Ash Loading Research Articles

An Investigation of the Influence of Paste's Rheological Characteristics on the Tensile Creep of HVFAC at Early Ages.

The rheological properties of concrete paste significantly influence its tensile creep behavior. In this study, the tensile creep behavior of high-volume fly ash concrete (HVFAC) employing the same cementitious pastes was experimentally investigated, and the rheological properties of the paste containing a high volume of fly ash using the nanoindentation (NI) technique was investigated in order to explore the influence of the paste's rheological properties (such as micro-mechanical properties and microscopic creep) on the early-age tensile creep of HVFAC. The results demonstrated that the micro-strain of paste containing a high volume of fly ash (HVFA) showed a larger value than that without fly ash. As the test age extends, a decreasing trend in microscopic creep was observed which could be attributed to the growth of the content of HD C-S-H (high density C-S-H) gel. Moreover, within the same age period, the experimental data revealed that the incorporation of fly ash resulted in the reduction of the values of the creep modulus C and characteristic time τ. The effects of fly ash dosages and loading age on the creep properties of concrete was consistent with the micro-creep properties of the cementitious paste. The tensile specific creep values derived from the ZC ("ZC" are initials for the word ''self-developed" in Chinese) model based on nanoindentation data closely match those obtained from experiments.

Speciation and Aqueous Dissolution of Macronutrients in Fire Ash: Variation across Ecosystems and the Effects on Nutrient Cycling.

This study investigated the speciation and aqueous dissolution of macronutrients in fire ash from diverse ecosystems and speciation of ash and smoke from laboratory burning, exploring the variations and their causes. The speciation of phosphorus (P), calcium (Ca), and potassium (K) in fire ash from five globally distributed ecosystems was characterized by using X-ray absorption spectroscopy and sequential fractionation. Aqueous dissolution of the macronutrients was measured by batch experiments at acidic and alkaline pHs. The results showed that P existed mainly as Ca phosphates, Ca as double carbonates, calcite, and sulfates, and most K was associated with Ca carbonates. Mineralogy and the relative abundance of the species were primarily controlled by elemental stoichiometry and fire temperature. Differences in Ca and P speciation existed between ash and smoke from laboratory burning, possibly caused by the temperature difference and/or mass fractionation during burning. The rates, extents, and pH dependencies of macronutrient dissolution differed among macronutrients and depended on their speciation, with K being highly soluble and the P and Ca regulated by solution pH. The variability in ash macronutrient chemistry and ecosystem-specific fire ash loads resulted in varying loads and availability of individual macronutrient from fire among ecosystems. This study provides a mechanistic understanding of how fires transform the chemistry of macronutrients and affect macronutrient returns to soils across different ecosystems, which is essential for evaluating the disturbance to ecosystem nutrient cycling by fires.

The use of rice husk ash as a potential filler in formulations of elastomeric compositions for rubber-metal vibration isolators

This study focused on the use of rice husk ash obtained by carbonation in a pyrolysis furnace at a temperature of 550 °C–600 °C to develop a formulation of an elastomeric composition intended for the manufacture of a rubber-metal vibration isolator with reduced environmental impact and a satisfactory set of operational properties. Nine compositions were prepared, comprising different dosages of rice husk ash. These were used as partial and/or complete replacements for N772 carbon black (10, 20, 30 and 40 wt%) and as additional fillers (5, 10, 15 and 20 wt%). Our results show that fully replacing carbon black with rice husk ash improves the technological characteristics of rubber compounds, which can contribute to a reduction in the energy intensity of the manufacturing process of products derived from them. The strength, hardness, and tear resistance of rubbers when replacing N772 with ash in a dosage of up to 20 wt% permit the production of compositions with a satisfactory set of strength properties. An increase in the dosage of ash in excess of 10 wt% when combined with N772 results in a deterioration in the basic physical and mechanical properties of rubbers. As the loading of rice husk ash in place of carbon black is increased, the resistance of the studied compositions to ozone is enhanced, as is the elastic recovery after a given deformation. This will lead to an increase in the service life of the finished product.

