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Öğe Co-pyrolytic performances, mechanisms, gases, oils, and chars of textile dyeing sludge and waste shared bike tires under varying conditions(Elsevier Science Sa, 2022) Tang, Xiaojie; Chen, Xi; He, Yao; Evrendilek, Fatih; Chen, Zhiyun; Liu, JingyongThe massive industrial wastes of textile dyeing sludge (TDS) and waste shared bike tires are becoming increasingly problematic environmentally and economically. Their co-pyrolysis maybe an affordable and ecofriendlier alternative so as to reduce their waste volumes and emissions, as well as recover value-added oils and chars. This study was the first to characterize the TDS co-pyrolysis with rubber (RT) versus polyurethane (PUT) tires and their performances, mechanisms, emissions, oils, and chars as a function of temperature and blend type and ratio. The co-pyrolysis increased the total weight loss from 51.76% with TDS to 55.30% with 50% TDS and 50% RT (TR55) and to 68.92% with TP55. TR55 and TP55 yielded the best performances, with the stronger synergistic effect with the TP than TR co-pyrolysis. The optimal reaction models were second-order (F2) and five-dimension diffusion (D5) for the two devolatilization sub-stages for TDS, two thirds-order (F1.5) for the TR55 and the second and fourth sub-stages of the TP55, and F2 for the first and third sub-stages of the TP55. The co-pyrolysis reduced emissions of CO, SO2, and nitrous compounds, did not change their temperature dependency, and produced more hydrocarbon products. The TR co-pyrolysis produced more D-limonene and isoprene and inhibited the isomerization of D-limonene. The TP co-pyrolysis further decomposed diaminodiphenylmethane into low-molecular weight benzene series such as toluene and styrene. The co-pyrolytic chars had higher branching degree of aliphatic side chain and bridge bond, with the TP ones having the enhanced char aromaticity.Öğe Dynamic pyrolysis behaviors, products, and mechanisms of waste rubber and polyurethane bicycle tires(Elsevier, 2021) Tang, Xiaojie; Chen, Zihong; Liu, Jingyong; Chen, Zhiyun; Xie, Wuming; Evrendilek, Fatih; Büyükada, MusaGiven their non-biodegradable, space-consuming, and environmentally more benign nature, waste bicycle tires may be pyrolyzed for cleaner energies relative to the waste truck, car, and motorcycle tires. This study combined thermogravimetry (TG), TG-Fourier transform infrared spectroscopy (TG-FTIR), and pyrolysis-gas chromato-graphy/mass spectrometry (Py-GC/MS) analyses to dynamically characterize the pyrolysis behavior, gaseous products, and reaction mechanisms of both waste rubber (RT) and polyurethane tires (PUT) of bicycles. The main devolatilization process included the decompositions of the natural, styrene-butadiene, and butadiene rubbers for RT and of urethane groups in the hard segments, polyols in the soft segments, and regenerated isocyanates for PUT. The main TG-FTIR-detected functional groups included C-H, C=C, C=O, and C-O for both waste tires, and also, N-H and C-O-C for the PUT pyrolysis. The main Py-GC/MS-detected pyrolysis products in the decreasing order were isoprene and D-limonene for RT and 4, 4 '-diaminodiphenylmethane and 2-hexene for PUT. The kinetic, thermodynamic, and comprehensive pyrolysis index data verified the easier decomposition of PUT than RT. The pyrolysis mechanism models for three sub-stages of the main devolatilization process were best described by two-dimensional diffusion and two second-order models for RT, and the three consecutive reaction-order (three-halves order, first-order, and second-order) models for PUT.