The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
K Ramamurthy - One of the best experts on this subject based on the ideXlab platform.
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properties of geopolymerised low calcium bottom ash aggregate cured at ambient temperature
Cement & Concrete Composites, 2013Co-Authors: S Geetha, K RamamurthyAbstract:Abstract This paper discusses the factors influencing the Pelletization and properties of lightweight aggregate using bottom ash through alkali activation and curing at ambient temperature. The experiments were designed using central composite design of Response surface methodology. The alkaline activators used for the synthesis of geopolymer aggregate are NaOH and Na 2 SiO 3 . Ca(OH) 2 has been used along with the alkaline activators to facilitate hardening of the geopolymer aggregate at ambient temperature. The influence of various factors and their interaction effects on the Pelletization efficiency, bulk density, ten percent fines value, open porosity and water absorption on geopolymer aggregate cured at ambient temperature were identified. Addition of Ca(OH) 2 resulted in the increase in Pelletization efficiency. The molarity of NaOH and dosage of Ca(OH) 2 enhanced the TPFV. The open porosity and water absorption of the aggregate reduced considerably with an increase in NaOH molarity and Na 2 SiO 3 /NaOH ratio.
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reuse potential of low calcium bottom ash as aggregate through Pelletization
Waste Management, 2010Co-Authors: S Geetha, K RamamurthyAbstract:Abstract Coal combustion residues which include fly ash, bottom ash and boiler slag is one of the major pollutants as these residues require large land area for their disposal. Among these residues, utilization of bottom ash in the construction industry is very low. This paper explains the use of bottom ash through Pelletization. Raw bottom ash could not be pelletized as such due to its coarseness. Though pulverized bottom ash could be pelletized, the Pelletization efficiency was low, and the aggregates were too weak to withstand the handling stresses. To improve the Pelletization efficiency, different clay and cementitious binders were used with bottom ash. The influence of different factors and their interaction effects were studied on the duration of Pelletization process and the Pelletization efficiency through fractional factorial design. Addition of binders facilitated conversion of low-calcium bottom ash into aggregates. To achieve maximum Pelletization efficiency, the binder content and moisture requirements vary with type of binder. Addition of Ca(OH) 2 improved the (i) Pelletization efficiency, (ii) reduced the duration of Pelletization process from an average of 14–7 min, and (iii) reduced the binder dosage for a given Pelletization efficiency. For aggregate with clay binders and cementitious binder, Ca(OH) 2 and binder dosage have significant effect in reducing the duration of Pelletization process.
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Influence of fineness of fly ash on the aggregate Pelletization process
Cement and Concrete Composites, 2007Co-Authors: R. Manikandan, K RamamurthyAbstract:Abstract One of the main issues associated with fly ash is the variation in the fineness of fly ash produced within a plant and between thermal power plants, due to the variation in the quality of coal used and the production technique adopted in which Pelletization of fly ash becomes complex. In this paper, the influence of fineness of fly ash is studied by collecting typical samples of fly ash from two thermal power plants. Significance of the factors influencing the Pelletization of fly ash was statistically determined by adopting 2 4 with eight run and 2 5 with sixteen run fractional factorial design for fly ash with fineness of 414 m 2 /kg and 257 m 2 /kg, respectively. Finer fly ash exhibits higher Pelletization efficiency as compared to coarser fly ash. Addition of clay binders like bentonite and kaolinite enhanced the Pelletization efficiency of coarser fly ash. Amount of binder content and moisture content varies with type of binder used (with fly ash having a fineness of 257 m 2 /kg), which is attributed to the difference in plasticity index. Addition of clay binder changes the relative influence of Pelletization factors.
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influence of Pelletization process on the properties of fly ash aggregates
Waste Management, 2006Co-Authors: K I Harikrishnan, K RamamurthyAbstract:A Pelletization process is used to manufacture artificial lightweight coarse aggregate using fly ash. Pelletization depends on the size of particles and their distribution, the wettability of particles and moisture content, along with the process related parameters. A review indicates that only limited studies have been reported on the Pelletization of fly ash aggregates. The influence of the following parameters has been studied: (i) speed of revolution of pelletizer disc, (ii) angle of pelletizer disc, (iii) moisture content, and (iv) duration of Pelletization. Fractional factorial experiments using the concept of Taguchi's orthogonal array is used in this study, which uses an orthogonal array table to arrange multifactor experiments and uses statistical methods to analyze the experimental results. The relative influence of the factors above and their interaction effects on the strength, water absorption and size growth of fly ash aggregates are discussed.