Investigation of diesel particulate filter performance under typical failure conditions

Investigation of diesel particulate filter performance under typical failure conditions

A Tribological investigation of fly ash particulate‐loaded E‐glass fiber reinforced interpenetrating polymer network composites

AbstractEnvironmentally‐friendly materials are increasingly sought in use of both structural and non‐structural applications. Most of the prominent places, particulates and fibers are exclusively utilized to reinforce polymeric composites, aiming to enhance their strength and provide effective protection against wear. Currently, one of the most pressing issues encountered in current industries are wear and tear, mostly happens during manufacturing and agricultural operations. To overcome this issue, the current study examines into exploring the effects of different weight ratios (0%, 1%, 3%, 5%, 7%, 9% by wt.%) of fly ash (FA) loading on the abrasive characteristics of Interpenetrating Polymer Networks (IPNs) composites strengthened with E‐Glass fibers. Abrasion tests, conducted in accordance with ASTM D99 standard which involves five control parameters: load, FA content, speed, sliding distance, and surface roughness. Experimental design utilized Taguchi's orthogonal array (L25), with opts ANOVA to identify significant control factors. Results indicate that the addition of FA substantially enhances the wear resistance of particulate‐loaded E‐Glass fiber reinforced IPN composites. Moreover, the specific wear rate is significantly influenced by the applied load and FA content. However experimental data suggests that optimal wear behavior for IPN composites occurs under the conditions of 50 N load, 3% FA content, 300 rpm speed, 4000 m sliding distance, and 0.3 μm disc roughness. Further, scanning electron microscopy was also employed to examine microstructural details to better know the micro‐mechanism behavior happens between the particulates with fiber and matrix reinforcement.Highlights Utilization of fly ash significantly enhances composite strength. IPN laminates fabricated with 0%–7% particulate loads. IPN laminates thoroughly evaluated through wear testing. DOE guided experimental design using L25 orthogonal array. SEM analysis reveals superior quality of fly ash‐loaded IPN.

Effect analysis on passive and active regeneration performance of catalytic diesel particulate filters at the equilibrium point in the presence of ash layer

AbstractCatalytic diesel particulate filters (CDPF) form the main post‐processing devices for the diesel engines. Particulates trapped by CDPF can be oxidized by nitrogen dioxide (NO2) and oxygen (O2). The CDPF passive and active regeneration model on platinum‐based catalyst in the presence of ash layer, including the mass, momentum, and enthalpy balances of the gas and the solid phase, the gas diffusion, and the kinetic of the soot oxidation reaction is performed and validated by the bench test. The effects of different temperatures on CDPF passive and active regeneration at the equilibrium point are analyzed. Further, the effective analysis of ash loading and ash layer distribution on the equilibrium state is conducted. The research on CDPF passive and active regeneration at the equilibrium point in the presence of ash layer provides a theoretical basis for CDPF application.

Adopting green absorbent for CO2 capture and agricultural utilization: Biogas slurry and biomass ash case

Adopting green absorbent for CO2 capture and agricultural utilization: Biogas slurry and biomass ash case

Influence of coal quality on the tendency for slagging formation on a spreader stoker boiler

ABSTRACT During the combustion of solid fuels in power generation systems, one of the biggest problems related to ash is the surface deposition and accumulation of molten or sintered slag, commonly known as slagging. This research evaluated the influence of coal quality on the tendency for slagging based on the evaluation of practical criteria for industry, such as traditional indices, ash load, and coal granulometry. The indices were evaluated from standardized analyses of the composition and fusibility temperatures of the ash of eight bituminous coals. Ash fusibility tests were performed in both oxidizing and reducing atmospheres. Under oxidizing conditions, iron had a dominant influence on the formation characteristics of slagging, resulting in higher melting temperatures. Coals with low frequencies of hard deposit formation, as determined by their ash composition, contributed significantly to deposition problems due to their high ash load and granulometry. Furthermore, large coal particles require more time to burn, which can lead to caking or slag and increased carbon loss in ash. Therefore, when using empirical indices to assess the tendency for slagging, it is essential to consider ash content and ensure an appropriate distribution of coal sizes for combustion.

