Different Types Of Ash Research Articles

Harnessing Ash for Sustainable CO2 Absorption: Current Strategies and Future Prospects.

This review explores the potential of using different types of ash, namely fly ash, biomass ash, and coal ash etc., as mediums for CO2 capture and sequestration. The diverse origins of these ash types - municipal waste, organic biomass, and coal combustion - impart unique physicochemical properties that influence their suitability and efficiency in CO2 absorption. This review first discusses the environmental and economic implications of using ash wastes, emphasizing the reduction in landfill usage and the transformation of waste into value-added products. Then the chemical/physical treatments of ash wastes and their inherent capabilities in binding or reacting with CO2 are introduced, along with current methodologies utilize these ashes for CO2 sequestration, including mineral carbonation and direct air capture techniques. The application of using ash wastes for CO2 capture are highlighted, followed by the discussion regarding challenges associated with ash-based CO2 absorption approach. Finally, the article projects into the future, proposing innovative approaches and technological advancements needed to enhance the efficacy of ash in combating the increasing CO2 levels. By providing a comprehensive analysis of current strategies and envisioning future prospects, this review aims to contribute to the field of sustainable CO2 absorption and environmental management.

Circular economy strategy for the valorization of fly ash as a substitute for cement in monoliths (resistance and reactivity evaluation)

AbstractFly ash is currently a problem in different companies, mainly in thermoelectric plants, which must follow a production and consumption model that involves reusing, renewing, and recycling, thus contributing to the circular economy. This work aims to evaluate the reactivity and compressive strength of different types of ashes in concrete monoliths. For this purpose, sugarcane bagasse (SCBA), bituminous coal (BC), and untreated hazardous waste (RUD) were evaluated as replacements for cement. Monoliths and mortars have been manufactured in different mixtures, taken to a curing room, and their compressive strength and reactivity have been determined at different times (up to 28 days for the monoliths and up to 90 for the mortars), mainly in order to check the formation of calcium silicate hydrate (CSH) gels. In the monolith tests, the best performances have been with SCBA and BC, which have been used for the manufacture of the mortars. On day 56, the behavior of the replacement of 30% fly ash (15% BC:15% SCBA) presents a type H mortar behavior, with better results than the control. By day 90, all replacements had the same resistance as M mortars and even higher resistances than the control. This demonstrates the feasibility of its use in the production of Portland cement for the manufacture of low‐performance inputs. This implies the possible reduction of impacts, both in waste disposal sites and in emissions caused by the construction industry, thus contributing to the circular economy.

Mechanisms of Chemical and Autogenous Shrinkage in Alkali-Activated Hybrid Systems

This study aimed to investigate the role of chemical and autogenous shrinkage as well as microstructure of a hybrid system composed of alkali-activated ash blended with portland cement. Three alkali-activated binders were produced with 30% portland cement and different types of ash (70% of bottom ash, 70% of rice husk ash, or 35% of each type of ash). Chemical shrinkage was measured by the buoyancy method. The microstructural and surface analysis were investigated by scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses. Autogenous shrinkage, rather than chemical shrinkage, was mainly responsible for the shrinkage observed in these sealed systems. The results showed that the main mechanism involved in the shrinkage of this hybrid system is associated with the microstructural reorganization of the aluminosilicates phases resulting from polymerization.

Evaluating the effect of steel fibers on the mechanical performance of high-volume fly ash concrete

The construction sector contributes significantly to environmental degradation by completely depleting energy resources. Cement industry emissions are the most significant contributors to climate change along with global warming. To address this issue, researchers are investigating different materials with cementing properties thereby replacing the cement in concrete either partially or completely. Various materials such as different types of ashes and slags have been effectively utilized as cement substitutes thereby making the concrete sustainable. Partial substitution of cement with fly ash has a positive impact on the overall performance of concrete but the incorporation of fly ash at a higher volume into the concrete reduces its characteristics. The objective of this work was to improve the overall performance of High-Volume Fly-Ash concrete by incorporating steel fibers with varying volume fractions. From this study, it can be inferred that reinforcing with steel fibers up to 1.2% fiber volume has compensated for the negative effect of HVFA by improving the overall properties.

Review of alternative ash aggregates in concrete-solution towards waste management and environmental protection.

