The Experts below are selected from a list of 897 Experts worldwide ranked by ideXlab platform
Yitian Fang - One of the best experts on this subject based on the ideXlab platform.
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exploration in Ash deposition ad behavior modification of low rank coal by manure addition
Energy, 2020Co-Authors: Chaoyue Zhao, Hongli Fan, Jiejie Huang, Mingxi Guo, Qianqian Guo, Yitian FangAbstract:Abstract High-alkali low-rank coal aggravates Ash deposition (AD) during conversion. To mitigate AD formation during its gasification, the AD characteristics of Xiaolongtan lignite (XLT) and Yima coal (YM), their variations from chicken or pig manure addition under a reducing atmosphere, and their mechanisms were investigated by using Ash Fusion Temperature tester, self-made AD analyzer, and X-ray diffractometer. The results indicated that the mass fraction of AD (MAD) of XLT was higher than that of YM because of the XLT with a high Ca, Fe, Na, and K content. At a low Temperature (
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prediction of Ash flow Temperature based on liquid phase mass fraction by factsage
Journal of The Energy Institute, 2020Co-Authors: Chaoyue Zhao, Yitian FangAbstract:Abstract To investigate the relationship between flow Temperature (FT) and the Temperature that corresponds to different liquid phase mass fractions, the FTs of 10 coal Ashes and 45 synthetic Ashes were tested by an Ash-Fusion-Temperature analyzer. The linear correlation between the FT and the Temperature that corresponded to a 90% liquid phase (T90) calculated by FactSage was: FT = 245.837 + 0.765T90, and its correlation coefficients was 0.91. This model may be more accurate for low Si/Al coal. The differences between measured and predicted FT based on the model were in the measuring error range.
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investigation on regulation mechanism of red mud on the Ash Fusion characteristics of high Ash Fusion Temperature coal
Fuel, 2019Co-Authors: Hongli Fan, Jiejie Huang, Mingxi Guo, Tao Wang, Yitian FangAbstract:Abstract Red mud (RM) used as a flux to decrease coal Ash Fusion Temperature (AFT) has great economic and environmental attractions. The effects of Bayer RM (BRM) and Sintering RM (SRM) on the AFTs of high silicon-aluminum coal (Jiaozuo coal (ZJ)) or high aluminum coal (Pingsuo coal (PS)) were investigated by X-ray fluorescence analysis, X-ray diffraction, and FactSage calculation. With increasing BRM/SRM mass ratio, the AFTs of JZ or PS mixture firstly decreased quickly and then slowly. When Ash flow Temperatures were decreased to
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Effect of Na2O in Ash Composition on Petroleum Coke Ash Fusibility
Energy & Fuels, 2019Co-Authors: Jiazhou Li, Jiansheng Zhang, Jiantao Zhao, Yitian FangAbstract:Petroleum coke (petcoke) Ash fusibility is closely related to the Ash-related fouling and slagging, which have significant effects on its clean and efficient utilization. Sodium (Na) element in petcoke Ash is considered to induce Ash fouling and slagging. In this paper, we investigate the effect of Na2O on the petcoke Ash fusibility from the perspectives of atmosphere, Na2O content, and Temperature. The crystalline minerals and surface morphologies of high-Temperature Ashes were determined by X-ray diffraction and scanning electronic microscopy, respectively. Thermodynamic software FactSage was applied to calculate the Ash melting process. The results show that the Ash Fusion Temperature (AFT) of petcoke Ash exhibits a continuous decline with the addition of Na2O at both oxidizing and reducing atmospheres, which is ascribed to the mineral transformation behaviors of high-Temperature Ashes. Under oxidizing atmosphere, the low-melting Na-bearing albite (NaAlSi3O8) formed at high-Temperature Ash with the add...
