The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Simon Edward Foster - One of the best experts on this subject based on the ideXlab platform.
-
synthesis of activated Ferrosilicon based microcomposites by ball milling and their hydrogen generation properties
International Journal of Hydrogen Energy, 2019Co-Authors: Paul Brack, Sandra E Dann, K G U Wijayantha, Paul Leonard Adcock, Simon Edward FosterAbstract:Abstract Ferrosilicon 75, a 50:50 mixture of silicon and iron disilicide, has been activated toward hydrogen generation by processing using ball milling, allowing a much lower concentration of sodium hydroxide (2 wt %) to be used to generate hydrogen from the silicon in Ferrosilicon with a shorter induction time than has been reported previously. An activation energy of 62 kJ/mol was determined for the reaction of ball-milled Ferrosilicon powder with sodium hydroxide solution, which is around 30 kJ/mol lower than that previously reported for unmilled Ferrosilicon. A series of composite powders were also prepared by ball milling Ferrosilicon with various additives in order to improve the hydrogen generation properties from Ferrosilicon 75 and attempt to activate the silicon in the passivating FeSi2 component. Three different classes of additives were employed: salts, polymers and sugars. The effects of these additives on hydrogen generation from the reaction of Ferrosilicon with 2 wt% aqueous sodium hydroxide were investigated. It was found that composites formed of Ferrosilicon and sodium chloride, potassium chloride, sodium polyacrylate, sodium polystyrene sulfonate-co-maleic acid or fructose showed reduced induction times for hydrogen generation compared to that observed for Ferrosilicon alone, and all but fructose also led to an increase in the maximum hydrogen generation rate. In light of its low cost and toxicity and beneficial effects, sodium chloride is considered to be the most effective of these additives for activating the silicon in Ferrosilicon toward hydrogen generation. Materials characterisation showed that neither ball milling on its own nor use of additives was successful in activating the FeSi2 component of Ferrosilicon for hydrogen generation and the improvement in rate and shortening of the induction period was attributed to the silicon component of the mixture alone The gravimetric storage capacity for hydrogen in Ferrosilicon 75 is therefore maintained at only 3.5% rather than the 10.5% ideally expected for a material containing 75% silicon. In light of these results, Ferrosilicon 75 does not appear a good candidate for hydrogen production in portable applications.
-
elucidating the process of hydrogen generation from the reaction of sodium hydroxide solution and Ferrosilicon
International Journal of Energy Research, 2017Co-Authors: Paul Brack, Sandra E Dann, Paul Leonard Adcock, K Upul G Wijayantha, Simon Edward FosterAbstract:For the first time, the process of hydrogen evolution from Ferrosilicon 75 using sodium hydroxide solution has been investigated as a function of temperature using a combination of X-ray photoelectron spectroscopy, X-ray diffraction and physical measurements. Ferrosilicon 75, a mixture of silicon (~50wt.%) and iron disilicide (~50wt.%), has been shown to produce hydrogen by the action of sodium hydroxide solution on the silicon only, with the iron disilicide acting in the role of spectator/protector species for the silicon. Neither iron disilicide alone nor Ferrosilicon 45, which does not contain a pure metallic silicon phase, was found to generate hydrogen under similar reaction conditions, further indicating that the presence of a pure metallic silicon phase is essential for hydrogen generation. As the iron disilicide acts as a diluent for the active silicon, it is hypothesized that this would result in a slower release of hydrogen than that which would be obtained from the reaction of silicon alone, which may be useful for applications which require a long-term, sustained release of hydrogen. A hydrogen yield of 462.5mL/g and a maximum hydrogen generation rate of 83mL/min g were obtained within 10min of reaction with 40wt.% NaOH at 348K.