Owing to the depletion of natural resources, new alternative materials are emerging in construction industry. Especially, development of alternative binders and aggregates using industrial by-products paves way for the development of eco-friendly concrete. As aggregates occupy about 60-70% of the volume of concrete, new alternative materials developed as a substitute for aggregates are considered as need of the day for achieving sustainability in concrete industry. In the past few decades, many industrial by-products are researched as an alternative for natural aggregates. Ash being the largely produced by-products from different industries, it has huge potential in the development of artificial aggregates. Nevertheless, ashes produced from different sources such as coal, municipal solid waste and biomass have different characteristics and affect the properties of aggregates made out of them. The volume of research works reported on development of ash aggregates all over the globe shows that there is a faster growth rate in the development of alternative aggregates and its utilization in concrete. In this context, the current study aims to review the literature reported on mortar/concrete made of ash aggregates from various sources such as thermal power stations, biomass and municipal solid waste incinerator. The characteristics of different types of ash, development of aggregate and its properties in mortar/concrete are reviewed. Based on the review, future recommendations and directions are provided to utilize more of ash aggregates in the place of natural aggregates to prevent depletion of natural resources.

Reduction of Phosphorous from Wastewater Through Adsorption Processes Reusing Wood and Straw Ash Produced in Bioenergy Facilities

The objective of this research is to analyse the feasibility of reusing the fly ash waste, which is produced in biomass plants, during the production of renewable energy, for controlling phosphorus contamination in the wastewater being processed in sewage treatment plants. The research examines the efficiency of using different types of ash, obtained from representative biomass materials after combustion in an energy plant (paulownia wood, wheat straw and barley straw), in removing phosphorus from water. The ashes were respectively mixed with synthetic water, rich in phosphorus; then, using batch experiments, the effects that the pre-treatment of ash, adsorbent dosage, contact time and temperature had on the adsorption process were studied. The main results show that phosphorus adsorption by the tested ashes augments as temperature increases. Similarly, the adsorbed amount of phosphorus increases by increasing the dose of the adsorbent. In addition, the adsorption of phosphorus by these three materials has been described well by the Langmuir isotherm equation. It has been found that the removal process of phosphorus was endothermic. Finally, this study concludes that waste ash from biomass plants can be used to remove phosphorus from wastewater in sewage treatment plants.

Different Effects of Ash Application on the Carbon Mineralization and Microbial Biomass Carbon of Reclaimed Mining Soils

Ash resulting from biomass energy resource utilization contains a wide range of metal oxides and hydroxides, which may influence the capacity of the ash to be used as a soil amelioration material. This study aimed to assess the effects of different ashes on changes in soil carbon (C) mineralization and soil microbial biomass carbon (MBC) in reclaimed mining soils (RMSs). Different levels (0, 25, 50, and 75 Mg ha−1) of three ashes (rice husk, oil palm shell, and coal fly ash) were applied to 10-year RMS for a 120-day incubation period. Carbon mineralization was measured over the 120-day incubation period, while MBC and selected chemical properties were quantified at the end of the incubation period. The results of the study showed that the application of rice husk and oil palm shell ash at all levels and coal fly ash at low levels (≤ 25 Mg ha−1) increased C mineralization and MBC. However, the C mineralization and MBC of the soil decreased significantly when the amount of added coal fly ash reached 75 Mg ha−1. These decreases in C mineralization and MBC may be ascribed to the harmful effect of high amounts of coal fly ash on microbial activity and the increased specific surface areas and contents of Ca, Mg, oxalate- and dithionite-extractable iron and aluminum in soil with high amounts of added coal fly ash. This study demonstrates that the application of different types of ash to RMS leads to different C mineralization and soil MBC responses.

