High Ash Content Research Articles

Experimental Study of Carbonation and Chloride Resistance of Self-Compacting Concretes with a High Content of Fly Ash and Metakaolin, with and Without Hydrated Lime

The durability of reinforced concrete is associated with several factors that can trigger the corrosion of reinforcement bars. Among these factors, the most significant are chloride-ion attack and carbonation. This study evaluated, through accelerated testing, self-compacting concretes (SCCs) with reduced cement content in binary, ternary, and quaternary mixtures using high-early-strength Portland cement, fly ash (FA), metakaolin (MK), and hydrated lime (HL). These systems are proposed to address the slow compressive strength gains at 28 days in concretes with high fly ash content and to minimise the effects of carbonation in concretes with high levels of mineral additives. Laboratory tests were conducted to measure chloride-ion migration in a non-steady-state system, accelerated carbonation in a controlled chamber, electrical resistivity, void indices, and compressive strength. Based on the results obtained, it was found that the combined use of MK, FA, and HL was effective in reducing cement consumption to extreme levels, such as 120 and 150 kg/m3, while still achieving durability indices superior to those of SCCs with cement consumption of 500 kg/m3.

Study on the Improvement Effect of Polypropylene Fiber on the Mechanical Properties and Freeze–Thaw Degradation Performance of High Fly Ash Content Alkali-Activated Fly Ash Slag Concrete

This article systematically investigated the improvement effect of polypropylene fiber (PPF) on the mechanical and freeze–thaw properties of alkali-activated fly ash slag concrete (AAFSC) with high fly ash content and cured at room temperature. Fly ash and slag were used as precursors, with fly ash accounting for 80% of the total mass. A mixed solution of sodium hydroxide and sodium silicate was used as alkali activator, and short-cut PPF was added to improve the performance of AAFSC. Firstly, the strength characteristics of AAFSC at different curing ages were studied. Then, key indicators such as morphology, residual compressive strength, weight loss, relative dynamic modulus of elasticity (RDME), and pore characteristics of AAFSC after different freeze–thaw cycles were tested and analyzed. The strength performance analysis showed that the optimal dosage of PPF was 0.90%. When the alkali equivalent of the alkali activator was increased from 4% to 6%, the frost resistance of AAFSC could be improved. Furthermore, adding 0.90% PPF could increase the freeze–thaw cycle number of AAFSC by about 50 times (measured by RDME). With the increase in freeze–thaw cycles, the porosity of AAFSC increased, the fractal dimension decreased, and the proportion of harmless and less harmful pores decreased, while the proportion of harmful and multiple harmful pores increased. The relationship model between the porosity and compressive strength of AAFSC after freeze–thaw cycles was established.

Advancing Energy Recovery: Evaluating Torrefaction Temperature Effects on Food Waste Properties from Fruit and Vegetable Processing

Most organic waste from food production is still not used for energy production. From the perspective of energy production, one option is to valorise the properties of organic waste. The fruit juice industry is growing rapidly and generates large amounts of waste. One of the main wastes in food and fruit juice processing is peach pits and apple peels. The aim of this study was to analyse the influence of torrefaction temperature on the properties of food waste, namely apple peels, peach pits and pea shells, in order to improve their energy value and determine their potential for further use and valorisation as a renewable energy source. The aim was to analyse the influence of different torrefaction temperatures on the heating value (HHV), mass yield (MY) and energy yield (EY) in order to better understand the behavior of the thermal properties of individual selected samples. The torrefaction process was carried out at temperatures of 250 °C, 350 °C and 450 °C. The obtained biomass was compared with dried biomass. For apple peels, HHV after torrefaction was (28 kJ/kg), MY decreased by (66–34%), while EY fell by (97–83%). Peach pits, despite a higher HHV after torrefaction (18 kJ/kg), achieved low MY (38–89%) and EY (59–99%), which reduces their efficiency in biochar production. Pea peels had EY (82–97%) and a lower HHV after torrefaction (11 kJ/kg), but their high ash content limits their wider use. The results confirm that, with increasing temperature, MY and EY for all selected biomasses decrease, which is a consequence of the degradation of hemicellulose and cellulose and the loss of volatile compounds. In most cases, increasing the torrefaction temperature improved the resistance to moisture adsorption, as this is related to the thermal process that causes structural changes. The results showed that the torrefaction process improved the hydrophobic properties of the biomass samples. Temperature was seen to have a great impact on mass energy efficiency. Apple peels generally had the highest mass and energy yield.

