Physicochemical properties of bottom ash obtained from an industrial CFB gasifier

Jiang, Denghao; Song, Weijian; Wang, Xiaofang; Zhu, Zhengwang

doi:10.1016/j.joei.2020.12.004

Cited by 12 publications

(4 citation statements)

References 38 publications

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“…In accordance with GB/T212-2008 [19] from China, the moisture, ash, volatile and fixed carbon in SLFC and SLFC-L were analyzed. Vario El III element equipment (Elemental UNICUBE, Frankfurt, Germany) was used to test the content of C, H, N, and S elements in the samples, and the content of O was calculated by difference [26]. Scanning electron microscopy (TESCAN MIRA4, Brno, Czech Republic) was carried out to characterize the surface morphology of SLFC and SLFC-L. An SDTQ-600 thermogravimetric analyzer (TA Instruments Limited, New Castle, DL, USA) was used to test the weight loss behavior of the samples, and the temperature was set from room temperature to 1000 • C with the heating rate of 10 • C/min with high-purity nitrogen as the carrier gas.…”

Section: Analysis Methodsmentioning

confidence: 99%

Effect of Solvent Treatment on the Composition and Structure of Santanghu Long Flame Coal and Its Rapid Pyrolysis Products

Guo,

Zhu,

et al. 2023

Molecules

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Easily soluble organic components in Santanghu long flame coal (SLFC) from Hami (Xinjiang, China) were separated by CS2 and acetone mixed solvent (v/v = 1:1) under ultrasonic condition, and the extract residue was stratified by carbon tetrachloride to obtain the light raffinate component (SLFC-L). The effect of solvent treatment on the composition and structure of the coal and its rapid pyrolysis products was analyzed. Solvent treatment can reduce the moisture content in coal from 9.48% to 6.45% and increase the volatile matter from 26.59% to 28.78%, while the macromolecular structure of the coal changed slightly, demonstrating the stability of coal’s complex organic structure. Compared with raw coal, the relative contents of oxygen-containing functional groups and aromatic groups in SLFC-L are higher, and the weight loss rates of both SLFC and SLFC-L reached the maximum at about 450 °C. In contrast, the loss rate of SLFC-L is more obvious, being 33.62% higher than that of SLFC. Pyrolysis products from SLFC at 450 °C by Py-GC/MS are mainly aliphatic hydrocarbons and oxygenated compounds, and the relative contents of aliphatic hydrocarbons decreased from 48.48% to 36.13%, while the contents of oxygenates increased from 39.07% to 44.95%. Overall, the composition and functional group in the coal sample were changed after solvent treatment, resulting in a difference in the composition and distribution of its pyrolysis products.

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Section: Analysis Methodsmentioning

confidence: 99%

Effect of Solvent Treatment on the Composition and Structure of Santanghu Long Flame Coal and Its Rapid Pyrolysis Products

Guo,

Zhu,

et al. 2023

Molecules

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“…24 From Figure 8c, it can also be found that there are a small number of bubble-like holes between the two regions, which might be due to the formation of small amounts of volatile FeCl 2 and FeCl 3 (melting point of each compound is 676 and 303 °C, respectively) during the formation of CLB under high temperature. 25 Thus, the production of FeCl 2 and FeCl 3 could accelerate the migration of Fe.…”

Section: Morphology and Element Distribution Of Clbmentioning

confidence: 99%

Characteristics of the Blockage from Air Nozzle Guide Duct in Circulating the Fluidized-Bed Coal Gasifier and Its Formation Mechanism