-
an old solution to a new problem hydrogen generation by the reaction of Ferrosilicon with aqueous sodium hydroxide solutions
Energy Science & Engineering, 2015Co-Authors: Paul Brack, Paul Leonard Adcock, Sandie E Dann, K Upul G Wijayantha, Simon Edward FosterAbstract:The chemical hydrogen storage properties of Ferrosilicon were investigated. A hydrogen yield of ~4.75 wt.% (with respect to the mass of Ferrosilicon) was estimated by the reaction of varying quantities of Ferrosilicon with 5 mL of 40 wt.% sodium hydroxide solution. The reaction of Ferrosilicon with aqueous sodium hydroxide solution to form hydrogen was found to have an activation energy of 90.5 kJ mol−1 by means of an Arrhenius plot. It was observed that the induction period of the hydrogen generation reaction varies exponentially with temperature. Although this combination of high activation energy and a lengthy induction period at low temperatures reduces the attractiveness of Ferrosilicon for portable hydrogen storage applications unless methods can be developed to accelerate the onset and rate of hydrogen generation, its low cost and widespread availability make it attractive for further studies focused on higher temperature stationary applications.
Veena Sahajwalla - One of the best experts on this subject based on the ideXlab platform.
-
Transforming Waste Printed Circuit Boards and Compact Discs for the Synthesis of Valuable Ferrosilicon Alloy
Journal of Sustainable Metallurgy, 2018Co-Authors: Ravindra Rajarao, Rifat Farzana, Veena SahajwallaAbstract:E-waste is the toxic legacy of our digital age, polluting drinking water and harming ecosystems all over the world. Printed circuit board (PCB) and compact disc (CD) are key components in most of the electrical and electronic components and considered to be the most problematic waste to recycle due to their heterogeneous combination of metal, polymer, and ceramics. In this study, a novel approach to transform waste PCB as a silicon source and waste CD as reductant carbon is investigated to produce Ferrosilicon alloy. Characterization of the nonmetallic fraction of PCB indicates the presence of 50% silica, and the waste CD char shows good-quality carbon as reductant. The Ferrosilicon synthesis process is based on carbothermal reduction and is carried out at 1550 °C under an argon atmosphere. The synthesized product was characterized using XRD, Raman, and EDS analysis, and the results indicated that the Ferrosilicon alloy phase was that of Fe_3Si with 14.8% silicon. This innovative approach of utilizing e-waste for synthesizing Ferrosilicon alloy can be a sustainable solution for recovering resources from electronic waste and minimizes the utilization of nonrenewable traditional raw materials.
-
characteristics of waste automotive glasses as silica resource in Ferrosilicon synthesis
Waste Management & Research, 2016Co-Authors: Rifat Farzana, Ravindra Rajarao, Veena SahajwallaAbstract:This fundamental research on end-of-life automotive glasses, which are difficult to recycle, is aimed at understanding the chemical and physical characteristics of waste glasses as a resource of silica to produce Ferrosilicon. Laboratory experiments at 1550°C were carried out using different automotive glasses and the results compared with those obtained with pure silica. In situ images of slag-metal separation showed similar behaviour for waste glasses and silica-bearing pellets. Though X-ray diffraction (XRD) showed different slag compositions for glass and silica-bearing pellets, formation of Ferrosilicon was confirmed. Synthesized Ferrosilicon alloy from waste glasses and silica were compared by Raman, X-ray photoelectron spectroscopy and scanning electron microscopy (SEM) analysis. Silicon concentration in the synthesized alloys showed almost 92% silicon recovery from the silica-bearing pellet and 74-92% silicon recoveries from various waste glass pellets. The polyvinyl butyral (PVB) plastic layer in the windshield glass decomposed at low temperature and did not show any detrimental effect on Ferrosilicon synthesis. This innovative approach of using waste automotive glasses as a silica source for Ferrosilicon production has the potential to create sustainable pathways, which will reduce specialty glass waste in landfill.
