Yazar "Wu, Xieyuan" seçeneğine göre listele

Listeleniyor 1 - 7 / 7
  • Küçük Resim
    Öğe
    Co-combustion of Zn/Cd-hyperaccumulator and textile dyeing sludge: Heavy metal immobilizations, gas-to-ash behaviors, and their temperature and atmosphere dependencies
    (Elsevier, 2023) Wu, Xieyuan; Chen, Zhiliang; Liu, Jingyong; Wei, Zebin; Chen, Zihong; Evrendilek, Fatih; Sun, Shuiyu; Chen, Zhibin
    This study quantified and revealed the temperature and atmosphere dependencies of the enrichment rates and speciation distributions of Zn and Cd and the behaviors of Cl and S for the co-combustion of a hyperaccumulator (SAH) of Zn and Cd and textile dyeing sludge (TDS) at a blend ratio of 3:1 (ST31). The addition of Al-rich TDS to SAH provided the chemisorption sites for Zn and Cd and generated stable Al/Si structures for their stabilization in the ST31 ash. The rising temperature and the atmosphere change from N-2/O-2 to CO2/O-2 transformed Zn and Cd into their oxidizable and residual fractions. Cl promoted the volatilizations of the heavy metals, with its content in the ST31 ash falling from 86.28% at 650 ? to 17.98% at 950 ?. The S content (31.08-33.86%) of the ST31 ash existed mainly as CaSO4 and was slightly higher in the CO2/O-2 than N-2/O-2 atmosphere (29.45%) since the high CO2 concentration adversely influenced the decomposition of CaCO3, while S indirectly affected the migrations of Zn and Cd. The combined results of the experiments, thermodynamic simulations, and multi-objective optimization pointed to 850 ? in the oxy-fuel atmosphere with 30% O-2 concentration as the optimal settings in order to stabilize Zn and Cd with an acceptable risk. The possible reaction pathways and immobilization mechanisms were also derived considering the interactions among minerals, Zn, Cd, Cl, and S.
  • Küçük Resim Yok
    Öğe
    Co-combustion of Zn/Cd-hyperaccumulator and textile dyeing sludge: Heavy metal immobilizations, gas-to-ash behaviors, and their temperature and atmosphere dependencies
    (Elsevier Science Sa, 2023) Wu, Xieyuan; Chen, Zhiliang; Liu, Jingyong; Wei, Zebin; Chen, Zihong; Evrendilek, Fatih; Sun, Shuiyu
    This study quantified and revealed the temperature and atmosphere dependencies of the enrichment rates and speciation distributions of Zn and Cd and the behaviors of Cl and S for the co-combustion of a hyperaccumulator (SAH) of Zn and Cd and textile dyeing sludge (TDS) at a blend ratio of 3:1 (ST31). The addition of Al-rich TDS to SAH provided the chemisorption sites for Zn and Cd and generated stable Al/Si structures for their stabilization in the ST31 ash. The rising temperature and the atmosphere change from N-2/O-2 to CO2/O-2 transformed Zn and Cd into their oxidizable and residual fractions. Cl promoted the volatilizations of the heavy metals, with its content in the ST31 ash falling from 86.28% at 650 ? to 17.98% at 950 ?. The S content (31.08-33.86%) of the ST31 ash existed mainly as CaSO4 and was slightly higher in the CO2/O-2 than N-2/O-2 atmosphere (29.45%) since the high CO2 concentration adversely influenced the decomposition of CaCO3, while S indirectly affected the migrations of Zn and Cd. The combined results of the experiments, thermodynamic simulations, and multi-objective optimization pointed to 850 ? in the oxy-fuel atmosphere with 30% O-2 concentration as the optimal settings in order to stabilize Zn and Cd with an acceptable risk. The possible reaction pathways and immobilization mechanisms were also derived considering the interactions among minerals, Zn, Cd, Cl, and S.
