BioEnergy Research最新文献

Tannery solid waste management posed significant environmental challenges, particularly due to the high organic load and potential toxicity of untreated fleshings. This study explored the Anaerobic co-digestion (AcoD) of chromium-free tannery fleshing, cow dung, and sewage to optimize biogas production under varying operational conditions. A multi-phase experiment was adopted, initially comparing room and controlled temperature conditions, followed by evaluations across mesophilic to lower thermophilic ranges (30–45 °C) and nine different substrate mix ratios. The highest methane yield and digestion performance were achieved at 45 °C with a substrate including a mix of fleshing, sewage, and cow dung as 1:2:1. Process parameters, primarily pH, COD reduction, volatile solid (VS) reduction, and volatile fatty acids-to-alkalinity ratio, were monitored to assess system stability. A Bayesian Network was constructed to model interdependencies among these variables, identifying temperature, initial volatile solids, and substrate-to-inoculum (S/I) ratio as key drivers of gas production. A sensitivity analysis based on mutual information and belief variance further highlighted their influence, providing a probabilistic framework for process optimization with strong interdependence, such as S/I ratio-pH (75.0%), S/I ratio-initial VS (61.5%), and VFA/Alkalinity ratio-temperature (61.6%). Thereafter, a Central Composite Design coupled with desirability analysis was used to identify optimal operational settings, followed by validation experiments, resulting only 5.6 ± 0.5% error. This study demonstrated a successful integration of experimental results and probabilistic modeling to enhance energy recovery from hazardous tannery waste, and its findings contributed to the sustainable waste-to-energy strategy as well as the circular bioeconomy.

The primary factors affecting the commercialisation and acceptability of microalgal-based biodiesel are the costs associated with upstream and downstream production processes. Optimising the growth conditions, upscaling, and ehancing the production of biodiesel in a novel, built, tubular, cylindrical, 10-litre photobioreactor is the main objective of this work. Standard methods were used to investigate physiological factors that affect biomass and lipid content. The optimisation process for culture conditions was achieved using a photobioreactor. Biomass concentration, lipid extraction, and quantification were accomplished using filtration, solvent extraction, and gravimetric techniques. During the process of converting lipids into biodiesel, sulphuric acid was employed as a catalyst. To characterise the biodiesel produced, gas chromatography-mass spectroscopy, American Society for Testing for Materials methods and predicted models based on fatty acid composition were used. The following physiological parameters were ideal for lipid production: 30 °C, photoperiod (16:08), light intensity (5000 lx), nitrogen source (NaNO₃), NaNO₃ (3 g/L), culture medium (BG-11), pH (7.5), salinity (30 PSU), carbon source (glucose), and glucose (15 g/L). The higher biomass concentration (15.50 ± 0.03), lipid content (72.95 ± 0.13), volumetric lipid productivity (2261.45 ± 0.41), and optimal biodiesel yield (80.46 ± 0.04%) were recorded after the fifth day of cultivation in the photobioreactor. Fatty acids made up 49.93% saturated, 34.67% monounsaturated, and 15.40% polyunsaturated fatty acids in the optimised biodiesel. The biodiesel’s property examined met international criteria. The designed tubular photobioreactor enhanced biomass, lipid and biodiesel yields, while the Coelastrum morum strain SP UID GQ375096.1 shows promise in the production of high-quality biodiesel, as the produced biodiesel satisfied international standards.

