The Experts below are selected from a list of 15105 Experts worldwide ranked by ideXlab platform
Fushen Zhang - One of the best experts on this subject based on the ideXlab platform.
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effective utilization of waste ash from msw and coal co combustion power plant Zeolite Synthesis
Journal of Hazardous Materials, 2008Co-Authors: Yun Fan, Fushen Zhang, Jianxin Zhu, Zhengang LiuAbstract:The solid by-product from power plant fueled with municipal solid waste and coal was used as a raw material to synthesize Zeolite by fusion-hydrothermal process in order to effectively use this type of waste material. The effects of treatment conditions, including NaOH/ash ratio, operating temperature and hydrothermal reaction time, were investigated, and the product was applied to simulated wastewater treatment. The optimal conditions for Zeolite X Synthesis were: NaOH/ash ratio=1.2:1, fusion temperature=550 degrees C, crystallization time=6-10 h and crystallization temperature=90 degrees C. In the Synthesis process, it was found that Zeolite X tended to transform into Zeolite HS when NaOH/ash ratio was 1.8 or higher, crystallization time was 14-18 h, operating temperature was 130 degrees C or higher. The CEC value, BET surface area and pore volume for the synthesized product at optimal conditions were 250 cmol kg(-1), 249 m(2) g(-1) and 0.46 cm(3) g(-1) respectively, higher than coal fly ash based Zeolite. Furthermore, when applied to Zn(2+) contaminated wastewater treatment, the synthesized product presented larger adsorption capacity and bond energy than coal fly ash based Zeolite, and the adsorption isotherm data could be well described by Langmuir and Freundlich isotherm models. These results demonstrated that the special type of co-combustion ash from power plant is suitable for synthesizing high quality Zeolite, and the products are suitable for heavy metal removal from wastewater.
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effective utilization of waste ash from msw and coal co combustion power plant Zeolite Synthesis
Journal of Hazardous Materials, 2008Co-Authors: Fushen ZhangAbstract:The solid by-product from power plant fueled with municipal solid waste and coal was used as a raw material to synthesize Zeolite by fusion-hydrothermal process in order to effectively use this type of waste material. The effects of treatment conditions, including NaOH/ash ratio, operating temperature and hydrothermal reaction time, were investigated, and the product was applied to simulated wastewater treatment. The optimal conditions for Zeolite X Synthesis were: NaOH/ash ratio = 1.2: 1, fusion temperature = 550 degrees C, crystallization time = 6-10 h and crystallization temperature = 90 degrees C. In the Synthesis process, it was found that Zeolite X tended to transform into Zeolite HS when NaOH/ash ratio was 1.8 or higher, crystallization time was 14-18 h, operating temperature was 130 degrees C or higher. The CEC value, BET surface area and pore volume for the synthesized product at optimal conditions were 250 cmol kg(-1), 249 m(2) g(-1) and 0.46 cm(3) g(-1) respectively, higher than coal fly ash based Zeolite. Furthermore, when applied to Zn2+ contaminated wastewater treatment, the synthesized product presented larger adsorption capacity and bond energy than coal fly ash based Zeolite, and the adsorption isotherm data could be well described by Langmuir and Freundlich isotherm models. These results demonstrated that the special type of co-combustion ash from power plant is suitable for synthesizing high quality Zeolite, and the products are suitable for heavy metal removal from wastewater. (c) 2007 Elsevier B.V. All rights reserved.
Xavier Querol - One of the best experts on this subject based on the ideXlab platform.
