Article
Thermodynamics
Yingwen Zhang, Chunbao Zhou, Yang Liu, Tianhao Zhang, Xiangtong Li, Long Wang, Jianjun Dai, Junshen Qu, Changfa Zhang, Mengyan Yu, Yanxin Yuan, Yajie Jin, Hejie Yu, Jie Fu
Summary: Efficient disposal and recycling of nonmetal materials from waste printed circuit boards (WPCBs) is challenging due to their toxicity and complexity. This study investigated the characteristics and energy recovery of products from WPCBs pyrolysis at different temperatures. Results showed that organic matter in WPCBs was almost completely recovered at 550 degrees C, with high phenols recovery and low brominated compounds. Pyrolysis oil with low moisture content could be directly separated in-situ from condensates, enhancing energy efficiency.
Article
Agricultural Engineering
Sonalben B. Prajapati, Alok Gautam, Shina Gautam
Summary: In this study, the pyrolysis of Printed circuit boards (PCBs), Cotton Stalk (CS), and their different compositions were analyzed using thermogravimetric analysis. The results showed that co-pyrolysis can reduce the production of phenolic compounds and bromides.
BIOMASS & BIOENERGY
(2023)
Article
Engineering, Environmental
Tianhao Zhang, Xiao Mao, Juanshen Qu, Yang Liu, Asif Ali Siyal, Wenya Ao, Jie Fu, Jianjun Dai, Zhihui Jiang, Zeyu Deng, Yongmeng Song, Daiying Wang, Chtaeva Polina
Summary: Microwave-assisted pyrolysis of waste printed circuit boards was studied, showing that increasing temperature led to higher pyrolysis conversion rates and changes in oil composition. Addition of ZSM-5 and kaolin promoted recombination reactions of pyrolysis products, increasing certain aromatic compounds in the oil while reducing non-condensable gases. Additionally, higher pyrolysis temperatures enhanced transfer of bromine, leading to improved bromine fixation efficiency in pyrolysis residues.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Engineering, Chemical
Yubo Liu, Jialiang Zhang, Xu Yang, Wenguang Yang, Yongqiang Chen, Chengyan Wang
Summary: In this study, microwave pyrolysis was used to recover valuable metals Cu, Sn, and Pb from waste printed circuit boards (WPCBs) with high recovery rates. The pyrolysis process generated solid products, oil, and gas, which can be utilized as fuel and raw materials for organic chemicals.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Zhiwei Peng, Jie Wang, Xin Zhang, Jiaxing Yan, Wenxing Shang, Jingfeng Yu, Guangyan Zhu, Mingjun Rao, Guanghui Li, Tao Jiang
Summary: 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. The results show that under optimal conditions, the pyrolyzed SPCB had higher contents of copper, tin, lead, and zinc. Metal discharge and volatilization were responsible for the loss of metals, and by controlling the pyrolysis conditions, the metals could be effectively enriched for subsequent treatment with high efficiency.
Article
Engineering, Environmental
Shuyu Chen, Run Li, Yaqi Shen, Lu Zhan, Zhenming Xu
Summary: This study conducted thermogravimetric analysis and kinetic analysis, revealing the positive self-catalytic influence of co-existing metals in waste printed circuit boards (WPCBs) during pyrolysis. It provides a theoretical basis for understanding the catalytic influence of these metals during the pyrolysis process.
FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Yu-Fong Huang, Szu-Ling Chou, Shang-Lien Lo
Summary: The study successfully recovered gold from waste printed circuit boards through processes such as microwave pyrolysis, acid leaching, solvent extraction, and oxidative precipitation. Efficient leaching of copper was achieved using a lixiviant composed of sulfuric acid and hydrogen peroxide, while gold leaching was efficient using thiourea, thiosulfate, and aqua regia. Organic solvents were ineffective in extracting gold ions from the leachate, thus oxidative precipitation process was applied. Gold precipitation efficiency was high using hydrogen peroxide or perchloric acid as oxidants. Microwave pyrolysis prevented gold loss, and perchloric acid exhibited higher selectivity for gold recovery.