Non-additive effects of leaf-litter flammability on eight subtropical tree species: Implications for forest species composition and fire susceptibility.

The readiness of leaf-litter to burn in the presence of fire differs greatly between species. Thus, forests composed of different species vary in their susceptibility to fire. Fire susceptibility of forests may also differ from the arithmetic means of flammability of their component species, i.e., non-additive effects exist. Here, we assessed nine indices of flammability and five physicochemical properties of the leaf litter of eight common subtropical tree species in China. We then tested the net effects on litter flammability of different mixtures of the eight species. We measured the following variables: time to ignition, combustion time, spread rate, ignition temperature, mass loss, maximum flame height and three temperature indices, moisture, cellulose, lignin and ash contents, and specific leaf area (SLA). Our results show that the flammability of leaf litter: time to ignition, combustion time, ignition temperature, and flame height, varies widely between the eight species. Time to ignition was short (<3s) for the three conifer species and Quercus variabilis and Q. aliena, but long (3.5-8.8s) for Q. fabri, Q. glauca, and Liquidambar formosana. The five species with a short time to ignition all have high cellulose and lignin contents, and SLA, and are highly flammable. In contrast, the three species with long time to ignition have low cellulose and lignin contents, and SLA, and high ash content. Cellulose and lignin contents, and SLA are the major drivers of litter flammability, and ash and moisture contents are important negative drivers. Mixed litters containing species with high cellulose and lignin contents and SLA have positive non-additive effects (synergistic) on overall flammability whereas those containing species with low cellulose and lignin contents, and SLA have negative non-additive effects (antagonistic) on flammability. These results are essential for assessing forest fire-risks and assisting species selection in plantations or fire-break forests as a part of a forest fire-management strategy.

Preparation of artificial aggregates with high fly ash content through air curing and carbonation curing

Preparation of artificial aggregates with high fly ash content through air curing and carbonation curing

Organoleptic and Physicochemical Profile Comparison of Cow Milk Yogurt and 'Eggurt' Made from Different Egg Whites

Yogurt is a widely consumed fermented dairy product known for its distinctive flavor, nutritional value, and health benefits. To expand its nutritional profile and enhance textural qualities, this study explores the use of egg whites as an alternative ingredient in yogurt production. The research compares the sensory and physicochemical properties of traditional milk yogurt with "eggurt" a yogurt variant made using different egg white sources: free-range chicken, caged chicken, and duck eggs. Four samples were prepared, including one control (milk yogurt) and three “eggurt” variants. Sensory quality was evaluated through organoleptic testing using a structured Likert scale to assess attributes such as color, surface gloss, aroma, mouthfeel, and flavor. Physicochemical analysis included moisture content, total dissolved solids, viscosity, ash content, and acidity measurements. Results showed that free-range “eggurt” was most like milk yogurt in terms of texture and flavor, displaying balanced viscosity and minimal surface liquid separation. In contrast, caged “eggurt” exhibited increased surface liquid, higher ash content, and stronger acidity, while duck eggurt was noted for its excessive thickness, very high viscosity, and pronounced acidity. These textural and compositional differences, despite the higher production costs, suggest that free-range “eggurt” is the most promising alternative, offering a comparable sensory experience to traditional yogurt while enhancing texture and overall quality.