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investigation on improve Ash Fusion Temperature aft of low aft coal by biomass addition
Fuel Processing Technology, 2019Co-Authors: Guixiu Wang, Hongli Fan, Mingxi Guo, Tao Wang, Yitian FangAbstract:Abstract The co-gasification of coal and biomass is of importance for coal clean conversion and biomass utilization on a large scale. To investigate the effecting behaviors of biomass on Ash Fusion characteristics of low Ash-Fusion-Temperature (AFT) coal, the Ash chemical properties of three materials (Shenmu coal (SM), chestnut shell (CS), and rice husk (RH)), the variations in SM mixed AFT with increasing CS or RH mass ratio and their mechanisms were explored through silicate-network structure theory, X-ray powder diffractometry, and FactSage software. The formations of anorthite, gehlenite and their eutectics caused SM with low AFT. An increased CS mass ratio led to the increasing contents of high melting-point (MP) kalsilite, lime and magnesia and the decreasing contents of low MP nepheline, olivine, and gehlenite, this made SM mixed AFTs increased gradually. Increasing high MP tridymite content led to SM mixed AFT mostly increased with increasing RH mass ratio. The Temperature that all minerals changed into liquid phase based on FactSage calculation could reflect the AFT variation of samples.
Zhongxiao Zhang - One of the best experts on this subject based on the ideXlab platform.
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kinetics of steam and co2 gasification with high Ash Fusion Temperature coal char under elevated pressure
Energy Sources Part A-recovery Utilization and Environmental Effects, 2017Co-Authors: Yanchi Jiang, Junjie Fan, Zhongxiao ZhangAbstract:A high Ash Fusion Temperature (AFT) coal char was gasified with steam and CO2 under elevated pressure in a modified pressurized thermogravimetric analyzer. The ambient pressure varied from 0.5 MPa ...
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experiment study on entrained flow gasification technology with dry slag by second stage water supply
Powder Technology, 2017Co-Authors: Junjie Fan, Yanchi Jiang, Zhongxiao ZhangAbstract:Abstract Experimental system of a new entrained flow gasifier with second-stage water supply (20 kg/h) was set up in this paper, and effect of molar ratio of O/C on Temperature distribution, syngas composition, carbon conversion and effective syngas were analyzed with a typical high AFT coal (Guizhou LJ coal). The results of non-second-stage water and second-stage water with changing molar ratio of O/C indicate that, when the molar ratio of O/C is larger than 0.96, gasification efficiency with dry slag by second-stage water would become better than non-second-stage water. Specifically, when the molar ratio of O/C was 1.1, the effective syngas fraction and carbon conversion of second-stage water gasification were 80.2% and 93.24% respectively. Correspondingly, the effective syngas fraction and carbon conversion of non-second-stage water gasification were 78.5% and 91.67% respectively. Furthermore, the gasification Temperature was lower than the Ash Fusion Temperature of test sample, the slag was non-melt during all the gasification experiments. The optimal gasification was conducted with the process Temperature under 1450 °C, which was lower than the Ash Fusion Temperature of LJ coal. These experimental results prove the applicability of entrained flow gasification technology with dry slag by second-stage water supply on using high AFT coals, which is helpful to generalize the large-scale gasification technology using abundant high AFT coals in China.
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prediction of coal Ash Fusion Temperature by least squares support vector machine model
Energy & Fuels, 2010Co-Authors: Bingtao Zhao, Zhongxiao ZhangAbstract:Coal Ash Fusion Temperature (AFT) is one important parameter for coal-fired boiler design and evaluation in a power plant. The relationship between coal AFT and the chemical composition of coal Ash is rather complex in nature and makes the modeling of AFT difficult. In this work, a least-squares support vector machine (LS-SVM) model, which was based on a dynamically optimized search technique with cross-validation, is developed to predict the coal Ash softening Temperature (ST). The accuracy of this LS-SVM model was verified by comparison with the experimental AFT data of different types of coal. Further, the comparison of the present LS-SVM model and the traditional models, for example, multilinear regressions (MLR) and multi-nonlinear models (MNR) as well as the artificial neural network (ANN) models, showed that the LS-SVM model was much better to provide the highest generalized accuracy with the mean squared error of 0.0128 and correlation coefficient of 0.9272. Furthermore, based on the LS-SVM model,...
