Biomass Conversion and Biorefinery最新文献

For the present study, the activated carbon were obtained from Lotus corniculatus L. as waste biomass using carbonization at 700 °C and alkali potassium hydroxide (KOH) chemical activation technique. Single gaseous benzene (C₆H₆) adsorption (SGBA) experiments were performed to benchmark the efficiency of the L. corniculatus-derived activated carbons (LCACs), which were LCAC2 (609 m² g⁻¹, KOH 1:2 w/w), LCAC3 (742 m² g⁻¹, KOH 1:3 w/w), and LCAC4 (826 m² g⁻¹, KOH 1:4 w/w), respectively. Also, the physicochemical properties of LCACs were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and proximate-elemental assessment. The isotherm models (Langmuir and Freundlich) of C₆H₆ demonstrate the complex adaptation results of LCAC4 at different relative humidity (RH) levels, and Freundlich isotherm is highly suitable to C₆H₆/LCAC4 as multilayer adsorption. Kinetic behavior was also analyzed and showed that of C₆H₆ is well illustrated by the pseudo second order (PSOM). The C₆H₆ competitive adsorption of LCAC2, LCAC3, and LCAC4 at 25 °C + 0 RH%, 25 °C + 80 RH%, 45 °C + 0 RH%, and 45 °C + 80 RH% corresponds to reductions of 12.9–11.6%, 7.8–11.5%, and 9.9–18.4%. The LCAC4 is confirmed to be a perfect adsorbent in the elimination of a single gaseous stream at 45 °C + 0 RH%. Regeneration showed that the LCAC4 maintained more than 25% of the initial adsorption capacity after five repeated adsorption–desorption cycles. The promising properties of LCAC4 are recommended to be exploited for the other volatile organic compounds in the gas phase in indoor environments, under the best conditions.

Torrefaction experiments of Rubberwood and Gliricidia were conducted at 250–300 °C for 30–60 min in a 3–9% oxygen environment to study the oxidative torrefaction behavior. The higher heating value of the torrefied Rubberwood increased from 18.9 to 24.68 MJ/kg and from 19.46 to 23.19 MJ/kg for Gliricidia under the most severe oxidative conditions. Effects of torrefaction conditions on the solid yield, VM removal, C enhancement, HHV enhancement, and energy yield were modeled using response surface methodology, and temperature and oxygen concentration mainly affected the torrefied biomass properties. Rubberwood recorded a significantly greater energy mass co-benefit index (EMCI) than Gliricidia. EMCI of oxidative torrefaction of Gliricidia showed no significant difference from that of inert conditions. A new severity factor was introduced for oxidative torrefaction, and the normalized severity factor showed a linear correlation with torrefied biomass properties, which could facilitate oxidative torrefaction modeling.

The purpose of this work is to study the efficiency of lead ions removal via adsorption onto created solid nanomaterials. Three solid adsorbents were synthesized as cellulose nanoparticles (CN) extracted from plant loofah sponge using alkali treatment and acid hydrolysis techniques, chitosan beads (CZ), and cellulose nanoparticles/chitosan beads composite (CZC). The generated solid adsorbents were investigated using TGA, N₂ adsorption/desorption, ATR-FTIR spectroscopy, SEM, TEM, XRD, and pH_PZC. Based on our findings, CZC had a pH_PZC of 7.2, a larger specific surface area (645.3 m²/g), and a total pore volume (0.372 cm³/g). The batch adsorption of lead ions was well-fitted by pseudo-second order, Elovich, Langmuir, Temkin, and Dubinin-Radushkevich on all the samples. Cellulose nanoparticles/chitosan composite had the highest Langmuir adsorption capacity (221.104 mg/g) at 47°C, 120 min as shaking time, 2 g/L as adsorbent dose, and pH 6.5. Nitric acid had the highest desorption percentage (92%). The thermodynamic investigation revealed that lead ion adsorption is endothermic, favorable, spontaneous, and physisorption. Our findings showed that CZC has a high adsorption capacity and rapid kinetics, indicating its potential for employment in water treatment.

Functional carbon-based materials play an important role in the field of energy and environmental protection, and how to prepare high-performance sustainable carbon-based materials is a current research hot spot. In this paper, the hydrothermal products of corn stover were used as precursors, and the carbon materials prepared in different ways were tested for their properties, and the synergistic effects of the two activation methods of secondary hydrothermal and pyrolysis with the catalysts were discussed. The results show that secondary hydrothermal can enrich the surface functional groups of the materials with higher product yields, but the effect on the specific surface area is weak. During pyrolysis, the content of functional groups decreases and the surface porosity increases due to the overflow of volatile matter; ZnCl₂ enhances the aromatization reaction during secondary hydrothermal process, and the specific surface area of the material is greatly increased by the etching effect during pyrolysis; both activation modes are able to realize the heterocyclic N doping through the addition of urea, and the pyrolysis process is able to produce more nitrogen-containing functional groups.

