Biomass Conversion and Biorefinery最新文献

The combustion of tobacco segments (including leaves and stems) is investigated using thermogravimetric analysis and fire propagation apparatus under varying heating conditions. The thermal pyrolysis experiments are conducted at three heating rates (10, 15 and 20 °C/min) in a mixed nitrogen and oxygen atmosphere. The kinetic analysis is carried out by applying the Flynn-Wall-Ozawa method, which reveals that tobacco stems exhibit significantly higher activation energy compared to the leaves. The activation energy (E_a) of various stem-leaf mixtures ranges from 108 to 215 kJ/mol, with a linear relationship between E_a and stem contents. Additionally, several combustion characteristics, including ignition time, effective heat of combustion (EHC), mass loss rate, smoke production rate and CO/CO₂ generating rates, are analyzed at external heat flux 15 and 25 kW/m². The various loss or production rates are found to be influenced by the external heat flux, generally with an increase occurring at higher fluxes and higher stem loadings. These findings provide valuable insights into establishing a method to accurately determine the uniformity of tobacco components, underscoring tobacco segments as promising and sustainable feedstock.

Life cycle assessments (LCA) of food waste (FW) recycling through industrial anaerobic processes, pyrolysis, and integrated waste treatment systems have been extensively reported. Among these processes, carbonization has emerged as a technique for converting moist FW into biochar (BC), primarily for soil remediation and climate change mitigation. The carbonization technology operates at a maximum temperature of 300 °C with a reaction time of 30 min. This study evaluates the environmental performance of BC production through the carbonization of FW in Bekasi, West Java, Indonesia, using LCA methodology. A life cycle impact assessment (LCIA) showed that this process would absorb 6.85 kg of CO₂eq per ton of BC produced, contributing to decarbonization and reducing the global warming potential (GWP). Regarding CO₂ emissions associated with BC production, CO₂eq from syngas and wood fires were identified as the major contributors. In contrast, terrestrial ecotoxicity (TEC) and human non-carcinogenic toxicity (HNCT) were the most dominant effects, with values of 745.1 kg 1,4-DCB and 680.7 kg 1,4-DCB. The impact of this process on TEC is related to wood combustion and the presence of phosphorus pentoxide (P₂O₅) and potassium oxide (K₂O) in the final product. Non-carcinogenic toxic effects in humans are due to the zinc (Zn) content of BC products. Offsetting the emissions associated with FW carbonization has the potential to protect the environment, as demonstrated by the functional impacts of the GWP (90%), FEC (55%), and HNCT (10%). Treating FW using a carbonation approach has shown environmental benefits for climate change mitigation and economic benefits in marketable BC.

Every year, an enormous number of leaves drop throughout the fall and winter months. The disposal of autumn leaves through landfill or incineration poses a significant environmental burden and represents a substantial underutilization of resources. In parallel, the development of low-cost, high-performance electrode materials remains a critical challenge in the field of supercapacitors. This study demonstrates an innovative approach to converting waste sycamore leaves into highly efficient porous carbon for supercapacitor electrodes via KOH activation. The resulting carbon material, synthesized at 800 ℃ exhibits a high specific surface area (843.58 m² g^− 1), a substantial pore volume (0.531 cm³ g^− 1), and beneficial co-doping with N (1.58 at%), O (28.13 at%), and P (0.41 at%) heteroatoms. These structural merits contribute to outstanding electrochemical performance, achieving a specific capacitance of 255.2 F g^− 1 at 1 A g^− 1 in a three-electrode system with 3 M KOH. Furthermore, the assembled supercapacitor device delivers high power and energy densities, making it a promising candidate for practical applications.

This study investigated the anaerobic co-digestion (Aco-D) of landfill leachate (LL), waste activated sludge (WAS), and sewage scum (SS) to optimize methane (CH₄) production and soluble chemical oxygen demand (sCOD) removal. This research aims to address the challenges of sludge management and landfill leachate treatment while exploring sustainable energy recovery through biogas. A batch biogas production test (BMP) was performed in reactors containing various volumetric mixtures of LL, WAS, and SS, with a focus on optimizing the mixing ratio to improve the CH₄ yield and sCOD removal. A modified Gompertz model was applied to analyze CH₄ production, and desirability analysis was used to determine the optimal co-substrate proportions. The results showed that the highest CH₄ yield of 435.4 ± 13.2 mL per gram of volatile solids (VS) was achieved with equal proportions of each substrate (1/3 LL, 1/3 WAS, 1/3 SS). Maximum sCOD removal (74.9%) occurred with a mixture containing 1/6 LL, 1/6 WAS, and 2/3 SS. The co-digestion impact factor (CIF) revealed a significant synergy (CIF = 1.73) in the 1/3 mixture. The study concluded that the inclusion of LL in Aco-D not only enhanced the solubilization of WAS and SS but also provided a buffering effect, improving overall biogas production and reducing the lag phase duration in SS digestion, which justified the synergy found between the co-substrates. These findings highlight the potential of using Municipal Wastewater Treatment Plant (MWWTP) effluents and landfill leachate for efficient waste-to-energy applications, offering a sustainable solution for sludge management and renewable energy generation.

