Biomass Fly Ash Research Articles

Primjenjivost metoda za ispitivanje pucolaniteta za procjenu reaktivnosti letećih pepela drvne biomase

Pozzolanic activity of materials can initially be assumed from the quantity of the pozzolanic oxides SiO2, Al2O3 and Fe2O3. Some of the methods for assessing pozzolanic reactivity of materials include measurement of CaO consumption (Frattini test), decrease in electrical conductivity and pH of a solution containing pozzolanic material, or measurement of an increase in strength of mortar with replacement of cement by pozzolanic material (strength activity index, SAI). The above-mentioned pozzolanicity tests are used in this study to evaluate reactivity of wood biomass fly ashes (WBA-F). The results presented in the paper show that only the SAI method can fully reveal the hydraulic and pozzolanic activity of WBA-F.

New geopolymers from industrial by-products: Olive biomass fly ash and chamotte as raw materials

This research presents the feasibility of a geopolymer fully prepared using chamotte, ceramic industry residue, and fly ash from olive biomass, residue from the olive oil industry. A typical ceramic characterization was carried out from a mechanical and physical standpoint, aimed at exploring their potential as a building material in order to reuse this currently unused waste and to reduce clay extraction operations. Based on the obtained tests results, binder samples showed promising mechanical properties with compressive strengths of over 50 MPa, leading to sustainable raw materials for traditional ceramics in certain applications.

Leaching Characteristics of Wood Biomass Fly Ash Cement Composites

Wood biomass ash (WBA) represents an environmental and economic problem for energy producers, and there have been extensive studies of using WBA as a raw material in construction products. This study investigates the leaching characteristics of WBA cement composites based on testing results. Currently, 70% of WBA is landfilled, and the rest is primarily used in agriculture; therefore, this study also addresses the leaching as a component of environmental safety of these two primary WBA management approaches. An analysis of the leaching characteristics of WBA, monolithic, and crushed cement composites is performed by replacing 15% of the cement with WBA. The study was conducted using three WBA samples collected from different power plants. Increased values of leaching from the WBA itself are indicative of potential issues that could occur in the case of its disposal. The study concluded that the WBA could be potentially environmentally acceptable as a raw material in the concrete industry because the heavy metals are stabilized within the cement matrix.

Assessment of Wood-Based Fly Ash as Alternative Cement Replacement

The abandonment of coal energy plants in the near future will result in a substantially reduced availability of the coal fly ash broadly used as an efficient supplementary material. In line with the growth of alternative and renewable energy resources, the amount of biomass-based ash rises substantially. Nevertheless, a diverse chemical composition prevents a broader utilization of biomass-based fly ash compared to coal ash on an industrial scale. On this account, the present work is aimed at investigating the basic physical and mechanical properties of concrete mortars modified by a high volume of biomass fly ash (BFA) from wood combustion. Delivered results confirm a significant potential of BFA in the building industry. Experimental analysis of concrete mortars with BFA reveals preservation or even improvement of compressive and bending strength up to 30 wt.% cement replacement. On the contrary, higher dosages induce a gradual decrease in mechanical performance. The performed Life Cycle Assessment analysis reveals the perspective of BFA incorporation taking into account environmental issues considering the ratio between preservation of mechanical performance per normalized endpoint environmental score that allows a direct comparison with other alternatives.

Biomass fly ash as an alternative to coal fly ash in blended cements: Functional aspects

The tightening of environmental standards in the EU including the presupposed abatement of coal combustion power plants presents an important impulse towards the transition to a circular economy. However, the achievement of this challenging goal requires a solution to a number of problems. One of the downstream problems consists in the fact that the application of fly ash originating in coal combustion (CFA) as a partial cement replacement might be gradually abandoned in future decades. The first reason may be economical as the increasing environmental regulations will probably result in its more costly processing. The second one is related to the increasing use of alternative energy sources which can lead to the decreasing availability of CFA. Biomass fly ash (BFA) originating from wood combustion can be considered as one of the prospective environmentally more friendly candidates for a partial replacement of CFA as supplementary cementitious material (SCM). In this paper, functional aspects of a possible replacement of CFA by BFA in blended cements are analyzed. Complex characterization of BFA performed prior to the other investigations reveals very good prerequisites for its use as SCM. The experimental analysis of functional properties of Portland cement-BFA based composites after 28-days curing shows the suitability of BFA as SCM for the cement replacement up to 30% by mass. The data collected after 90 and 180 days of curing indicate a substantial improvement of strength of all analyzed composites. The significantly lower content of hazardous elements in BFA in a comparison with CFA presents another benefit; it can be used in blended cements without any further processing or treatment.