A Comprehensive Assessment of the Nutritional Value, Antioxidant Potential, and Genetic Diversity of Fenneropenaeus merguiensis from Three Different Regions in China

Fenneropenaeus merguiensis is one of the largest species of penaeid shrimp. It has a wide distribution of germplasm resources in the South China Sea and the southeastern coastal regions of China, yet its germplasm characteristics remain insufficiently understood. Therefore, we conducted analyses of basic nutritional components, amino acids, fatty acids, antioxidant indices, and genetic diversity in three F. merguiensis populations (FmRP, FmSZ, FmSY). The results showed a significant difference in ash content, with FmSZ having the highest ash content (1.77 g/100 g) (p &lt; 0.05). A total of 17 amino acids were detected, and FmSZ exhibited higher concentrations of most amino acids, especially essential amino acids (p &lt; 0.05). The analysis of fatty acid composition revealed significant differences between the populations, with FmSY potentially having a nutritional advantage overall (p &lt; 0.05). In terms of antioxidant capacity and genetic diversity, there were no significant differences in total antioxidant capacity (T-AOC), catalase (CAT), or superoxide dismutase (SOD) among the populations (p &gt; 0.05). However, genetic analysis indicated that FmSZ had the lowest inbreeding coefficient and relatively higher genetic diversity. In conclusion, among the three F. merguiensis populations, FmSZ has relatively higher nutritional quality and genetic diversity, and F. merguiensis is a high-quality aquatic product worth promoting. The analysis and characterization of various aspects of F. merguiensis from the three locations provide important information and data support for germplasm resources and genetic breeding efforts.

Comparative downdraft gasification performance using falcata wood pellets and chips

Abstract Tropical off-grid regions are rich in biomass resources like Falcata, a fast-growing tree species. This study examines the optimal form of Falcata wood, comparing pellets (FWP) and chips (FWC) for community-based gasification systems using a downdraft gasifier. Key methods included feedstock uniformity assessment, syngas composition analysis, and efficiency calculations. Results showed FWP provided better uniformity and consistent feeding, while FWC may need further processing for improved efficiency. FWC had a higher heating value (17.92 MJ/kg) and volatile matter (84.29%) than FWP, which had more fixed carbon (18.20%) but also higher ash content (1.98%). FWP produced syngas with higher CO and H2 concentrations, leading to better overall syngas quality, while FWC yielded more non-combustible CO2. Energy Conversion Efficiency (ECE) and Gas Efficiency (GE) indicated that FWP is four times more effective and twice as efficient for gasification compared to FWC. The study concludes that both forms can produce high-quality syngas, but further research is needed to assess the economic viability and optimize gasification parameters for improved efficiency.

The Effect of Harvest Time and Plantation Age on the Yield, Chemical Composition, and Calorific Value of Reed Canary Grass (Phalaris arundinacea L.) Intended for Energy Purposes