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experimental study on gasification characteristics and slagging behavior of chinese typical high Ash Fusion Temperature coal in lab scale downflow gasifier
Asia-Pacific Journal of Chemical Engineering, 2009Co-Authors: Zhongxiao Zhang, Nobusuke Kobayashi, Guilin Piao, Shigekatsu Mori, Yoshinori ItayaAbstract:In order to extend the applicability of entrained flow gasification technology by using Chinese high Ash Fusion Temperature (AFT) coal with dry Ash extraction, gasification characteristics and slagging behavior of Chinese high AFT coal were studied in a lab scale downflow gasifier. The results showed that under this experimental condition, the optimum Temperature window which is suitable for dry Ash extraction with high AFT coal ranges from 1573 to 1623 K, as well as the corresponding optimum O2/coal mass ratio ranges from 0.93 to 1.13. The cold gas efficiency and carbon conversion are around 42 and 90%, respectively in this experiment. The slag on the bottom of the gasifier and in the cyclone existed, on the whole, as solid except that some small parts were melted with several micrometers in diameter, while the slag in the bag filter had remained unmelted when continue operating at an optimum condition for 1.5 h. Due to the small percentage of melted parts in the slag, the tendency of plugging is small and the problems of plugging can be avoided at the exit of gasifier by gasifying Chinese high AFT coal at around 1623 K. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Hongli Fan - One of the best experts on this subject based on the ideXlab platform.
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exploration in Ash deposition ad behavior modification of low rank coal by manure addition
Energy, 2020Co-Authors: Chaoyue Zhao, Hongli Fan, Jiejie Huang, Mingxi Guo, Qianqian Guo, Yitian FangAbstract:Abstract High-alkali low-rank coal aggravates Ash deposition (AD) during conversion. To mitigate AD formation during its gasification, the AD characteristics of Xiaolongtan lignite (XLT) and Yima coal (YM), their variations from chicken or pig manure addition under a reducing atmosphere, and their mechanisms were investigated by using Ash Fusion Temperature tester, self-made AD analyzer, and X-ray diffractometer. The results indicated that the mass fraction of AD (MAD) of XLT was higher than that of YM because of the XLT with a high Ca, Fe, Na, and K content. At a low Temperature (
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investigation on regulation mechanism of red mud on the Ash Fusion characteristics of high Ash Fusion Temperature coal
Fuel, 2019Co-Authors: Hongli Fan, Jiejie Huang, Mingxi Guo, Tao Wang, Yitian FangAbstract:Abstract Red mud (RM) used as a flux to decrease coal Ash Fusion Temperature (AFT) has great economic and environmental attractions. The effects of Bayer RM (BRM) and Sintering RM (SRM) on the AFTs of high silicon-aluminum coal (Jiaozuo coal (ZJ)) or high aluminum coal (Pingsuo coal (PS)) were investigated by X-ray fluorescence analysis, X-ray diffraction, and FactSage calculation. With increasing BRM/SRM mass ratio, the AFTs of JZ or PS mixture firstly decreased quickly and then slowly. When Ash flow Temperatures were decreased to
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investigation on improve Ash Fusion Temperature aft of low aft coal by biomass addition
Fuel Processing Technology, 2019Co-Authors: Guixiu Wang, Hongli Fan, Mingxi Guo, Tao Wang, Yitian FangAbstract:Abstract The co-gasification of coal and biomass is of importance for coal clean conversion and biomass utilization on a large scale. To investigate the effecting behaviors of biomass on Ash Fusion characteristics of low Ash-Fusion-Temperature (AFT) coal, the Ash chemical properties of three materials (Shenmu coal (SM), chestnut shell (CS), and rice husk (RH)), the variations in SM mixed AFT with increasing CS or RH mass ratio and their mechanisms were explored through silicate-network structure theory, X-ray powder diffractometry, and FactSage software. The formations of anorthite, gehlenite and their eutectics caused SM with low AFT. An increased CS mass ratio led to the increasing contents of high melting-point (MP) kalsilite, lime and magnesia and the decreasing contents of low MP nepheline, olivine, and gehlenite, this made SM mixed AFTs increased gradually. Increasing high MP tridymite content led to SM mixed AFT mostly increased with increasing RH mass ratio. The Temperature that all minerals changed into liquid phase based on FactSage calculation could reflect the AFT variation of samples.