-
synthesis of Ferrosilicon alloy using waste glass and plastic
Materials Letters, 2014Co-Authors: Rifat Farzana, Ravindra Rajarao, Veena SahajwallaAbstract:Abstract Automotive waste glass and plastic contribute significantly to current environmental problems. Hence developing new solutions which use them as raw materials for other products should be considered. In this paper a novel approach to synthesize Ferrosilicon alloy by using waste automotive glass, bakelite and iron oxide as resources is reported. The synthesis is based on reduction at 1550 °C by using bakelite as a carbon source, therefore as reducing agent, iron oxide as precursor and automotive glass as silicon source. XRD pattern, EDS spectra, SEM, LECO and ICP results clearly show that the reduced product is a Ferrosilicon alloy, and associated extent of reduction is investigated by an IR gas analyzer. This innovative approach could be an alternative for synthesis of Ferrosilicon alloy. It could reduce the industry's reliance on conventional raw materials which include quartz as a source of silicon and coke as a source of carbon.
-
dynamic wetting of graphite and sic by Ferrosilicon alloys and silicon at 1550 c
Isij International, 2006Co-Authors: Pedro Yunes J Rubio, Lang Hong, N Sahachaudhury, Russell Bush, Veena SahajwallaAbstract:Silicon-rich ferroalloys and coke are two of the most important raw materials used in the scrap-iron process, both reacting during melting. Fundamental study of high temperature interaction of Ferrosilicon–graphite provides key knowledge for understanding the interfacial reaction and wettability at the solid/liquid interface. Although a large body of work has investigated the wettability for silicon and Ferrosilicon on SiC, the dynamic wetting and the associated interfacial phenomena of the Ferrosilicon alloys–graphite system has not been investigated in depth. Using the sessile droplet method, the dynamic wetting of synthetic graphite by liquid Ferrosilicon alloys containing 24.7 and 74% Si and silicon (98.5% Si) at 1550°C is reported. A sharp decrease in contact angle was observed for high-silicon ferroalloys and silicon, until full wetting was reached within 90 s. However, the wettability changed slowly for FeSi 24.7% (FeSi 24.7) and the final contact angle remained constant at around 70°. X-ray diffraction (XRD) investigations were carried out on the graphite/metal droplet interface to study the interfacial products formed and its influence on the wetting phenomena. The dynamic wetting is seen to be strongly dependent on the time required for the formation of SiC in the interface of Ferrosilicon–graphite.
-
Dynamic Wetting of Graphite and SiC by Ferrosilicon Alloys and Silicon at 1550°C
Isij International, 2006Co-Authors: Pedro J. Yunes Rubio, Russell Bush, Lang Hong, N. Saha-chaudhury, Veena SahajwallaAbstract:Silicon-rich ferroalloys and coke are two of the most important raw materials used in the scrap-iron process, both reacting during melting. Fundamental study of high temperature interaction of Ferrosilicon–graphite provides key knowledge for understanding the interfacial reaction and wettability at the solid/liquid interface. Although a large body of work has investigated the wettability for silicon and Ferrosilicon on SiC, the dynamic wetting and the associated interfacial phenomena of the Ferrosilicon alloys–graphite system has not been investigated in depth. Using the sessile droplet method, the dynamic wetting of synthetic graphite by liquid Ferrosilicon alloys containing 24.7 and 74% Si and silicon (98.5% Si) at 1550°C is reported. A sharp decrease in contact angle was observed for high-silicon ferroalloys and silicon, until full wetting was reached within 90 s. However, the wettability changed slowly for FeSi 24.7% (FeSi 24.7) and the final contact angle remained constant at around 70°. X-ray diffraction (XRD) investigations were carried out on the graphite/metal droplet interface to study the interfacial products formed and its influence on the wetting phenomena. The dynamic wetting is seen to be strongly dependent on the time required for the formation of SiC in the interface of Ferrosilicon–graphite.
Paul Brack - One of the best experts on this subject based on the ideXlab platform.
