The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Vikto Hacke - One of the best experts on this subject based on the ideXlab platform.
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a thermodynamic analysis of the reformer Sponge Iron cycle
Journal of Power Sources, 2006Co-Authors: S D Frase, Michael Monsberge, Vikto HackeAbstract:A mathematical model of the reformer Sponge Iron cycle (RESC) is presented. The model is based on a thermodynamic analysis of the process, simulating the complete hydrogen production cycle including the hydrocarbon reformer, the Sponge Iron reactor (SIR) and the auxiliary devices required to operate the process. A parametric process analysis is performed in order to investigate the effect of different levels of operating temperature and different recycle rates on the RESC system performance. A number of gaseous and liquid hydrocarbons are investigated as candidate fuels for applications requiring an on-site hydrogen production capacity. Hydrocarbon to hydrogen conversion efficiencies are presented, along with a full analysis of mass and energy balances. An additional hydrocarbon burner unit running with the same fuel as the RESC hydrogen production cycle is considered as heat source for the endothermic conversion process of hydrocarbon fuel into hydrogen. The mathematical RESC model provides a sound base for further developments of the system, and will be applied in theoretical studies performed in parallel to investigations with a laboratory-scale unit operated at Graz University of Technology.
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a novel process for stationary hydrogen production the reformer Sponge Iron cycle resc
Journal of Power Sources, 2003Co-Authors: Vikto HackeAbstract:Abstract The reformer Sponge Iron cycle (RESC) is discussed as a new process for stationary hydrogen production. The RESC is based on the Sponge Iron reaction process in combination with a reformer unit. The Sponge Iron reaction process is a cyclic process for water splitting, whereby a syngas is consumed. The syngas reacts with Iron oxide (magnetite, Fe3O4) to produce a reduced form of Iron oxide (wuestite or Iron). The reduced Iron oxide is re-oxidised with steam to form magnetite and hydrogen. This process is now combined with the reformer to enhance the overall efficiency considerably. The reformer is operated with methane or liquid hydrocarbons and carbon dioxide and steam out of the Sponge Iron reaction process off-gas are used for the reforming reaction. Experimental investigations concentrate on the lifetime analysis of the contact mass of the Sponge Iron reaction process and the catalyst performance under given temperature conditions, and syngas and off-gas compositions as discussed in this paper.
Shabina Khanam - One of the best experts on this subject based on the ideXlab platform.
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computational fluid dynamics analysis of Sponge Iron rotary kiln
Case Studies in Thermal Engineering, 2017Co-Authors: Gajendra Kuma Gaurav, Shabina KhanamAbstract:Abstract 2D CFD model of rotary kiln of Sponge Iron process is developed to study the effects of angle of inclination, number of rotation and mass flow rate of Iron ore on output parameters. Based on grid independent test for temperature profile optimum mesh size is selected. The result shows that optimum angle of inclination, number of rotation and flow rate of Iron ore are found as 2.7 degree, 4.8 rpm and 10 kg/s, respectively. At these optimum conditions the % metallization is predicted as 89.5%, which is 3.24% less in comparison to the existing system. The temperature profiles of gas and bed are also found within acceptable temperature limits. The results are compared well with the published work as well as industrial data.
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analysis of temperature profile and metallization in rotary kiln of Sponge Iron process through cfd
Journal of The Taiwan Institute of Chemical Engineers, 2016Co-Authors: Gajendra Kuma Gaurav, Shabina KhanamAbstract:Abstract The present paper deals with 2D CFD model of Sponge Iron rotary kilns. Using this model the effects of variations of input parameters, such as angle of inclination, number of rotation and mass flow rate of Iron ore are studied on output parameters like Fe content, temperature profile. These ranges of input parameters are found from industrial practice. For this purpose different models of CFD such as Species transport model, k-epsilon viscous model, Discrete Ordinates (DO) and P1 model, and finite rate/eddy dissipation model are used to find Fe content, temperature profiles. The results of the 2D CFD model show that optimum angle is found as 2.8°. The optimum number of rotation and flow rate of Iron ore is found as 4.7 and 5.83 kg/s, respectively. At these optimum conditions the Fe content is predicted as 92%, which is 4.5% more in comparison to existing system that is being operated at angle of inclination, number of rotation and mass flow rate of Iron ore as 2.5°, 4.3 rpm and 5.83 kg/s, respectively. The temperature profiles of gas and bed are also found within acceptable temperature limits. The results are compared well with the published work.