Combined Ash and Soot Monitoring for Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor

Increasingly stringent emission limits have made particulate filters necessary for gasoline engines. Similar to diesel applications, gasoline particulate filters (GPFs) can be monitored by differential pressure measurement or by the radio-frequency-based filter diagnosis (RF sensor). In addition to measuring the soot loading, ash detection is critical for monitoring the GPF over the entire vehicle lifetime. Because the RF sensor detects the filter loading through a change in the dielectric properties of the GPF, it can detect not only soot but also ash. In diesel applications, the RF sensor has already demonstrated its potential for ash detection. To verify the feasibility of simultaneous ash and soot monitoring for GPFs, filters were loaded with ash on an engine test bench and measured on a lab test bench under defined synthetic exhaust gas conditions. By evaluating resonant modes, soot and ash could be clearly distinguished, as ash mainly affects the resonant frequency, while soot also changes the quality factor due to its high dielectric losses. However, higher soot loadings could not be detected by the resonant parameters, but instead by a frequency-averaged transmission signal. While the presence of ash caused an offset in this signal, its sensitivity to soot was not affected. Thus, the influence of ash can be corrected if the signal in the soot-free filter state is known, e.g., from the behavior of the resonant parameters. Therefore, even with a continuously increasing ash loading over the lifetime of a vehicle, an accurate soot detection is possible with the RF sensor.

Characteristics of ash formed by different lubricant additives and its effect on DPF performance

Characteristics of ash formed by different lubricant additives and its effect on DPF performance

Physicochemical characteristics of ash-bridges in diesel particulate filter

Physicochemical characteristics of ash-bridges in diesel particulate filter

A review of regeneration mechanism and methods for reducing soot emissions from diesel particulate filter in diesel engine.

With the global emphasis on environmental protection and the proposal of the climate goal of "carbon neutrality," countries around the world are calling for reductions in carbon dioxide, nitrogen oxide, and particulate matter pollution. These pollutants have severe impacts on human lives and should be effectively controlled. Engine exhaust is the most serious pollution source, and diesel engine is an important contributor to particulate matter. Diesel particulate filter (DPF) technology has proven to be an effective technology for soot control at the present and in the future. Firstly, the exacerbating effect of particulate matter on human infectious disease viruses is discussed. Then, the latest developments in the influence of key factors on DPF performance are reviewed at different observation scales (wall, channel, and entire filter). In addition, current soot catalytic oxidant schemes are presented in the review, and the significance of catalyst activity and soot oxidation kinetic models are highlighted. Finally, the areas that need further research are determined, which has important guiding significance for future research. Current catalytic technologies are focused on stable materials with high mobility of oxidizing substances and low cost. The challenge of DPF optimization design is to accurately calculate the balance between soot and ash load, DPF regeneration control strategy, and exhaust heat management strategy.

Chemical characteristics of wildfire ash across the globe and their environmental and socio-economic implications

The mobilisation of potentially harmful chemical constituents in wildfire ash can be a major consequence of wildfires, posing widespread societal risks. Knowledge of wildfire ash chemical composition is crucial to anticipate and mitigate these risks. Here we present a comprehensive dataset on the chemical characteristics of a wide range of wildfire ashes (42 types and a total of 148 samples) from wildfires across the globe and examine their potential societal and environmental implications. An extensive review of studies analysing chemical composition in ash was also performed to complement and compare our ash dataset. Most ashes in our dataset had an alkaline reaction (mean pH 8.8, ranging between 6 and 11.2). Important constituents of wildfire ash were organic carbon (mean: 204gkg-1), calcium, aluminium, and iron (mean: 47.9, 17.9 and 17.1gkg-1). Mean nitrogen and phosphorus ranged between 1 and 25gkg-1, and between 0.2 and 9.9gkg-1, respectively. The largest concentrations of metals of concern for human and ecosystem health were observed for manganese (mean: 1488mgkg-1; three ecosystems>1000mgkg-1), zinc (mean: 181mgkg-1; two ecosystems>500mgkg-1) and lead (mean: 66.9mgkg-1; two ecosystems>200mgkg-1). Burn severity and sampling timing were key factors influencing ash chemical characteristics like pH, carbon and nitrogen concentrations. The highest readily dissolvable fractions (as a % of ash dry weight) in water were observed for sodium (18%) and magnesium (11.4%). Although concentrations of elements of concern were very close to, or exceeded international contamination standards in some ashes, the actual effect of ash will depend on factors like ash loads and the dilution into environmental matrices such as water, soil and sediment. Our approach can serve as an initial methodological standardisation of wildfire ash sampling and chemical analysis protocols.