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Ash Fusion Temperature regulation mechanism of Xiangyang coal by coal blending
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: Hongli Fan, Fenghai LiAbstract:The modifications in the low Ash Fusion Temperature (AFT) of Xiangyang coal (XY) were investigated by blending it with three high AFT coals [Jincheng coal (JC), Sunjiahao coal (SJH), and Shajuzi coal (SJZ)], respectively. These three coals all improved XY AFT effectively. With the JC mass ratio varying from 0 to 50%, the AFT of XY/JC gradually increased. The AFT of XY/SJH increased significantly (0–30%), slowly (30–40%), and rapidly (40–50%) with increasing SJH content. For SJZ, the AFT of XY/SJZ increased quickly (0–30%) and very slowly (30–50%). For XY entrained-flow gasification, the appropriate blending ratios of JC, SJH, and SJZ were 40–50%, 30–40%, and 20–40%, respectively. X-ray diffraction, scanning electron microscopy, and FactSage thermodynamic calculation were applied to investigate the effects of mineral transformation on AFT. Quartz (SiO2), anorthite (CaAl2Si2O8), diopside (CaMgSi2O6), and hedenbergite (CaFeSi2O6) were detected in XY Ash at 1100 °C. As the mass ratios of high AFT coals increased, the obvious increase in anorthite content led to the rise in the AFT of XY/JC; mullite (Al6Si2O13); and corundum (Al2O3) with a high melt point formed in Ashes causing the increase in the AFTs of XY/SJH and XY/SJZ, respectively.
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modification of Ash Fusion behavior of coal with high Ash Fusion Temperature by red mud addition
Fuel, 2017Co-Authors: Huixia Xiao, Hongli Fan, Quanrun Liu, Qianqian GuoAbstract:Abstract The influences of two red mud (RM) samples (ZZ and ZM) on Fusion behaviors of three high Ash Fusion Temperature (AFT) coals (FZ, JC and JZ) were investigated. It was evaluated by determining AFTs of coals, RMs, and the mixtures of coal Ash with RM, as well as their compositions of Ashes and mineral. The results showed that the contents of CaO, Fe2O3, and Na2O in RMs were higher than those in coal Ashes, which caused RMs’ AFTs lower than those of coals. The formation of high melting-point mullite might be the main factor causing coal AFTs higher. With the increase in RM mass ratio, the increasing amount of low-melting eutectic (anorthite (CaAl2Si2O8), fayalite (Fe2SiO4), and anorthite (Na-rich) (Ca,Na)(Si,Al)4O8)) and amorphous matter made AFTs lower. ZZ reduced AFTs obviously than ZM because the content of Na2O in ZZ was higher than that in ZM. Owing to lower ion potential of Na+ than those of Ca2+ and Fe2+, Na+ is easier to enter into the lattice of mullite and results in the reduction of AFTs.
Haifeng Liu - One of the best experts on this subject based on the ideXlab platform.
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morphological evolution of a single char particle with a low Ash Fusion Temperature during the whole gasification process
Energy & Fuels, 2018Co-Authors: Ming Liu, Zhongjie Shen, Qinfeng Liang, Haifeng LiuAbstract:Morphological evolution of single char particle with low Ash Fusion Temperature (Tf ) was investigated during the whole gasification process using high Temperature stage microscope. The experimental results showed that the shrinkage ratio of char particles above the Tf (1300 °C) was higher than that below the deformation Temperature (1000 °C) finally. The TEM and SEM analysis results showed that the Ash was a dispersed distribution in coal char. Dispersed molten slag aggregated to molten slag layer during the gasification process at the Temperature above Tf, which evidently hindered the difFusion of gasifying agent. Therefore, there was a critical shrinkage ratio during the gasification process when the Temperature above the Tf, and the critical shrinkage ratio of XLT char particles was 0.7-0.8. The SEM-EDS analysis results indicated that the critical points in the shrinkage rate curve were related to the molten slag on char surface. And the reaction mechanism was analyzed, the calculating critical thickn...