Based on our own research conducted on a purpose-built plantation, the production capacity of reed canary grass (Phalaris arundinacea L.) was assessed depending on the age of the plantation and the date of the biomass harvest. The aim of this study was to assess the influence of the harvest date and plantation age on the yield, chemical composition, and calorific value of reed canary grass intended for energy purposes. The biomass on the plantation was cut twice during the growing season (summer/winter). The obtained biomass was analyzed for its ash content and selected elements, i.e., nitrogen, phosphorus, potassium, calcium, magnesium, sodium, sulfur, and chlorine. The total moisture, calorific value in working condition, and combustion heat were also assessed. The two-cut harvest system allowed us to obtain 3.85 t∙ha−1 of biomass from reed canary grass in the first year of cultivation. The highest biomass yields were obtained in the third and sixth years of cultivation and amounted to 8.50 and 8.75 t∙ha−1, respectively. Regardless of the age of the plantation, the biomass yield harvested in the summer period was always higher than the yield obtained from the winter harvest. The contents of some elements in the biomass also depended on the age of the plantation and the harvest date. The biomass of reed canary grass obtained from the summer harvest of the annual plantation was characterized by a high content of nitrogen (1.97% d.m.), potassium (2.35% d.m.), and phosphorus (0.31% d.m.) compared to the content of these elements in the biomass obtained from the three- and six-year plantations. In the case of sodium, the highest content (0.072% d.m.) was found in the biomass obtained from the summer harvest of the three-year plantation, and the lowest was obtained from the winter harvest of the six-year plantation (0.037% d.m.). The average sulfur content was the highest in the biomass obtained from the annual plantation, regardless of the harvest date (0.20% d.m.—summer harvest and 0.21% d.m.—winter harvest). On the other hand, the lowest amount of sulfur was contained in the biomass obtained from the winter harvest of the six-year plantation (0.12% d.m.). Only the magnesium content (from 0.09% d.m. to 0.14% d.m.) in the biomass remained at a similar level, regardless of the age of the plantation or the harvest date. The calcium content was the highest in the biomass obtained from the winter harvest of the annual plantation (0.35% d.m.), and the lowest was obtained from the six-year-old plantation, also from the winter harvest. In addition, the moisture and ash content of the obtained biomass depended on the age of the plantation and the harvest date. The highest moisture content (12.50%) was characteristic of the biomass harvested in the summer period from the one-year plantation. On the other hand, the lowest moisture content was found for the biomass harvested in the winter period from the six-year plantation. The highest ash content was obtained from biomass harvested in the summer period from the one-year plantation (75 g∙kg−1 d.m.) and the three-year plantation (69 g∙kg−1 d.m.). The lowest ash content was obtained from the winter harvest from the six-year plantation (45 g∙kg−1 d.m.). The highest calorific value of 16.0–16.2 MJ∙kg−1 d.m. was obtained for biomass harvested in the sixth year of the study (irrespective of the harvest date). The value of the combustion heat was also dependent on the age of the plantation and the date of the biomass harvest. The highest value for the combustion heat of 17.5 MJ∙kg−1 d.m. was obtained for biomass harvested in the winter period from the six-year plantation

The flotation deashing separation performance of high-ash fine coal-slime using humic acid depressant and insights to its depressant mechanism

Effective inhibition of clay minerals remains a challenge in the flotation separation of fine coal with high ash content. The quest for efficient, environmentally friendly, and cost-effective depressants to improve the flotation efficiency of fine coal-slime has become a focus of current research. Humic acid (HA), a macromolecular organic compound widely present in nature, is known for its non-toxic, low-cost, and biodegradable properties. In this study, the potential selective depressant HA was utilized to enhance the recovery of low-ash clean coal in the coal-kaolinite system. Adsorption and inhibition mechanisms were explored through contact angle measurements, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) methods. Flotation tests demonstrated that HA, at varying dosages, significantly increased combustible matter recovery while reducing ash recovery compared to conventional flotation. Optimal conditions, with an HA dosage of 750 g/t, resulted in a combustible matter recovery of 40.56 % and an ash content of 17.77 % in the clean coal. Contact angle measurements confirmed that high-dosage HA significantly reduces the coal surface hydrophobicity, resulting in a rapid decline in the recovery of combustible matter. It did not significantly alter the contact angle of kaolinite, however, across the entire range of HA dosages. Furthermore, XPS studies revealed that the reduction in hydrophobicity on the coal surface after HA adsorption is mainly attributed to the coverage of surface carbon–carbon/carbon-hydrogen groups (C–C/C–H) and the increased presence of carbonyl groups (C = O). Additionally, the study found that HA predominantly adsorbs on the Si-OH groups of kaolinite. Finally, AFM results showed that the primary mechanism underlying the altered heterocoagulation behavior between coal and kaolinite is HA’s effect on their interaction forces. The optimal flotation results achieved at the HA dosage of 750 g/t are primarily attributed to the consistent presence of repulsive forces during the approach process and weak adhesion forces during the retraction process between coal and kaolinite, thus reducing kaolinite coating on the coal surface. These findings provide a promising direction for utilizing HA to enhance flotation deashing of high-ash coal-slime.

