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Ash-to-emission pollution controls on co-combustion of textile dyeing sludge and waste tea
(Elseiver, 2021) Cai, Haiming; Liu, Jingyong; Kuo, Jiahong; Xie, Wuming; Evrendilek, Fatih; Zhang, Gang
Given the globally increased waste stream of textile dyeing sludge (TDS), its co-combustion with agricultural residues appears as an environmentally and economically viable solution in a circular economy. This study aimed to quantify the migrations and chemical speciations of heavy metals in the bottom ashes and gas emissions of the co-combustion of TDS and waste tea (WT). The addition of WT increased the fixation rate of As from 66.70 to 83.33% and promoted the chemical speciation of As and Cd from the acid extractable state to the residue one. With the temperature rise to 1000 degrees C, the fixation rates of As, Cd, and Pb in the bottom ashes fell to 27.73, 8.38, and 15.40%, respectively. The chemical speciation perniciousness of Zn, Cu, Ni, Mn, Cr, Cd, and Pb declined with the increased temperature. The ash composition changed with the new appearances of NaAlSi3O8, CaFe2O4, NaFe(SO4)(2), and MgCrO4 at 1000 degrees C. The addition of WT increased CO2 and NOx but decreased SO2 emissions in the range of 680-1000 degrees C. ANN-based joint optimization indicated that the co-combustion emitted SO2 slightly less than did the TDS combustion. These results contribute to a better understanding of ash-to-emission pollution control for the co-combustion of TDS and WT. (C) 2021 Elsevier B.V. All rights reserved.
Bottom slag-to-flue gas controls on S and Cl from co-combustion of textile dyeing sludge and waste biochar: Their interactions with temperature, atmosphere, and blend ratio
(Elseiver, 2022) Huang, Hongyi; Liu, Jingyong; Evrendilek, Fatih; Zhang, Gang; Sun, Shuiyu; He, Yao
S and Cl distribution patterns and their evolution pathways were quantified during the co-combustions of textile dyeing sludge (TDS) and waste biochar (BC). S in the flue gas rose from 10.60% at 700 degrees C to 45.09% at 1000 degrees C for the mono-combustion of TDS in the air atmosphere. At 1000 degrees C, S in the bottom slag and flue gas grew by 2.65% and fell by 2.11%, respectively, for the TDS mono-combustion in the 30%O2/70%CO2 atmosphere. The 40% BC addition increased the S retention in the bottom slag by 30.39% and decreased its release to the flue gas by 34.50% by changing the evolution of CaSO4 and enabling more K to fix S as K2SO4. The decomposition of inorganic Cl was the main source of the Cl-containing gases. The 20%O2/80%CO2 atmosphere (36.29%) and 40% BC addition (27.26%) had higher Cl in the bottom slag than did TDS mono-combusted at 1000 degrees C (25.60%) by inhibiting the decomposition of organic Cl. Our study provides insights into the co-combustion of TDS and BC and controls on S and Cl for a cleaner production. Future research remains to conducted to verify scale-up experiments.
(Co-)combustion behaviors and products of spent potlining and textile dyeing sludge
(Elsevier Sci Ltd, 2019) Sun, Guang; Zhang, Gang; Liu, Jingyong; Xie, Wuming; Evrendilek, Fatih; Büyükada, Musa
Co-combustion performances, ashes, gases and thermodynamics were quantified for spent potlining (SPL) and textile dyeing sludge (TDS) (with)out CaO. During the four decomposition stages of the blends according to the (D)TG experiments, the interaction among Na, Ca, F, Al, and S led to CaAl2O4, CaF2, and Na2SO4 which converted inorganic compounds into ash. Increased comprehensive combustion index, and decreased burnout temperature with 50% SPL indicated a better combustion and char burnout, and a shorter combustion process. CaO reduced the F volatilization and increased F- in the residual ash with 10% CaO. NaF was completely converted into CaF2 reducing the toxicity of soluble F- in the residual ash. The predom diagram of Na-Ca-F-S using thermal simulations showed the stable existence regions of CaF2 and Na2SO4. The changed migration mechanisms of F- and S caused ash compositions to consist of Na2SO4 and CaF2 for the co-combustions, and of NaF and CaSO4 for the mono-combustions. 10% CaO promoted CaF2, Na2SO4, CaAl2O4, and to a lesser extent, Fe2O3. The main gases evolved from the co-combustion included HF, SO2, COS, CS2, HCN, NH3, NO, and NO2. (C) 2019 Elsevier Ltd. All rights reserved.