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simulation of rotary kiln used in Sponge Iron process using ann
International journal of engineering and technology, 2014Co-Authors: Anil K Poonia, Shabina KhanamAbstract:In the present study, estimation of actual output parameters is carried out for a Sponge Iron production process by designing a Multilayer Perceptron model that uses a momentum learning algorithm. For this purpose data of temperature profile of rotary kiln are collected from typical Sponge Iron plant, which correlate four air inlets and twelve temperatures measured at different lengths of the kiln. Four different topologies are proposed for this data set to optimize the regression coefficients (R2). Firstly, these topologies are used to identify optimum value of output parameters based on value of R2. These values of output parameters meet the process requirements. Further, a better option is found to compute actual input parameters correspond to desired output. The analysis shows that to get desired output the input parameters are varied maximum by 38.9% in comparison to input parameters used in the industry.
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recovery and utilization of waste heat in a coal based Sponge Iron process
Chemical Engineering and Processing, 2012Co-Authors: Vivek Kuma, Shabina KhanamAbstract:Abstract The present work is an attempt to conserve energy in coal based Sponge Iron industry incorporating certain design modifications without disturbing the process technology. A typical Sponge Iron plant has been investigated to find out the potential areas where energy is being wasted. To recover heat from these areas two design modifications, Case-1 and Case-2, are proposed. Case-1 accounts for preheating of air using waste gas exiting from ESP. However, for Case-2 initially water is heated using hot Sponge Iron exiting rotary kiln and further hot water is used to preheat air. To compute coal demand of modified designs a model is developed based on heat of reactions, feed preheating, sensible and radiation losses, etc. Preheating of air up to 170 °C for Case-1 reduces coal consumption by 8.7%. Consequently, waste gas generation reduces by 16.7%. Thus, for Case-1 profit is Rs 9.6 million/year. However, for Case-2 preheating of air to 80 °C before entering the kiln reduces coal and water consumption by 7.2% and 96.3%. Consequently, cooling tower capacity is reduced by 37.2%. Due to 27.8% less profit for Case-1 in comparison to Case-2 Case-1 offers higher payback period than that of Case-2. Thus, Case-2 is selected as best proposed design.
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design modifications for energy conservation of Sponge Iron plants
Journal of Thermal Science and Engineering Applications, 2011Co-Authors: Anil K Prasad, Radha Krishna Prasad, Shabina KhanamAbstract:During the operation in the coal based Sponge Iron plant, a tremendous amount of heat is generated and significant part of this heat, associated with the waste gas, remains unutilized. It appears worth interesting to modify the process that facilitates the integration of heat available with the waste gas. In the present paper, for the utilization of heat of waste gas, two modifications, namely, case-1 and case-2, are proposed based on preheating of inlet streams. In case-1, preheating of feed material is considered, whereas in case-2, preheating of feed material as well as air is accounted. These cases are then compared with the existing waste heat recovery system of the plant based on coal consumption, operating and capital costs, profit, and payback period. It is found that both cases are better than the existing heat recovery system of the plant. However, case-2 is selected as the best heat recovery option. In comparison to the existing system, case-2 reduces coal and water consumption by 30.5% and 72.6%, respectively. Further, case-2 releases minimum waste gas to the atmosphere that makes the process envIronment friendly.
Dionysios D Dionysiou - One of the best experts on this subject based on the ideXlab platform.