Shahab Sokhansanj - One of the best experts on this subject based on the ideXlab platform.
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Pelletization properties of refuse derived fuel effects of particle size and moisture content
Fuel Processing Technology, 2020Co-Authors: Hamid Rezaei, Shahab Sokhansanj, Fahimeh Yazdanpanah, Jim C LimAbstract:Abstract The energy-contained fraction of the municipal solid waste (MSW) is called refuse-derived fuel (RDF). RDF has a diverse blend of various materials and thus its physical properties and chemical composition are not predictable. Pelletization is one way to reduce the variability of RDF for applications like combustion. In this research, a typical RDF sample was constructed by blending four components of paper, plastic, wood and household organics. The entire blend was subjected to size reduction, drying and wetting. The influence of particles passed through 2, 4 and 6-mm grinder screen size and moisture contents 15, 20, 25 and 30% w.b. on the durability and density of pellets was investigated. The 4-mm RDF sample consumed higher energy and produced pellets with a lower durability than pellets from larger particles. The 6-mm grinder screen produced large pieces of paper and plastics that reduced the free flow of the blend into the pellet die. The RDF sample with an initial moisture content of 20% consumed the lowest Pelletization energy. The force vs. deformation curve for compaction of the material to form pellets exhibited rigid material characteristics.
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Pelletization of refuse derived fuel with varying compositions of plastic paper organic and wood
Sustainability, 2020Co-Authors: Hamid Rezaei, Jim C Lim, Fahimeh Yazdan Panah, Shahab SokhansanjAbstract:The combustible fraction of municipal solid waste (MSW) is called refuse-derived fuel (RDF). RDF is a blend of heterogeneous materials and thus its handling is challenging. Pelletization is an efficient treatment to minimize the heterogeneity. In this research, typical RDF compositions were prepared by mixing several mass fractions of paper, plastic, household organic and wood. The collected compositions were ground, wetted to 20% moisture content (wet basis) and pelletized. Increasing the plastic content from 20% to 40% reduced the Pelletization energy but increased the pellet’s calorific value. Pellets with higher plastic content generated more dust when exposed to shaking. Making durable pellets with 40% plastic content needed an increase in die temperature from 80 °C to 100 °C. Increasing the paper content from 30% to 50% increased the durability but consumed higher energy to form pellets. Paper particles increased the friction between pellet’s surface and die wall as was evident from expulsion energy. Force versus displacement curve for material compression revealed that the RDF compositions have rigid material characteristics.
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co Pelletization of microalgae chlorella vulgaris and pine sawdust to produce solid fuels
Fuel Processing Technology, 2018Co-Authors: Hasti Hosseinizand, Shahab Sokhansanj, Jim C LimAbstract:Abstract Handling, storage, and transportation of dried microalgae is challenging due to its low density. In addition, using pure microalgae as fuel is currently not economically feasible. In the present research, the Pelletization of microalgae Chlorella vulgaris blends and sawdust was studied. Pelletization of pure Chlorella occurred in two distinct regions of particles' rearrangement and particles' deformation. However, there was no clear separation between the two regions when sawdust was added to Chlorella. Adding microalgae Chlorella to sawdust resulted in a decrease in densification energy and improvement in pellets' properties, i.e. higher durability, density, and heating value, lower porosity, moisture absorption, and pellets' expansion. Testing densification temperatures of 50, 75, and 100 °C revealed that by increasing the temperature from 50 to 75 °C, the pellets' quality was improved. However, further temperature increase to 100 °C enhanced properties of the pellets that had a higher fraction of sawdust. Similarly, increasing the compressive force from 2500 to 3500 N improved properties of the pellets having more sawdust. The results showed that adding microalgae to sawdust not only eliminates the need for elevated densification temperature and force, but also results in the production of pelleted fuels with improved quality.