Minerālo saistvielu pētījumi Silikātu materiālu institūtā

Parādīti pēdējās desmitgades pētījumi minerālo saistvielu jomā. Pētīta dažādu aktīvo ķīmisko piedevu ietekme uz betona struktūru, mehāniskajām un fizikālajām īpašībām. Novērtēta iegūto betonu korozijas izturība pret sulfātu sāļu šķīdumiem. Pētīta dažādu rūpniecisko blakus produktu – pelnu – kā pucolānu piedevas ietekme uz betona īpašībām.Investigation of Mineral Binders in the Institute of Silicate MaterialsThe influence of natural and artificial pozzolanic and micro-filler additives on the cement paste hydration process, structure, properties was studied. Different additives and chemical compositions were used: micro- and nano-silica, amorphous silicon dioxide synthesized by sol-gel method, glass powder, highly disperse sand, different types of ash. The pozzolanic activity of additives mainly depends on quantity and specific surface area, i. e., the dispersity of active SiO2 and Al2O3. Depending on the pozzolanic activity chemical additives can be used as concrete aggregates or as active additives.The influence of superplasticizer Semflow MC (SP) on microstructure and properties of concrete was investigated. The compressive strength of concrete with SP increased to 154 MPa, corresponding to HPC. The capillary absorption of water and solutions containing sulphate ions into HPC depends on amount of SP. The depth of penetration of solution in the samples decreases consistently by increasing the amount of SP. The formation of crystalline phase during maturation was analysed, and it was found that by increasing testing time the amount of portlandite decreased and calcium hydrosilicate formed. The concrete samples with low W/C ratio, pozzolanic additives and SP up to 2.5 % according mechanical and chemical properties conform to the characteristics of HPC. The investigated concrete has high chemical resistance to solutions containing sulphate ions.Keywords – binders, concrete, pozzolanic additives, ash, concrete corrosion

Foamed Polyurethane Composites with Different Types of Ash – Morphological, Mechanical and Thermal Behavior Assessments

Incorporation of two types of ash particles into flexible polyurethane foams has been investigated, wood ash from gasification process and fly ash resulting from coal burning in power plant. Samples were modified with 5, 10 and 15 wt% of fillers. Structure, mechanical and thermal properties of obtained foams were investigated. Incorporation of both types of ash particles resulted in materials showing satisfactory mechanical properties, simultaneously decreasing their density. Addition of fly ash inhibited noticeably thermal degradation of material, because of the thermal insulation effect of gas trapped in the spherical ash particles. Results of research show that fly ash can be successfully used as a modifier of thermal properties in polyurethane foams, enhancing the economical aspect of the production through the decrease of material's density and incorporation of low cost filler.

Risk assessment of replacing conventional P fertilizers with biomass ash: Residual effects on plant yield, nutrition, cadmium accumulation and mycorrhizal status

Reutilizing biomass ashes in agriculture can substitute inputs of P from finite primary sources. However, recycling of ashes is disputed due to their content of toxic substances such as heavy metals. This study evaluates the potential risk of replacing easily soluble inorganic P fertilizer with P in biomass ashes in a barley crop grown on soil with adequate P status. Two contrasting doses of three different types of ashes were applied to an agricultural field with spring barley and compared to similar doses of triple-superphosphate fertilizer. In the second growing season after biomass ash application, grain, straw and root dry matter yield, and P and Cd uptake were determined. Resin-extractable P was measured in soil and the symbiotic arbuscular mycorrhizal fungal activity, colonization, and community composition were assessed. Crop yield was not affected by ash application, while P-uptake and mycorrhizal status were slightly enhanced with high ash applications. Changes to the mycorrhizal community composition were evident with high ash doses. Cadmium uptake in aboveground plant tissue was unaffected by ash treatments, but increased in roots with increasing doses. Consequently, we conclude that fertilization with biomass ashes can replace conventional fertilizers without risk to barley crops in the short term.

Rapid toxicity screening of gasification ashes

The solid residues including bottom ashes and fly ashes produced by waste gasification technology could be reused as secondary raw materials. However, the applications and utilizations of these ashes are very often restricted by their toxicity. Therefore, toxicity screening of ash is the primary condition for reusing the ash. In this manuscript, we establish a standard for rapid screening of gasification ashes on the basis of in vitro and in vivo testing, and henceforth guide the proper disposal of the ashes. We used three different test models comprising human cell lines (liver and lung cells), Drosophila melanogaster and Daphnia magna to examine the toxicity of six different types of ashes. For each ash, different leachate concentrations were used to examine the toxicity, with C0 being the original extracted leachate concentration, while C/C0 being subsequent diluted concentrations. The IC50 for each leachate was also quantified for use as an index to classify toxicity levels. The results demonstrated that the toxicity evaluation of different types of ashes using different models is consistent with each other. As the different models show consistent qualitative results, we chose one or two of the models (liver cells or lung cells models) as the standard for rapid toxicity screening of gasification ashes. We may classify the gasification ashes into three categories according to the IC50, 24h value on liver cells or lung cells models, namely “toxic level I” (IC50, 24h>C/C0=0.5), “toxic level II” (C/C0=0.05<IC50, 24h<C/C0=0.5) and “toxic level III” (IC50, 24h<C/C0=0.05). Such a simple yet informative approach can help to determine the toxic effects of various types of ashes generated in gasification plants every day. Subsequently, appropriate disposal methods can be recommended for each toxicity category.