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new insight into the cosolvent effect on the degradation of tetrabromobisphenol a tbbpa over millimeter scale palladised Sponge Iron pd s fe0 particles
Chemical Engineering Journal, 2019Co-Authors: Zheng Huang, Dongyang Deng, Junqi Qiao, Yaling Che, Dionysios D DionysiouAbstract:Abstract The exploration of an effective treatment is necessary to eliminate the emerging envIronmental pollutant tetrabromobisphenol A (TBBPA). In this study, a direct reduction reaction was adopted to synthesize millimetre-scale palladised Sponge Iron (Pd0-s-Fe0), the main influencing factors were further explored, the degradation intermediates were identified in detail, and the cosolvent effect on the degradation mechanism was determined. The results show that (1) within a 30 min reaction, Pd(II) ions in aqueous solution were successfully decorated onto the s-Fe0 surface as supported by XPS, SEM, EDS, and ICP-OES analyses, (2) after 120 min of reaction, the normalized removal of TBBPA was ∼92.2% over 0.06 wt%-Pd0-s-Fe0, compared with 98.2% over 0.06 wt%-Pd-nZVI and 44.4% over bare nZVI. Moreover, the extend of debromination of TBBPA surprisingly increased as the ratio of the CH3OH:H2O cosolvent decreased, compared with the debromination rates that were greatly restricted in CH3OH (100%, v/v), CH2Cl2 (100%, v/v) and isopropanol (100%, v/v), respectively. Furthermore, the O-methylation reactions over Pd0-s-Fe0 produced unique intermediates, including 2,6-dibromo-4-(2-(3,5-dibromo-4-methoxyphenyl)propan-2-yl)phenol (MeO-TBBPA) and 5,5′-(propane-2,2-diyl)bis(1,3-dibromo-2-methoxy-benzene) (diMeO-TBBPA) with lower toxicity. This study greatly enriches knowledge regarding the degradation mechanism of TBBPA over millimetre-scale Sponge Iron.
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envIronmental application of millimetre scale Sponge Iron s fe0 particles iv new insights into visible light photo fenton like process with optimum dosage of h2o2 and rhb photosensitizers
Journal of Hazardous Materials, 2017Co-Authors: Yongming Ju, Yunjiang Yu, Mingdeng Xiang, Liangzhong Li, Dongyang Deng, Xiaoyan Wang, Dionysios D DionysiouAbstract:Abstract In this study, we firstly develop the photo-Fenton-like system with millimetric Sponge Iron (s-Fe0), H2O2, visible light (vis, λ ≥ 420 nm) and rhodamine B (RhB), and present a comprehensive study concerning the mechanism. Thus, we investigate (1) the adsorption of RhB onto s-Fe0, (2) the photo-Fenton-like removal of RhB over Iron oxides generated from the corrosion of s-Fe0, (3) the homogeneous photo-Fenton removal of RhB over Fe2+ or Fe3+, (4) the Fe3+-RhB complexes, and (5) the photo-Fenton-like removal of tetrabromobisphenol A (TBBPA). The results show that neither the adsorption process over s-Fe0 nor the photo-Fenton-like process over FeOOH, Fe3O4 and Fe2O3, achieved efficient removal of RhB. For comparison, in homogeneous photo-Fenton process, the presence of Fe3+ ions, rather than Fe2+ ions, effectively eliminated RhB. Furthermore, the UV–vis spectra showing new absorbance at ∼ 285 nm indicate the complexes of RhB and Fe3+ ions, adopting vis photons to form excited state and further eject one electron via ligand-to-metal charge-transfer to activate H2O2. Additionally, efficient TBBPA removal was obtained only in the presence of RhB. Accordingly, the s-Fe0– based photo-Fenton-like process assisted with dyestuff wastewater is promising for removing a series of persistent organic pollutants.