Evaluation of Physico-Chemical and Microbiological Parameters of the Types of Wheat Flour Produced in Milling Company

Wheat flour is one of the most used ingredients in bakery products, based on its nutritional and technological properties. Also in recent years, with the increase in the variety of dough products, there has also been an increase in the types of wheat flour in a way that suits the needs of the market. This study aims to analyze the physico-chemical and microbiological characteristics of some types of wheat flour produced by a milling company, which are used for different purposes, such as: white flour, brown flour, whole meal flour, etc. In total, 6 wheat flour samples of different types were analyzed for: moisture, ash, gluten, acidity, water activity and total microbiological load. The results showed that the moisture content is below 14.5 % for all samples. The range of ash content varies from 0.46-1.29% and is different based on the type of flour, because it represents the total amount of minerals present in wheat flour. Acidity is the most used parameter to determine storage conditions and all samples had a low value of 0.09-0.21 %.The wet gluten content of the flour samples varies between the range of 27.3-34.4 %, the highest value of gluten was detected in brown flour. From the microbiological analyzes carried out, we see that the wheat flour samples analyzed result in a low microbial load. Based on the results of the analyzed samples, all types of wheat flour produced by this company have good quality in terms of the analyzed parameters. Usually, the quality of the final product depends on the quality of the raw ingredients. So, the study of the quality of wheat flour in terms of physico-chemical and microbiological parameters also means a higher quality and safety of bakery products.

Investigation of Lubricant Additive Interactions on Gasoline Particulate Filters

<div>To understand how the composition of novel lubricant additives and their ash interact with gasoline particulate filters (GPFs), an accelerated aging protocol was conducted using three lubricant additive formulations and two GPF types. The additive packages (adpaks) consisted of Ca+Mg detergent in a 3:1 or 0:1 ratio and an anti-wear component—either zinc dialkyl dithiophosphate (ZDDP) or a novel phosphonium-phosphinate ionic liquid (IL) substitute. The particulate sampling captured amount/compositions of particulate matter (PM) generated, total particulate number, and size distribution. Five ash loadings were completed. GPF position and adpak composition affected the backpressure, ash composition, ash morphology, and captured mass. The particulate sampling indicated that the ash component consisted primarily of particles less than 50 nm in size and that the Mg-only adpak resulted in more particulate of 50–400 nm in size. Postmortem materials characterization indicated GPFs in the underfloor position had deeper penetration of ash into the walls compared to the close-coupled position. Additionally, the Mg-only adpak had a higher filter collection efficiency (>90%) and the ash particles consisted of a higher concentration of dense ash material. In contrast, four of the 3:1 Ca:Mg lubricant adpaks resulted in a collection efficiency of only 40–50%. Although the collection efficiency was higher with the Mg-only adpak, the ash layer in the GPF was not thicker, nor was the penetration into the wall more significant, and surprisingly the full useful life (FUL) backpressure was lower than with Ca:Mg adpaks. The higher density of the Mg-derived ash was the only detectable difference. A possible explanation of this observation is that Mg ash has a lower melting point and is more susceptible to densification during combustion or GPF regeneration. The substitution of IL in place of the ZDDP did not lead to any notable changes in collection efficiency or location of the ash.</div>

Ash aerosol particle size distribution, composition, and deposition behavior while co-firing coal and steam-exploded biomass in a 1.5 MWth combustor

Ash aerosol particle size distribution, composition, and deposition behavior while co-firing coal and steam-exploded biomass in a 1.5 MWth combustor

Microstructural and Thermal Behaviour of Composite Material from Recycled Polyethylene Terephthalate and Fly Ash