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, Xiaojie
Hazardous 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 co
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, Xiaojie
Hazardous 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. © 2022
Fates of heavy metals, S, and P during co-combustion of textile dyeing sludge and cattle manure
(Elseiver, 2023) Zhang, Junhui; Chen, Jiacong; Liu, Jingyong; Evrendilek, Fatih; Zhang, Gang; Chen, Zhibin
The co-combustion of textile dyeing sludge (TDS) and cattle manure (CM) may enhance circularity in terms of resource and pollution controls. However, the pollutant migrations and transformations of ashes and their characterization during the co-combustion are still unclear. This study aimed to quantify the transformation and migration behaviors of the co-combustion ashes, as well as the interactions involved via thermogravimetric experiments and thermodynamic simulations. The addition of TDS facilitated the conversions of Ni and Cr from the extractable form to the stable one, increasing their environmental safety. P dominated S for the reaction with Ca which promoted the generation of S-containing gas emission and apatite P. The reactions between the minerals in CM and Ca in TDS generated calcium silicate, decreasing the S-fixation ability of Ca, while increasing the emission of S-containing gases. Our findings provide insights into the interactions among the minerals, the heavy metals, and the specific elements and their impacts on pollutant emissions, thus enhancing pollution control strategies.
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.
Performance and mechanism of bamboo residues pyrolysis: Gas emissions, by-products, and reaction kinetics
(Elseiver, 2022) Zhang, Gang; Feng, Qiuyuan; Hu, Jinwen; Sun, Guang; Evrendilek, Fatih; Liu, Hui; Liu, Jingyong
The performances and reaction kinetics of the bamboo shoot leaves (BSL) pyrolysis were characterized integrating thermogravimetry, Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography/mass spectrometry analyses. The high volatiles and low ash, N, and S contents of BSL rendered its pyrolysis suitable for bio-oil generation. The main mass loss of BSL pyrolysis occurred in the devolatilization stage between 200 and 550 C. The peak temperatures of pseudo-hemicellulose, cellulose and lignin pyrolysis in BSL were 248.04, 322.65 and 383.51 C, respectively, while their average activation energies estimated by Starink method were 144.29,175.79 and 243.02 kJ/mol, respectively. The one-dimensional diffusion mechanism (f (alpha) = 1/(2 alpha)) best elucidated the hemicellulose reaction. The cellulose (f (alpha) = 0.74 (1 - alpha)[-ln (1 - alpha)]-13/37) and lignin (f (alpha) = 0.35 (1 - alpha)[-ln (1 - alpha)]-13/7) reactions were best described by the nucleation mechanisms. The estimated kinetic triplets accurately predicted the pyrolysis process. 619.3 C and 5 C/min were determined as the optimal pyrolytic temperature and heating rate. The C-containing gases were dominant among the non-condensable gases evolved from the pyrolysis. The NO(x )precursors (NH3 and HCN) were found more important than NO emission in pollution control. 2,3-dihydrobenzofuran, (1-methylcyclopropyl) methanol, heptanal, acetic acid, and furfurals were the main pyrolytic by-products. BSL-derived biochar is a relatively pure carbon-rich material with extremely low N and S content. The BSL pyrolysis yielded a promising performance, as well as value-added by-products to be utilized in the fields of bioenergy, fragrance, and pharmaceuticals.
