Frontiers of Environmental Science & Engineering
·
2021
·Vol. 16
·期 7
·1-13
·
IF 4.357
Li Qian,Zhong Zhaoping,Du Haoran,Zheng Xiang,Zhang Bo,Jin Baosheng
Pyrolysis is a promising technique used for treating of sewage sludge. However, the application of pyrolysis products is limited due to the presence of heavy metals. In this study, sewage sludge mixed with kaolin/zeolite was pyrolyzed in a rotary kiln, aiming to improve the immobilization of heavy metals in pyrolytic carbon. The total concentrations, speciation distributions, leaching toxicities, and potential ecological risk indices of heavy metals in pyrolysis biochar were explored to examine the effects of kaolin/zeolite and pyrolytic temperature on immobilizing heavy metals. Further, mineral composition and surface morphology of biochar were characterized by X-ray diffraction and scanning electron microscopy to reveal the potential mechanism of immobilizing heavy metals. Increasing pyrolysis temperature facilitated the stabilization of heavy metals in pyrolysis biochar. The proportions of stable heavy metals in biochar obtained at 650°C were 54.50% (Cu), 29.73% (Zn), 79.29% (Cd), 68.17% (Pb) and 86.70% (Cr). Compared to sewage sludge, the potential contamination risk index of pyrolysis biochar obtained at 650°C was reduced to 17.01, indicating a low ecological risk. The addition of 7% kaolin/zeolite further reduced the risk index of co-pyrolysis biochar prepared at 650°C to 10.86/15.28. The characterization of biochar revealed that increase in the pyrolysis temperature and incorporation of additives are conducive to the formation of stable heavy metal-inorganics. This study demonstrates that the formation of stable mineral compounds containing heavy metals is the key to stabilizing heavy metals in pyrolysis biochar.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2024
·
IF 5.5
Thanh-Binh Nguyen,Quoc-Hoang Do,Chiu-Wen Chen,Wei-Hsin Chen,Xuan-Thanh Bui,Cheng-Di Dong
Background This study investigates the synthesis of biochar from cow manure at various pyrolysis temperatures and its effectiveness in dye adsorption, focusing on how temperature influences the adsorption capacities of biochar towards MB and MO. Methods Biochar was produced at four pyrolysis temperatures (300, 500, 700, and 900 °C), labeled CMBC-x. Adsorption capacities for MB and MO were tested. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) identified functional groups involved in dye adsorption. Findings Biochar produced at 900 °C (CMBC900) showed the highest adsorption capacities: 200 mg g -1 for MB and 147 mg g -1 for MO. For a dye mixture, CMBC900 adsorbed 104.5 mg g -1 of MB and 98.7 mg g -1 of MO, indicating efficient separation. CMBC900 maintained high efficiency after ten cycles, with 97.5 % for MB and 90.5 % for MO. These findings highlight the robustness and long-term potential of CMBC900 as an adsorbent. Converting agricultural waste into biochar offers an economically viable solution for waste management and environmental protection by removing harmful dyes from wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2016
·
IF 4.12
Erwei Leng,Yang Wang,Xun Gong,Biao Zhang,Yang Zhang,Minghou Xu
The influence of KCl and CaCl 2 on the primary reactions of cellulose pyrolysis is studied using a wire-mesh reactor from 250 °C to 600 °C, focusing on the reaction intermediates. A pre- column derivatization with benzoyl chloride prior to HPLC analysis is applied for the quantification of anhydro-sugars (levoglucosan, cellobiosan, maltosan) from pyrolysis. At low temperatures, the additions of inorganics salts, especially CaCl 2 , weakens hydrogen bonds, resulting in high yields of levoglucosan and cellobiosan from the cleavage of glycosidic bonds rather than from dehydration reactions . At elevated temperatures, dehydration reactions in the sugar units are mainly responsible for the destruction of sugar rings followed by the scission of pyran rings, leading to the weight-loss of CaCl 2 -loaded cellulose in the form of low molecular weight organic species. Meanwhile, accumulated unsaturated structures suppress the cleavage of glycosidic bonds, leading to the formation of char. However, KCl appears to catalyze the cleavage of glycosidic bonds or the scission of pyran rings directly, which perhaps occurs through a homolytic mechanism, leading to low molecular weight species. Furthermore, maltosan is shown to be a secondary product and is catalyzed by KCl and CaCl 2 indirectly through the repolymerization of levoglucosan in the solid phase. A modified mechanism is also proposed regarding cellulose pyrolysis and the primary catalysis of KCl and CaCl 2 .
