Study on CO2 gasification of biochar in molten salts: Reactivity and structure evolution

Xie, Yingpu; Yang, Haiping; Zeng, Kuo; Zhu, Youjian; Hu, Junhao; Mao, Qiaoting; Liu, Qingchuan; Chen, Hanping

doi:10.1016/j.fuel.2019.06.022

Cited by 53 publications

(20 citation statements)

References 45 publications

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“…The I D /I (GR?-VR?VL) was representative of the ratio between large and small aromatic ring (Zhang et al 2017). The S band reflected the substituted and cross-linking structures (Xie et al 2019). All these structural parameters increased after the HF pickling.…”

Section: Discussionmentioning

confidence: 99%

Effect of ash removal on structure and pyrolysis/gasification reactivity of a Chinese bituminous coal

Gong

Ding

et al. 2020

Int J Coal Sci Technol

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In this study, the effect of ash removal on Shenfu bituminous coal was investigated. The coal was pretreated by hydrofluoric acid (HF) pickling, and the raw/pretreated coal chars were prepared at 900 °C in a fixed bed reactor. The structure of coal and char were detected by Fourier transform infrared (FTIR) and Raman spectroscopy. The reactivity was tested in a thermogravimetric analyzer, including coal pyrolysis and char gasification. The reaction kinetics was analyzed through the Coats–Redfern method, master plots, the model-free and model-fitting method. The results show that the HF pickling can remove silicon from coal efficiently, and the macromolecular framework of coal is quite stable according to FTIR. The Raman parameters imply some carbonaceous structure on coal surface changed. For slow pyrolysis of coal, the effect of heating rate is considered. The changes of pyrolysis characteristics and kinetics are insignificant. For char gasification, the reactivity under isothermal and non-isothermal condition are discussed with an emphasis in different residence time of devolatilization process. In kinetic control region (low temperature), the activation energy (Ea) is very close (about 240 kJ/mol) for all chars. With the temperature increases, the reactivity of raw coal char is more easily suffered by diffusion. The random pore model is more suitable for the ash-free coal char, and the char with long residence time has a larger value of structural parameter ψ and smaller value of pre-exponential factor A. The Ea calculated by model-fitting and model-free method were in good agreement.

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Section: Discussionmentioning

confidence: 99%

Effect of ash removal on structure and pyrolysis/gasification reactivity of a Chinese bituminous coal

Gong

Ding

et al. 2020

Int J Coal Sci Technol

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“…Similar work was also conducted by Dai et al [ 14 ] Guizani et al [ 16 ] suggested that pyrolysis resulted in the coalescence, ordering, and rearrangement of aromatic ring structures, which was related to char reactivity. [ 17 ] In addition, Elliott and Baker [ 18 ] believed that the increase of alkali and alkaline earth metals (AAEMs) was conducive to the improvement of char reactivity, so the whole gasification process could be carried out under relatively mild temperature conditions. At the same time, torrefaction can effectively reduce the generation of soot and tar, thus improving the energy utilization efficiency of the gasifier.…”

Section: Introductionmentioning

confidence: 99%

Integration of Biomass Torrefaction and Gasification based on Biomass Classification: A Review

Gong

Areeprasert

et al. 2021

Energy Tech

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Trace element migration and structure evolution are related to biomass gasification performance, which varies to a certain extent during torrefaction. This substantial summary of the integrated process based on biomass classification has practical significance for the consumption and commercialization of a bio‐refinery. Herein, biomass is divided into two categories and an understanding of the relevant variations is presented during the integrated two processes according to the classification. The effects of torrefaction on the organic (hemicellulose, cellulose, and lignin) and inorganic components (trace elements), and the physicochemical structural evolution (morphology, pore structure, functional groups) of biomass are reviewed. The differences (syngas generation and tar formation) between raw and torrefied biomass gasification are compared. Meanwhile, the effects of torrefaction on gasification performance and the possible gasification mechanisms are reviewed regarding pore structure, carbon structure, surface area, and alkali and alkaline earth metals (AAEMs). The gasification of the torrefied biomass materials on a pilot‐scale is outlined. Finally, future directions and technological challenges associated with the integrated technologies are proposed. More scaling‐up experiments should be conducted to investigate the mass and heat transfer in reactors during amplification and to improve the reactor's adaptability to biomass species in the contexts of economy and society.

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“…These electronic properties are derived from the shape, size, crystal types, and compositions that rely on synthesis methods [9]. Many methods are used in the synthesis of inorganic substances, such as solid-state reactions, precursor polymeric, electrochemical cells [10], galvanic cells [11], molten salts [12], microwave, Pechini [13], Czockhralski [14], co-precipitation [15], flame spray [16] and sol-gel [2]. The sol-gel method is of much interest due to its advantages, such as easy stoichiometric control, good homogeneity, and low calcination temperature.…”

Section: Introductionmentioning

confidence: 99%

Sol-Jel Tekniği ile Sentezlenmiş Sr0,5Ca0,5WO4 Fosforunda Eu3+ İyonunun Lüminesans, TL Kinetik Parametreler ve Elektrokimyasal Davranışındaki Rolü

Katı

Keski̇n

Türemiş

et al. 2021

El-Cezeri Fen Ve Mühendislik Dergisi

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The Eu 3+ doped Sr 0,5 Ca 0,5 WO 4 has been synthesized by the sol-gel method for the first time. The phosphors were analyzed by XRD, SEM, DTA/TG optical absorption spectra, radioluminescence (RL), photoluminescence (PL), and thermoluminescence (TL) spectra. The energy transfer mechanism was determined on Eu 3+ doped Sr 0,5 Ca 0,5 WO 4 phosphor. The XRD results reveal that the samples exhibit a tetragonal scheelite structure. FT-IR spectra provide the proof of scheelite structure with W-O anti-symmetric stretching vibration in [WO 4 ] 2tetrahedrons at 750-910 cm -1 . The Sr 0,5 Ca 0,5 WO 4 phosphor showed a broad emission between 350-750 nm with a maximum of 506 nm. Sr 0,5 Ca 0,5 WO 4 :0.5Eu 3+ phosphor exhibit characteristic emissions of Eu +3 (545, 592, 614, 650, and 700 nm) in the RL spectrum. The host material has excellent energy transfer efficiency for lanthanide ions. The kinetic parameters were calculated by the computerized glow curve deconvolution (CGCD) analysis method. As a result of CGCD, three peaks (E trap :0.74-1.46 eV) for un-doped Sr 0,5 Ca 0,5 WO 4 and five peaks (E trap :0.75-1.28 eV) for Sr 0,5 Ca 0,5 WO 4 : Eu 3+ were determined under main TL glow curve. In the cyclic voltammogram of the doped sample, an oxidation peak of about -0.4 eV, which is thought to be derived from Eu 3+ , was observed. Based on the results, the Sr 0,5 Ca 0,5 WO 4 :Eu +3 phosphors may be potential applicants for LEDs.

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Study on CO2 gasification of biochar in molten salts: Reactivity and structure evolution

Cited by 53 publications

References 45 publications

Effect of ash removal on structure and pyrolysis/gasification reactivity of a Chinese bituminous coal

Effect of ash removal on structure and pyrolysis/gasification reactivity of a Chinese bituminous coal

Integration of Biomass Torrefaction and Gasification based on Biomass Classification: A Review

Sol-Jel Tekniği ile Sentezlenmiş Sr0,5Ca0,5WO4 Fosforunda Eu3+ İyonunun Lüminesans, TL Kinetik Parametreler ve Elektrokimyasal Davranışındaki Rolü

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