-
synthesis of activated Ferrosilicon based microcomposites by ball milling and their hydrogen generation properties
International Journal of Hydrogen Energy, 2019Co-Authors: Paul Brack, Sandra E Dann, K G U Wijayantha, Paul Leonard Adcock, Simon Edward FosterAbstract:Abstract Ferrosilicon 75, a 50:50 mixture of silicon and iron disilicide, has been activated toward hydrogen generation by processing using ball milling, allowing a much lower concentration of sodium hydroxide (2 wt %) to be used to generate hydrogen from the silicon in Ferrosilicon with a shorter induction time than has been reported previously. An activation energy of 62 kJ/mol was determined for the reaction of ball-milled Ferrosilicon powder with sodium hydroxide solution, which is around 30 kJ/mol lower than that previously reported for unmilled Ferrosilicon. A series of composite powders were also prepared by ball milling Ferrosilicon with various additives in order to improve the hydrogen generation properties from Ferrosilicon 75 and attempt to activate the silicon in the passivating FeSi2 component. Three different classes of additives were employed: salts, polymers and sugars. The effects of these additives on hydrogen generation from the reaction of Ferrosilicon with 2 wt% aqueous sodium hydroxide were investigated. It was found that composites formed of Ferrosilicon and sodium chloride, potassium chloride, sodium polyacrylate, sodium polystyrene sulfonate-co-maleic acid or fructose showed reduced induction times for hydrogen generation compared to that observed for Ferrosilicon alone, and all but fructose also led to an increase in the maximum hydrogen generation rate. In light of its low cost and toxicity and beneficial effects, sodium chloride is considered to be the most effective of these additives for activating the silicon in Ferrosilicon toward hydrogen generation. Materials characterisation showed that neither ball milling on its own nor use of additives was successful in activating the FeSi2 component of Ferrosilicon for hydrogen generation and the improvement in rate and shortening of the induction period was attributed to the silicon component of the mixture alone The gravimetric storage capacity for hydrogen in Ferrosilicon 75 is therefore maintained at only 3.5% rather than the 10.5% ideally expected for a material containing 75% silicon. In light of these results, Ferrosilicon 75 does not appear a good candidate for hydrogen production in portable applications.
-
elucidating the process of hydrogen generation from the reaction of sodium hydroxide solution and Ferrosilicon
International Journal of Energy Research, 2017Co-Authors: Paul Brack, Sandra E Dann, Paul Leonard Adcock, K Upul G Wijayantha, Simon Edward FosterAbstract:For the first time, the process of hydrogen evolution from Ferrosilicon 75 using sodium hydroxide solution has been investigated as a function of temperature using a combination of X-ray photoelectron spectroscopy, X-ray diffraction and physical measurements. Ferrosilicon 75, a mixture of silicon (~50wt.%) and iron disilicide (~50wt.%), has been shown to produce hydrogen by the action of sodium hydroxide solution on the silicon only, with the iron disilicide acting in the role of spectator/protector species for the silicon. Neither iron disilicide alone nor Ferrosilicon 45, which does not contain a pure metallic silicon phase, was found to generate hydrogen under similar reaction conditions, further indicating that the presence of a pure metallic silicon phase is essential for hydrogen generation. As the iron disilicide acts as a diluent for the active silicon, it is hypothesized that this would result in a slower release of hydrogen than that which would be obtained from the reaction of silicon alone, which may be useful for applications which require a long-term, sustained release of hydrogen. A hydrogen yield of 462.5mL/g and a maximum hydrogen generation rate of 83mL/min g were obtained within 10min of reaction with 40wt.% NaOH at 348K.