SUSTAINABLE ENVIRONMENT RESEARCH
(2022)
Article
Environmental Sciences
Weifang Chen, Yongkai Shu, Yonglun Li, Yanjun Chen, Jianbo Wei
Summary: Co-pyrolysis with iron oxides and iron salts can increase the yield of liquid product rich in phenol, reduce the release of brominated organics to liquid, and produce solid residuals rich in iron oxides, glass fibers, and charred organics. Gaseous products contain CO2, CH4, and H2.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Green & Sustainable Science & Technology
Ye Chen, Sha Liang, Keke Xiao, Jingping Hu, Huijie Hou, Bingchuan Liu, Huali Deng, Jiakuan Yang
Summary: The global increase in e-waste generation poses a significant challenge for sustainable development, with a growing demand for efficient and environmentally friendly recycling and disposal strategies. A cost-effective approach involving crushing pretreatment combined with pyrolysis has been developed for recovering metals from waste printed circuit boards. Optimal conditions for energy consumption and metal recovery were achieved at a particle size of 4.0 cm and a pyrolysis temperature of 330 degrees C. Notably, the recovery efficiency for Cu and Sn reached 92.38% and 99.80% respectively.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Environmental Sciences
Qihao Jiang, Hanlin Wang, Jingxin Liu, Teng Wang, Meng Mei, Si Chen, Jinping Li
Summary: The study systematically investigated the behaviors, kinetics, and mechanisms of waste printed circuit boards pyrolysis, revealing the pyrolysis mechanisms through analyzing the pyrolysis process and volatile products.
JOURNAL OF MATERIAL CYCLES AND WASTE MANAGEMENT
(2022)
Article
Chemistry, Multidisciplinary
Jiahui Wang, Zhaojun Chen, Hui Du, Ruitong Gao, Lingen Zhang
Summary: Catalytic pyrolysis is a promising technology for energy recovery and bromide removal from nonmetals of waste printed circuit boards, with the capillary action of molten NaOH-KOH enhancing pyrolysis efficiency. Achieving maximum debromination efficiency and lower activation energy, the study offers insights for improving recycling of plastics by removing contamination.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Mohamed Khalil, Jamal Chaouki, Jean-Philippe Harvey
Summary: Electronic products consist of a wide range of materials that make it difficult to recycle individual components. Therefore, end-of-life electronic products are usually shredded and sent to pyrometallurgical processes to recover valuable metals. One major issue in recycling is the release of gaseous brominated species that need to be captured or stabilized, highlighting the importance of understanding the chemical interactions between various components in these processes.
ADVANCED SUSTAINABLE SYSTEMS
(2022)
Article
Engineering, Environmental
Chuan Ma, Shogo Kumagai, Yuko Saito, Tomohito Kameda, Toshiaki Yoshioka
Summary: Fast co-pyrolysis is a promising technique for solving environmental issues and recovering value-added products from polymer wastes. This study comprehensively investigated the co-pyrolysis of printed circuit boards and waste tires, finding that increasing the temperature during pyrolysis improved the interactions between the two materials and increased the formation of aliphatic and aromatic compounds, as well as promoting the formation of p-cymene.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Environmental Sciences
Jingxin Liu, Qihao Jiang, Hanlin Wang, Jinping Li, Wenjuan Zhang
Summary: The study showed that in-situ metals accelerated the production of light hydrocarbons and aromatic compounds, leading to a characteristic pyrolysis temperature of IB approximately 15 degrees lower than that of LP. The presence of metals lowered the energy barrier and increased the reaction extent, while inhibiting the formation of brominated volatiles.
Article
Materials Science, Multidisciplinary
Kang Yan, Chongwei Liu, Liping Liu, Min Xiong, Jiongtong Chen, Zhongtang Zhang, Shuiping Zhong, Zhifeng Xu, Jindi Huang
Summary: The effective recycling of waste printed circuit boards (WPCBs) can help conserve resources and reduce environmental pollution. This study investigates the pyrolysis and combustion characteristics of WPCBs in different atmospheres through thermogravimetric and Gaussian fitting analyses. The study also analyzes the pyrolysis products and combustion processes of WPCBs using thermogravimetric and Fourier transform infrared analyses (TG-FTIR) and thermogravimetry-mass spectrometry (TG-MS). The findings suggest that the pyrolysis and combustion processes of WPCBs involve multiple overlapping reactions. This study provides a theoretical basis for pollution control, process optimization, and reactor design in the pyrolysis of WPCBs.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2022)