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densified biocoal from woodchips is it better to do torrefaction before or after densification
Applied Energy, 2014Co-Authors: Bahman Ghiasi, Linoj Kumar, Takaaki Furubayashi, Xiaotao Bi, Shahab SokhansanjAbstract:Torrefied biomass represents a high quality renewable energy commodity that can be used to substitute fossil fuels such as coal. However, densification processes such as pelletisation is necessary to improve the tradability of “low-dense” torrefied biomass. In this work, two process pathways were assessed for energy and mass balance in making torrefied pellets from softwood chips and qualities of the resulting torrefied pellets were compared. Pathway I involve drying the wood chips, torrefaction, grinding followed by densification. In pathway II, wood chips were dried, ground, densified and finally torrefied. The results showed that it was difficult to bind the torrefied biomass particles and a binding agent was necessary to enable their effective pelletisation with reasonable energy consumption. In contrary, Pelletization of raw materials was possible without using binding agents and when the “raw wood pellets” were torrefied, the pellets surprisingly stayed intact and had several promising properties such as higher energy/carbon value, reduced moisture content and higher stability in water. In addition, the pathway II was more efficient in terms of overall energy and material balance.
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Binderless Pelletization of Biomass
2005 Tampa FL July 17-20 2005, 2005Co-Authors: Shahab Sokhansanj, Xiaotao Bi, Parisa Zaini, Sudhagar Mani, Lope G. TabilAbstract:A cost-effective pelletized biomass is a key to the success of bio-based industry. Low production costs along with safe handling of biomass will make biomass competitive with fossil fuels. Recent advances in biochemical treatments and force-deformation research point to a possible breakthrough in the age-old pelleting/cubing. The structure of lignocellulosic biomass consists of complex molecules of cellulose, hemicellulose and lignin. Modifying the structure of cellulose-hemicelluloselignin matrix can enhance binding characteristics of lignocellulosic biomass. Furthermore. The research reported in this paper demonstrates that by optimizing a combination of physico-chemical treatments of biomass before and during its densification will improve the hardness and durability of pelletized biomass.
Raffaele Cioffi - One of the best experts on this subject based on the ideXlab platform.
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recycling of mswi fly ash by means of cementitious double step cold bonding Pelletization technological assessment for the production of lightweight artificial aggregates
Journal of Hazardous Materials, 2015Co-Authors: Francesco Colangelo, Francesco Messina, Raffaele CioffiAbstract:Abstract In this work, an extensive study on the recycling of municipal solid waste incinerator fly ash by means of cold bonding Pelletization is presented. The ash comes from an incineration plant equipped with rotary and stoker furnaces, in which municipal, hospital and industrial wastes are treated. Fly ash from waste incineration is classified as hazardous and cannot be utilized or even landfilled without prior treatment. The Pelletization process uses cement, lime and coal fly ash as components of the binding systems. This process has been applied to several mixes in which the ash content has been varied from 50% (wt.%) up to a maximum of 70%. An innovative additional Pelletization step with only cementitious binder has been performed in order to achieve satisfactory immobilization levels. The obtained lightweight porous aggregates are mostly suitable for recovery in the field of building materials with enhanced sustainability properties. Density, water absorption and crushing strength ranged from 1000 to 1600 kg/m3, 7 to 16% and 1.3 to 6.2 MPa, respectively, and the second Pelletization step increased stabilization efficiency. The feasibility of the process has been analyzed by testing also concrete specimens containing the artificial aggregates, resulting in lightweight concrete of average performance.
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use of cement kiln dust blast furnace slag and marble sludge in the manufacture of sustainable artificial aggregates by means of cold bonding Pelletization
Materials, 2013Co-Authors: Francesco Colangelo, Raffaele CioffiAbstract:In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding Pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding Pelletization process in artificial aggregate sustainable production.
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use of cement kiln dust blast furnace slag and marble sludge in the manufacture of sustainable artificial aggregates by means of cold bonding Pelletization
Materials, 2013Co-Authors: Francesco Colangelo, Raffaele CioffiAbstract:In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding Pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding Pelletization process in artificial aggregate sustainable production.
Francesco Colangelo - One of the best experts on this subject based on the ideXlab platform.
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recycling of mswi fly ash by means of cementitious double step cold bonding Pelletization technological assessment for the production of lightweight artificial aggregates
Journal of Hazardous Materials, 2015Co-Authors: Francesco Colangelo, Francesco Messina, Raffaele CioffiAbstract:Abstract In this work, an extensive study on the recycling of municipal solid waste incinerator fly ash by means of cold bonding Pelletization is presented. The ash comes from an incineration plant equipped with rotary and stoker furnaces, in which municipal, hospital and industrial wastes are treated. Fly ash from waste incineration is classified as hazardous and cannot be utilized or even landfilled without prior treatment. The Pelletization process uses cement, lime and coal fly ash as components of the binding systems. This process has been applied to several mixes in which the ash content has been varied from 50% (wt.%) up to a maximum of 70%. An innovative additional Pelletization step with only cementitious binder has been performed in order to achieve satisfactory immobilization levels. The obtained lightweight porous aggregates are mostly suitable for recovery in the field of building materials with enhanced sustainability properties. Density, water absorption and crushing strength ranged from 1000 to 1600 kg/m3, 7 to 16% and 1.3 to 6.2 MPa, respectively, and the second Pelletization step increased stabilization efficiency. The feasibility of the process has been analyzed by testing also concrete specimens containing the artificial aggregates, resulting in lightweight concrete of average performance.