Study on the Properties of High Fly Ash Content Alkali-Activated Fly Ash Slag Pastes and Fiber-Reinforced Mortar Under Normal Temperature Curing.

In order to efficiently utilize industrial solid waste while minimizing the preparation cost of engineering materials and the technical difficulty of construction, this paper prepared a high fly ash content alkali-activated fly ash slag composite system at normal temperatures and conducted an in-depth investigation on it. A systematic study was conducted on the workability, mechanical properties, and microstructures of the alkali-activated fly ash slag pastes, including setting times, strength, phase, and molecular structures. We then designed and prepared fiber-reinforced alkali-activated fly ash slag mortar and studied the effects of the alkali activator modulus, glass fiber (GF), and polypropylene fiber (PPF) on the workability, mechanical properties, and frost resistance of the mortar. The following main conclusions were drawn: By adjusting the modulus of alkali activator for alkali-activated fly ash slag pastes, characteristics that meet engineering requirements could be obtained. The compressive strength of the pastes decreased with increasing proportions of fly ash, and it first increased and then decreased with increases in the activator modulus. The flexural strength decreased to varying degrees as the modulus of the activator increased. Through SEM, fly ash particles with different reaction degrees could be observed, indicating that the reaction was still ongoing. The addition of GF and PPF reduced the fluidity of mortar and significantly improved its strength and frost resistance. Fiber had the most significant effect on improving the strength of the mortar, as an activator modulus of 1.0. 0.45% PPF increased the flexural and compressive strength of the mortar by 14.33% and 29.1%, respectively, while 0.90% GF increased the flexural and compressive strength of the mortar by 3.12% and 19.21%, respectively. The frost resistance of the mortar with an activator modulus of 1.0 was significantly better than that of the mortar with an activator modulus of 1.4. 0.45% PPF and reduced the quality loss rate of the mortar by 49.30%, effectively delaying the deterioration of its freeze-thaw performance.

An assessment of Rare Earth Elements in borehole cores from the Ermelo, Witbank and Waterberg Coalfields, South Africa: Focus on mode of occurrence

There is currently limited knowledge concerning South African coal deposits as hosts for rare earth elements (REE). This project aims to determine the concentration of REE, including yttrium and scandium (REY+Sc) in various coal seams and adjacent sediments in borehole cores from the Ermelo, Witbank, and Waterberg coalfields in South Africa. Coal petrography (maceral count and vitrinite reflectance), XRD, XRF, sequential chemical extraction procedure (SCEP) before ICP-MS, and mineral liberation analysis (MLA) were conducted on the coal and associated sediment samples. The coals were inertinite-rich, medium-rank bituminous coal, with moderate to high ash content. The two dominant minerals in all the coalfields are kaolinite and quartz, except for sample ZBS2M, where dolomite was dominant. The dominant major oxides are Al2O3, SiO2, Fe2O3, and CaO, which concur with the XRD results. The ICP-MS results following SCEP indicated that both coal and the associated sediments were light REY+Sc dominant. There was also an elevation of medium REY+Sc in the Witbank coal's associated sediment samples. Notably, the samples with the highest REY+Sc results were the sediment samples. The Waterberg samples had the lowest REY+Sc from both the coal (less than 2 μg/g to 7 μg/g) and associated sediments (2 μg/g to 15 μg/g). While the highest REY+Sc was yielded from the Witbank-associated sediments (500 μg/g to 2,500 μg/g). The carbonate fraction step proved to be the most successful leaching step, as most REY+Sc was recovered in that step for all coalfields. In addition to the carbonate fraction, the silicates and sulfide fraction in the Witbank samples, and the ion-exchangeable fraction for the Waterberg-associated sediments samples proved successful in leaching out the REY+Sc. MLA determined that monazite and xenotime in all the coal samples were the REY+Sc-bearing minerals.

