Search Results (58)

Since 2024, most electricity production on Réunion Island has been achieved through combustion of biomass, using either imported wood pellets or locally produced bagasse. Their combustion generates two types of ash, depending on the biomass source: Wood Biomass Fly Ash (WBFA) and SugarCane Bagasse Ash (SCBA). Their chemical compositions differ significantly, leading to different potential applications. The composition of SCBA is similar to that of Coal Fly Ash (CFA), with low variability between batches. Therefore, SCBA could be used as an alternative to CFA, as a Supplementary Cementitious Material (SCM) or in composite cements. SCBA also meets most of the requirements of the NF EN 450-1 standard. However, grinding of SCBA appears necessary to achieve mechanical performance required by the standard. In contrast, WBFA exhibits variable chemical composition, mainly due to differences in pellet origin prior to combustion. Nevertheless, WBFA contains significant levels of chloride ions and sulfate, which may act as activators for materials such as GGBS or metakaolin (MK). Although the high unburned carbon content of WBFA increases water demand, their incorporation into GGBS-based binders (SSC or CEM III) or metakaolin-based systems shows promising potential, particularly for improving early strength. Full article

Filter cake (or cachaza), a residue generated in the artisanal production of panela, represents an under-explored source of renewable energy in the Ecuadorian Amazon. Valorizing filter cake could reduce the use of solid biomass and emissions associated with traditional combustion. Our objective was to determine the energy potential of the biogas obtained and its contribution to the sustainability of the panela (unrefined cane sugar) production system. A sequential procedure was applied that included the physicochemical characterization of filter cake, feed flow modeling, and stoichiometric simulation under mesophilic conditions. The anaerobic digestion of filter cake with the optimal Composition 6 generated up to 1736.40 m³·day⁻¹ of biogas with 40.7% methane and a calorific value of 14,350 kJ·m⁻³. This was enough to replace 1.24 t·day⁻¹ of wood or 2.38 t·day⁻¹ of bagasse in the production system. This represents an annual saving of 631.08 t of solid biomass, equivalent to conserving 3.63 ha·year⁻¹ of the Amazon rainforest. The Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) analysis showed impacts on climate change (17.40 kg CO₂ eq/m³) and acidification (0.00516 kg SO₂ eq/m³), attributable to unburned methane and residual H₂S. Meanwhile, the social assessment using the Occupational Health and Safety Potential (OHSP) indicator showed high risks in terms of handling filter cake and cleaning the digestate. Full article

Recent tailing dam failures in Brazil have been attributed to liquefaction. Chemical stabilization offers a promising solution to enhance the strength and stiffness of tailings and mitigate liquefaction potential. This study investigated the mechanical and microstructural behavior of gold mine tailings (GMTs) stabilized using (i) an alkali-activated binder composed of sugar cane bagasse ash (SCBA), hydrated eggshell lime (HEL), and sodium hydroxide (NaOH) and (ii) Portland cement (PC). Drained and undrained triaxial shear tests and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) analyses were performed. Specimens stabilized with Portland cement exhibited a strong strain-softening behavior and the highest strength, with 5.3 MPa under 200 kPa confining pressure compared to 2.3 MPa for alkali-activated samples and 740 kPa for untreated GMTs. The addition of either binder also increased both the peak effective friction angle and the critical state stress ratio, confirming an enhanced shear strength. SEM-EDS analyses confirmed the formation of cementitious reaction products, explaining these improvements. This research validates both binders as viable solutions for tailing stabilization, with the novel alkali-activated binder offering a sustainable alternative for large-scale applications. Full article

The success of optimal ruminant production relies heavily on feed efficiency to deliver the necessary nutrients to animals. Nutritional deficiencies in livestock pose a significant challenge in regions experiencing prolonged fluctuations in resource availability and quality. In this context, the present study aimed to investigate the cumulative gas production (CGP) and in vitro degradability of silages made from spineless forage cactus (a native species) combined with high-fiber ingredients, to evaluate their viability as a sustainable, low-cost alternative to animal feed. The experiment involved ensiling spineless cactus genotypes with varying levels of sugarcane bagasse (0, 150, 300, 450, and 600 g/kg of dry matter) and a 1% urea–ammonium sulfate solution. The results indicated that for all genotypes studied, the CGP curves from silage composed solely of forage cactus differed significantly from those containing bagasse, which exhibited an initial phase characterized by little or no gas production. In vitro degradability was negatively influenced by the inclusion of bagasse at any level, resulting in decreased dry matter and organic matter degradability, as well as reduced CGP with increasing bagasse concentration. Therefore, the study demonstrated that the proposed combination of ingredients represents a promising sustainable feed supplement to enhance animal nutrition. Silage containing 150 g/kg of bagasse treated with urea offers a favorable balance between the energy required by rumen microflora and the benefits of fiber presence. Full article