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use of cement kiln dust blast furnace slag and marble sludge in the manufacture of sustainable artificial aggregates by means of cold bonding Pelletization
Materials, 2013Co-Authors: Francesco Colangelo, Raffaele CioffiAbstract:In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding Pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding Pelletization process in artificial aggregate sustainable production.
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use of cement kiln dust blast furnace slag and marble sludge in the manufacture of sustainable artificial aggregates by means of cold bonding Pelletization
Materials, 2013Co-Authors: Francesco Colangelo, Raffaele CioffiAbstract:In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding Pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding Pelletization process in artificial aggregate sustainable production.
Anand R Sanadi - One of the best experts on this subject based on the ideXlab platform.
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reprint of pelletizing properties of torrefied wheat straw
Biomass & Bioenergy, 2013Co-Authors: Wolfgang Stelte, Lei Shang, Niels Peter K Nielsen, Hans Ove Hansen, Jonas Dahl, Anand R SanadiAbstract:Abstract Combined torrefaction and Pelletization are used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. However, Pelletization of torrefied biomass can be challenging and in this study the torrefaction and pelletizing properties of wheat straw have been analyzed. Laboratory equipment has been used to investigate the pelletizing properties of wheat straw torrefied at temperatures between 150 and 300 °C. IR spectroscopy and chemical analyses have shown that high torrefaction temperatures change the chemical properties of the wheat straw significantly, and the pelletizing analyses have shown that these changes correlate to changes in the pelletizing properties. Torrefaction increase the friction in the press channel and pellet strength and density decrease with an increase in torrefaction temperature.
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pelletizing properties of torrefied wheat straw
Biomass & Bioenergy, 2013Co-Authors: Wolfgang Stelte, Lei Shang, Niels Peter K Nielsen, Hans Ove Hansen, Jonas Dahl, Anand R SanadiAbstract:Combined torrefaction and Pelletization are used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. However, Pelletization of torrefied biomass can be challenging and in this study the torrefaction and pelletizing properties of wheat straw have been analyzed. Laboratory equipment has been used to investigate the pelletizing properties of wheat straw torrefied at temperatures between 150 and 300 °C. IR spectroscopy and chemical analyses have shown that high torrefaction temperatures change the chemical properties of the wheat straw significantly, and the pelletizing analyses have shown that these changes correlate to changes in the pelletizing properties. Torrefaction increase the friction in the press channel and pellet strength and density decrease with an increase in torrefaction temperature.
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Recent developments in biomass Pelletization - a review
BioResources, 2012Co-Authors: Wolfgang Stelte, Jens K. Holm, Anand R Sanadi, Lei Shang, Jesper Ahrenfeldt, Ulrik B. HenriksenAbstract:The depletion of fossil fuels and the need to reduce greenhouse gas emissions has resulted in a strong growth of biomass utilization for heat and power production. Attempts to overcome the poor handling properties of biomass, i.e. its low bulk density and inhomogeneous structure, have resulted in an increasing interest in biomass densification technologies, such as Pelletization and briquetting. The global pellet market has developed quickly, and strong growth is expected for the coming years. Due to an increase in demand for biomass, the traditionally used wood residues from sawmills and pulp and paper industry are not sufficient to meet future needs. An extended raw material base consisting of a broad variety of fibrous residues from agriculture and food industries, as well as thermal pre-treatment processes, provides new challenges for the pellet industry. Pellet production has been an established process for several decades, but only in the past five years has there been significant progress made to understand the key factors affecting pelletizing processes. A good understanding about the pelletizing process, especially the processing parameters and their effect on pellet formation and bonding are important for process and product optimization. The present review provides a comprehensive overview of the latest insights into the biomass Pelletization processes, such as the forces involved in the pelletizing processes, modeling, bonding, and adhesive mechanisms. Furthermore, thermal pretreatment of the biomass, i.e. torrefaction and other thermal treatment to enhance the fuel properties of biomass pellets are discussed.