Evaluation of the Chemical Composition and Feeding Value of Sweet Orange Pulp and Pineapple Peel Meals as Fibre Sources in Pigs’ Rations

The piggery industry in Nigeria is on the verge of collapsing due to the high cost of conventional feed resources including wheat offal and palm kernel cake that usually form bulk in the diets of pigs. This study was, therefore, designed to compare the chemical composition of orange pulp meal, pineapple peel meal, and wheat offal and evaluate their feeding value in pig rations. The orange pulp and pineapple peels were dried on a concrete floor and analyzed for chemical composition. Three experimental diets were formulated with orange pulp and pineapple peel meals replacing wheat offal as a fibre source. Thirty crossbred (Chester white x Landrace) growing pigs with an average initial weight of 8.20 -- 8.75kg were distributed into three groups, with ten animals per group, and assigned to the three experimental diets. The average daily feed intake and weight gain were monitored throughout the 56-day duration of the experiment. Seven days to the end of the experiment, three pigs randomly selected for the digestibility trial were individually housed in metabolism crates and allowed 5 days of adaptation to the crates and feed before faecal collection commenced. Animals were fed the experimental diets at approximately 4% of their body weight, and the faeces of the animals were collected for 5 days. The determination of the nutrient composition of feed and faecal samples was performed. Data collected were subjected to analysis of variance using a completely randomized design. The result indicated that samples were significantly (P&lt;0.05) different in crude protein composition, with the wheat offal having the highest value corresponding to 9.21 ± 0.12%. Orange pulp had the highest content of ash (6.72 ± 0.12%). The gross energy values were 15.23MJ/kg, 15.31MJ/kg and 16.15MJ/kg for pineapple peel, orange pulp and wheat offal, respectively. The highest manganese concentration was observed in wheat offal (5.19± 0.11mg/l), while orange pulp and wheat offal were higher in sodium and phosphorus concentrations. The pigs fed an orange pulp meal diet recorded the highest average daily weight gain (0.31 kg) and a superior feed conversion ratio (4.19) relative to others. Digestibility values were similar across the three treatment groups. It was, therefore, concluded that orange pulp and pineapple peal meal could serve as alternative fibre sources in growing pigs' rations. Key words: Wheat offal, pineapple peel, orange pulp, growing pigs, digestibility

Nutritional and Phytochemical Profile of Commonly Consumed Spices in Nigeria

Background: Spices which are widely used in Nigeria have aroma, enhance taste of food and Possess medicinal values. Objectives: This study aimed to determine the nutritionaland phytochemical profile of commonly consumed spices in Nigeria. Materials and Methods: Raw materials and other ingredients used for this study were purchased from Oja-Oba in Owo Local Government, Ondo State. The spices were analysed for proximate and mineral components using standard method as described by AOAC (2012). Sodium and potassium were determined using flame photometer and calcium, selenium, copper, zinc, magnesium, and iron were determined using atomic absorption spectrophotometer. Phytochemical analyses were carried out using standard procedures. Results: The proximate composition showed that protein was significantly (p≤0.05) high at 14.41% in Uziza seed and low at 11.60% in tumeric. Ginger contained high moisture content at 10.63%, while Uziza seed had the least value of 8.58%. High ash content was recorded in gingerat 5.27% and lowest at 3.70% in Uziza. Tumeric had the highest value of 65.57% for carbohydrate, while Uziza had the least value of 60.06%. Mineral composition showed high value of calcium in Uziza seed (402.03mg/100g). Nutmeg showed a high value of magnesium (13.3mg/100g) and turmeric indicated the highest value of potassium (405.43mg/100g), sodium (135.17mg/100g) for Uziza seed. The highest content of iron was recorded at 3.34mg/100g. Turmeric had a high value of zinc at 3.77 mg/100g and copper at 97 mg/100g, respectively. The spices contained an appreciable amount of phytochemicals. However, turmeric was significantly higher in alkaloids, flavonoids and polyphenols. Conclusion:This study showed that spices have greater use in medicine and as a food supplement.