Öğe Energetic, bio-oil, biochar, and ash performances of co-pyrolysis-gasification of textile dyeing sludge and Chinese medicine residues in response to K 2 CO 3, atmosphere type, blend ratio, and temperature(Science Press, 2024) Zhang, Gang; Chen, Zhiyun; Chen, Tao; Jiang, Shaojun; Eurendilek, Fatih; Huang, Shengzheng; Tang, XiaojieHazardous waste stream needs to be managed so as not to exceed stock- and rate-limited properties of its recipient ecosystems. The co-pyrolysis of Chinese medicine residue (CMR) and textile dyeing sludge (TDS) and its bio-oil, biochar, and ash quality and quantity were characterized as a function of the immersion of K 2 CO 3 , atmosphere type, blend ratio, and temperature. Compared to the mono-pyrolysis of TDS, its co-pyrolysis performance with CMR (the comprehensive performance index (CPI)) significantly improved by 33.9% in the N 2 atmosphere and 33.2% in the CO 2 atmosphere. The impregnation catalyzed the co-pyrolysis at 370 degrees C, reduced its activation energy by 77.3 kJ/mol in the N 2 atmosphere and 134.6 kJ/mol in the CO 2 atmosphere, and enriched the degree of coke gasification by 44.25% in the CO 2 atmosphere. The impregnation increased the decomposition rate of the co-pyrolysis by weakening the bond energy of fatty side chains and bridge bonds, its catalytic and secondary products, and its bio-oil yield by 66.19%. Its bio-oils mainly contained olefins, aromatic structural substances, and alcohols. The immersion of K 2 CO 3 improved the aromaticity of the coÖğe Energetic, bio-oil, biochar, and ash performances of co-pyrolysis-gasification of textile dyeing sludge and Chinese medicine residues in response to K2CO3, atmosphere type, blend ratio, and temperature(Chinese Academy of Sciences, 2024) Zhang, Gang; Chen, Zhiyun; Chen, Tao; Jiang, Shaojun; Evrendilek, Fatih; Huang, Shengzheng; Tang, XiaojieHazardous waste stream needs to be managed so as not to exceed stock- and rate-limited properties of its recipient ecosystems. The co-pyrolysis of Chinese medicine residue (CMR) and textile dyeing sludge (TDS) and its bio-oil, biochar, and ash quality and quantity were characterized as a function of the immersion of K2CO3, atmosphere type, blend ratio, and temperature. Compared to the mono-pyrolysis of TDS, its co-pyrolysis performance with CMR (the comprehensive performance index (CPI)) significantly improved by 33.9% in the N2 atmosphere and 33.2% in the CO2 atmosphere. The impregnation catalyzed the co-pyrolysis at 370°C, reduced its activation energy by 77.3 kJ/mol in the N2 atmosphere and 134.6 kJ/mol in the CO2 atmosphere, and enriched the degree of coke gasification by 44.25% in the CO2 atmosphere. The impregnation increased the decomposition rate of the co-pyrolysis by weakening the bond energy of fatty side chains and bridge bonds, its catalytic and secondary products, and its bio-oil yield by 66.19%. Its bio-oils mainly contained olefins, aromatic structural substances, and alcohols. The immersion of K2CO3 improved the aromaticity of the co-pyrolytic biochars and reduced the contact between K and Si which made it convenient for Mg to react with SiO2 to form magnesium-silicate. The co-pyrolytic biochar surfaces mainly included -OH, -CH2, C=C, and Si-O-Si. The main phases in the co-pyrolytic ash included Ca5(PO4)3(OH), Al2O3, and magnesium-silicate. © 2022Öğe Oxy-fuel and air atmosphere combustions of Chinese medicine residues: Performances, mechanisms, flue gas emission, and ash properties(Pergamon-Elsevier Science Ltd, 2022) Chen, Zhiyun; Liu, Jingyong; Chen, Huashan; Ding, Ziyi; Tang, Xiaojin; Evrendilek, FatihThis study aims to quantify the combustion performances, mechanisms, and ash characteristics of Chinese medicine residues (CMR) in the air and oxy-fuel atmospheres. The CMR combustion underwent water loss (<150 degrees C) and the decomposition of the main organic components (150-560 degrees C). The CMR combustion performed better in the air than 8-2/CO2-O-2 atmosphere experimentally, as was also evidenced by the joint optimization based on artificial neural network. The rising oxygen fraction of the three oxy-fuel atmospheres improved the oxy-fuel combustion performance by 76.7%. The air atmosphere led to a higher activation energy at the start (275.15 kJ/mol) and end (520.91 kJ/mol) of the main reaction, while the oxy-fuel atmosphere resulted in a higher activation energy of 400.22 kJ/mol with the conversion degree of 0.7. Its reaction mechanism followed the sequence type (Fn) and changed from F3 to F2 in the 8-2/CO2-O-2 atmosphere and from F2.4 to F2.5 in the air atmosphere and flue gas functional groups included CO2, H2O, C=O, and C-(O)H. The oxy-fuel atmosphere was more prone to slagging than the air atmosphere. The ash in the oxy-fuel atmosphere was easily formed calcium carbonate and calcium hydroxyphosphate. (C) 2021 Elsevier Ltd. All rights reserved.
