WASTE MANAGEMENT
·
2021
·
IF 7.145
Chenyu Wang,Wei Zhu,Xihui Fan
Supercritical water gasification (SCWG) is considered a promising technology for sewage sludge (SS) treatment and utilization; however, char produced by a side reaction has become a bottleneck in SCWG. In this study, SS and its model compound (10% humic acid) were treated in an autoclave by SCWG at 400 °C for 30 min and by hydrothermal carbonization (HTC) at 250 °C for 300 min. The char yield was 15.4% in SCWG and 41.3% in HTC. The chars were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller (BET) analysis, and elemental analysis. By comparing the properties the char produced by SCWG and the hydrochar produced by HTC, which has been considered a valuable product, the feasibility of using char as an additional product in SCWG was explored. Compared with the char produced by HTC, the char generated in SCWG exhibits a lower BET specific surface area (8.257 and 15.782 m 2 /g) and combustion activity, a higher proportion of small pores (with pore sizes of 1–2 nm), and greater thermal stability. The formation pathway of the two types of chars is related to both dehydration and aromatization; decarboxylation also occurs in char formation during SCWG. Humus was proved to be related to char formation during the SCWG of SS based on experimental results obtained with the model compound. This work provides insights needed to guide follow-up treatments or utilization of the char produced during the SCWG of SS.
研究领域:
环境科学
·
能源技术
✓ 已验证
DOI
PubMed
高影响因子
Biochar
·
2021
·Vol. 3
·期 3
·391-405
·
IF 0
Li Chao,Sun Yifan,Zhang Lijun,Wang Changxu,Zhang Shu,Li Qiaoling,Xu Leilei,Hu Xun
Biomass and pig manure have distinct compositions and the co-pyrolysis of them has gained much attention. However, the influence of volatiles interaction on the properties of the char was still unclear. In this study, lignin was selected as the model component of biomass with pig manure for co-pyrolysis at 600 °C. The results indicate that volatiles from co-pyrolysis promoted re-condensation reaction, resulting in the higher char yield (48.0% in co-pyrolysis versus 31.0% in pyrolysis of single manure) and the formation of more aromatics in bio-oil. The co-pyrolysis also facilitated the dehydrogenation and dehydration reactions, which accounted for the elimination of oxygen and nitrogen contents and thus a higher carbon content (64.7% in the co-pyrolysis versus the averaged value of 46.4% from the pyrolysis of single feedstock), higher crystallinity and thermal stability of the char. The in-situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) characterization results demonstrated that the functionalities abundances of char with temperature was influenced by volatiles interaction via accelerating the carbonization reaction. In addition, the high heating value (HHV) of char was obviously improved by cross-interaction of volatiles during co-pyrolysis (24.4 MJ/Kg in co-pyrolysis versus averaged value of 15.1 MJ/Kg from single pyrolysis), implying that the co-pyrolysis enhanced the energy density of the resulting char. Graphic abstract
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
DOI
FLAVOUR AND FRAGRANCE JOURNAL
·
2025
·
IF 2
Xi Jiang,Jian Wu,Lucan Zhao,Jun Wang,Weiqiang Xiao,Zhen Chen,Jian Jiang,Miao Liang,Jiaqi Wang,Junsong Zhang
Different types of tobacco should exhibit significant differences in pyrolysis behaviour and pyrolytic aroma components distribution due to their intrinsic microstructures and chemical composition features but rarely be compared. Herein, the pyrolysis characteristics of three types of tobacco (oriental tobacco, burley tobacco and flue-cured tobacco) were studied by using thermogravimetric technique combined with thermal analysis kinetics method. The weight loss processes of each tobacco sample can be divided into four stages, namely dehydration, decomposition of volatile components, decomposition of hemicellulose and cellulose, and decomposition of lignin and carbonisation. Different types of tobacco exhibited various pyrolysis characteristic parameters in terms of T i , T f , DTG max , and CPI, indicating an obvious difference in the thermal decomposition characteristics of tobacco. And then a stepwise heating strategy was designed to in-depth investigate the pyrolysis characteristics and release behaviour of aroma components at different thermal weight loss stages by using the self-built infrared tube furnace combined with Cambridge filter capture system. The weight loss stages II and III would generate most of the aroma components for each type of tobacco. The release amount of oxygen heterocyclic and ketone compounds exhibited the order of flue-cured tobacco (558.90 μg·g −1 ) > burley tobacco (423.44 μg·g −1 ) > oriental tobacco (291.55 μg·g −1 ) during the four stages. The release amount of nitrogen heterocyclic compounds exhibited the order of burley tobacco>flue-cured tobacco>oriental tobacco, while the organic acids exhibited the opposite order. Furthermore, the physicochemical properties of biochar generated from different types of tobacco were characterised and compared by elemental analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). This study may provide guidelines for the rational utilisation of different types of tobacco leaves in related products.