Thermal behaviors of fluorine during (co-)incinerations of spent potlining and red mud: Transformation, retention, leaching and thermodynamic modeling analyses
(Pergamon-Elsevier Science Ltd, 2020) Zhang, Gang; Sun, Guang; Liu, Jingyong; Evrendilek, Fatih; Büyükada, Musa; Xie, Wuming
Spent potlining (SPL) as a hazardous solid waste has a high content of inorganic fluorine. This study aimed at characterizing its transformation, retention and leaching behaviors with(out) the addition of red mud (RM) during the SPL incineration. The RM addition positively affected its retention and leaching rates. Its Ca-containing compounds caused Na3AlF6 and NaF to turn into more CaF2. 30% RM converted water-soluble NaF into more stable CaF2 than did SPL at 850 degrees C, thus reducing the leaching rate by 45.15%. 30% RM captured HF through its Ca content and enhanced its retention rate by 66.96%. 66.01% of the total fluorine was stably retained in the bottom ash, and thus, significantly reduced the toxicity of the SPL incineration products. SiO2 and Al2O3 exerted a thermally positive effect on NaF turning into CaF2. The fluoride retention of the bottom ash was mainly dominated by CaF2 and NaF with(out) RM. Smaller, coarser and more loose structures of the co-incinerated solid particles pointed to a synergistic interaction between SPL and RM. (C) 2020 Elsevier Ltd. All rights reserved.
Thermal behaviors, combustion mechanisms, evolved gasses, and ash analysis of spent potlining for a hazardous waste management
(Chinese Academy of Sciences, 2021) Sun, Guang; Zhang, Gang; Liu, Jingyong; Evrendilek, Deniz Eren; Büyükada, Musa
An unavoidable but reusable waste so as to enhance a more circular waste utilization has been spent potlining (SPL) generated by the aluminum industry. The combustion mechanisms, evolved gasses, and ash properties of SPL were characterized dynamically in response to the elevated temperature and heating rates. Differential scanning calorimetric (DSC) results indicated an exothermic reaction behavior probably able to meet the energy needs of various industrial applications. The reaction mechanisms for the SPL combustion were best described using the 1.5-, 3- and 2.5-order reaction models. Fluoride volatilization rate of the flue gas was estimated at 2.24%. The SPL combustion emitted CO2, HNCO, NO, and NO2 but SOx. The joint optimization of remaining mass, derivative thermogravimetry, and derivative DSC was achieved with the optimal temperature and heating rate combination of 783.5 °C, and 5 °C/min, respectively. Interaction between temperature and heating rate exerted the strongest and weakest impact on DSC and remaining mass, respectively. The fluorine mainly as the formation of substantial NaF and CaF2 in the residual ash. Besides, the composition and effect of environment of residual solid were evaluated. The ash slagging tendency and its mineral deposition mechanisms were elucidated in terms of turning SPL waste into a benign input to a circular waste utilization.
Thermogravimetric and mass-spectrometric analyses of combustion of spent potlining under N-2/O-2 and CO2/O-2 atmospheres
(Pergamon-Elsevier Science Ltd, 2019) Sun, Guang; Zhang, Gang; Liu, Jingyong; Xie, Wuming; Kuo, Jiahong; Lu, Xingwen; Büyükada, Musa; Evrendilek, Fatih
Thermal decomposition and gaseous evolution of the spent potlining (SPL) combustion were quantified using thermogravimetric and mass-spectrometric analyses in CO2/O-2 and N-2/O-2 atmospheres using three heating rates (15, 20 and 25 degrees C/min). The thermal decomposition of SPL occurred mainly between 450 and 800 degrees C. Based on the four kinetic methods of Friedman, Starink, Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa under the various conversion degrees (alpha) from 0.1 to 0.7, the lowest apparent activation energy was estimated at 149.81 kJ/mol in the 70% CO2 /30% O-2 atmosphere. The pre-exponential factor, and changes in entropy, enthalpy and free Gibbs energy were also estimated. The reaction model did not suggest a single reaction of the SPL combustion. With the alpha value of 0.25-0.7, the following function best described the reaction based on the Malek method: f(alpha) = 1/2 alpha and G(alpha) = ln alpha(2). The gases released during the combustion process included CO2, CO, NOx, HCN, and HF. (C) 2019 Elsevier Ltd. All rights reserved.