This research explores the multifaceted applications of Magnolia champaca, encompassing the characterization of vegetable oils and biodiesels for potential use in CI engines. The biodiesel produced from M. champaca is shown to meet ASTM and European standards, albeit with differences in properties compared to conventional diesel. Engine performance and emission characteristics of biodiesel blends (B10, B20, and B30) are evaluated in a CI engine and compared with diesel. While the blends adhere to standards, performance metrics exhibit lower values for torque, brake power, and thermal efficiency compared to diesel due to differences in density, viscosity, and heating value. CO emissions decrease with engine speed from 2000 to 3000 rpm due to higher in-cylinder temperatures, while they increase from 3000 to 4000 rpm due to reduced oxidation time. Biodiesel blends emit less CO than diesel but have higher NO_x emissions due to factors like earlier nozzle opening and advanced injection. Additionally, Magnolia champaca de-oiled cake (MCDC) is investigated as a promising feedstock for biofuel production through pyrolysis, broadening the scope of sustainable energy sources. The study unveils the pyrolytic valorization of MCDC, generating bio-oil with superior calorific values (27.52 MJ/kg). The solid co-product, biochar, boasts a high calorific value (27.12 MJ/kg), making it an exceptional choice for use as a solid fuel. Furthermore, its properties, such as a pH of 10.77, render it ideal for various applications, including the treatment of acidic soils. Moreover, an investigation has been carried out to explore the knock-down and mortality effects of a mosquito repellent formulated with MCDC as an active ingredient against Aedes aegypti and Culex quinquefasciatus mosquitoes—significant vectors of various diseases. MCDC repellent showed the highest mortality rate against Ae. aegypti mosquitoes at 30% active ingredient and against Cx. quinquefasciatus mosquitoes at 35% active ingredient. Notably, de-oiled seed cakes of M. champaca prove effective in mosquito-repellent formulations, demonstrating the versatility and potential of M. champaca-derived products for various applications.

The synthesis of nanoparticles using green approaches is gaining unique importance due to its low cost, biocompatibility, high productivity, purity, and being environmentally friendly. So, the current study focused on the green synthesis of zinc oxide nanoparticles (ZnO-NPs) using plant extracts from Fumaria officinalis and Peganum harmala. The characterization was accomplished using techniques such as UV–vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The UV-absorption peaks were observed at 294 and 303 nm. The resulting FT-IR of ZnO-NPs biosynthesized from F. officinalis shoot extract depicts different bands as 593 cm⁻¹, 991 cm⁻¹, 1030 cm⁻¹, and 1229 cm⁻¹, while ZnO-NPs biosynthesized from P. harmala seeds show bands at 600 cm⁻¹, 642 cm⁻¹, 944 cm⁻¹, and 1038 cm⁻¹. FT-IR analysis depicted different functional groups belonging to halo compounds, alkenes, and sulfur oxides. XRD analysis was performed in order to study the structural parameters of ZnO-NPs. XRD analysis confirmed that the average grain size of ZnO-NPs from F. officinalis was 19.55 nm, and the Bragg angles were recorded as 23.25°, 31.75°, 34.4°, 36.25°, 47.5°, 56.55°, 62.8°, and 67.9°. The average grain size for zinc oxide nanoparticles from P. harmala seeds extract was calculated at 25.10 nm, and the Bragg angles are 32.32°, 34.9°, 36.8°, 48.12°, 57.16°, 63.45°, 68.52°, and 69.65°. Moreover, SEM analysis showed that nanoparticles from both plant extracts have irregular rods and dispersed spherical morphology. The most pronounced increases in antioxidant activity against 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid [ABTS] were detected at the high concentrations of ZnO-NPs (400 µg/mL) biosynthesized from F. officinalis (41.67%) and from P. harmala (39.79%), while the lower activity was recorded at a minimum concentration of 50 µg/mL of ZnO-NPs biosynthesized from F. officinalis (30.34%) and from P. harmala (30.28%). Antibiotics revealed smaller inhibition zones of 16 and 17.5 mm, while the higher concentrations of ZnO-NPs (800 µg/mL) biosynthesized from F. officinalis and P. harmala displayed strong antibacterial activity against Staphylococcus aureus with inhibition zones of about 29 and 23 mm and Clavibacter michiganensis with inhibition zones of about 21 and 19 mm, respectively. Antimicrobial resistance is one of the principal global health problems, and it is imperative to develop new drugs to reduce the spread of antimicrobial-resistant microorganisms. So, our finding concludes that we should use the high concentrations of ZnO-NPs (400 µg/mL) biosynthesized from F. officinalis and P. harmala as antioxidant and antibacterial compounds.