This study investigates biochar-enriched organic fertilizers made from bagasse, ash, spent wash, and cane tops, assessing their impact on corn growth over 45 days. A randomized complete block design with three replicates was used, testing six formulations with biochar levels at 0%, 10%, and 20%, along with soil-only and commercial fertilizer controls. Treatments T5 (bagasse + ash + spent wash + cane tops), T11 (T5 + 10% biochar), and T17 (T5 + 20% biochar) showed the best results for plant height, leaf development, and biomass production, with T17 performing the best for growth, biomass, and girth. The biochar in T17 had a pH of 9.37 ± 0.16, 18.00 ± 1.25% ash content, and a surface area of 144.58 m²/g. Nutrient analysis of the compost showed 2.85% potassium, 1.12% phosphorus, 1.85% nitrogen, 4.1% calcium, 0.23% magnesium, and 130 mg/kg zinc. The elemental composition was 68.50% carbon, 4.50% hydrogen, 6.00% nitrogen, and 25.30% oxygen, with 85.00% total organic carbon (TOC). This study concludes that T17 is the most effective formulation, offering both environmental and financial benefits, with composting potentially generating $11.16 million in profit, compared to the $19.32 million spent annually on waste management in Sri Lanka’s sugar industry. Full article

Ethanol and xylitol are valuable bioproducts synthesized by non-conventional yeasts from lignocellulosic sugars. However, their biosynthesis requires distinct cultivation conditions. This study evaluated the production of ethanol and xylitol by Clavispora lusitaniae using saccharified sugarcane bagasse (SSCB) under three aeration conditions: microaerobic (C1), anaerobic (C2), and a combination of anaerobic followed by a microaerobic phase (C3). Ethanol production was maximum under anaerobic conditions (C2), followed by combined anaerobic–microaerobic conditions (C3). Meanwhile, xylitol production was most efficient under microaerobic conditions (C1). Notably, anaerobic conditions were ineffective for xylitol production. Enzyme activities of xylose reductase (XR) and xylitol dehydrogenase (XDH), key enzymes in xylose metabolism, were highest under microaerobic conditions with activities of 2.88 U/mg and 1.72 U/mg, respectively, after 48 h of culture. Gene expression analysis of XYL1 and XYL2 correlated with the corresponding enzyme activities (XR) and (XDH) with increased levels of 32.38 and 7.88 fold, respectively, compared to the control in C1. These findings suggest that C. lusitaniae co-produces ethanol efficiently under anaerobic conditions, while xylitol biosynthesis is optimized under microaerobic conditions when using xylose-rich saccharified lignocellulosic substrates. Full article

Arsenic (As), a highly toxic and carcinogenic heavy metal, poses significant risks to soil and water quality, while oxytetracycline (OTC), a widely used antibiotic, contributes to environmental pollution due to excessive human usage. Addressing the coexistence of multiple pollutants in the environment, this study investigates the simultaneous adsorption of As(III) and OTC using a novel bimetallic zinc-iron-modified biochar (1Zn-1Fe-1SBC). The developed adsorbent demonstrates enhanced recovery, improved adsorption efficiency, and cost-effective operation. Characterization results revealed a high carbon-to-hydrogen ratio (C/H) and a specific surface area of 1137 m² g⁻¹ for 1Zn-1Fe-1SBC. Isotherm modeling indicated maximum adsorption capacities of 34.7 mg g⁻¹ for As(III) and 172.4 mg g⁻¹ for OTC. Thermodynamic analysis confirmed that the adsorption processes for both pollutants were spontaneous (ΔG < 0), endothermic (ΔH > 0), and driven by chemical adsorption (ΔH > 80 kJ mol⁻¹), with increased system disorder (ΔS > 0). The adsorption mechanisms involved multiple interactions, including pore filling, hydrogen bonding, electrostatic attraction, complexation, and π-π interactions. These findings underscore the potential of 1Zn-1Fe-1SBC as a promising adsorbent for the remediation of wastewater containing coexisting pollutants. Full article