Jiao,

Mo,

Zhao

et al. 2024

ACS Omega

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Blockage is often generated in the air nozzle guide duct in a circulating fluidized-bed coal gasifier (CFBG), especially with Zhundong sub-bituminous coal (ZSBC) as the raw material. A typical example is found in one CFBG sample from Xinjiang Yihua Chemical Industry Co, Ltd. The serious blockage can be observed obviously. As so far, it is not clear for the characteristics and generation mechanism of the blockage. For analysis, the blockage can be classified into two parts, wall-layer blockage (WLB) and center-layer blockage (CLB). To inhibit its formation, it is of significance to analyze the composition, surface morphology, and formation mechanism of the two blockages. In our experiments, WLB and CLB were tested by XRF, XRD, FTIR, SEM-EDS, and SEM-mapping methods. Results showed that WLB presents high content of Fe, Cr, and Ni, and Fe mainly existed in the form of metal oxides. CLB is dominated by Si (43.04%), derived from silica and alkali and alkaline-earth metals silicates, and the migration of Fe, Cr, and Ni elements from the duct material was observed. Compared with WLB, from FTIR analysis, CLB contains more inorganic minerals, and the absorption peak of inorganic minerals is mainly attributed to asymmetric Si−O−Si. Many fine particles are attached to the surface of the WLB, while the surface of the CLB is smooth, and there is noticeable raised texture, which is presumed to be the result of particle melting and agglomerating as the bottom ash enters the duct in the gasification process. For the formation of the blockage, this paper speculates that it is mainly due to the difference in flow resistance near the air nozzle outlet, resulting in the formation of a flow dead zone at the bottom of the gasifier, which leads to large amounts of ash overcoming the outlet resistance and leaking into the air nozzle, and next, the ash corrodes in the tube, resulting in wall deposition and ultimately blocking the air guide duct. Two methods can be tried to avoid or inhibit the formation of blockage in the duct, including optimizing air nozzle with more wear-resistant and heat-resistant materials and adjusting the distance between air nozzles to avoid mutual interference from ash particles.

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“…They have indicated that, in comparison to surface area, the impact of the active site is more significant on reactivity. The active sites or carbon structure in char is commonly characterized using Raman spectra [14][15][16]. Guizani et al [17] observed the relationship between carbon structure and the reactivity of char and found that the reactivity index (R index ) has a good linear relationship with I V /I D .…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Thermal Reduction of CO2 by Activated Solid Carbon-Based Fuels

Zhang,

Liang,

Zhu

et al. 2024

Energies

Self Cite

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For achieving CO2 thermal reduction, a technology combining solid carbon activation and high-temperature CO2 reduction was proposed, named as activated-reduction technology. In this study, this technology is realized by using a circulating fluidized bed and downdraft reactor. Reduced agent parameters (O2/C and CO2 concentration) greatly affect the reduction effect of CO2. In addition, the effect of the activation process on different carbon-based materials can help to broaden the range of carbon-based materials used for CO2 reduction, which is also an important issue. The following three points have been studied through experiments: (1) the influence of the characteristics of the reduced agent (CO2 concentration and O2/C) on CO2 reduction; (2) the performance of different chars in CO2 reduction; and (3) the activation effect of solid carbon. The activation process can develop the pore structure of coal gasification char and transform it into activated char with higher reactivity. The CO concentration in the tail gas is a crucial factor limiting the effectiveness of CO2 reduction, with an experimentally determined upper limit of around 55% at 1200 °C. If CO concentration is far from the upper limit, temperature becomes the significant influencing factor. When the reduced agent O2/C is 0.18, the highest net CO2 reduction of 0.021 Nm3/kg is achieved at 60% CO2 concentration. When the reduced agent CO2 concentration is 50%, the highest net CO2 reduction of 0.065 Nm3/kg is achieved at 0.22 O2/C. Compared with CPGC, YHGC has higher reactivity and is more suitable for CO2 reduction. The activation process helps to reduce the differences between raw materials.

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Physicochemical properties of bottom ash obtained from an industrial CFB gasifier

Cited by 12 publications

References 38 publications

Effect of Solvent Treatment on the Composition and Structure of Santanghu Long Flame Coal and Its Rapid Pyrolysis Products

Effect of Solvent Treatment on the Composition and Structure of Santanghu Long Flame Coal and Its Rapid Pyrolysis Products

Characteristics of the Blockage from Air Nozzle Guide Duct in Circulating the Fluidized-Bed Coal Gasifier and Its Formation Mechanism

Experimental Study on the Thermal Reduction of CO2 by Activated Solid Carbon-Based Fuels

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