-
an old solution to a new problem hydrogen generation by the reaction of Ferrosilicon with aqueous sodium hydroxide solutions
Energy Science & Engineering, 2015Co-Authors: Paul Brack, Paul Leonard Adcock, Sandie E Dann, K Upul G Wijayantha, Simon Edward FosterAbstract:The chemical hydrogen storage properties of Ferrosilicon were investigated. A hydrogen yield of ~4.75 wt.% (with respect to the mass of Ferrosilicon) was estimated by the reaction of varying quantities of Ferrosilicon with 5 mL of 40 wt.% sodium hydroxide solution. The reaction of Ferrosilicon with aqueous sodium hydroxide solution to form hydrogen was found to have an activation energy of 90.5 kJ mol−1 by means of an Arrhenius plot. It was observed that the induction period of the hydrogen generation reaction varies exponentially with temperature. Although this combination of high activation energy and a lengthy induction period at low temperatures reduces the attractiveness of Ferrosilicon for portable hydrogen storage applications unless methods can be developed to accelerate the onset and rate of hydrogen generation, its low cost and widespread availability make it attractive for further studies focused on higher temperature stationary applications.
B. Machulec - One of the best experts on this subject based on the ideXlab platform.
-
Estimation of Carbon Balance in Reaction Zones of a Submerged-Arc Furnace during Ferrosilicon Smelting
Solid State Phenomena, 2020Co-Authors: B. Machulec, Grzegorz KopećAbstract:Based on the electrical parameters of a 20 MVA Ferrosilicon furnace, a methodology of identification of characteristic Ferrosilicon smelting states described as carbon excess and carbon deficiency in the reaction zones ('over-coked', 'under-coked') has been presented. Relations between the electrical parameters and assessments made by furnace operators regarding characteristic furnace states related to amounts of carbon in the reaction zones have been demonstrated. The results show that the reactive power measurements as well as the k, c3 (Andreae’s, Westly’s) parameters, provide the same information on the furnace state and have a close relation with resistivity of the current-conducting zones. Similar information on the level of carbon balance in the reaction zones is obtained from the harmonic analysis of phase voltages and currents or measurements of higher harmonic components using high-pass filters.
-
Comparison the Physico-Chemical Model of Ferrosilicon Smelting Process with Results Observations of the Process under the Industrial Conditions
Archives of Metallurgy and Materials, 2016Co-Authors: B. Machulec, W. BialikAbstract:Based on the minimum Gibbs Free Enthalpy algorithm (FEM), model of the Ferrosilicon smelting process has been presented. It is a system of two closed isothermal reactors: an upper one with a lower temperature T1, and a lower one with a higher temperature T2. Between the reactors and the environment as well as between the reactors inside the system, a periodical exchange of mass occurs at the moments when the equilibrium state is reached. The condensed products of chemical reactions move from the top to the bottom, and the gas phase components move in the opposite direction. It can be assumed that in the model, the Reactor 1 corresponds to the charge zone of submerged arc furnace where heat is released as a result of resistive heating, and the Reactor 2 corresponds to the zones of the furnace where heat is produced by electric arc. Using the model, a series of calculations was performed for the Fe-Si-O-C system and was determined the influence of temperatures T1, T2 on the process. The calculation results show a good agreement model with the real Ferrosilicon process. It allows for the determination of the effects of temperature conditions in charge zones and arc zones of the Ferrosilicon furnace on the carbothermic silica reduction process. This allows for an explanation of many characteristic states in the Ferrosilicon smelting process.
-
Selection of Carbon Reducers for the Ferrosilicon Smelting Process
Solid State Phenomena, 2016Co-Authors: Grzegorz Kopeć, B. MachulecAbstract:Selection of reducing agents for the Ferrosilicon smelting process requires consideration of several difficult to reconcile criteria. The carbon reducers are not only a source of carbon as a substrate of the silica reduction reaction, but also play an important role by acting as a gas filter at the upper zones in working space of the Ferrosilicon furnace. Reactivity of carbon reducers to SiO and degree of conversion on the SiC carbide are directly affecting the silicon recovery as well as the efficiency of the Ferrosilicon process. The simultaneous fulfillment all requirements are difficult to satisfy by using only one type the reducer in the charge for the Ferrosilicon process. This requires the use of a mixture reducers, and the adoption of a compromise that all requirements are met in the best possible extent. To choose the composition of carbon reducers mixture has been used simple physico-chemical model of the Ferrosilicon process with two reaction zones between which there is a mass transfer. It has been shown that in the charge for the Ferrosilicon furnace about 30% mass of Cfix carbon resulting from the reaction stoichiometry of silica reduction process should be in the form of the reducer with increased to SiO reactivity.
