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China
| | - Mi Lin
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China
| | - Zichun Yao
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China
| | - Jie Zhu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China
| | - Jujun Ruan
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China.
| | - Yetao Tang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China
| | - Rongliang Qiu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, 135 Xingang Xi Road, Guangzhou, 510275, People's Republic of China
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9
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Abstract
Microwave-assisted pyrolysis is a promising thermochemical technique to convert waste polymers and biomass into raw chemicals and fuels. However, this process involves several issues related to the interactions between materials and microwaves. Consequently, the control of temperature during microwave-assisted pyrolysis is a hard task both for measurement and uniformity during the overall pyrolytic run. In this review, we introduce some of the main theoretical aspects of the microwaves–materials interactions alongside the issues related to microwave pyrolytic processability of materials.
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10
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Feng Y, Wang W, Wang Y, Sun J, Zhang C, Shahzad Q, Mao Y, Zhao X, Song Z. Experimental study of destruction of acetone in exhaust gas using microwave-induced metal discharge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:788-795. [PMID: 30031337 DOI: 10.1016/j.scitotenv.2018.07.183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 07/03/2018] [Accepted: 07/14/2018] [Indexed: 06/08/2023]
Abstract
Volatile organic compounds (VOCs) are air pollutants that pose a major concern, and novel treatment technologies must be continuously explored and developed. In this study, microwave-induced metal discharge was applied to investigate the destruction of acetone as a representative model VOC compound. Results revealed that metal discharge intensity largely depended on microwave output power and the number of metal strips. Microwave metal discharge exerted the distinct combined effects of intense heat, strong light, and plasma. In the case of MW without metal discharge, the decrease in acetone at 200 ppm was remarkably limited (approximately 5.5% (mol/mol)). By contrast, in the case of microwave-induced metal discharge, a considerably high destruction efficiency of up to 65% (mol/mol) was obtained at low concentrations. This finding highlights the potential of microwave-induced discharge for VOC removal. Initial assessment indicated that energy consumption can be acceptable.
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Affiliation(s)
- Yukun Feng
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
| | - Wenlong Wang
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China.
| | - Yican Wang
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
| | - Jing Sun
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China.
| | - Chao Zhang
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
| | - Qamar Shahzad
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
| | - Yanpeng Mao
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
| | - Xiqiang Zhao
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
| | - Zhanlong Song
- National Engineering Lab for Coal-fired Pollutants Emission Reduction, Shandong Provincial Key Lab of Energy Carbon Reduction and Resource Utilization, Shandong University, Jinan 250061, China
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11
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Study on the Promotion Effect of Microwave-Metal Discharge on the Microwave Pyrolysis of Electronic Waste. ACTA ACUST UNITED AC 2015. [DOI: 10.4028/www.scientific.net/amr.1088.843] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper discussed the role of microwave-metal discharge on the microwave induced pyrolysis of electronic waste. Two kinds of waste printed circuit boards (WPCB) were selected as the representatives of electronic waste and their pyrolysis processes under both conventional and microwave heating schemes were studied comparatively to reveal the effect of metal discharge. The copper-clad laminated printed circuit board (PCB) is deficient in absorbing microwaves, leading to inefficient microwave pyrolysis of this kind of electronic waste. The discharge caused by introducing metalliferous materials with metal tips or corners in the electromagnetic fields can result in high local temperature and complement the deficiency in the microwave absorption. The pyrolytic process can be promoted greatly by the thermal effect of discharge in the beginning and the enhanced consequent wave-absorption capacity as a result of the generated pyrolytic coke.
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12
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Grause G, Fonseca JD, Tanaka H, Bhaskar T, Kameda T, Yoshioka T. A novel process for the removal of bromine from styrene polymers containing brominated flame retardant. Polym Degrad Stab 2015. [DOI: 10.1016/j.polymdegradstab.2014.12.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Lin KH, Chiang HL. Liquid oil and residual characteristics of printed circuit board recycle by pyrolysis. JOURNAL OF HAZARDOUS MATERIALS 2014; 271:258-265. [PMID: 24637450 DOI: 10.1016/j.jhazmat.2014.02.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/20/2014] [Accepted: 02/21/2014] [Indexed: 06/03/2023]
Abstract
Non-metal fractions of waste printed circuit boards (PCBs) were thermally treated (200-500°C) under nitrogen atmosphere. Carbon, hydrogen, and nitrogen were determined by elemental analyzer, bromine by instrumental neutron activation analysis (INAA), phosphorus by energy dispersive X-ray spectrometer (EDX), and 29 trace elements by inductively coupled plasma atomic emission spectrometer (ICP-AES) and mass spectrometry (ICP-MS) for raw material and pyrolysis residues. Organic compositions of liquid oil were identified by GC (gas chromatography)-MS, trace element composition by ICP system, and 12 water-soluble ions by IC (ionic chromatography). Elemental content of carbon was >450 mg/g, oxygen 300 mg/g, bromine and hydrogen 60 mg/g, nitrogen 30 mg/g, and phosphorus 28 mg/g. Sulfur was trace in PCBs. Copper content was 25-28 mg/g, iron 1.3-1.7 mg/g, tin 0.8-1.0mg/g and magnesium 0.4-1.0mg/g; those were the main metals in the raw materials and pyrolytic residues. In the liquid products, carbon content was 68-73%, hydrogen was 10-14%, nitrogen was 4-5%, and sulfur was less than 0.05% at pyrolysis temperatures from 300 to 500°C. Phenol, 3-bromophenol, 2-methylphenol and 4-propan-2-ylphenol were major species in liquid products, accounting for >50% of analyzed organic species. Bromides, ammonium and phosphate were the main species in water sorption samples for PCB pyrolysis exhaust.
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Affiliation(s)
- Kuo-Hsiung Lin
- Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan
| | - Hung-Lung Chiang
- Department of Health Risk Management, China Medical University, Taichung, Taiwan.
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14
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Kinetic Study of the Pyrolysis of Waste Printed Circuit Boards Subject to Conventional and Microwave Heating. ENERGIES 2012. [DOI: 10.3390/en5093295] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Wang W, Liu Z, Sun J, Ma Q, Ma C, Zhang Y. Experimental study on the heating effects of microwave discharge caused by metals. AIChE J 2012. [DOI: 10.1002/aic.13766] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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16
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Sun J, Wang W, Liu Z, Ma C. Recycling of Waste Printed Circuit Boards by Microwave-Induced Pyrolysis and Featured Mechanical Processing. Ind Eng Chem Res 2011. [DOI: 10.1021/ie2013407] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jing Sun
- National Engineering Laboratory for Coal-fired Pollutants Emission Reduction, Energy and Power Engineering School, Shandong University, 17923 Jingshi Road, Jinan 250061, PR China
| | - Wenlong Wang
- National Engineering Laboratory for Coal-fired Pollutants Emission Reduction, Energy and Power Engineering School, Shandong University, 17923 Jingshi Road, Jinan 250061, PR China
| | - Zhen Liu
- National Engineering Laboratory for Coal-fired Pollutants Emission Reduction, Energy and Power Engineering School, Shandong University, 17923 Jingshi Road, Jinan 250061, PR China
| | - Chunyuan Ma
- National Engineering Laboratory for Coal-fired Pollutants Emission Reduction, Energy and Power Engineering School, Shandong University, 17923 Jingshi Road, Jinan 250061, PR China
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