Waste-Derived carbon porous materials for enhanced performance in adsorption chillers: A Step toward a circular economy

In this study, a comprehensive examination of commercial activated carbons and novel porous carbon materials derived from waste was conducted to evaluate their potential as bed materials in adsorption chillers driven by waste heat. The research uniquely focuses on synthesizing and analyzing sorbents from two distinct waste sources: lignin and excavated waste, aiming to expand the sustainable application of waste-derived materials. A thorough characterisation of the sorption properties was performed using mercury intrusion porosimetry, low-temperature gas adsorption, and dynamic vapour sorption measurements with methanol. These techniques provided detailed insights into the microporous structure and surface areas of the materials, ranging from 500 to 2000 m2/g for the activated carbons. Notably, the lignin-derived magnetic biochar demonstrated an exceptionally well-developed surface area and superior sorption properties at operational conditions of 30 °C, reaching relative adsorption of 59.89 % at P/Po of 100 %—up to 70 % higher than that of commercially available activated carbons. This material’s performance highlights its potential as a high-efficiency adsorbent in adsorption chillers, surpassing many commercially available options. However, the char obtained from excavated waste exhibited limitations due to high ash and heavy metal content (786 mg/kg Pb and 127 mg/kg Zn), suggesting challenges for its use in activated carbon synthesis. This study bridges a critical knowledge gap by exploring innovative pathways for utilizing waste-derived porous carbon materials in adsorption cooling, thus contributing to the development of sustainable, waste-based solutions for heat-driven cooling applications.

Nutritional differences in eggs, chicken, and plantain from agroecological, conventional, and commercial systems: a case study in Valle del Cauca, Colombia

ABSTRACT This case study examines the nutritional differences between agroecological, conventional, and commercial products in Valle del Cauca, Colombia. Using a participatory methodology with local farmers, eggs, chicken, and plantain were selected for analysis. Moisture, protein, fat, ash, phosphorus, potassium, calcium, and magnesium contents were compared across the three production systems. Statistical analyses included ANOVA and MANOVA. Results indicate that agroecological products from the studied farms tended to have lower moisture content. Agroecological eggs showed higher fat content (11.09 g/100 g vs 9.32 g/100 g conventional and 8.45 g/100 g commercial). Agroecological chicken presented higher protein content (22.37 g/100 g vs 20.73 g/100 g conventional and 18.1 g/100 g commercial) and potassium (281 mg/100 g vs 298 mg/100 g conventional and 213 mg/100 g commercial). Agroecological plantain had higher ash content (0.85 g/100 g vs 0.77 g/100 g conventional and 0.79 g/100 g commercial) and calcium (8 mg/100 g vs 5 mg/100 g conventional and 6 mg/100 g commercial). These differences were statistically significant (p < 0.05). While these findings suggest potential nutritional benefits of agroecological production in this region, further studies with a larger number of replicates are needed to confirm these trends on a broader scale.

Upgrading pyrolysis carbon black by recyclable ferrate/alkaline treatment with the assistance of ultrasound

The recycling of pyrolysis carbon black (CBp) from waste tires is crucial in consideration of the conservation of secondary resources and the alleviation of potential hazardous effects on the environment. However, the high ash content, low surface activity and big particle size limit its high-value utilization, such as the reinforcing of tires. In this work, a novel approach of upgrading CBp derived from waste tires has been developed by a combination of recyclable ferrate/alkaline treatment and ultrasound. In this approach, the ferrate/alkaline is used to remove impurities of CBp and introduce oxygen groups with high activities, and the ultrasound can break the agglutinated CBp particles and accelerate the impurities reduction effectively. Upgrading conditions including temperature, reaction time, and reagent ratio were explored and optimized. Compared with non-upgraded CBp (n-CBp), the upgraded CBp (u-CBp) had a much lower content of impurities (1.74%) and a comprehensive promotion in physicochemical properties. The u-CBp exhibited superior in-rubber performance to the commercial carbon black (N550/N660). Furthermore, the ferrate can be recycled to upgrade CBp several times. This method offered a promising solution of CBp upgrading and waste tire recycling and contribute to the closed-loop recycling of waste tires and environmental sustainability.