Nowadays, the environmental impact of plastic waste is crucial, and in the energy industry, fly ash, a type of solid waste, has also prompted severe ecological and safety concerns. In this study, we synthesised composite material from two industrial wastes: recycled polyethylene terephthalate (rPET) as the matrix and fly ash as the filler. The effect of different fly ash loadings on the thermal behaviour and microstructure of the composite material using rPET were evaluated. Various loading amounts of fly ash, up to 68%, were added in the rPET mixtures, and composites were made using a single-threaded bar’s barrel extruder. The feeding zone, compression zone, and metering zone made up the three functional areas of the extruder machine with a single-flighted, stepped compression screw. The composite materials were subjected to DSC and SEM equipped with EDX spectroscopy tests to examine their thermal behaviour and microstructural development. It was found that the thermal behaviour of rPET improved with the addition of fly ash but degraded as the fly ash loading increased to 68%, as confirmed by the DSC study. The composites’ microstructural development revealed an even filler distribution within the polymer matrix. However, when the fly ash loading increased, voids and agglomeration accumulated, affecting the composites’ thermal behaviour.

A novel reutilization of ash from biomass gasification process: Feasibility and products improvement analysis

A novel reutilization of ash from biomass gasification process: Feasibility and products improvement analysis

Modified coal fly ash for textile dye removal from industrial wastewater

Complex dyes have an adverse impact on the environment since they have a high aqueous solubility and are very challenging to be removed using conventional approaches. A series of batch tests were performed to determine the optimum parameters for the direct blue 78 dye adsorption process as a function of chemically treated coal fly ash (TCFA) Effect of fly ash dose, contact time and dye initial concentration were studied using an industrial wastewater. A pilot plant, consisting of three stages; mixing, sedimentation and filtration was designed and implemented to investigate the ability of TCFA to remove COD, BOD5, TDS and TSS from textile wastewater under optimal conditions. A series of fly ash physico-chemical analysis including particles size analysis, zeta potential, XRD, EDX, BET, SEM and FTIR were investigated. The results showed that the particles size and zeta potential for raw coal fly ash were 1.2 µm and −20.70 mv. Chemical treatment process using hydrochloric acid resulted reducing the particles size of fly ash from 1.2 µm to 0.95 µm. Zeta potential value increased to + 7.20 mv. Batch adsorption process showed that the removal efficiency decreased as the primary dye concentration increased. It increased when fly ash loading and contact time increased. Dyes removal was achieved up to 99.7% using TCFA loading 3gL−1 for initial dye concentration10 mgL−1. Studies on equilibrium revealed that the equilibrium data was closely fitted to the Freundlich and Langmuir isotherm models. Kinetic study of adsorption process was studied in detial. Based on high correlation coefficient (R2 = 0.999), the results were followed pseudo second-order model.

Evaluation and bias correction of probabilistic volcanic ash forecasts

Abstract. Satellite retrievals of column mass loading of volcanic ash are incorporated into the HYSPLIT transport and dispersion modeling system for source determination, bias correction, and forecast verification of probabilistic ash forecasts of a short eruption of Bezymianny in Kamchatka. The probabilistic forecasts are generated with a dispersion model ensemble created by driving HYSPLIT with 31 members of the NOAA global ensemble forecast system (GEFS). An inversion algorithm is used for source determination. A bias correction procedure called cumulative distribution function (CDF) matching is used to very effectively reduce bias. Evaluation is performed with rank histograms, reliability diagrams, fractions skill score, and precision recall curves. Particular attention is paid to forecasting the end of life of the ash cloud when only small areas are still detectable in satellite imagery. We find indications that the simulated dispersion of the ash cloud does not represent the observed dispersion well, resulting in difficulty simulating the observed evolution of the ash cloud area. This can be ameliorated with the bias correction procedure. Individual model runs struggle to capture the exact placement and shape of the small areas of ash left near the end of the clouds lifetime. The ensemble tends to be overconfident but does capture the range of possibilities of ash cloud placement. Probabilistic forecasts such as ensemble-relative frequency of exceedance and agreement in percentile levels are suited to strategies in which areas with certain concentrations or column mass loadings of ash need to be avoided with a chosen amount of confidence.