Zeaxanthin is a xanthophyll produced by plants, algae, and microorganisms. Its production by bacteria is a rapidly expanding field, as consumers shift their demand from synthetic to natural products and sustainable production methods. In this study, the potential of eucalyptus enzymatic hydrolysate and corn steep liquor (CSL) were evaluated as substrates for the production of zeaxanthin by Flavobacterium sp. To be used as fermentation media, strategies such as the use of surfactants and the supplementation with xylanases were evaluated for the preparation of the eucalyptus hydrolysates to enhance the concentration of glucose and xylose as fermentable sugars. The selected hydrolysis condition for eucalyptus hydrolysate preparation was employing a cellulase to xylanase (C:X) ratio of 2:1 with PEG6000 supplementation, enabling a 33% reduction in cellulase by xylanase supplementation without affecting glucose and xylose yields (52% and 68%, respectively). Microbial fermentation in bioreactor of eucalyptus hydrolysate supplemented with CSL resulted in a zeaxanthin and total carotenoids concentration of 0.60 mg/L and 0.97 mg/L, respectively. Thus, CSL supplementation under controlled bioreactor conditions increased zeaxanthin yield from 0.032 mg/g in flasks to 0.096 mg/g, highlighting its potential as an economical strategy to improve efficiency. This study contributes to the valorization of eucalyptus residues as cost-effective sources to produce high valuable compounds with biotechnological applications.

India is on track to achieve ethanol-blending with gasoline of 20% (E20) by mid-2025, with the aim of upgrading to E25 by 2030, contributing toward the Sustainable Development Goals 7 and 13. The government is targeting a more diversified portfolio, transitioning from a sugarcane-based ethanol to a rice and maize-based ethanol mix. This study evaluates for the first time the economic and environmental impacts of achieving E25 blending by 2030 using the input–output framework. Results show that maize-based ethanol production has the highest positive macroeconomic impact across total output, GDP, and employment by 0.53%, 0.48%, and 1.69%, respectively, and the least water and GHG footprint compared to sugarcane and rice-based ethanol production. This diversification leads to marginal price impacts with 1.47% when balanced between sugar and grain-based ethanol and 1.15% when met through 100% maize-based ethanol. However, the procurement of 43 million tonnes of maize would require diverting two-thirds of the current production area of maize toward the fuel market, which has the potential to Generate substantially higher inflationary pressures in the food market. Furthermore, rice and maize-based ethanol leads to the production of 13.5 million tonnes of Dried Distillery Grains, accounting for 13.2% of the livestock feed requirement. Policymakers need to take into consideration the synergy between agriculture and ethanol industries while targeting the decarbonization of the road transportation sector with the long-term goal of net-zero emissions by 2070.

Mesua ferrea Linn (MFL) is an evergreen flowering tree in the family Clusiaceae and mainly grown in South Asia and Southeast Asia, particularly Sri Lanka, India, and Myanmar. MFL seeds have high oil content ranging from 75 to 80% by weight. In this work, MFL seed oil was hydroprocessed in a 2-liter batch reactor at 400 °C and 5 bar initial H₂ pressure using biomass wastes supported Ni/Mo and commercial Pd/C catalysts for one hour. Catalytic hydroprocessing produced about 92% biocrude that was distilled using a True Boiling Point (TBP) distillation unit in accordance with ASTM D2892 and ASTM D5236 specifications. On volume basis, the green gasoline (35–140 °C) fraction was found to be 6–10%, the green kerosene/aviation fuel (140–180 °C) of 5–7%, and the green diesel (180–370 °C) fraction of 33–35%, in addition to 7–9% of the wax (370–482 °C). The total distillates recovery from TBP distillation unit was 51–65% of the original biocrude. The density for gasoline fraction varies in the range 0.74–0.76 g cc^− 1, 0.82–84 g cc^− 1 for kerosene fraction and 0.83–0.85 g cc^− 1 for diesel fraction. In contrast, kinematic viscosity for gasoline fraction (0.64 cSt) is slightly higher than that of petro-gasoline (0.37–0.44 cSt). However, kinematic viscosity for kerosene fraction (0.93 cSt) is very close to petro-kerosene (1-5.2 cSt) and it falls within the acceptable range for diesel fraction (2.8 cSt). Moreover, higher heating values and flash points for distillate fractions vary in between 40 and 45 MJ kg^− 1 and 36–80 °C respectively. The observed fuel properties of most of the distillate’s fractions were comparable to petroleum counterparts, indicating that they could be used as an equivalent substitute for petro-fuels.