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x ray powder diffraction based method for the determination of the glass content and mineralogy of coal co combustion fly ashes
Fuel, 2010Co-Authors: Oriol Font, Xavier Querol, Natalia Moreno, Sergi Diez, M T Izquierdo, E Alvarez, Josep Elvira, Diano Antenucci, Henk Nugteren, F PlanaAbstract:Abstract The relevance of Al–Si glass in a number of fly ash applications, such as use as a pozzolanic material, Zeolite Synthesis, and geopolymer production, necessitated research towards investigation of methods for an easy and consistent determination of the glass content in this coal (co)-combustion by-products. A glass standard-addition X-ray powder diffraction (XRD)-based method is proposed in this study as an alternative to the non straightforward procedure of conventional methods for determining the amorphous components, mainly by difference of the total mass and the addition of quantified crystalline species. A >99% Al–Si glass slag sample was selected as a standard for glass. A number of glass standard/fly ash mixtures were performed on Fluidized Bed Combustion (FBC) and pulverized coal combustion (PCC) fly ashes and subsequently analyzed by XRD. The method provides results closer to quantitative proportions of the Al–Si amorphous material of this (co)-combustion by-product, with a range of values
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differential behaviour of combustion and gasification fly ash from puertollano power plants spain for the Synthesis of Zeolites and silica extraction
Journal of Hazardous Materials, 2009Co-Authors: Oriol Font, Xavier Querol, A Lopezsoler, Natalia Moreno, Sergi Diez, Pilar Coca, Garcia F PenaAbstract:Abstract Coal gasification (IGCC) and pulverised coal combustion (PCC) fly ashes (FAs), obtained from two power plants fed with the carboniferous bituminous coal from Puertollano (Spain), were characterised and used as raw materials for Zeolite Synthesis by direct conversion (DC) and by alkaline fusion (Fu), and SiO 2 extraction (Si-Ex) at laboratory scale. The Puertollano FAs are characterised by a high SiO 2 content (59%) with respect to EU coal FAs. High Zeolite Synthesis yields were obtained from both FAs by using conventional alkaline activation. However, the Si extraction yields were very different. The results of the Zeolite Synthesis from the Si-bearing extracts from both FAs demonstrated that high purity Zeolites with high cation exchange capacity (CEC, between 4.3 and 5.3 meq/g) can be produced. The solid residue arising from Si-Ex is also a relatively high NaP1 Zeolite product (CEC 2.4–2.7 meq/g) equivalent to the DC products. The zeolitic materials Synthesised from both FAs by Fu showed an intermediate (between the high purity Zeolites and the DC products) Zeolite content with CEC values from 3.4 to 3.7 meq/g. Low leachable metal contents were obtained from high purity A and X Zeolites and Zeolite material Synthesised by Fu for PCC FA.
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pure Zeolite Synthesis from silica extracted from coal fly ashes
Journal of Chemical Technology & Biotechnology, 2002Co-Authors: Natalia Moreno, J M Andres, Xavier Querol, Felicia Plana, Maria Janssen, Heng NugterenAbstract:Pure Zeolites can be Synthesised from silica extracted from fly ash by alkaline leaching. If the process is optimised the solid residue arising from this extraction may also contain a relatively high content of zeolitic material mixed with residual fly ash components. Both the pure and the impure zeolitic material have a high potential for application in wastewater and flue gas-cleaning technologies. The silica extraction potential of 23 European coal fly ashes covering most of the possible fly ash types is investigated in this study. Optimisation of leaching processes, by varying temperature, time and alkali/fly ash rates, permitted extraction yields up to 140g of SiO 2 per kg using a single step process, but the extraction yields may reach up to 210g/kg by applying thermal pre-treatments prior to the extraction. The solid residue arising from the silica extraction experiments shows a high NaP1 Zeolite content. A high Si/Al ratio of the glass matrix, the occurrence of easily soluble silica phases in the original fly ash and a high reactive surface area were found to be the major parameters influencing silica extraction. High purity 4A and X zeolitic material was obtained by combining the silica extracts from the Meirama fly ash and a waste solution from the Al-anodising industry. The results allowed conversion of the silica extraction yields to an equivalent 630 g of pure 4A-X Zeolite per kg of fly ash with a cation exchange capacity of 4.7meq/g.
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a fast method for recycling fly ash microwave assisted Zeolite Synthesis
Environmental Science & Technology, 1997Co-Authors: Xavier Querol, R Juan, J M Andres, Andres Alastuey, A Lopezsoler, Felicia Plana, Pedro Ferrer, Carmen RuizAbstract:Zeolitic material was synthesized from fly ash by conventional and microwave-assisted hydrothermal alkaline activation experiments. The Zeolite Synthesis was studied as a function of temperature, time, and activation solution concentration. K+-Na+/NH4+ exchange properties of the zeolitic material synthesized were studied as a function of time and Zeolite type. The zeolitic material synthesized from the same fly ash by changing the Synthesis parameters contained: NaP1, hydroxysodalite, hydroxycancrinite, analcime, tobermorite, and nepheline hydrate using NaOH as an activation agent and F linde Zeolite, kalsilite, and phil lipsite-KM Zeolite from KOH activation. Synthesis yields and Zeolite types obtained from the microwave and conventional experiments were very similar, but the activation time needed was drastically reduced by using microwaves (from 24−48 h to 30 min). Consequently, the industrial application of the Synthesis process is enhanced by the microwave-assisted method. From this point of view, t...