Pond Ash Based Controlled Low Strength Flowable Fills for Geotechnical Engineering Applications

Granular materials are conventionally used as backfills behind retaining walls and many other filling applications. Normally, the backfills are compacted in layers at a relative compaction of not less than 95 % of the Standard Proctor unit weight at desired water content. Depending on the type of backfill material, suitable compaction equipments are selected for compacting the material. Usually, coarse grained materials like gravel, sand, Pond ash, crushed rock pieces and cobble are used as backfill materials. As a replacement to the conventionally used backfill materials, controlled low strength materials (CLSM or flowable fills) are also used, especially in areas where compaction equipments cannot be mobilized. This paper reviews the effective utilization of different types of ashes in flowable fill production and the main properties, advantages and applications in geotechnical engineering practice. Experimental results of a flowable fill made of a local Pond ash are also presented in this paper.

Kvaliteta strukture telesa iz pepela na osnovi različnih vrst pepela

Kvaliteta strukture telesa iz pepela na osnovi različnih vrst pepela

Modification of microporous polyurethane elastomers with different types of ash—morphological, mechanical, and thermal studies

Incorporation of wood ash particles from wood gasification into microporous polyurethane elastomers has been investigated and compared to addition of commercially available microspheres resulting from coal burning. Samples were modified with 3 and 6 wt% of fillers. Structure, mechanical, and thermal properties of obtained elastomers were investigated. Incorporation of both types of ash particles decreased the density of polyurethanes simultaneously increasing their tensile strength and elongation at break. Addition of microspheres caused changes in segment structure of polyurethane, which had negative impact on thermal stability. Although the use of ash from wood pyrolysis enhanced thermal stability of elastomers, causing “labyrinth effect,”, which inhibited significantly thermal degradation of material. Results of research show that wood ash can be successfully used as a modifier of mechanical and thermal properties in polyurethane elastomers. POLYM. COMPOS., 37:881–889, 2016. © 2014 Society of Plastics Engineers

Reactive pozzolanas from rice husk ash: An alternative to cement for rural housing

This paper discusses the properties of rice husk ash samples produced from different types of field ovens to compare the performance of the ovens and to identify the most feasible method to produce a reactive pozzolana as an alternative to cement for building applications requiring lower strengths. Different types of ashes are produced and long-term strength of rice husk ash pozzolanas with lime or cement is investigated to suggest a sustainable affordable option in rural building applications, especially for rural housing in Kerala, a southern state of India.

Effects of Volcanic Ash on Computers and Electronic Equipment

Computers and electronic equipment are an important component of the infrastructure of our modern environment. It is therefore essential that we know the effects of volcanic ash on such equipment. This paper presents the results of a pilot study to test computers and cooling fans in an ash-charged environment to assess their vulnerability. In the experiment, ash was poured on to computers and cooling fans in a sealed 0.216 m3 perspex box, with the effects on both the ash and the equipment monitored. Three different types of ash (1996 Ruapehu andesitic ash, Sakurajima andesitic ash and Kaharoa rhyolitic ash) were used in the experiments. In the first experiment each type of ash was photographed by Scanning Electron Microscope (SEM), then passed through the bearing unit of a cooling fan and photographed again afterwards. The bearings within the cooling fan continued to work even after 720 h of testing and there was no significant abrasion of the fan-shaft bearing. The ash was however fragmented, suggesting that the brittle ash shattered to fine ‘dust’, which caused significantly less abrasion to the bearings or shaft than expected. Three computers were then tested in the sealed box. Ash was introduced at increasing rates to simulate catastrophic entry of ash into a work environment, and computers were tested throughout using the BURNIN® testing programme. Failure times ranged from 100 to 150 h; most failures occurring when humidity was increased by spraying water mist into the airflow. If dried out the computers continued to operate again if failure was not catastrophic. Card slot edge connectors proved to be one of the weakest links, as a bridge of ash formed across the gap. They were also subject to abrasion with some of the gold plating being removed. This did not however cause operating difficulties. The conclusions are that computers are more resilient than originally thought, unless the ash is moist. Simple ‘low-tech’ procedures should be adequate to protect computers from small amounts of dry and moist ash contamination.