Moisture Damage Resistance of Grave Emulsion Manufactured with Waste Biomass Fly Ashes

Biomass combustion is an economic and environmentally friendly source of energy with a growing demand. Nevertheless, the environmental management of fly ashes generated during energy production must be improved. In this regard, this study analyses the feasibility of using biomass fly ashes from the paper industry (BioFAPI) as filler in cold asphalt mixture (type grave emulsion GE1). The chemical and mineralogical composition of BioFAPI samples were analysed by means of X-ray fluorescence spectroscopy and X-ray diffraction. A qualitative evaluation of their morphology was performed using a scanning electron microscope. In addition, the grain-size distribution was obtained by means of light-scattering analysis techniques. Finally, immersion-compression tests were conducted in order to analyse the stripping potential of the grave emulsion manufactured using BioFAPI as filler. These results were compared with those of a control mixture. In this case, the use of BioFAPI as filler led to mixtures with adequate moisture damage resistance. Also, the compression strength of the mixture containing BioFAPI was higher than that of the control mixture. Thus, BioFAPI could be successfully used as filler for grave emulsion. It is a new eco-friendly way to promote the sustainable management of fly ashes from biomass combustion.

Zeolites‐containing geopolymers obtained from biomass fly ash: Influence of temperature, composition, and porosity

AbstractIn this research, compositional and processing parameters were varied to obtain zeolites‐containing geopolymers using mainly biomass fly ash wastes. In addition to curing temperatures, another primary factor affecting the typologies of the resulting zeolites was composition. The mixture composition used in the synthesis crucially affects the nature of the zeolitic crystalline phases in the geopolymeric matrix. Using 10 mol/L NaOH solution, faujasite‐type zeolites produced in geopolymers show a surface area of ~100 m2/g (BET), while those prepared by 8 mol/L NaOH solution have a much lower surface area of ~19 m2/g.

Wood biomass fly ash ameliorates acidic, low-nutrient hydromorphic soil & reduces metal accumulation in maize

Biomass-fuelled facilities generate alkaline and mineral-/nutrient-enriched co-product (ash) that has to be appropriately managed, and preferably reused. The assumption that wood biomass fly ash (BFA) could be used in chemical amelioration of soil acidity and fertility was tested by: i) physicochemical characterisation of BFA and ii) bioassay with maize grown in acidic (pHKCl 4.68) hydromorphic soil amended with BFA (0–10% w/w). Scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction revealed non-homogeneous (ir)regular spherical/porous agglomerated particle morphology and distinctive distribution of Si-/Ca-/K-based minerals, while secondary ion mass spectrometry, for the first time, confirmed their isotopic (six Ca, three Si/Mg and two K isotopes) diversity. BFA addition strongly shifted soil pHKCl (up to 9.1), raised salinity (by > 8.2-fold) and the content of most phytonutrients (up to 5.4-fold); however, BFA amendments at >1.25% restricted the maize root and shoot growth, likely due to alkaline stress as indicated by necrotic/chlorotic symptoms at >5.0% rate. The BFA amendments increased total concentration of metals in soil (without exceeding the levels recognised as contamination); however, phytoextraction of Cd, Zn, Mn, Cu and Mo was significantly supressed (Cd by almost 12-fold), confirming that BFA improved soil-plant metal immobilisation, shifting rhizosphere biogeochemistry towards chemisorption/precipitation reactions. Even though results revealed a strong liming and P–K–Ca–Mg–Zn–Mn–Cu enrichment potential of BFA, to avoid possible negative environmental implications (saline/alkaline stress, metal contamination, adverse effects on soil microbiome), quantitative and qualitative ex ante evaluation of the BFA/soil matrix combinations is essential before application to ameliorate suboptimal (acidic, low-nutrient) or metal-contaminated soils.