Y Q Xi - One of the best experts on this subject based on the ideXlab platform.
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a comprehensive review on the applications of coal fly ash
Earth-Science Reviews, 2015Co-Authors: X S Ji, J H Tang, L Q Ge, Y Q Xi, Prabir Kumar SarkerAbstract:Abstract Coal fly ash, an industrial by-product, is derived from coal combustion in thermal power plants. It is one of the most complex anthropogenic materials, and its improper disposal has become an environmental concern and resulted in a waste of recoverable resources. There is a pressing and ongoing need to develop new recycling methods for coal fly ash. The present review first describes the generation, physicochemical properties and hazards of coal fly ash at the global level, and then focuses on its current and potential applications, including use in the soil amelioration, construction industry, ceramic industry, catalysis, depth separation, Zeolite Synthesis, etc. Finally, the advantages and disadvantages of these applications, the mode of fly ash utilization worldwide and directions for future research are considered.
Zhengang Liu - One of the best experts on this subject based on the ideXlab platform.
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effective utilization of waste ash from msw and coal co combustion power plant Zeolite Synthesis
Journal of Hazardous Materials, 2008Co-Authors: Yun Fan, Fushen Zhang, Jianxin Zhu, Zhengang LiuAbstract:The solid by-product from power plant fueled with municipal solid waste and coal was used as a raw material to synthesize Zeolite by fusion-hydrothermal process in order to effectively use this type of waste material. The effects of treatment conditions, including NaOH/ash ratio, operating temperature and hydrothermal reaction time, were investigated, and the product was applied to simulated wastewater treatment. The optimal conditions for Zeolite X Synthesis were: NaOH/ash ratio=1.2:1, fusion temperature=550 degrees C, crystallization time=6-10 h and crystallization temperature=90 degrees C. In the Synthesis process, it was found that Zeolite X tended to transform into Zeolite HS when NaOH/ash ratio was 1.8 or higher, crystallization time was 14-18 h, operating temperature was 130 degrees C or higher. The CEC value, BET surface area and pore volume for the synthesized product at optimal conditions were 250 cmol kg(-1), 249 m(2) g(-1) and 0.46 cm(3) g(-1) respectively, higher than coal fly ash based Zeolite. Furthermore, when applied to Zn(2+) contaminated wastewater treatment, the synthesized product presented larger adsorption capacity and bond energy than coal fly ash based Zeolite, and the adsorption isotherm data could be well described by Langmuir and Freundlich isotherm models. These results demonstrated that the special type of co-combustion ash from power plant is suitable for synthesizing high quality Zeolite, and the products are suitable for heavy metal removal from wastewater.
Ryong Ryoo - One of the best experts on this subject based on the ideXlab platform.
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Self-organization of silicates on different length scales exemplified by amorphous mesoporous silica and mesoporous Zeolite beta using multiammonium surfactants
RSC Advances, 2020Co-Authors: María J. Castro, Ryong Ryoo, Pit Losch, Christophe Farès, Mohamed Haouas, Françis Taulelle, Eric Breynaert, Christine E.a. Kirschhock, Woojin Park, Wolfgang SchmidtAbstract:In this study the structure directing effect of a gemini-type piperidine-based multi-ammonium surfactant during hydrothermal Zeolite Synthesis was investigated for two cases: with and without a source of aluminum. The absence of an aluminum source led to the formation of an amorphous mesoporous MCM-48 type silica material, while the presence of aluminum guaranteed the formation of Zeolite beta with a hierarchical pore system. The two opposing cases were studied in a time and temperature-dependent manner. The mobility and through space interaction of these large surfactant molecules were studied by liquid state nuclear magnetic resonance (NMR) at a temperature relevant to hydrothermal Synthesis (363 K) in pure water and upon addition of an aluminum and silicon source. In the gel state, at different stages of aging and hydrothermal Synthesis, low angle X-ray diffraction (XRD) and solid state magic angle spinning nuclear magnetic resonance (1H MAS NMR) spectrometry determined the developing order within the system. At each of these different Synthesis steps the respective intermediate materials were calcined. Transmission electron microscopy then allowed closer inspection of the locally developing mesoscopic order, while N2physisorption was used to follow the evolution of porosity.