Evaluation of blends of high and low calcium fly ashes for use as supplementary cementing materials

Abstract The present paper outlines the results of a research attempt aimed at developing and evaluating the performance of ternary blended cements, incorporating mixtures of two different types of fly ash (of high and low calcium content). The main target of this study was to investigate whether and by what means, the introduction of a certain type of fly ash into a fly ash–cement (FC) matrix containing a different type of ash, can improve the performance of the initial binary system. For achieving this, new pozzolans were prepared by mixing, in selected proportions, a high lime fly ash with an ash of lower calcium content. The efficiency of the new materials was examined in terms of active silica content, pozzolanic activity potential, strength development, k -values and progress of the pozzolanic action by means of fixed lime capabilities. The results obtained demonstrated that the mixtures containing equal amounts of each fly ash were the most effective for moderate cement substitution, whilst for higher replacements the intermixture possessing the highest active silica content shows supremacy at almost all hydration ages. The superior performance of the ternary fly ash blends was mainly attributed to synergistic effects detected for all the ashes utilized. These were quantified in each case and almost linear correlations were obtained with the k -values of the most efficient ternary mixes.

A model to predict erosion on mild steel surfaces impacted by boiler fly ash particles

Fly ash particles entrained in the flue gas from boiler furnaces in coal-fired power stations can cause serious erosive wear on steel surfaces along the flow path. Such erosion can, as a particular example, reduce significantly the operational life of the mild steel heat transfer plates that are used in rotary regenerative heat exchangers (‘air heaters’) that extract heat from the flue gas and transfer it to the incoming boiler combustion air. This paper describes research into fly ash impingement erosion on such surfaces. The effect of the ash particle impact velocity and impact angle on the erosive wear of mild steel surfaces, using three different power station ash types, was determined through experimental investigations. The experimental data were used to calibrate a fundamentally-derived model for the prediction of erosion rates. The model incorporates the properties of the ash particles and the target metal surface, as well as the characteristics of the ash particle motion in the form of the impingement velocity and the impingement angle. When tested using the three different types of ash, the experimentally-calibrated general model yielded results that generally differed by less than 15% from the values that had been measured experimentally.

MSWI ashes as mineral additions in concrete

The paper describes the results of a research aimed at studying the effect of replacing part of portland cement with fly ash and bottom ash, both from municipal solid waste incinerators (MSWIs). Fly ash was subjected to a washing treatment to reduce the chloride content, while bottom ash was subjected to dry or wet grinding underwater. Concretes with addition of different types of ashes, including a traditional coal fly ash (FA), were manufactured. Fresh and hardened properties of the concretes were compared in order to study the advantages and the side effects of each type of addition. Results showed that MSWI bottom ash is potentially attractive as mineral addition for the production of concrete, provided that the risk of entrapment of hydrogen bubbles produced by corrosion of aluminium metallic particles in the fresh concrete is prevented. This could be achieved by wet grinding the bottom ash so that reactions leading to gas development exhaust within the slurry before this is added to the concrete mixture. However, by considering bottom ashes from different incinerators, a great variability was observed in the time required to complete the hydrogen gas production. Nevertheless, when the hydrogen development in the fresh concrete could be avoided, wet ground MSWI bottom showed a good pozzolanic behavior and proved to give a significant contribution to the development of the strength and impermeability of concrete.

The chemistry and mineralogy of the Negev oil shale ashes

The characteristic feature of the oil shale ashes produced by fluidized bed combustion (700–800 °C) in PAMA's demonstration power plant is the large amount of amorphous phases, Ca–Al-silicates and Al-silicates, together with anhydrite and lime. Practically all the S and heavy metals in the oil shales are retained in the ash, which, from an ecological point of view, is important. Two kinds of ashes were examined: industrial ashes produced at PAMA's demonstration plant and ashes produced in laboratory experiments. Three different types of ash are produced at the demonstration plant. Ash Cooler (AC), which is comparable to bottom ash in coal power plants. This ash is produced from oil shale subjected to the lowest temperatures and is the most coarse-grained. It contains relatively larger quantities of unaltered minerals (calcite, clays, apatite, etc.) than the other two. The two other ashes Boiler Bank (BB) and Fly Ash (FAS) are not much different from each other and both may be compared to fly ash in coal power plants. Both BB and FAS ashes contain more authigenic (formed in the boiler) phases than AC. The results of the laboratory experiments show that the main factor in the raw material controlling the mineralogy and chemistry of the oil shale ashes is the Al 2O 3 concentration (clay content), and not the organic matter concentration.