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2023
·
IF 5.7
Yongdi He,Jinou Song,Jiuzhong Yang,Yuan Zhuang,Liang Qiu,Zhijun Li,Shubao Song,Yongfeng Liu,Jibiao Xie
In order to investigate the species pool and primary channels of initiated pyrolysis of n- hexane, the low-pressure (30 Torr, 4.0 kPa) flow reactor pyrolysis of n- hexane initiated by 5% 1- nitropropane ( 1- NP) was studied experimentally in a wide range of temperature from 623 K to 1223 K. Combined with synchrotron vacuum ultraviolet (SVUV) photoionization mass spectra scanned at photon energies ranging from 9.0 to 14.7 eV and near-threshold photoionization efficiency (PIE) spectra, 29 pyrolysis species, covering C 1 –C 6 hydrocarbons and several pyrolysis species containing O or N atoms, were identified. Based on the ion signal intensities of the visible peaks in the mass spectra, the mole fraction profiles of all the experimental species were evaluated. The experimental results suggested that the initial pyrolysis temperature of n- hexane was reduced by approximately 275–325 K. On the basis of the mole fraction profiles and the initial formation temperatures reported in this work and rate coefficients proposed in previous studies, the 1- NP-initiated pyrolysis mechanisms of n- hexane were discussed. It was suggested that n- hexane was dominantly consumed by the H-abstraction reactions by the attack of OH radical in this work. The 1- NP-initiated pyrolysis of n- hexane mainly proceeded via reactions to produce C 3 H 6 + C 3 H 7 , or 1- C 4 H 8 + C 2 H 5 , or 1- C 5 H 10 + CH 3 .
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Fangjun Chen,Jinze Dai,Henrik Ström,Yi Ouyang,Muhammad Shahzad Khurram,Bilainu Oboirien,Lin Lang,Qingang Xiong
The mechanisms by which calcium-rich inorganics within pulp and paper mill sludge (PPMS) influence the pyrolysis of its organic components remain largely unexplored. This study investigated the effects of inorganic constituents on the evolution of pyrolysis products from major organic components (cellulose, plastics, lipids, proteins, and ink) in PPMS through fixed-bed pyrolysis experiments. The results demonstrated that inorganics significantly promoted secondary tar reactions by improving heat transfer, providing catalytic sites, and prolonging the residence time of pyrolysis vapors. These effects markedly increased gas yields, particularly CO 2 (e.g., by 29.27–35.41 mL/g for cellulose), and decreased tar yields (e.g., by 10.27–11.38 wt% for cellulose), while also altering tar composition. Specifically, calcium-rich inorganics catalyzed the conversion of cellulose into small ketone molecules such as hydroxyacetone, reducing the proportions of anhydrosugars and furans. For plastics, PPMS ash promoted the β -scission of long-chain aliphatic hydrocarbons and the transformation of monocyclic hydrocarbons into polycyclic aromatic hydrocarbons while also increasing char formation. For lipids, calcium-rich inorganics effectively catalyzed the decarboxylative ketonization of palmitic acid to produce 2-heptadecanone. For proteins, PPMS ash suppressed NH 3 release and promoted nitrogen migration into nitrogen-containing heterocyclic compounds. For ink, the inherently high ash content limited the regulatory effect of additional ash. Overall, this study provides mechanistic insights into PPMS pyrolysis and supports its sustainable conversion.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2014
·
IF 2.633
Jun-Bo Zhang,Xiu-Li Wang,Qiu-Xia He,Hai-Bo Zhao,Yu-Zhong Wang
Poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) is a commercialized semicrystalline high-temperature thermoplastic polyester, but its flammability restricted its applications in some fields. A third monomer , 2-(6-oxido-6H-dibenz < c,e > <1,2> oxaphosphorin-6-yl)-1,4-hydroxyethoxy phenylene (DOPO-HQ-HE), was used to synthesize an intrinsic flame-retardant copolyester through trans-esterification and polycondensation . Its chemical structure was confirmed by 1 H NMR and ICP-AES. The crystallization behavior of PCTDs was investigated by DSC and WAXD , and found that the introduction of DOPO-HQ-HE slightly reduced the crystallization ability of PCT. TGA results showed that the incorporation of phosphorus-containing monomer improved the thermal stability of copolyesters both in nitrogen and air. Flynn–Wall–Ozawa method was used to analyze the thermal degradation kinetics of copolyesters, and found that the apparent activation energy was enhanced. The microscale combustion calorimetry (MCC) showed that PCTDs had lower heat release rate and total heat release than PCT. The results of the limiting oxygen index (LOI), the UL-94 vertical and the cone calorimeter test indicated that DOPO-HQ-HE endowed PCTDs with flame-retardant properties to some extent. Besides this, the cone calorimeter results show that the introduction of DOPO-HQ-HE remarkably suppressed the smoke release of PCT. The pyrolysis behaviors of PCT and PCTDs were investigated by Py-GC-MS, and found that the decomposition of PCT chains usually happened at ester bond and followed the random chain scission mechanism. The introduction of DOPO-HQ-HE almost had no effect on the thermal degradation mechanism of PCT.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2022