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envIronmental application of millimetre scale Sponge Iron s fe0 particles iii the effect of surface silver
Journal of Hazardous Materials, 2015Co-Authors: Xiaoya Wang, Jiande Fang, Runlong Liu, Suku Zhang, Dionysios D DionysiouAbstract:To enhance the dechlorination reactivity of millimetric Sponge Iron (s-Fe(0)), a facile one-pot method was used to decorate s-Fe(0) with Ag(+) ions under ambient conditions. The results recorded by X-ray diffraction patterns, X-ray photoelectron spectra and high-resolution transmission electron microscopy demonstrated that the growth of Ag(0) was dominated primarily by (111) plane with a mean length of ∼20 nm. The roles of Ag(0) loading, catalyst dosage, particle size, initial pH and contaminant concentration were assessed during the removal of pentachlorophenol (PCP). Catalyst recyclability was also studied. The results revealed that 3-5mm s-Fe(0) particles with 5 wt% Ag(0) loading exhibited the best performance with a dose of 3.0 g per 60 mL PCP solution. In addition, the dechlorination of PCP followed two-step, pseudo-first-order reaction kinetics, and Ag(0)-s-Fe(0) was advantageous compared with bimetals of nanoscale zero-valent Iron, Iron power and Iron flakes. The dechlorination mechanism of PCP over Ag(0)-s-Fe(0) was attributed to the surface Ag(0) decoration, which catalyzed the formation of reactive hydrogen atoms for indirect reaction, and the direct electron transfer via Fe-Ag(0) galvanic cells for direct reaction. This suggests that Ag-based bimetals of s-Fe(0) have great potential in the pretreatment of organic halogen compounds in aqueous solution.
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envIronmental application of millimeter scale Sponge Iron s fe0 particles ii the effect of surface copper
Journal of Hazardous Materials, 2015Co-Authors: Xiaowe Liu, Xiaoya Wang, Jiande Fang, Runlong Liu, Yanya Yang, Dongyang Wei, Dionysios D DionysiouAbstract:To enhance the catalytic reactivity of millimeter-scale particles of Sponge Iron (s-Fe(0)), Cu(2+) ions were deposited on the surface of s-Fe(0) using a simple direct reduction reaction, and the catalytic properties of the bimetallic system was tested for removal of rhodamine B (RhB) from an aqueous solution. The influence of Cu(0) loading, catalyst dosage, particle size, initial RhB concentration, and initial pH were investigated, and the recyclability of the catalyst was also assessed. The results demonstrate that the 3∼5 millimeter s-Fe(0) particles (s-Fe(0)(3∼5mm)) with 5wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu(0)-s-Fe(0) showed excellent stability after five reuse cycles. Cu(0)-s-Fe(0) possesses great advantages compared to nanoscale zero-valent Iron, Iron power, and Iron flakes as well as its bimetals. The surface Cu(0) apparently catalyzes the production of reactive hydrogen atoms for indirect reaction and generates Fe-Cu galvanic cells that enhance electron transfer for direct reaction. This bimetallic catalyst shows great potential for the pre-treatment of recalcitrant wastewaters. Additionally, some oxides containing Iron element are selected to simulate the adsorption process. The results prove that the adsorption process of FeOOH, Fe2O3 and Fe3O4 played minor role for the removal of RhB.
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envIronmental application of millimetre scale Sponge Iron s fe0 particles i pretreatment of cationic triphenylmethane dyes
Journal of Hazardous Materials, 2015Co-Authors: Xiaowe Liu, Jua Kang, Xiaoya Wang, Yukui Zhang, Jiande Fang, Dionysios D DionysiouAbstract:Abstract To investigate the removal capability of millimetric zero valent Iron (mmZVI), Sponge Iron (s-Fe0) particles were characterized with XRD, XPS, TEM, HRSEM and EDS techniques. Moreover, the roles of particle size, catalyst dosage, dye concentration, mixing conditions (e.g. ultrasound (US), stirring or shaking), and regeneration treatment were studied with the removal of cationic triphenylmethane dyes. Notably, the reduction process was also revealed as compared to nanoscale zero valent Iron (nZVI), microscale Iron power, and Iron scurf. Furthermore, the reductive mechanism was exemplified with brilliant green. The results demonstrated that (1) the synergetic effect between US and s-Fe0 greatly enhanced the removal of dyes, (2) the dosage of preferred s-Fe0 (1–3 mm) particles was optimized as 30.0 g/L; (3) reuse cycles of s-Fe0 catalyst were enhanced with the assistance of diluted HCl solution; (4) the main degradation routes included the cleavage of conjugated structure reactions, N-de-ethylation reactions, hydroxylation reactions, the removal of benzene ring reactions, and opening ring reactions. Accordingly, the pretreatment of aqueous solution over s-Fe0 was hypothesized to achieve mainly through direct reduction reaction by electron transfer and indirect reductive reactions by the highly activated hydrogen atom. Additionally, decoration with noble metals was utilized to reveal the reaction mechanism.
