Yazar "Liu, Chao" seçeneğine göre listele

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    Bioenergy and emission characterizations of catalytic combustion and pyrolysis of litchi peels via TG-FTIR-MS and Py-GC/MS
    (Pergamon-Elsevier Science Ltd, 2020) Liu, Chao; Liu, Jingyong; Evrendilek, Fatih; Xie, Wuming; Kuo, Jiahong; Büyükada, Musa
    This study characterized the catalytic combustions and emissions of litchi peels as a function of five catalysts as well as the effect of the best catalyst on the pyrolysis by-products. Na2CO3 and K2CO3 accelerated the devolatilization but delayed the coke burnout, while Al2O3 enhanced the coke oxidation rate. Both comprehensive combustion index and average activation energy dropped with the added catalysts. CO2, CO, and H2O were the main combustion gases between 300 and 510 degrees C. CO2, C-H, C=O, and C-O were generated from the pyrolysis between 200 and 430 degrees C above which CO2 and CH4 were slightly released. Total H2O, CO2, CO, NOx and SOx emissions declined with the added catalysts among which K2CO3 performed better. The main pyrolytic by-products at 330 degrees C were terpenoids and steroids (71.87%), phenols (15.51%), aliphates (9.95%), and small molecules (2.78%). At 500 degrees C, terpenoids and steroids (78.35%), and small molecules (3.20%) rose, whereas phenols (12.87%), and aliphates (5.83%) fell. Fatty acid, and ester decreased, while terpenoids, and steroids increased with MgCO3 at 330 degrees C. Litchi peels appeared to be a promising biowaste, with MgCO3 as the optimal catalytic option in terms of the bioenergy performance, and emission reduction. (C) 2019 Elsevier Ltd. All rights reserved.
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    Evaluation of reaction mechanisms and emissions of oily sludge and coal co-combustions in O-2/CO2 and O-2/N-2 atmospheres
    (PERGAMON-ELSEVIER SCIENCE LTD, 2021) Zou, Huihuang; Liu, Chao; Evrendilek, Fatih; He, Yao; Liu, Jingyong
    Oxy-fuel combustion technology presents promising potential for the thermal disposal of hazardous waste to alleviate the global greenhouse effect on the environment and human well-being. In this study, the co-combustion reaction mechanisms and cleaner and efficient performances of oily sludge (OS) and coal in the oxy-fuel (O-2/CO2) and air (O-2/N-2) atmospheres were characterized. With O-2 concentration of 21% and at 20 degrees C/min, the ignition and burnout temperatures of the OS combustion were slightly worse in the oxy-fuel (403 and 531 degrees C) than air (407 and 535 degrees C) atmosphere. The rising O-2 concentration increased the comprehensive combustion characteristic index from 1.11 x 10(-7) to 4.29 x 10(-7) in the air atmosphere and 1.02 x 10(-7) to 4.10 x 10(-7) in the oxy-fuel atmosphere. Based on the master-plots method, the three combustion stages of light oil, heavy oil, and fixed carbon were best described by the three-dimensional diffusion, interfacial reaction, and random nucleation growth models, respectively. The reaction mechanisms were independent of heating rate, O-2 concentration, and atmosphere type. The co-combustion interaction between 70% OS and 30% coal reduced NO and SO2 emissions. Our findings can provide new insights into achieving their cleaner and more efficient co-combustion performance and its operational optimization. (C) 2021 Elsevier Ltd. All rights reserved.
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    The mixture of sewage sludge and biomass waste as solid biofuels: Process characteristic and environmental implication
    (Pergamon-Elsevier Science Ltd, 2019) Chen, Jiacong; He, Yao; Liu, Jingyong; Liu, Chao; Xie, Wuming; Büyükada, Musa; Evrendilek, Fatih
    Oxy-fuel and air atmospheres were used to (co-)combust sewage sludge (SS) and biomass waste, coffee ground residues (CG) via thermogravimetric analysis (TGA). The combustion behavior of SS did not differ significantly in both atmospheres. The replacement of 79%N-2 by 79%CO2 significantly influenced the char combustion of CG. Synergistic effect of the blends in the oxy-fuel was weaker than air condition. Activation energy of the co-combustion in the second stage was lower in the oxy-fuel than air atmosphere. The gaseous emissions during blend fuel combustion were investigated by online mass spectrometry (MS). Results show that the gas emissions of different fuels show different stage characteristics. CH3, H2O, C2H2 and NO emissions peaked from the volatiles combustion of CG, while the co-combustion led to SO2 increment. Besides, the composition of the solid residues was examined by X-ray fluorescence spectrometer (XRF), and their impact on environment was evaluated. The compositions of the solid residues pointed to the ability of SS to lower the fouling and slagging risks of CG. This investigation aimed to afford a fully understanding for the co-combustion progress of SS and CG under air and oxy-fuel environments and its implication for environment. (C) 2019 Elsevier Ltd. All rights reserved.
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    Thermodynamic behaviors of Cu in interaction with chlorine, sulfur, phosphorus and minerals during sewage sludge co-incineration
    (Chemical Industry Press, 2018) Liu, Jingyong; Liu, Chao; Sun, Guang; Xie, Wuming; Dang, Xiao'e; Kuo, Jiahong; Chang, Kenlin; Büyükada, Musa; Evrendilek, Fatih
    Thermodynamic equilibrium calculations were performed to reveal effects of interactions among Cl, S, P and other minerals on Cu migration. Our results showed that HCl(g), SO2(g) and (P2O5)(2)(g) were released from the sewage sludge co-incineration. Cl was found to weaken adsorption of Cu by Al2O3, CaO and Fe2O3, while S delayed reactions of Fe2O3 and Al2O3 with Cu, with P having no effect on reactions between the minerals and Cu. Among the coupled systems of Cl,S and P, the co-existences of Cl and S, and Cl, S and P were determined to inhibit Cu volatilization, and the co-existence of Cl and P had an enhancing effect. Cu migration was affected only by S in the S and P system. With the SiO2, CaO and Al2O3 system, both Cl alone and Cl and P led to failed reactions between the minerals and Cu. In the systems of S, S and Cl, S and P, and S, Cl and P, the migration behavior of Cu was mainly affected by S at low temperatures and by Cl at high temperatures, whereas P had no effect on Cu migration during the entire process. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.
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    Thermogravimetric analysis of (co-)combustion of oily sludge and litchi peels: combustion characterization, interactions and kinetics
    (Elsevier Science Bv, 2018) Liu, Chao; Liu, Jingyong; Sun, Guang; Xie, Wuming; Kuo, Jiahong; Büyükada, Musa; Evrendilek, Fatih
    The thermal characteristics and kinetics of oily sludge, litchi peels and their blends were comprehensively evaluated using thermogravimetric experiments under air atmosphere. Results showed that devolatilization, ignition and burnout indices of litchi peels were higher than those of oily sludge, with better combustion characteristics. However, co-combustion performance decreased with increased litchi peels & action. Such interactions as inhibition effect on devolatilization and promotion effect on char oxidation of oily sludge occurred. Average activation energy was estimated at 118.1 kJ/mol for oily sludge and 215.2 kJ/mol for litchi peels using the Kissinger-Akahira-Sunose integral method and reached its minimum value with the addition of 15%-20% litchi peels. Trend of activation energy was consistent with the interaction analysis during co-combustion process. Kinetic triplets were also estimated using the integral master-plots method, while the most suitable reaction model for three stages of oily sludge and their blends was proposed.