title: The effect of additives on migration and transformation of gaseous pollutants in the vacuum pyrolysis process of waste printed circuit boards.
abstract: The effect of six additives (CaCO3, HZSM-5, CaO, Al2O3, FeOOH and Ca(OH)2) on the generation, migration, transformation and escaping behaviours of typical gaseous pollutants in the pyrolysis process were studied by vacuum pyrolysis experiments on epoxy resin powder from waste printed circuit boards with tube furnace. The results show that the additives Al2O3, CaO, Ca(OH)2and FeOOH could reduce the yield of the gas phase. The removal rates of pollutants, such as benzene, toluene, ethyl benzene, phenol, p-xylene, HBr, NO2and SO2in the gaseous products, has changed variously with the increasing percentage of the above additives. Judging from the control of gas-phase pollutant discharge, the calcium-base additives are superior to the others. Ca(OH)2has the best inhibition effect among them. The increase of the pyrolysis temperature and vacuum degree enhanced the volatility of organic pollutants and weakened the Ca(OH)2inhibition effect on organic pollutants, while it improved the removal rate of SO2. Under the condition of 500 °C pyrolysis temperature and 0.09 MPa vacuum degree, when the additive proportion of Ca(OH)2was one-fifth, the average removal rate of pollutants in gas phase is up to 66.4%.
authors.affiliation: 1 School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China.|2 Guangdong Petrol-chemical Technology School, Foshan, P.R. China.
authors.forename: Yibiao
authors.initials: Y
authors.lastname: Xie
authors.affiliation: 1 School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China.|3 Guangdong Polytechnic of Environmental Protection Engineering, Foshan, P.R. China.
authors.forename: Shuiyu
authors.initials: S
authors.lastname: Sun
authors.affiliation: 1 School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China.
authors.forename: Jingyong
authors.initials: J
authors.lastname: Liu
authors.affiliation: 1 School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China.|4 Key Laboratory of Comprehensive Utilization of Resources and Cleaner Production, Department of Education of Guangdong Province, Guangzhou, P.R. China.
authors.forename: Weixiong
authors.initials: W
authors.lastname: Lin
authors.affiliation: 1 School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China.|4 Key Laboratory of Comprehensive Utilization of Resources and Cleaner Production, Department of Education of Guangdong Province, Guangzhou, P.R. China.
authors.forename: Nanwei
authors.initials: N
authors.lastname: Chen
authors.affiliation: 1 School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China.|4 Key Laboratory of Comprehensive Utilization of Resources and Cleaner Production, Department of Education of Guangdong Province, Guangzhou, P.R. China.
authors.forename: Maoyou
authors.initials: M
authors.lastname: Ye
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002119:Calcium Carbonate / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D059029:Electronic Waste; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D005740:Gases; D010087:Oxides / Q000737:chemistry; D012037:Refuse Disposal; D013696:Temperature; D014618:Vacuum; D018505:Waste Management / Q000379:methods*; D014992:Xylenes
chemical_list: D017610:Calcium Compounds; D004785:Environmental Pollutants; D005740:Gases; D010087:Oxides; D014992:Xylenes; C031286:4-xylene; C016538:lime; D002119:Calcium Carbonate; D000537:Aluminum Oxide
keywords: Vacuum pyrolysis; additives; brominated epoxy resin; gas-phase pollutants; waste printed circuit boards