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effective utilization of water hyacinth resource by co gasification with coal rheological properties and Ash Fusion Temperatures of hyacinth coal slurry
Industrial & Engineering Chemistry Research, 2013Co-Authors: Haifeng Liu, Qiang Zhang, Hui ZhaoAbstract:Water hyacinth has attracted extensive attention due to its capability to capture carbon dioxide and remove excess nutrients and toxic metal ions; however, its exuberant growth also leads to environmental problems. In this study, water hyacinth was introduced to prepare bioslurry fuels with coal in the entrained-flow gasification process. Water hyacinth was modified with the addition of Fe2(SO4)3. Rheological properties and Ash Fusion Temperatures of the modified-hyacinth-coal slurry (MHCS) were investigated. MHCS with solids loading of 60.0 wt % was prepared by adding 19.2 g of modified water hyacinth to 100 g of coal that showed more stability and shear-thinning behavior (thixotropy) than those of coal-water slurry. The Ash Fusion Temperatures of most water hyacinth-coal blends are lower than those of coal and water hyacinth. The modified water hyacinth could further reduce the Ash Fusion Temperature of coal because low-melting eutectic mixtures were formed.
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the influence of phosphorus on Ash Fusion Temperature of sludge and coal
Fuel Processing Technology, 2013Co-Authors: Qiang Zhang, Haifeng Liu, Yaping QianAbstract:Abstract Sewage sludge gasification can result in significant environmental benefits. However, the influence of sewage sludge on the process is not recognized in an adequate degree. The purpose of the present study was to investigate the Ash Fusion Temperature (AFT) of coal-sewage sludge (SS) and the influence of phosphorus on it. Ash Fusion characteristics of six types of coals, one type of sewage sludge, and the corresponding coal-sewage sludge blends were measured. Chemical and mineralogical compositions of blended Ashes at different Temperatures were determined. Ash Fusion Temperatures of most coals are lowered by adding sewage sludge, because Ca and Na in sewage sludge Ash can react with refractory minerals from coal to form low Temperature eutectic. The influence of phosphorus on mixture AFT depends greatly on the Al 2 O 3 /(CaO + Na 2 O + K 2 O) (A/CNK) molar ratio of bulk Ash. Phosphorus tends to react with calcium to form refractory minerals in subaluminous systems (A/CNK 1).
Jixin Qian - One of the best experts on this subject based on the ideXlab platform.
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predicting coal Ash Fusion Temperature based on its chemical composition using aco bp neural network
Thermochimica Acta, 2007Co-Authors: Mingguang Wu, Jixin QianAbstract:Coal Ash Fusion Temperature is important to boiler designers and operators of power plants. Fusion Temperature is determined by the chemical composition of coal Ash, however, their relationships are not precisely known. A novel neural network, ACO-BP neural network, is used to model coal Ash Fusion Temperature based on its chemical composition. Ant colony optimization (ACO) is an ecological system algorithm, which draws its inspiration from the foraging behavior of real ants. A three-layer network is designed with 10 hidden nodes. The oxide contents consist of the inputs of the network and the Fusion Temperature is the output. Data on 80 typical Chinese coal Ash samples were used for training and testing. Results show that ACO-BP neural network can obtain better performance compared with empirical formulas and BP neural network. The well-trained neural network can be used as a useful tool to predict coal Ash Fusion Temperature according to the oxide contents of the coal Ash.
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predicting coal Ash Fusion Temperature using hybrid of ant colony algorithm and bp neural network
International Conference on Industrial Informatics, 2006Co-Authors: Yanpeng Liu, Jixin QianAbstract:A novel algorithm based on the hybrid of ant colony algorithm and BP algorithm (ACA-BP) is presented in this paper. It adopts ACA to search the optimal combination of weights in the solution space, and then uses BP to obtain the accurate optimal solutions. The proposed method can obtain better generalization ability. Compared with BP neural network, the ACA-BP neural network can achieve better performance in predicting the coal Ash Fusion Temperature.