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 In this research, green synthesis of high-surface graphene nanosheets using processed Arthrospira platensis biomass as a novel precursor was produced. A two-step thermal process was employed in this study; the pre-carbonization was carried out at 400 ^◦C for 3 h, and the catalytic pyrolysis was done at 550 ^◦C for 3 h using potassium hydroxide as an activating agent. The experimental yield was 2.03 ± 0.37%compared to 18.85% obtained with Aspen Plus software, indicating the influence of real-world processing factors not captured in the simulation. Characterization results showed that the graphene nanosheets were well produced. Field emission scanning electron microscopy (FESEM) revealed a sheet-shape material, and energy-dispersive X-ray spectroscopy (EDX) showed 84.73 ± 0.16 wt% of carbon content. X-ray diffraction (XRD) also proved the presence of hexagonal carbon crystal structures with characteristic peaks at ~ 25.6° and ~ 42.8°, and Raman spectroscopy confirmed the graphene-like features with I_D/I_G ratio of 0.971. The nitrogen adsorption/desorption analysis showed that the fabricated materials had exceptional large surface area of ~ 1439.5434 m²/g, an average pore size of ~ 2.4654 nm, and total pore volume of ~ 0.8872 cm³/g. Fourier transform infrared spectroscopy (FTIR) revealed several changes in the functional groups after thermal processing. The findings of this study showed that the processed Arthrospira platensis biomass can be considered as a promising sustainable precursor for the production of high quality graphene nanosheets with potential applications in various industrial processes, including separation, biosensors, and energy storage devices.

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The development of cost-effective and sustainable heterogeneous catalysts from renewable resources plays a vital role on the biodiesel production process. In this study, Borassus flabellifer biomass was collected, processed and calcined to synthesize a novel heterogeneous catalyst for production of biodiesel by using transesterification process. The characterization studies such as FTIR, TGA, DSC, XRD and FE-SEM were conducted to elucidate its functional groups, crystalline phases, surface morphology, surface area and thermal stability. The transesterification process was chosen to prepare canola biodiesel from raw oil with the aid of a novel catalyst by varying process parameters. The Response Surface Methodology (RSM) was adopted to optimize the operating parameters for obtaining maximum biodiesel yield. Furthermore, machine learning based Random Forest (RF) technique was utilized to model for the prediction of biodiesel yield based on the experimental data. The RSM approach demonstrates an optimum condition of methanol to oil ratio (12:1), reaction temperature (65 °C) and catalyst concentration (5 wt %) results a maximum biodiesel yield of 96.24%. The RF model was exhibited a strong predictive accuracy by achieving a high coefficient of determination (R² = 0.9785) along with low error values (MAE = 0.3505 and RMSE = 0.4473), indicating its reliability and robustness in predicting biodiesel yield. These findings demonstrate the potential of Borassus biomass as a sustainable heterogeneous catalyst for the biodiesel production and emphasize the role of machine learning based optimization and integration to enhance the biodiesel synthesis.

Cell wall composition influences biomass use as a forage and as a feedstock for biofuel and chemical conversion. To examine the influence of environment on composition of switchgrass (Panicum virgatum L.), we utilized a multi-environment experiment consisting of clones of switchgrass genotypes grown at up to ten locations in the continental US. We tested the influence of different milling treatments on biomass composition trait predictions via near-infrared reflectance spectroscopy (NIRS). We found that most compositional trait predictions (29/34) were significantly different (P < 0.05) when a single lot of biomass was subjected to disparate milling treatments, i.e., knife milling vs. knife milling with an additional cyclone milling. Further, depending on the plant material tested, three to eight compositional trait predictions vary (P < 0.05) when identical biomass was knife milled at different sites followed by cyclone milling at a single site, including for traits such as Klason lignin, nitrogen, and carbon. In some cases, variation due to milling site exceeded environmentally induced compositional variation of a single switchgrass genotype grown at different sites. From these observations, we recommend a protocol with two sequential millings that decouples growth environment from a particular mill. Utilizing this approach, we found that 46/46 biomass composition traits from the warm season herbaceous forage and switchgrass bioethanol NIRS equations vary significantly (P < 0.001) in clones of a switchgrass genotype (WBC) grown at ten sites, with the growth site representing the largest average source of variation (41%). This multi-site milling approach can be used to examine environmental and gene-by-environment influences on composition with the goal of optimizing cell wall composition in different environments for biomass utilization.