Increasing demands for plastic materials create a serious restraint on environmental sustainability and restraint the utilization of synthetic products to fabricate the materials for the extended endurance of future generations. In the present research, plant-based products like aloe vera, corn, eucalyptus, and soybean fibers were selected as a reinforcement. All these plant-based fibers were reinforced with epoxy polymer (Araldite LY 556) to develop the composite materials. Epoxy-based biocomposites have numerous applications ranging from automobile, aerospace, and structural or non-structural components due to their lightweight and high specific strength. Among all the developed composites, the soybean-epoxy composite displayed the roughest surface, while the aloe vera-epoxy composite had the smoothest surface. However, aloe vera-epoxy composite absorbed more of the amount of water than any other composite within the water absorption test. Soybean-epoxy composite absorbed maximum heat at a glass transition temperature of 363.987 °C. The composite made of soybean and epoxy had the greatest flexural strength and modulus, followed by composites made of aloe vera-epoxy, eucalyptus-epoxy, and corn-epoxy. The soybean-epoxy composite had a greater tensile strength and tensile modulus, whereas the corn-epoxy composite had a larger elongation at break, followed by the soybean-epoxy, eucalyptus-epoxy, and aloe vera-epoxy composites. The impact strength of the soybean-epoxy composite was greater. The soybean-epoxy composite showed reduced fiber debonding, which may have contributed to the composite’s higher mechanical strength. As a result, it was discovered that soybean outperformed other composites in most of the tests, with aloe vera coming in second.

This study investigates into the mechanical properties of a Cocos nucifera fiber-reinforced polyester matrix composite under alkali-treated (NaOH) and untreated conditions, along with the effects of nanoclay (NC) and egg shell powder (ESP). The samples were prepared by the compression molding process with different weight percentages of NC and ESP. The composites underwent thorough analysis for both morphological and mechanical properties. The void content and density of the composites are regulated by the alkali treatment applied to the composites. In the alkali-treated composites, the maximum absorption rates reached were 10% and 9%. Notably, the tensile strength exhibited a slight enhancement in alkali-treated composites with 1 wt% NC and 2 wt% ESP, reaching 12.92 MPa. Flexural and impact strength were good in the combination of equal wt% of filler addition, like 48.13 MPa and impact strength of 3.78 J, respectively. Morphological investigations on fractured surfaces of untreated and alkali-treated composites elucidated the interfacial relationship between components, with alkali-treated composites showcasing superior interfacial strength compared to their untreated composites.

Deep eutectic solvents (DES) are becoming popular in energy storage applications, especially as electrolytes because of their favorable properties like low toxicity, great biodegradability, high thermal stability, and availability. To design, optimize, and develop new lithium-ion battery electrolytes, it is important to understand the physicochemical properties and molecular interactions of these green solvents. In this respect, the density (ρ) and sound speed (u) at four distinct temperatures were measured and at different concentrations of lithium perchlorate (LiClO₄) solutions of the ethaline DESs along with dextrose and L-tyrosine as additives. In the whole concentration range, using density and speed of sound, physical parameters like apparent and partial molar volumes (({V}_{varnothing }) and ({V}_{varnothing }^{0})), apparent and partial molar isentropic compressions (({K}_{varnothing ,S}) and ({K}_{varnothing ,S}^{0})), and limiting molar expansibilities (left({phi }_{E}^{0}right)) were calculated and results indicate that solvent-solvent interactions are dominant over solute-solute interactions with the rise in temperature and potentially enhancing ion solvation. Also, Hepler’s constant and other metrics demonstrate the structure breaker behavior of the studied systems. Cyclic voltammetry (CV) studies were also conducted to predict the electrochemical working stability of the studied systems. FTIR studies were also done to further analyze the interactions.

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This paper presents a comprehensive characterization of hybrid fiber and bioceramic reinforced polyester composites, focusing on their mechanical, fatigue, and flammability, creep, and water absorption properties. The investigation explores the influence of fiber stacking sequence and the integration of Si₃N₄ particles on the performance of the composites. Mechanical tests reveal significant enhancements in the tensile and flexural strength with variations in composition and stacking sequence. The alternating arrangement of basalt and pineapple fibers in the composites demonstrates synergistic reinforcement effects, while Si₃N₄ particle incorporation further improves mechanical properties. Fatigue testing highlights the role of Si₃N₄ particles in enhancing fatigue resistance, with composites exhibiting extended fatigue life. Creep behavior analysis indicates reduced creep strain with Si₃N₄ particle incorporation, emphasizing their role in enhancing creep resistance. Flammability testing underscores the influence of material composition on fire safety characteristics, with composites achieving varying self-extinguishing rates. Water absorption testing reveals increased water uptake in composites containing natural fibers, emphasizing the need for careful consideration of fiber composition in applications exposed to humid environments. SEM analysis provided insights into microstructural features and interfacial characteristics, revealing the presence of Si₃N₄ particles and fiber-related phenomena. Overall, this study provides valuable insights into the multifaceted performance of hybrid fiber and bioceramic reinforced polyester composites, offering implications for diverse engineering applications requiring elevated strength, durability, and fire safety in structural, defense, automotives, and drones.