·
IF 6.437
Weixi Zhang,Haodi Tan,Yingquan Chen,Haiping Yang,Hanping Chen
The pyrolysis of hydrochar from hydrothermal treatment of kitchen waste was investigated, including the process parameters and characteristics of pyrolysis products. A novel process, KOH-assisted catalytic pyrolysis , was proposed to simultaneously produce oil and char products with high quality. The optimum pyrolysis temperature was 550 ℃, at which the three-state products presented better properties. Four zeolite catalysts were investigated to improve the quality of the oil product. SAPO presented the highest promoting effect on aromatic hydrocarbons, whereas HZSM-5 promoted the selectivity of nitrogen components. Upon KOH addition, the selectivity of aromatic hydrocarbons increased from 42.2% to 98.8% for HZSM-5, whereas oxygen- and nitrogen-containing substances disappeared. In addition, the char S BET increased from 7.16 to 1753.57 m 2 /g, with specific capacitance of 206 F/g and methylene blue adsorption capacity of 317.68 mg/g. The results provide a useful background for the development of the treatment of hydrochar.
研究领域:
环境科学
·
能源工程
✓ 已验证
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2017
·
IF 5.589
Haoran Yuan,Honggang Fan,Rui Shan,Mingyang He,Jing Gu,Yong Chen
The mechanism of synergistic effects occurred during co-pyrolysis of cellulose (CE) and high-density polyethylene (HDPE), mixed at various mass ratios (3:1, 1:1, 1:3 w/w), was studied by thermogravimetric analysis coupled with mass spectrometry (TG-MS) and pyrolysis-gas chromatography coupled with mass spectrometry (Py-GC/MS). The TG analysis showed that the co-pyrolysis process was divided into two-stages: the first stage was the decomposition of CE (at 260 °C–410 °C), and the second stage between 410 °C and 527 °C was mainly the decomposition of HDPE. The experimental mass loss values of the mixtures were greater than the estimated values, which confirmed a synergistic effect in the co-pyrolysis of CE and HDPE. The results of MS and Py-GC/MS indicated that the effects of co-pyrolysis promoted the release of small-molecule volatile (H 2 O, CO/C 2 H 4 , CO 2 ), and the promotion effect was strongest when the ratio was 1:3. Hydrogen transfer from the scission of HDPE could be provided for the decomposition of CE, and the oxygen-containing compounds from CE could promote the chain scission and cracking of HDPE. When the CE/HDPE ratio was less than 1:1, the production of carbohydrate, aldehyde, ketone, and furan groups assigned to CE pyrolysis was suppressed, and the production of alkane and alkene groups was promoted. The decomposition pathways in the co-pyrolysis process of CE and HDPE were proposed.
研究领域:
能源与燃料
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化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
WASTE MANAGEMENT
·
2021
·
IF 7.145
Xiefei Zhu,Zejun Luo,Xifeng Zhu
Enriching high-value chemicals from the pyrolysis of agricultural and forestry waste is an efficient way to achieve sustainable development and large-scale application of biomass pyrolysis. Phenols, as important chemical raw materials, spices and food additives, have attracted widespread attention. Herein, a novel technical route of torrefaction pretreatment combined with fractional condensation in pyrolysis loop was proposed to enrich the phenols in liquid products. In this study, the enrichment of phenols from the pyrolysis loop of walnut shell under the combination of torrefaction and fractional condensation was explored using a fixed-bed pyrolysis reactor equipped with a three-stage condensation system. Simultaneously, the effects of torrefaction on feedstocks were investigated through a thermogravimetric analyzer based on the characteristics of feedstocks. The results showed that the torrefaction and pyrolysis loop had a negative impact on the pyrolysis efficiency and the yield of liquid products, while the change in the condensation efficiency depended on the combined effects of torrefaction and pyrolysis loop. In addition, phenols tended to be enriched in the second condensation stage, especially phenol, o-cresol, 4-ethylphenol. Importantly, torrefaction could significantly enrich phenols in the liquid products, and the enrichment of phenols is relatively increased by 109.44% at least. Moreover, the pyrolysis loop was also beneficial to the enrichment of phenols, which was at least 90% higher than that of walnut shell. This study provided a potential route to enrich high value-added products from the pyrolysis loop of lignocellulosic biomass.