-
The Use of Thermo-Gravimetric Studies for the Assessment of Technological Properties of Quartzites for the Ferrosilicon Smelting Process
Solid State Phenomena, 2016Co-Authors: Janusz Węgrzyn, B. MachulecAbstract:The most objective methods of determining the usefulness of quartzite for the Ferrosilicon smelting process are industrial research methods, but such studies are long-lasting and costly. In order to test the usefulness of thermo-gravimetric method to evaluate technological properties of quartzites in a laboratory, thermo-gravimetric studies of quartzites samples from various deposits were carried out. These quartzites are used or were used as a raw material in industrial Ferrosilicon process. The study consisted of measuring the weight loss of powder samples in the form of mixture of quartz with graphite of molar ratio SiO2 + 3C during heating under an argon atmosphere in the temperature range up to 1500°C. The evaluation of technological properties of quartzites was done by comparing the curves of relative weight loss with industrial technological data of the Ferrosilicon smelting process. It was established that the results of thermo-gravimetric studies show satisfying agreement with observations of industrial process, whereas quartzites of improved technological properties revealed a lower weight loss in thermo-gravimetric studies. Studies of this type can be useful as one of the methods of objective assessment of usefulness of quartzites for the Ferrosilicon smelting process.
-
Importance of Electrodes Slipping Algorithm for the Ferrosilicon Smelting Process
Solid State Phenomena, 2016Co-Authors: B. Machulec, W. BialikAbstract:The electric arc is one of the most unstable parts of the electrical circuit of submerged-arc furnaces in the Ferrosilicon smelting process. In the carbothermal silica reduction electric arc has an important role as a high temperature heat source, and its presence is essential for the proper Ferrosilicon process flow. Presence of the of electric arc and temperature conditions of the Ferrosilicon process have a direct relationship with position of the electrodes tip and electrodes slipping. In the ferroalloy industry position of electrodes tip as similar as metallurgical parameters of the process are not directly measured. Most often these assessments are still based to a large extent on intuition and experience operating staff of the furnaces, and have qualitative and subjective character. In order to check the existing algorithm of electrodes slipping was carried out statistical studies of the FeSi75 Ferrosilicon smelting process. The study was conducted at discrete intervals ∆t = 8h using data recorded by the furnace computer measuring system and methods of statistical data processing. It was found that the size of the electrodes slipping, and Cfix ratio in the feed are correlated and are among the most important parameters which have an impact on the technical and economic indicators of the process.
Paul Leonard Adcock - One of the best experts on this subject based on the ideXlab platform.
