The chemical recycling of poly(ethylene terephthalate) (PET) is very attractive as PET bottle waste provides an abundant clean material with low levels of additives. One of the most promising processes is glycolysis, which depolymerizes PET in the presence of ethylene glycol. For this process, it is necessary to think through the whole concept, from the waste material to the newly polymerized virgin polymer.
View Article and Find Full Text PDFThe increasing contamination of the environment with microplastic requires efficient methods for the separation and detection of these plastic particles. In this work, we present a protocol that uses Fenton oxidation to remove biological material, centrifugation to separate microplastics from soil, and Nile Red staining, fluorescence microscopy, and image processing to detect and quantify of microplastic. The main component of this work was the separation process using centrifugation.
View Article and Find Full Text PDFIn this work, a Japanese cedar wood sample was treated during the first step at ambient temperature and atmospheric pressure using several concentrations of sulfuric acid (H2SO4) in a stirred flask. During this pretreatment C-O bonds of cellulose, hemicellulose, and lignin were cleaved. The second step involved the pyrolysis of the pretreated wood sample at 550 °C in a quartz glass tube reactor.
View Article and Find Full Text PDFThe possibility of simultaneous recovery of benzene and metals from the hydrolysis of poly(ethylene terephthalate) (PET)-based materials such as X-ray films, magnetic tape, and prepaid cards under a steam atmosphere at a temperature of 450 °C was evaluated. The hydrolysis resulted in metal-containing carbonaceous residue and volatile terephthalic acid (TPA). The effects of metals and additives on the recovery process were also investigated.
View Article and Find Full Text PDFThe thermal degradation of flame retardant containing high-impact polystyrene (HIPS-Br), one of the most commonly employed plastics in electric and electronic appliances, was examined by thermogravimetry coupled with mass spectroscopy (TG-MS) in order to understand the threat that is posed by the release of hazardous brominated compounds. The HIPS samples contained decabromodiphenylether (DPE) and decabromodibenzyl (DDB) as the flame retardants as well as Sb2O3 as the synergist. The largest number of brominated compounds was obtained in the presence of DPE and Sb2O3 and DDB without Sb2O3.
View Article and Find Full Text PDFWe investigated the effectiveness of sodium hydroxide/ethylene glycol (NaOH/EG) for dehalogenation of automobile shredder residue (ASR) using a ball mill. Efficient dehalogenation was achieved at atmospheric pressure by combining the use of EG (196 degrees C b.p.
View Article and Find Full Text PDFMagnesium-aluminum oxide (Mg-Al oxide) obtained by thermal decomposition of Mg-Al layered double hydroxide (Mg-Al LDH) effectively removed HCl from gaseous streams. HCl removal was greater in the presence of added water vapor at all temperatures examined and increased with decreasing temperature in both the presence and absence of added water vapor. Wet and dry removal of gaseous HCl were attributed to the production of MgCl2 .
View Article and Find Full Text PDFTetrabromobisphenol-A (TBBA) is the most common brominated fire retardant. In this study, a TBBA containing paper laminated printed circuit board (PCB) prepared from novolac was pyrolysed by both TGA and in a quartz glass reactor between 40 and 1,000 degrees C. The products were online detected by MS.
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