  • Küçük Resim
    Öğe
    Emission-to-ash detoxification mechanisms of co-combustion of spent pot lining and pulverized coal
    (Elsevier, 2021) Chen, Zihong; Liu, Jingyong; Chen, Laiguo; Evrendilek, Fatih; Xie, Wuming; Wu, Xieyuan
    In response to the global initiative for greenhouse gas emission reduction, the co-combustion of coal and spent pot lining (SPL) may cost-effectively minimize waste streams and environmental risks. This study aimed to quantify the emission-to-ash detoxification mechanisms of the co-combustion of SPL and pulverized coal (PC) and their kinetics, gas emission, fluorine-leaching toxicity, mineral phases, and migrations. The main reaction covered the ranges of 335-540 ?C and 540-870 ?C while the interactions occurred at 360-780 ?C. The apparent activation energy minimized (66.99 kJ/mol) with 90% PC addition. The rising PC fraction weakened the peak intensity of NaF and strengthened that of Ca2F, NaAlSiO4, and NaAlSi2O6. The addition of PC enhanced the combustion efficiency of SPL and raised the melting temperature by capturing Na. PC exhibited a positive effect on solidifying water-soluble fluorine and stabilizing alkali and alkaline earth metals. The leaching fluorine concentrations of the co-combustion ashes were lower than did SPL mono-combustion. The main gases emitted were HF, NH3, NOx, CO, and CO2. HF was largely released at above 800 ?C. Multivariate Gaussian process modelbased optimization of the operational conditions also verified the gas emissions results. Our study synchronizes the utilization and detoxification of SPL though co-combustion and provides insights into an eco-friendlier lifecycle control on the waste-to-energy conversion.
  • Küçük Resim
    Öğe
    Flue gas-to-ash desulfurization of combustion of textile dyeing sludge: Its dependency on temperature, lignocellulosic residue, and CaO
    (Elsevier B.V., 2020) Huang, Jianli; Wu, Xieyuan; Liu, Jingyong; Chang, Kenlin; Evrendilek, Fatih; Liang, Guanjie
    Flue gas-to-ash controls on sulfur (S) species of the combustion of textile dyeing sludge (TDS) are pivotal in the achievement of circular and cleaner economies. This experimental study aimed to characterize S transformations in TDS as a function of temperature (600–1000 °C) and blend ratios of spent mushroom substrate (SMS) and calcium oxide (CaO) through thermodynamic equilibrium simulations. The conversion ratio of S to flue gas from the mono-combustion of TDS rose by 29.7% between 600 and 1000 °C and was 92.9% at 1000 °C. The increasing sulfur dioxide (SO2) emission with the high temperature occurred from the decomposition of sulfates. The conversion of S to SO2 decreased significantly with an increase in SMS from 10 to 50% and enhanced the S distribution in fly ash. Potassium and phosphorous in SMS appeared to play a significant role in the conversion of S. The addition of CaO exhibited a good desulfurization performance, with the S content of ash peaking at 5.2% at 800 °C with 7% CaO. The desulfurization efficiency of CaO highly depended on the temperature and blend ratios. The addition of SMS facilitated the agglomeration to form large particles at 1000 °C and formed more micro pores on their surfaces. Our equilibrium simulations pointed to the important role of CaO-assisted co-combustion versus mono-combustion of TDS in the S retention as well as to the enhanced decomposition of calcium sulfate (CaSO4) by SMS. Chlorine had a better affinity toward potassium to promote the release of gaseous potassium chloride (KCl) which in turn appeared to react with SO2 in flue gas and formed sulfates through sulfation reaction.