Optimization of FAME production from blends of waste cooking oil and refined palm oil using biomass fly ash as a catalyst

One of the problems associated with biomass combustion is the amount of fly ashes generated and its subsequent management. The search for ways of valorizing these ashes has been a challenge for the academic and industrial community. On the other hand, used cooking oils are wastes which management is quite difficult, by they have a very important energetic potential. The goal of this work was to optimize the Fatty Acid Methyl Esters (FAME) process, recovering two residual materials (waste cooking oils (WCO), and biomass fly flash (BFA)). The optimization of the process was achieved using the response surface methodology and a Box-Benhken experimental design applied to mixtures of WCO and refined palm oil (RPO), using BFA as catalyst. The influence on FAME yield of four variables (catalyst loading, methanol/oil molar ratio, RPO/WCO ratio and reaction temperature) was studied. The higher FAME yield achieved was 73.8% for the following operating conditions: 13.57 wt% of catalyst loading, 6.7 of methanol/oil molar ratio, 28.04 wt% of RPO in the oil mixture with WCO and 55 °C for the reaction temperature. The reusability of the BFA catalyst in the process was also studied through three successive usage cycles finding no loss of catalytic activity.

Investigation on mechanical and microstructural properties of alkali-activated materials made of wood biomass ash and glass powder

The possibility of the application of biomass fly ash (BFA) as a precursor material for the synthesis of alkali-activated materials (AAM) is presented in this paper. Glass powder (GP) was tested as an additional substrate in a synthesis process. Different mixtures of samples were produced: four mixtures using only BFA for different NaOH concentrations and nine mixtures where BFA was partially replaced by the GP. Three different NaOH concentrations were applied here. Compressive and flexural strength after 7 and 14 days were performed. The microstructure and the chemical composition of samples were obtained. The results show that the compressive and flexural strength of materials increased with the increase of NaOH concentration and the decrease of the GP content in a mixture. The samples were also characterized by the high porosity with some voids and microcracks. The poorly dissolved BFA particles were also noted in a matrix.

Repurposing Fly Ash Derived from Biomass Combustion in Fluidized Bed Boilers in Large Energy Power Plants as a Mineral Soil Amendment

This research involved studying the physico-chemical parameters of fly ash derived from the combustion of 100% biomass in bubbling and circulating fluidized bed boilers of two large energy plants in Poland. Chemical composition revealed that ash contains substantial amounts of CaO (12.86–26.5%); K2O (6.2–8.25%); MgO (2.97–4.06%); P2O5 (2–4.63%); S (1.6–1.83%); and micronutrients such as Mn, Zn, Cu, and Co. The ash from the bubbling fluidized bed (BFB) was richer in potassium, phosphorus, CaO, and micronutrients than the ash from the circulating fluidized bed (CFB) and contained cumulatively less contaminants. However, the BFB ash exceeded the threshold values of Cd to be considered as a liming amendment. Additionally, according to our European Community Bureau of Reference (BCR) study Pb and Cd were more mobile in the BFB than in the CFB ash. Except for a low nitrogen content, the ash met the minimum requirements for mineral fertilizers. Acute phytotoxicity revealed no inhibition of the germination and seed growth of Avena sativa L. and Lepidium sativum plants amended with biomass ash. Despite the fact that low nitrogen content excludes the use of biomass fly ash as a sole mineral fertilizer, it still possesses other favorable properties (a high content of CaO and macronutrients), which warrants further investigation into its potential utilization.

Biomass ash characterization, fusion analysis and its application in catalytic decomposition of methane

The biomass utilization for power generation is one of the efficient pathways to reduce greenhouse gas emissions. However, the high ash formation in biomass fed power plants raises several concerns, especially ash handling and its utilization. In this study, the biomass ash characterization, ash fusion analysis and its utilization as a catalyst in methane (CH4) decomposition were systematically investigated. The biomass bottom ash (BBA) and biomass fly ash (BFA) were modified using laboratory synthesized CeO2 nanoparticles to enhance the fusion temperature. The BBA, BFA and modified CeO2-BBA/BFA samples were characterized by ultimate analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF) analysis to investigate the physicochemical properties and its suitability for the catalysis applications. The detailed characterization inferred that BFA has significant potential in improving the ash fusion temperature as well as suitable for catalysis of fuel processing due to the presence of metal oxides such as Fe2O3, SiO2, CaO, Al2O3 and its porous structure. Furthermore, the most suitable BFA was impregnated with cobalt (Co). Co loaded BFA was employed for CH4 decomposition at 700 °C for H2 production in a fixed bed reactor. The Co/BFA demonstrated a stable catalytic activity of more than 330 min on stream with optimum H2 yield of 30%. The direct employment of BFA as catalyst support shows potential in further catalytic applications and material applications.