The complex structure of the plant cell wall makes it difficult to use the biomass produced by biosynthesis. For this reason, the search for new strains of microorganisms capable of efficiently degrading fiber is a topic of interest. For these reasons, the present study aimed to evaluate both the microbiological and enzymatic characteristics of the fungus Curvularia kusanoi L7strain. For this, its growth in different culture media was evaluated. Wheat straw mineralization was evaluated by gas chromatography assisted by infrared spectroscopy. The production of endo- and exoglucanase, laccase, and peroxidase enzymes in submerged solid fermentation of wheat and sugarcane bagasse were characterized. The strain efficiently mineralized raw wheat straw, showing a significant decrease in signals associated with cellulose, hemicellulose, and lignin in the infrared spectra. High enzyme productions were achieved in submerged solid fermentation of both substrates, highlighting the high production of endoglucanases in sugarcane bagasse (2.87 IU/mL) and laccases in wheat (1.64 IU/mL). It is concluded that C. kusanoi L7 is an ascomycete with a versatile enzyme production that allows it to exhaustively degrade complex fibers such as raw wheat straw and sugar cane bagasse, making it a microorganism with great potential in the bioconversion of plant biomass. Full article

The sugar industry must be managed in a manner that encourages innovation with regard to the waste generated throughout the process. The organic load of sugar mill waste is high, as is its potential to pollute water bodies at various stages of the production process, including cooling bearings, mills, sugar cane washing, bagasse waste and cleaning products. It is therefore necessary to identify treatment mechanisms that not only reduce this waste but also return purer water to the environment, combining the reuse of water in various applications. The objective of this study was to analyze the results of the physical and chemical properties of the effluents generated and the principal treatment technologies employed for the remediation of industrial wastewater from sugar factories. The wastewater from Mozambique’s sugar mills has high levels of dissolved or suspended solids, organic matter, pressed mud, bagasse and atmospheric pollutants. The BOD/COD ratio is low (<2.5), indicating the need for secondary treatment or, more specifically, biological treatment. This can be achieved through humid systems built from stabilization ponds, with the resulting water suitable for reuse in agricultural irrigation. In this work, an educational proposal has been developed for engineering students where they learn to calculate and optimize, among other parameters, the natural wastewater treatment and compare it with a conventional wastewater treatment. Full article

Activated carbons are commonly used for adsorption/depollution applications, but only a few studies are related to their lubricating properties. In order to investigate a new family of friction reducers, the tribological properties of biochars and derived activated carbons obtained from sugar cane bagasse are investigated. Activated carbons are obtained from either a physical (steam water) or chemical (with phosphoric acid) activation process. The tribological tests show that the activated carbons present very low friction coefficients, close to 0.08. The correlation of textural and tribological investigations shows that the specific surface area of the compounds as well as the microporous and mesoporous domain extensions are key parameters to optimize the friction reduction properties of activated carbons. The friction properties of the compounds are improved if the mesoporous domain extension is above 40% of the total porous volume. This study shows that local biomass waste valorization is possible and that sugar cane bagasse-derived activated carbons appear as interesting new friction reduction additives for lubricants. Full article

This research developed a low-cost nano-bio-adsorbent using sugar cane bagasse-based nanocrystals incorporated with magnetic iron oxide nanoparticles (CNCs-MIONPs). The adsorbent demonstrated excellent Cr(VI) adsorption efficiency at an optimal pH of 2.0, an initial concentration of 0.5 mg/L, and a contact time of 90 min with a shaking rate of 250 rpm, achieving a removal efficiency of 91.78%. The increased surface area, smaller particle size, and the nanocomposite’s active sites facilitated chromium species’ immobilisation, enhancing chromate ion removal. The adsorption process involved chemisorption, where valence forces such as electron sharing or exchange occur between the adsorbate and sorbent. The modified CNCs-MIONPs showed improved sorption efficiency, suggesting potential applications in water treatment plants, both for domestic and industrial wastewater. Full article