Effect of different drying techniques on the physicochemical and nutritional properties of Moringa oleifera leaves powder and their application in bakery product

The study analyzed the influence of drying methods and conditions on the quality of moringa leaves powder (MLP) and determined the optimal MLP to wheat flour ratio for cake development. Cabinet drying temperatures enhanced mass and tapped density but reduced the angle of repose, water retention capacity, and oil retention capacity. The moisture content of cabinet-dried MLP samples exhibited a substantial reduction as temperature is increased. The crude protein and fat content increased with increasing drying temperatures. Vacuum dried samples had the highest fiber content (16.62 g/100 g). Cabinet dried samples at 60 °C had the highest ash content (8.37 g/100 g). The energy obtained from MLP dried in a cabinet at 70 °C was the highest (383.33 Kcal/kg). The mineral composition of MLP in vacuum drying showed the largest growth. Sun drying was less efficient in preserving antioxidant components, while vacuum drying was the most successful. But sun drying was more cost effective than that of other drying methods. The composition of cakes formulated from MLP and wheat flour blends exhibited notable variations characterized by an increase in protein content and decrease in carbohydrate content with the incorporation of MLP. 5 % and 10 % MLP enriched cakes showed the best customer acceptance.

Assessment of the use of biochar from the slow pyrolysis of walnut and almond shells as an energy carrier

ABSTRACT This study explores the energy applications and combustion kinetics of biochar produced from walnut and almond shells through pyrolysis. Using macro-thermogravimetric analysis at heating rates of 10, 15, and 20 K min−1, a multi-step mechanism involving two parallel reactions was used to model thermal decomposition. Bioenergy indices revealed that walnut shell-based biochar (WSB) produced at 773 K and 873 K displayed superior biofuel potential due to its high energy density and low ash content, while almond shell-based biochar (ASB) at 673 K demonstrated the best overall bioenergy performance. Among the tested heating rates, 15 K min−1 provided optimal results for ignition, combustion, and burnout indices, with WSB showing the highest overall combustion performance. Kinetic analysis using the Coats-Redfern method demonstrated the highest R2 values and minimized RMSE and SSE. The activation energy for the first pseudo-component ranged from 54.91 to 129.84 kJ mol−1 for ASB and from 61.71 to 141.85 kJ mol−1 for WSB. For the second pseudo-component, the activation energy ranged from 25.21 to 159.32 kJ mol−1 for ASB and 25.63 to 96.25 kJ mol−1 for WSB. These findings emphasize the potential of WSB and ASB biochar for bioenergy applications, with WSB exhibiting the best combustion characteristics.

Thermogravimetric Assessment of Biomass: Unravelling Kinetic, Chemical Composition and Combustion Profiles

Thermogravimetric analysis (TGA) was performed on six samples of pine wood, poplar sawdust and olive residue, and the kinetic parameters were evaluated by using isoconversional models. The hemicellulose, cellulose and lignin contents were also estimated using the Fraser–Suzuki deconvolution method. In addition, a range of thermodynamic parameters and combustion indices was calculated. Significant correlations were found between the kinetic, thermodynamic and combustion parameters. The ignition index showed an inverse relationship with the activation energy, whereas the burnout index correlated with enthalpy values for most samples. Higher heating rates during TGA increased ignition and combustion efficiencies but decreased combustion stability. Differences in behaviour were detected between the olive residues, which had a much higher lignin content (51.2–56.9%), and the woody biomass samples (24.2–29.2%). Moreover, the sample with the highest ash content also exhibited some distinctive characteristics, including the lowest high heating value and ignition index, coupled with the highest activation energy, indicating a less favourable combustion behaviour than the other samples. The particle size of the samples was also found to be critical for both combustion efficiency and safety.