-
synthesis of activated Ferrosilicon based microcomposites by ball milling and their hydrogen generation properties
International Journal of Hydrogen Energy, 2019Co-Authors: Paul Brack, Sandra E Dann, K G U Wijayantha, Paul Leonard Adcock, Simon Edward FosterAbstract:Abstract Ferrosilicon 75, a 50:50 mixture of silicon and iron disilicide, has been activated toward hydrogen generation by processing using ball milling, allowing a much lower concentration of sodium hydroxide (2 wt %) to be used to generate hydrogen from the silicon in Ferrosilicon with a shorter induction time than has been reported previously. An activation energy of 62 kJ/mol was determined for the reaction of ball-milled Ferrosilicon powder with sodium hydroxide solution, which is around 30 kJ/mol lower than that previously reported for unmilled Ferrosilicon. A series of composite powders were also prepared by ball milling Ferrosilicon with various additives in order to improve the hydrogen generation properties from Ferrosilicon 75 and attempt to activate the silicon in the passivating FeSi2 component. Three different classes of additives were employed: salts, polymers and sugars. The effects of these additives on hydrogen generation from the reaction of Ferrosilicon with 2 wt% aqueous sodium hydroxide were investigated. It was found that composites formed of Ferrosilicon and sodium chloride, potassium chloride, sodium polyacrylate, sodium polystyrene sulfonate-co-maleic acid or fructose showed reduced induction times for hydrogen generation compared to that observed for Ferrosilicon alone, and all but fructose also led to an increase in the maximum hydrogen generation rate. In light of its low cost and toxicity and beneficial effects, sodium chloride is considered to be the most effective of these additives for activating the silicon in Ferrosilicon toward hydrogen generation. Materials characterisation showed that neither ball milling on its own nor use of additives was successful in activating the FeSi2 component of Ferrosilicon for hydrogen generation and the improvement in rate and shortening of the induction period was attributed to the silicon component of the mixture alone The gravimetric storage capacity for hydrogen in Ferrosilicon 75 is therefore maintained at only 3.5% rather than the 10.5% ideally expected for a material containing 75% silicon. In light of these results, Ferrosilicon 75 does not appear a good candidate for hydrogen production in portable applications.
-
elucidating the process of hydrogen generation from the reaction of sodium hydroxide solution and Ferrosilicon
International Journal of Energy Research, 2017Co-Authors: Paul Brack, Sandra E Dann, Paul Leonard Adcock, K Upul G Wijayantha, Simon Edward FosterAbstract:For the first time, the process of hydrogen evolution from Ferrosilicon 75 using sodium hydroxide solution has been investigated as a function of temperature using a combination of X-ray photoelectron spectroscopy, X-ray diffraction and physical measurements. Ferrosilicon 75, a mixture of silicon (~50wt.%) and iron disilicide (~50wt.%), has been shown to produce hydrogen by the action of sodium hydroxide solution on the silicon only, with the iron disilicide acting in the role of spectator/protector species for the silicon. Neither iron disilicide alone nor Ferrosilicon 45, which does not contain a pure metallic silicon phase, was found to generate hydrogen under similar reaction conditions, further indicating that the presence of a pure metallic silicon phase is essential for hydrogen generation. As the iron disilicide acts as a diluent for the active silicon, it is hypothesized that this would result in a slower release of hydrogen than that which would be obtained from the reaction of silicon alone, which may be useful for applications which require a long-term, sustained release of hydrogen. A hydrogen yield of 462.5mL/g and a maximum hydrogen generation rate of 83mL/min g were obtained within 10min of reaction with 40wt.% NaOH at 348K.
-
an old solution to a new problem hydrogen generation by the reaction of Ferrosilicon with aqueous sodium hydroxide solutions
Energy Science & Engineering, 2015Co-Authors: Paul Brack, Paul Leonard Adcock, Sandie E Dann, K Upul G Wijayantha, Simon Edward FosterAbstract:The chemical hydrogen storage properties of Ferrosilicon were investigated. A hydrogen yield of ~4.75 wt.% (with respect to the mass of Ferrosilicon) was estimated by the reaction of varying quantities of Ferrosilicon with 5 mL of 40 wt.% sodium hydroxide solution. The reaction of Ferrosilicon with aqueous sodium hydroxide solution to form hydrogen was found to have an activation energy of 90.5 kJ mol−1 by means of an Arrhenius plot. It was observed that the induction period of the hydrogen generation reaction varies exponentially with temperature. Although this combination of high activation energy and a lengthy induction period at low temperatures reduces the attractiveness of Ferrosilicon for portable hydrogen storage applications unless methods can be developed to accelerate the onset and rate of hydrogen generation, its low cost and widespread availability make it attractive for further studies focused on higher temperature stationary applications.