Torrefaction-assisted oxy-fuel co-combustion of textile dyeing sludge and bamboo residues toward enhancing emission-to-ash desulfurization in full waste circularity
(Elsevier Science Ltd, 2022) Hu, Jinwen; Song, Yueyao; Liu, Jingyong; Evrendilek, Fatih; Zhang, Gang
Emission-to-ash desulfurization and full waste circularity can be enhanced by the proper selection of multiple wastes and operational conditions. In this context, a new combination of textile dyeing sludge (TDS), bamboo residues (BR), torrefaction, and oxy-fuel (O-2/CO2) atmosphere was proposed in this study. Their blend (0.5TDS) torrefied at 250 degrees C (T250) improved its co-combustion performance by 17.30% based on the comprehensive combustion index (CCI). The CCI value of T250 in the oxy-fuel atmosphere of 20% O-2/80% CO2 was about 3.6 times that of the mono-combustion of TDS in the air atmosphere. The co-combustion interaction reduced SO2 emission since the increased alkali metals and alkaline earth metals (especially K) preferentially reacted with S to form sulfate at <= 700 degrees C. Compared to the air mono-combustion of TDS, T250 in 20% O-2/80% CO2 reduced SO2 emission (mg/MJ) by 55.09%. With the temperature rise from 700 to 900 ?, K-sulfate was completely transformed into aluminosilicate and released the captured SO2 in which case Ca became the main S-fixing agent. The shift from air to 20% O-2/80% CO2 retained sulfate in the bottom ash. Our findings provide new and practical insights into sustainable, efficient, and clean co-combustion and energy utilization.
Turning the co-combustion synergy of textile dyeing sludge and waste biochar into emission-to-bottom slag pollution controls toward a circular economy
(Pergamon-Elsevier Science Ltd, 2022) Huang, Hongyi; Liu, Jingyong; Liu, Hui; Evrendilek, Fatih; Zhang, Gang; He, Yao
The co-combustion performance of textile dyeing sludge (TDS) and waste biochar (BC) was explored in terms of their decomposition behaviors, gas emission patterns, bottom slag characteristics, and elemental transformations. The decompositions of both TDS and BC were divided into four stages, with the largest heat release from the fixed carbon combustion. Their synergy effect occurred in the range of 530-700 degrees C. The average activation energy was 172.13 kJ/mol for TDS, 250.31 kJ/mol for BC, and lowest (169.41 kJ/mol) for 60TDS40BC (60% TDS and 40% BC). The 40% BC addition decreased total SO2 emission by 70.79% but increased total NO emission by 19.43% when compared to the TDS mono-combustion at 1000 degrees C. The 40% BC addition inhibited the formations of sulfoxide, sulfone/sulfonic acid, and amine nitrogen, as well as the decomposition of sulfate but promoted the decomposition of pyridinic nitrogen. The main mineral phases of the bottom slags at 700 degrees C included Fe2O3 and CaSO4 for TDS, while that for 60TDS40BC was CaSO4, NaCl, and K5Al5Si3O16. Our results provide new ideas for the resource utilization and pollution control of TDS and BC, make the disposal of TDS cleaner and more efficient, and help to promote the sustainable development of the environment.
Water-soluble fluorine detoxification mechanisms of spent potlining incineration in response to calcium compounds
(Elsevier Sci Ltd, 2020) Zhang, Gang; Sun, Guang; Chen, Zihong; Evrendilek, Fatih; Liu, Jingyong
In this study, the detoxification mechanisms of water-soluble fluorine in the bottom ash and the distribution of fluorine during the spent potlining (SPL) incineration were characterized in response to four calcium compounds using an experimental tube furnace. CaSiO3, CaO, Ca(OH)(2), and CaCO3-assisted SPL incineration converted NaF to low toxicity compounds in the bottom ash yielding a conversion range of 54.24-99.45% relative to the individual SPL incineration. The two main mechanisms of the fluorine transformation were the formations of CaF2 and Ca4Si2O7F2. The fluorine transformation efficiency was greater with CaSiO3 than CaO, Ca(OH)(2), and CaCO3. Our simulations demonstrated that SiO2 enhanced the conversion of NaF. The fluorine leaching content of the bottom ash was estimated at 13.71 mg,L-1 after the SPL co-incineration with CaSiO3 (Ca:F = 1.2:1). The acid-alkali solutions had no significant effect on the fluorine leaching content of the bottom ash when 3 <= pH <= 12. Fluorine during the SPL co-incineration with CaSiO3 (Ca:F = 1.2:1) at 850 degrees C for 60 min was partitioned into 83.37, 13.90, and 2.72% in the bottom ash, fly ash, and flue gas, respectively. The transformation and detoxification mechanisms of water-soluble fluorine provide new insights into controls on fluorine emission from the SPL incineration. (C) 2020 Elsevier Ltd. All rights reserved.

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