研究领域:
生物质能
·
化学工程
·
可持续发展
✓ 已验证
DOI
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2021
·Vol. 15
·期 12
·2000514
·
IF 2.821
Fan Xie,Hua Tang,Xin Zhao,Meng Li,Lu Li,Jiang Cheng
Silver antimony sulfide (AgSbS 2 ) has attracted great interest as a photovoltaic absorber, attributed to its suitable energy gap, large absorption coefficient, and being of relatively earth-abundant elements. However, the applications of AgSbS 2 are very limited due to the immaturity of the fabrication technology. A novel spray pyrolysis method for AgSbS 2 film deposition is reported. Selenization is the most important step to improve the device performance. The composition analysis shows that the S element in AgSbS 2 can be partly substituted by Se via heating the sample in Se vapor at 400 °C for several minutes. X-ray diffraction shows that the selenized film contains AgSbS 2 , AgSbSe 2 , and AgSbS 2− x Se x without other impurities. The Hall effect confirms a carrier concentration of 3.31 × 10 18 cm −3 , which is significantly higher than that of the untreated film and those processed in other atmospheres. The optical measurement indicates that the optical absorbance of the selenized AgSbS 2 is tremendously improved. In addition, a cascade-type energy level with the bandgap varying from 1.15 eV at the surface to 1.68 eV into the bulk is formed, resulting in an ideal energy level matching. Because of these beneficial factors, the efficiency improves significantly from 0.27% to 1.30%.
研究领域:
材料科学
·
光伏技术
·
物理化学
✓ 已验证
DOI
高影响因子
Applications in Energy and Combustion Science
·
2021
·
IF 0
Huiyan Zhang,Bingbing Luo,Kai Wu,Han Wu,Jiajun Yu,Siyu Wang
Catalytic fast pyrolysis of lignin is easy to cause agglomeration and coking, resulting in low-yield aromatic hydrocarbons. Catalytic pyrolysis of modified lignin combined with metal-modified HZSM-5 was proposed to enhance the aromatic yield. The experiment results showed that chemical modification with Ca(OH) 2 not only inhibited the agglomeration behavior of lignin but also increased the yield of light phenolic compounds. Moreover, Ca 2+ -loaded lignin combined with metal-modified HZSM-5 was conducive to the formation of aromatics. The total yield of aromatics from the catalytic fast pyrolysis of Ca 2+ -loaded lignin over Zn/HZSM-5 was improved from 31.1 to 46.1 mg/g. The mechanism insight showed that Ca 2+ modification realized the chemical combination between Ca 2+ and the functional groups which are responsible for the agglomeration of lignin, and then the introduction of the Zn species suppressed the hydrogen transfer reaction and enhanced the dehydrogenation pathway, resulting in the increase of aromatic yield.
研究领域:
化学工程
·
能源科学
·
材料科学
✓ 已验证
DOI
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2026
·
IF 6.7
Wenyan Mu,Tao Wang,Qu Zhang,Xianze Wang,Haozhao He,Dongling Wu
To achieve efficient upgrading and clean utilization of lignite-derived tar, an integrated zeolite modification strategy based on deep eutectic solvents (DESs) was developed, in which a Fe-based DES system was constructed with FeCl 3 ·6 H 2 O and CF 3 COOH. This DES realized the simultaneous acid modification and metal incorporation of ultrastable Y (USY) zeolite, thereby simplifying the catalyst preparation process. Characterization results revealed that DES treatment at an optimal molar ratio of 1:9 preserved the structural integrity of the Faujasite framework while inducing a hierarchical “micropore-sacrifice/mesopore-compensation” architecture. Meanwhile, Fe species were introduced uniformly, leading to the reduction of Brønsted acid sites and the enhancement of Lewis acid sites, thereby constructing multifunctional catalytic centers with synergistic acidity and redox activity. Mechanistic analysis demonstrated that DES-induced mesoporosity enhanced mass transfer and diffusion, while the cooperation between Fe redox sites and Lewis acid sites facilitated C-C and C-O bond cleavage as well as aromatization reactions. In the fixed-bed pyrolysis of NMH lignite, the optimized catalyst exhibited superior catalytic performance: the light oil fraction in tar increased from 16.86 % to 27.94 %, the relative content of light tar reached 75.61 %, gas yield reached 21.53 %, and PAHs content dropped sharply. Furthermore, the catalyst was confirmed to possess superior reusability in successive runs. This study highlights DES as tunable functional media, serving as an efficient platform for the integrated regulation of zeolite structure, acidity, and activity. Consequently, it provides a novel strategy for fabricating high-performance modified molecular sieve catalysts, which are applicable to the clean and value-added conversion of coal pyrolysis tar.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）