title: Liquid oil and residual characteristics of printed circuit board recycle by pyrolysis.
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.
authors.affiliation: Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan.
authors.forename: Kuo-Hsiung
authors.initials: KH
authors.lastname: Lin
authors.affiliation: Department of Health Risk Management, China Medical University, Taichung, Taiwan. Electronic address: hlchiang@mail.cmu.edu.tw.
authors.forename: Hung-Lung
authors.initials: HL
authors.lastname: Chiang
mesh_terms: D003201:Computers; D055615:Electrical Equipment and Supplies; D059029:Electronic Waste; D006358:Hot Temperature; D008670:Metals / Q000032:analysis; D009821:Oils / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000032:analysis; D059027:Recycling / Q000379:methods*; D018505:Waste Management / Q000379:methods*
chemical_list: D008670:Metals; D009821:Oils; D011078:Polychlorinated Biphenyls
keywords: Pyrolysis oil; Residues; Water-soluble ionic species