Recovery of Biomass Fly Ash and HDPE in Innovative Synthetic Lightweight Aggregates for Sustainable Geotechnical Applications

Sustainable development principles aim to re-utilize wastes to reduce their impact on the environment. In this context, the present contribution shows preliminary results on the preparation of innovative synthetic lightweight aggregates, starting from biomass-derived fly ash and high-density polyethylene (HDPE), to be used in geotechnical applications. The present work focuses on the manufacturing process of aggregate blends (including the selection of the right proportions of the two components) as well as on the relative determination of (i) physical–chemical properties (i.e., chemical composition, morphological analysis, mineral leachability, water absorption, specific gravity, grain size distribution); (ii) permeability features and (iii) mechanical properties (one-dimensional compression and shear strength behavior). The results, gathered from the new synthetic lightweight aggregates and compared with the corresponding ones obtained in a previous study conducted on natural and synthetic lightweight aggregates, appear promising for a potential utilization in geotechnical engineering.

Selection of Novel Geopolymeric Mortars for Sustainable Construction Applications Using Fuzzy Topsis Approach

Construction is recognized as one of the most polluting and energy consuming industries worldwide, especially in developing countries. Therefore, Research and Development (R&D) of novel manufacturing technologies and green construction materials is becoming extremely compelling. This study aims at evaluating the reuse of various wastes, originated in the Kraft pulp-paper industry, as raw materials in the manufacture of novel geopolymeric (GP) mortars whose properties fundamentally depend on the target application (e.g., insulating panel, partition wall, structural element, furnishing, etc.). Five different wastes were reused as filler: Two typologies of Biomass Fly Ash, calcareous sludge, grits, and dregs. The produced samples were characterized and a multi criteria analysis, able to take into account not only the engineering properties, but also the environmental and economic aspects, has been implemented. The criteria weights were evaluated using the Delphi methodology. The fuzzy Topsis approach has been used to consider the intrinsic uncertainty related to unconventional materials, as the produced GP-mortars. The computational analysis showed that adding the considered industrial wastes as filler is strongly recommended to improve the performance of materials intended for structural applications in construction. The results revealed that the formulations containing 5 wt.% of calcareous sludge, grits, and dregs and the one containing 7.5 wt.% of calcareous sludge, grits, dregs, and Biomass Fly Ash-1 have emerged as the best alternatives. Furthermore, it resulted that the Biomass Fly Ash-2 negatively influences the structural performance and relative rank of the material. Finally, this case study clearly shows that the fuzzy Topsis multi-criteria analysis represents a valuable and easy tool to investigate construction materials (either traditional and unconventional) when an intrinsic uncertainty is related to the measurement of the quantitative and qualitative characteristics.

Highly efficient lead extraction from aqueous solutions using inorganic polymer foams derived from biomass fly ash and metakaolin

This work reports a simple and safe, but powerful, route to depollute lead-containing aqueous solutions. Inorganic polymer foams (cm-size) were used as bulk-type adsorbents. The influence of the specimens' porosity and activator molarity on the foams' physical properties and on their lead extraction ability was studied. Then, the best performing samples were deeply evaluated as lead adsorbents by studying the impact of pH, lead concentration, contact time, ionic strength and solution volume. Lead sorption kinetics is strongly affected by the pollutant concentration, pH and the solution ionic strength. Under the most favourable conditions the foams showed an impressive removal capacity (105.9 mg/g at pH 5, 23 °C, C0 = 800 ppm, deionised water), surpassing all other reported values on the use of bulk-type inorganic polymers. The foams’ lead uptake is 2.3 times higher than the previous best performing bulk-type specimens (mm-size spheres), and sorption is 12.5–15 times faster. The foams can be easily regenerated using mild acidic conditions, and then reused as adsorbent, suggesting that the main adsorption mechanism is ion exchange.

INFLUENCE OF AGRICULTURAL BIOMASS FLY ASH CEMENT SUBSTITUTION ON THE CARBONATION OF CEMENT AND POLYMER-CEMENT COMPOSITES

Practical use of a new type of combustion waste such as an agricultural biomass fly ash in the building materials requires an assessment of its performance. The paper presents the investigation results on the influence of cement substitution (5% and 30%) by this ash on the cement and polymer-cement composites resistance to carbonation. The composites resistance was assessed on the basis of carbonation process over time (up to 360 days) using the phenolphthalein method. It was found that fly ash from agricultural biomass increases the susceptibility to carbonation of polymer-cement composites to a lesser extent than cement composites compared to composites containing siliceous coal fly ash.