The rising energy consumption, energy crises, industrial growth, and environmental pollution have prompted a shift towards renewable energy resources. This study investigates the dynamic behavior of high-viscosity fluids in stirred tanks, both baffled and non-baffled, relevant for laboratory applications and biogas production. A cylindrical tank with four vertical baffles was analyzed, focusing on the flow field, turbulent kinetic energy, and its dissipation rates at rotational speeds of 20, 40, and 60 rpm. Comparisons between experimental and simulated results highlighted an acceptable 6% error in power consumption and Reynolds number predictions. At different rotational speeds, the radial velocities measured along the blades were 0.237, 0.130, and 0.041 m/s for the baffled tank, and 0.226, 0.128, and 0.041 m/s for the non-baffled tank, respectively. Furthermore, an increase in vertical flow contributed to greater turbulence intensity. The turbulent kinetic energy for baffled and non-baffled vessels at these speeds was recorded as 0.0215, 0.0102, 0.0024 m²/s² and 0.0188, 0.0091, 0.0022 m²/s², respectively. Dissipation rates were 0.049, 0.011, 0.0006 m²/s³ and 0.037, 0.0091, 0.0005 m²/s³. The findings confirm that baffled configurations enhance radial flow and mixing efficiency. The final cumulative biogas production results after 19 days of operation showed significant differences in the performance of each stirring speed. The amounts of biogas collected were 367, 488, 418, and 325 L at stirring speeds of 0, 20, 40, and 60 rpm, respectively. The optimal stirring speed was 20 rpm, yielding a positive energy balance of 4.424 MJ, the highest net energy efficiency. These findings suggest that moderate stirring with baffles optimizes both methane output and energy performance.

Anaerobic digestion (AD) is a sustainable waste-to-energy technology that addresses both environmental pollution and renewable energy generation. This study investigates the potential use of parboiled rice mill wastewater (PRMWW), assesses the energy balance of its co-digestion process, and addresses water requirements in AD. Since PRMWW has an unbalanced nutrient profile, particularly low in carbon, its co-digestion with lignocellulosic substrates such as rice straw (RS) can enhance overall digestion efficiency by improving the nutrient balance and promoting lignocellulose degradation. RS was incorporated into PRMWW to balance the carbon-to-nitrogen (C/N) ratio and provide structural carbon for enhanced biogas production. Various co-substrate combinations with different C/N ratios were tested under mesophilic conditions. The study investigated the effect of RS particle size on biogas production and observed that medium-sized particles (1.18–2.36 mm) yielded higher biogas compared to small (0.6–1.18 mm) and large (2.36–4.75 mm) particles. The corresponding biogas yields were 363, 439, and 313 mL/g VS_added for small, medium, and large particles, respectively. Additionally, it was observed that increasing the C/N ratio beyond a certain point reduced biogas production due to nitrogen limitation. At C/N = 23 with RS particles of medium, methane and biogas yields were 235 and 439 mL/gVS_added, respectively, with an 83% reduction in volatile solids (VS). The impact of the inoculum-to-substrate (I/S) ratio (0.5 to 4) on digester performance was also examined. The optimal I/S = 1 produced significant yields of 443 mL/gVS for biogas and 267 mL/gVS for methane, with 72% biodegradability. The modified gompertz model (MGM) showed the highest methane production (268.59 mL/gVS) after a lag period of 2.60 ± 0.71 days. The energy balance analysis of anaerobic co-digestion (ACoD) of PRMWW and RS reveals a net energy gain of 43.75 kWh/MgVS, demonstrating superior energy yield compared to mono-digestion.