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Capping with multivalent surfactants for Zeolite nanocrystal Synthesis
WILEY-V C H VERLAG GMBH, 2018Co-Authors: Jinhwan Jung, Jaeheon Kim, Hye Sun Shin, Ryong RyooAbstract:Multiammonium surfactants exhibited a remarkable capping effect for Zeolite Synthesis in the forms of nanoparticles, nanorods, and nanosponges in cases where common monovalent surfactants failed. A nanorod-shaped mordenite Zeolite synthesized in this manner showed significantly enhanced catalytic lifetimes in acid-catalyzed cumene Synthesis reactions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.283
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Mesopore expansion of surfactant-directed nanomorphic Zeolites with trimethylbenzene
ELSEVIER SCIENCE BV, 2018Co-Authors: Jinhwan Jung, Ryong RyooAbstract:The Synthesis of Zeolite using multiammonium surfactants as the hierarchical structure-directing agent has been investigated with a particular focus on mesopore expansion by trimethylbenzene (TMB) addition during the Synthesis of nanosponge beta, MTW and MRE Zeolites. The results showed that mesopore diameters of these Zeolites could be increased according to the amount of TMB added to the Zeolite Synthesis reaction mixture but only when the Na + content was sufficiently high. The expansion was reversed when the Synthesis mixture was reheated following TMB removal by solvent extraction. The thickness of the mesopore walls did not change during the consecutive pore expansion and shrinking processes. A transmission electron microscopic investigation revealed that the process is likely occurring through recrystallization of the Zeolite frameworks, as promoted by Na+. The mesopore diameter of the nanosponge beta Zeolite could be increased to 15 nm using this method. This Zeolite exhibited four times the adsorption capacity for lysozyme (molecular dimension: 2.0 × 2.5 × 4.3 nm3) at 298 K, compared to the TMB-untreated Zeolite, which possessed 3.8 nm mesopores. © 2014 Elsevier Inc. All rights reserved.6
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mesopore expansion of surfactant directed nanomorphic Zeolites with trimethylbenzene
Microporous and Mesoporous Materials, 2014Co-Authors: Jinhwan Jung, Ryong RyooAbstract:Abstract The Synthesis of Zeolite using multiammonium surfactants as the hierarchical structure-directing agent has been investigated with a particular focus on mesopore expansion by trimethylbenzene (TMB) addition during the Synthesis of nanosponge beta, MTW and MRE Zeolites. The results showed that mesopore diameters of these Zeolites could be increased according to the amount of TMB added to the Zeolite Synthesis reaction mixture but only when the Na+ content was sufficiently high. The expansion was reversed when the Synthesis mixture was reheated following TMB removal by solvent extraction. The thickness of the mesopore walls did not change during the consecutive pore expansion and shrinking processes. A transmission electron microscopic investigation revealed that the process is likely occurring through recrystallization of the Zeolite frameworks, as promoted by Na+. The mesopore diameter of the nanosponge beta Zeolite could be increased to 15 nm using this method. This Zeolite exhibited four times the adsorption capacity for lysozyme (molecular dimension: 2.0 × 2.5 × 4.3 nm3) at 298 K, compared to the TMB-untreated Zeolite, which possessed 3.8 nm mesopores.
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Bulk crystal seeding in the generation of mesopores by organosilane surfactants in Zeolite Synthesis
J. Mater. Chem. A, 2014Co-Authors: Jaeheon Kim, Seung Jun Lee, Ryong RyooAbstract:Zeolites of MOR, CHA, and FAU-X topologies were conventionally synthesized using Na+ or an organic structure-directing agent, except that organosilane surfactants were added as a mesopore-generating agent. The organosilanes were represented by the structural formula (CH3O)3Si–C3H6–N+(CH3)2CnH2n+1, where n was varied from 12 to 16 and 18. Each Zeolite Synthesis was seeded with a small amount of bulk Zeolites of the same structure type. The Synthesis result indicated that the bulk Zeolite seeds disappeared completely from the Zeolite products, indicating their disintegration into tiny fragments that were undetectable by high-resolution transmission electron microscopy. Nevertheless, the Zeolite seeding caused a dramatic decrease in Synthesis time. More importantly, crystal seeding, in comparison to unseeded Synthesis, was highly effective in extending the organosilane-directed mesopore-generating strategy to a wide range of mesoporous and Zeolite structures.