研究领域:
化学工程
·
烟草科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2020
·
IF 4.3
Chao Li,Chenting Zhang,Guoming Gao,Mortaza Gholizadeh,Shu Zhang,Leilei Xu,Lijun Zhang,Qingyin Li,Xun Hu
In this study, the co-pyrolysis of pig manure with cellulose and glucose were investigated at various heating rates. The results demonstrated that potential cross-interaction of the volatiles from the co-pyrolysis facilitated the cracking reaction, resulted in the formation of less charry products and less tarry compounds in the co-pyrolysis. The volatiles interaction also enhanced the evolution of the organics with the π-conjugated ring structures in the bio-oil and remarkably affect the char properties. The dehydration and condensation reactions were promoted during the fast co-pyrolysis of manure with cellulose and glucose, leading to the increased carbon content (from 20.0%–46.5 and 43.0 %), the higher thermal stability, and the enhanced crystallinity of carbon structure in the char formed. In addition, the in-situ Diffuse Reflection Infrared Fourier Transform Spectroscopy (DRIFTS) characterization indicates that the interaction of volatiles in the co-pyrolysis obviously affected the evolution of the functionalities of the char and the reaction network. Additionally, the HHV (37.2 and 37.9 vs 28.0 MJ/Kg) and the energy yield (66.3 and 68.2 vs 66.2 %) of the char from the co-pyrolysis was higher than that of the manure, which was beneficial for the utilize of the char as solid fuel.
研究领域:
能源与环境科学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2023
·
IF 8.1
Qiao Xiong,Yinqiu Li,Chaohua Hou,Jie Yang,Xiangjun Zhou,Xiao Ma,Xiangru Zuo,Xiang Wu
The concentration of microplastics (MPs) in sewage sludge (SS) ranged from 1600 to 56400 particles per kilogram of dried SS (MPs: dried SS = 0.14–5.09), so its effect on SS pyrolysis performance should not be negligible. This study attempted to investigate the effect of typical MPs, including polypropylene (PP), polyethylene (PE), and polyvinyl chloride (PVC), on the pyrolysis performance (pyrolysis characteristics and major gaseous product evolution) of SS and their biochar characteristics via thermogravimetry-mass spectrometry (TG-MS) and physicochemical property analysis of biochar. The results showed that the PVC MPs enhanced the pyrolysis of SS, while the PP and PE MPs had an inhibitory effect. The total amounts of gas products tended to decrease with all MPs addition. However, the proportions of combustible components (H 2 , CH 4 , and C 2 H 2 ) increased. Among the biochar products, the presence of PVC MPs during the pyrolysis of SS resulted in a more porous, stable and aromatic biochar.
研究领域:
环境科学
·
能源与燃料
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Kangxin Xiao,Huan Liu,Yang Li,Linlin Yi,Xiuju Zhang,Hongyun Hu,Hong Yao
For efficient hydrothermal treatment of biomass, this study aims to figure out the correlations between complex chemical constitution of orange peel (OraPeel) as typical bio-waste and the physicochemical structure of its derived hydrochar , which could be utilized to adjust hydrochar properties for specific applications (e.g., adsorbent, fuel) by regulating respective proportions of each component in bio-waste. Cellulose, hemicellulose and lignin were used as the control variables of feedstocks composition in this work. After hydrothermal process, lignin added feedstock produced more hydrochar, which contained rougher surface with nearly doubled BET areas and more benzene rings. Hemicellulose-aided hydrochar possessed higher density of carbonaceous microspheres and richer hydroxyl. This char was simultaneously covered by more esters or lactones with more aromatic oxygen-containing groups inside. Similar to hemicellulose, cellulose improved the formation of diverse oxygenous groups but reduced the size of microspheres on hydrochar.
研究领域:
环境科学
·
生物质能源
·
环境工程
·
材料化学
·
废物资源化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）