Gajendra Kuma Gaurav - One of the best experts on this subject based on the ideXlab platform.
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computational fluid dynamics analysis of Sponge Iron rotary kiln
Case Studies in Thermal Engineering, 2017Co-Authors: Gajendra Kuma Gaurav, Shabina KhanamAbstract:Abstract 2D CFD model of rotary kiln of Sponge Iron process is developed to study the effects of angle of inclination, number of rotation and mass flow rate of Iron ore on output parameters. Based on grid independent test for temperature profile optimum mesh size is selected. The result shows that optimum angle of inclination, number of rotation and flow rate of Iron ore are found as 2.7 degree, 4.8 rpm and 10 kg/s, respectively. At these optimum conditions the % metallization is predicted as 89.5%, which is 3.24% less in comparison to the existing system. The temperature profiles of gas and bed are also found within acceptable temperature limits. The results are compared well with the published work as well as industrial data.
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analysis of temperature profile and metallization in rotary kiln of Sponge Iron process through cfd
Journal of The Taiwan Institute of Chemical Engineers, 2016Co-Authors: Gajendra Kuma Gaurav, Shabina KhanamAbstract:Abstract The present paper deals with 2D CFD model of Sponge Iron rotary kilns. Using this model the effects of variations of input parameters, such as angle of inclination, number of rotation and mass flow rate of Iron ore are studied on output parameters like Fe content, temperature profile. These ranges of input parameters are found from industrial practice. For this purpose different models of CFD such as Species transport model, k-epsilon viscous model, Discrete Ordinates (DO) and P1 model, and finite rate/eddy dissipation model are used to find Fe content, temperature profiles. The results of the 2D CFD model show that optimum angle is found as 2.8°. The optimum number of rotation and flow rate of Iron ore is found as 4.7 and 5.83 kg/s, respectively. At these optimum conditions the Fe content is predicted as 92%, which is 4.5% more in comparison to existing system that is being operated at angle of inclination, number of rotation and mass flow rate of Iron ore as 2.5°, 4.3 rpm and 5.83 kg/s, respectively. The temperature profiles of gas and bed are also found within acceptable temperature limits. The results are compared well with the published work.
L I Yungang - One of the best experts on this subject based on the ideXlab platform.
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cadmium removal from wastewater by Sponge Iron sphere prepared by charcoal direct reduction
Journal of Environmental Sciences-china, 2009Co-Authors: L I Junguo, L I YungangAbstract:Sponge Iron sphere (SIS), made of concentrated Iron powder and possessed high activity and intension, was prepared through the process of palletizing, roasting and direct reduction by charcoal. The Sponge Iron sphere could remove most of Cd(2+) from wastewater. The results showed the Cd(2+) removal followed the first order reaction. Initial pH value played an important role in Cd(2+) removal. With original initial pH, Cd(2+) removal decreased to the minimum and then increased slightly with the rising of original concentration. The removal rate constant was -0.1263 and -0.0711 h(-1), respectively, under the Cd(2+) concentration of 50 and 200 mg/L. When the initial pH was adjusted to 3.0, the removal rate constant could increase to -9.896 and -4.351 h(-1), respectively. The removal percentage almost reached to 100% when Cd(2+) concentration was below 100 mg/L. While Cd(2+) concentration was above 100 mg/L, Cd(2+) removal percentage decreased slightly. In dynamic experiments, the column filled with Sponge Iron sphere exhibited favorable permeability. There was no sphere pulverization and conglutination between spheres. In contrast to the static state experiments, the Cd(2+) removal percentage in dynamic state experiment was lower, and the removal Cd(2+) quantity was 1.749 mg/g.