  • Küçük Resim
    Öğe
    Gas-to-ash detoxification feasibility and pathways by co-combustion of spent pot lining and food waste shells
    (Elsevier Science Ltd, 2022) Chen, Zihong; Liu, Jingyong; Wu, Xieyuan; Liu, Weizhen; Zhang, Gang; Evrendilek, Fatih
    Seeking substitutions for Ca-bearing reagents, this study explored the synergistic co-disposal and co-circularity of spent pot lining (SPL) and food waste shells (oyster, clam, and egg shells) in an eco-friendly way. This study is first to evaluate the feasibility of their co-combustions with or without their mechanochemical activation (MCA) toward the gas-to-ash detoxification of fluorine (F). 50% calcined oyster shell fixed about 97.87% of the F content of SPL in the blend ash and outperformed 50% CaO. MCA weakened the diffraction peaks of graphite carbon by favoring the fixation performance through which collisions between particles and the mixing uni-formity were promoted. The combination of 10% SiO2 and 40% calcined clam or egg shells raised the F fixation rate to 98.72 and 99.23%, respectively. F was converted to the complex F-Si-Ca compounds rather than to CaF2. Ca and Si compounds facilitated stabilizing F and Na synchronously and formed NaCa2SiO4F. The leaching F concentration of the ash was less than 100 mg/L, meeting the Chinese criterion (GB 5085.3-2007). The recycling of the food waste shells performed effectively in the cleaner disposal process of SPL by suppressing fluorine emissions.
  • Küçük Resim
    Öğe
    Oxy-fuel and air combustion performances and gas-to-ash products of aboveground and belowground biomass of Sedum alfredii Hance
    (ELSEVIER SCIENCE SA, 2021) Wu, Xieyuan; Wei, Zebin; Liu, Jingyong; Chen, Zihong; Evrendilek, Fatih
    The eco-friendly disposal choices of phytoremediation biomass still remain to be explored. This study characterized the combustions of Sedum alfredii Hance (SAH) in response to its aboveground (SAH-A) and belowground (SAH-B) parts, the oxy-fuel (CO2/O2) and air (N2/O2) atmospheres, temperature, and heating rate. The decomposition behaviors, gas-to-ash characteristics, thermo-kinetic parameters, and mineral transformations were quantified. In both atmospheres, the combustion performances were better for SAH-A than SAH-B at the same heating rate. In the range of 400.0-598.8 degrees C, the maximum mass loss rate of both samples obviously decreased and delayed with CO2 replacing N2 at the same oxygen concentration. The SAH-A and SAH-B combustions in both atmospheres emitted C- (CO2, CO, CH4, and small molecular organic substances) and N-containing (HCN and NH3) gases. In both atmospheres, the temperature dependency of the gas emissions remained the same. Both empirical indices and ternary phase diagrams indicated that both samples had a high deposition risk. Thermochemical equilibrium simulations were used to predict the slagging risk in response to ash mineral transformations. Our findings can provide new insights into the combustion dynamics of phytoremediation biomass and its effect on CO2 capture, utilization, and storage in mitigating climate change.
  • Küçük Resim
    Öğe
    Oxy-fuel co-combustion dynamics of phytoremediation biomass and textile dyeing sludge: Gas-to-ash pollution abatement
    (Elsevier, 2022) Wu, Xieyuan; Liu, Jingyong; Wei, Zebin; Chen, Zihong; Evrendilek, Fatih; Huang, Wenxiao
    The environmental pressures of major wastes in the circular economies can be abated leveraging the complementarity and optimal conditions of their co-combustion. The oxy-fuel co-combustion of phytoremediation biomass of Sedum alfredii Hance (SAH) and textile dyeing sludge (TDS) may be a promising choice for sustainable CO2 capture and a waste-to-energy conversion. This study characterized and quantified their co-combustion performances, kinetics, and interactions as a function of blend ratio, atmosphere type, and temperature. With a focus on the characteristic el-ements of SAH (Ca, K, Zn, and Cd) and TDS (Al and S), changes in the mineral phases and ash melting and slagging trends of K2O-Al2O3-SiO2 and CaO-Al2O3-SiO2 systems were quantified. The Zn and Cd residual rates of the co-combustion of 75% SAH and 25% TDS rose by 58.52% and 5.93%, respectively, in the oxy-fuel atmosphere at the 30% oxygen concentration, relative to the mono-combustion of SAH in the air atmosphere. The co-combustion in the oxy-fuel atmosphere at the 20% oxygen concentration delayed the release peaks of SO2, C2S, and H2S, while the Ca-rich SAH captured S in TDS through the formation of CaSO4. Our findings provide new and practical insights into the oxy-fuel co-combustion toward the enhanced co-circularity.