Biochar (BC) and hydrochar (HC) have attracted considerable attention owing to their versatile characteristics and proven effectiveness in diverse technical fields. Solid BC is generated as a result of the dry carbonisation process of pyrolysis, in contrast to the slurry HC, which is produced during the hydrothermal carbonisation process. In this study, we evaluated the adsorption potential of two hydrochar samples (HCs) and three biochar samples (BCs) produced from sugar cane bagasse. The adsorption capacity of these samples was tested for ammonium, nitrate, and phosphate ions under various conditions. The BCs and HCs were subjected to characterisation using a CHNS/O analyser, the zeta potential, and Fourier transform infrared (FTIR). Elevating the pyrolysis temperature of the biochar resulted in changes in the fixed carbon and ash contents, while the volatile matter and H/C and O/C atomic ratios decreased. As the residence time increased, the H/C ratio and volatile matter content of the hydrochars (HCs) decreased. However, the fixed carbon content, ash content, and O/C and C/N ratios exhibited an increase. Thermodynamics, adsorption isotherms, and pH were also taken into consideration. The FTIR spectra analysis indicated that the carboxyl and ester functional groups present in both the BCs and HCs displayed reduced peak intensities subsequent to the adsorption of the three ions. While the adsorption was exothermic, we noticed that the adsorption capacity increased with temperature. The results indicate that sorption was homogenous across all binding sites, as evidenced by the optimal fit to the Langmuir isotherm. The research findings indicate that the adsorption capacity of various BC and HC adsorbents is significantly influenced by the surface area of the adsorbents in the case of nitrate and phosphate, but in the case of ammonia, adsorption is dictated by the functional polar groups present on the adsorbent surface. Full article

The sustainable management of agricultural residues is a pivotal element in ensuring the sustainable development of agriculture. This is based on strategies that include the reutilization of residues as a substrate for the cultivation of economically significant mushroom species. The primary aim of this investigation is to assess the viability of utilizing two of the most prevalent agricultural residues in Ecuador as a substrate for the cultivation of hybrids within the Pleurotus genus. This assessment includes an evaluation of the nutritional and productivity parameters exhibited by the resulting mushrooms, employing multivariate statistical methodologies. The hybrid strains were developed by crossing compatible neohaplonts obtained through chemical dedikaryotization. A total of five neohaplonts of Pleurotus ostreatus as parental strain P1 and five monokaryons of Pleurotus djamor as parental strain P2 were randomly crossed in all possible combinations. Two parental hybrid strains, H1 and H2, were produced. These hybrids were cultivated using agricultural waste substrates, specifically, green banana leaves (GBL) and sugarcane bagasse (SB). Two distinct treatments or mixtures were tested: M1 (composed of 80% SB and 20% GBL) and M2 (composed of 20% SB and 80% GBL). It was found that the M1 blend promotes mushroom growth, yielding superior properties attributable to the higher proportion of nutritional content derived from sugarcane bagasse. Full article

To meet the increasing needs of fuels, especially non-fossil fuels, the production of “bio-oil” is proposed and many efforts have been undertaken to find effective ways to transform bio-wastes into valuable substances to obtain the fuels and simultaneously reduce carbon wastes, including CO₂. This work is devoted to the gasification of sugar cane bagasse to produce CO in the process assisted by CO₂. The metals were varied (Fe, Co, or Ni), along with their amounts, in order to find the optimal catalyst composition. The materials were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron diffraction, and were tested in the process of CO₂-assisted gasification. The catalysts based on Co and Ni demonstrate the best activity among the investigated systems: the conversion of CO₂ reached 88% at ~800 °C (vs. 20% for the pure sugarcane bagasse). These samples contain metallic Co or Ni, while Fe is in oxide form. Full article

The need to reduce the dependency of chemicals on fossil fuels has recently motivated the adoption of renewable energies in those sectors. In addition, due to a growing population, the treatment and disposition of residual biomass from agricultural processes, such as sugar cane and orange bagasse, or even from human waste, such as sewage sludge, will be a challenge for the next generation. These residual biomasses can be an attractive alternative for the production of environmentally friendly fuels and make the economy more circular and efficient. However, these raw materials have been hitherto widely used as fuel for boilers or disposed of in sanitary landfills, losing their capacity to generate other by-products in addition to contributing to the emissions of gases that promote global warming. For this reason, this work analyzes and optimizes the biomass-based routes of biochemical production (namely, hydrogen and ammonia) using the gasification of residual biomasses. Moreover, the capture of biogenic CO₂ aims to reduce the environmental burden, leading to negative emissions in the overall energy system. In this context, the chemical plants were designed, modeled, and simulated using Aspen plus™ software. The energy integration and optimization were performed using the OSMOSE Lua Platform. The exergy destruction, exergy efficiency, and general balance of the CO₂ emissions were evaluated. As a result, the irreversibility generated by the gasification unit has a relevant influence on the exergy efficiency of the entire plant. On the other hand, an overall negative emission balance of −5.95 kg_CO2/kg_H2 in the hydrogen production route and −1.615 kg_CO2/kg_NH3 in the ammonia production route can be achieved, thus removing from the atmosphere 0.901 t_CO2/t_biomass and 1.096 t_CO2/t_biomass, respectively. Full article