Influence of Biomass Fly Ash on Sulfate Attack of Cement Stone

AbstractThe aim of this work was to investigate the influence of tribochemically activated biomass fly ash on a sulfate attack of cement stone. A weight of 5%, 15%, and 25% of the portland cement w...

Utilization of Biomass Fly Ash for Improving Quality of Organic Dye-Contaminated Water.

Development of innovative methodologies to convert biomass ash into useful materials is essential to sustain the growing use of biomass for energy production. Herein, a simple chemical modification approach is employed to functionalize biomass fly ash (BFA) with 3-aminopropyltriethoxy silane (APTES) to develop an inexpensive and efficient adsorbent for water remediation. The amine-functionalized BFA (BFA–APTES) was fully characterized by employing a range of characterization techniques. Adsorption behavior of BFA–APTES was evaluated against two anionic dyes, namely, alizarin red S (ARS) and bromothymol blue (BTB). In the course of experimental data analysis, the computation tools of data fitting for linear and nonlinear form of Langmuir, Freundlich, and the modified Langmuir–Freundlich adsorption isotherms were used with the aid of Matlab R2019b. In order to highlight the misuse of linearization of adsorption models, the sum of the squares of residues (SSE) values obtained from nonlinear models are compared with R2 values obtained from the linear regression. The accuracy of the data fitting was checked by the use of SSE as an error function instead of the coefficient of determination, R2. The dye adsorption capacity of BFA–APTES was also compared with the nonfunctionalized BFA. The maximum adsorption capacities of BFA–APTES for ARS and BTB dye molecules were calculated to be around 13.42 and 15.44 mg/g, respectively. This value is approximately 2–3 times higher than the pristine BFA. A reasonable agreement between the calculated and experimental values of qe obtained from the nonlinear form of kinetic models verified the importance of using equations in their original form. The experimentally calculated thermodynamic parameters including molar standard Gibbs free energy (ΔadGm0) and molar standard enthalpy change (ΔadHm0) reflected that the process of adsorption of dye molecules on the BFA–APTES adsorbent was spontaneous and exothermic in nature. Moreover, the used BFA–APTES adsorbent could be regenerated and reused for several cycles with significant dye adsorption capacity. The remediation capability of the BFA–APTES adsorbent against ARS dye was also demonstrated by packing a small column filled with the BFA–APTES adsorbent and passing a solution of ARS through it. Overall, we provide a simple and scalable route to convert BFA into an efficient adsorbent for water remediation applications.

Study of cure conditions effect on the properties of wood biomass fly ash geopolymers

This work investigated the influence of processing parameters on properties of geopolymers based on wood biomass fly ash. Five curing methods were applied, with and without moisture and temperature control, associated with 2 concentrations of alkali activators, sodium silicate and sodium hydroxide (1.0 and 1.5 weight ratios), and a fixed composition (75wt.% wood biomass fly ash and 25wt.% metakaolin). Cured geopolymers were characterized by compressive strength tests after 28 days and by analytical techniques to evaluate morphology and internal structure. The results showed different physical and chemical properties tailored by the processing parameters variation, suggesting several applications. For instance, the samples obtained with hydrothermal conditions and SS:SH=1.0 might be used for adsorption of pollutants, and those produced at room condition with SS:SH=1.5 may be employed as dense mortars. Most importantly, a low-energy curing method at room temperature enabled to produce geopolymers with mechanical properties in the order of magnitude of those obtained at higher times or temperatures.

Long-term willows phytoremediation treatment of soil contaminated by fly ash polycyclic aromatic hydrocarbons from straw combustion

A three-year experiment was conducted to investigate willows of Salix × smithiana Willd. (S. smithiana) phytoremediation of soil contaminated by polycyclic aromatic hydrocarbons (PAHs) derived by fly ash from biomass combustion. The total removal of ash PAHs in phytoremediation treatment was 50.9% after three consecutive years while the ash PAHs were decreased in natural attenuated soil by 9.9% in the end of the experiment. The ash and spiked PAHs with low and medium molecular weight were susceptible to be removed in higher rates than high molecular weight PAHs. Lower bioconcentration factors of individual PAHs were observed in willow shoots than in roots. The estimated relative direct removal of PAHs by S. smithiana in phytoremediation was significantly lower than 1% suggesting that the contribution of S. smithiana to take up PAHs from soil was negligible and the degradation of PAHs occurred mainly in soil. Phytoremediation using S. smithiana could be seen as a feasible and environmentally friendly approach of arable soils impacted by a PAH contaminated biomass fly ash.