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The transport sector significantly contributes to global greenhouse gas (GHG) emissions, primarily due to its reliance on fossil fuels. This paper investigates the potential and impacts of using alternative fuels in Serbia. By applying the conservative and optimistic approach, the potential for 2030 and 2050 for feedstocks originating from agriculture, the food industry, the commercial sector, municipal sector, and forestry. This paper sets out to determine the potential of feedstocks to produce alternative fuels, such as biomethane, lignocellulosic bioethanol, hydrotreated vegetable oil, hydrogen, and synthetic fuels. Results indicate that the total potential of all feedstocks is about 7.6 and 10.2 million tons (Mt) of fresh mass (2.2 and 3.1 Mt of dry mass) for 2030 in the conservative and optimistic approach, respectively. For the year 2050, the estimated potential is approximately 10.9 and 14.9 Mt of fresh mass (2.8 and 4.0 Mt of dry mass) in the conservative and optimistic approach, respectively. In 2030, the energy potential of alternative fuels is projected to reach 402 and 571 kilotons of oil equivalent (ktoe) under the two approaches, respectively. By 2050, this potential is estimated to increase to about 523 and 759 ktoe. The determined potential of alternative fuels could meet up to 23% of Serbia’s estimated transport energy needs in 2030 and up to 35% in 2050, potentially reducing GHG emissions by 28% and by 62% respectively. The targets set for 2030 can be comfortably achieved without using renewable electricity, which would be necessary, though, in 2050.

Lubricating greases, as semi-fluid or semi-solid lubricants, have become indispensable in industrial sectors such as manufacturing, mining, and transportation ​​owing to​​ their exceptional lubrication performance and unique characteristics. Although petroleum-based greases currently dominate the global market, the growing environmental concerns and gradual depletion of fossil resources have prompted accelerated research endeavors toward sustainable alternatives. Bio-based lubricating greases have ​​garnered global attention due to​​ their biodegradability, renewability, and non-toxicity. This study presents a comprehensive review of research advances in the field​​ to systematically evaluate the development potential of bio-based greases, aiming to promote their further development and application. The work methodically investigates the definition and evaluation methods of bio-based greases, centering around raw materials and modification strategies for the three core components: base oils, thickeners, and additives. The survey ​​emphasizes​​ changes in physicochemical properties and lubrication characteristics of biomaterials ​​before and after modification​​, as well as ​​contrasts​​ in production processes between bio-based greases and conventional counterparts. Furthermore, the research ​​explores​​ the current status and future directions of the global bio-based grease industry through ​​multifaceted​​ perspectives, including policy support, market trends, and feasibility analysis. Bio-based lubricating greases represent a highly promising lubricant for future applications; however, currently in its early development phase​​, bio-based grease technology ​​demands a prioritized investigation into​​ critical challenges such as economic evaluation, environmental impact assessment, and industrial-scale application ​​to enable​​ its commercialization.

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Biomass-derived microporous carbon-based supercapacitors have recently gained considerable attention, primarily due to their exceptional cost-efficiency and significant contribution to promoting social sustainability. In this study, the long-fiber plant okra stem was selected as a precursor for carbon materials. Utilizing its natural channels, microporous carbon electrode materials were successfully synthesized through direct pyrolysis combined with KOH activation. The optimized carbon electrode was then used to fabricate a symmetric supercapacitor. At a relatively low activation temperature of 500 °C, the symmetric supercapacitor exhibited excellent electrochemical performance. The specific capacitance reached 100.3 F g^− 1 when tested at a current density of 0.2 A g^− 1. Furthermore, after 10,000 charge-discharge cycles at a current density of 2 A g^− 1, the supercapacitor retained 97% of its original capacitance, demonstrating outstanding cycling stability. This configuration not only enhanced the overall performance and durability but also significantly improved safety, making it well-suited for applications in electronic devices.

Endemic fluorosis in human skeletal frameworks is caused by drinking water with a high amount of fluoride ions (F⁻). Addressing the challenge necessitates the development of a high-performance adsorbent for F⁻ removal in aqueous media. Thus, the current study evaluates the performance of BC associated with persulfate (PS) for F⁻ removal for the first time (BC/PS system). The adsorption performance of the BC/PS system was tested at 10 mg/L initial concentration and pH = 7 while varying the contact time (1–5 min). Additionally, a persulfate-treated BC (BC-PS) was prepared and tested for F⁻ adsorption. The modified adsorbent (BC-PS) was characterized to evaluate the morphology, surface area, surface functional groups and chemical composition materials. The BC/PS system showed significantly higher F⁻ removal efficiency (52.1% to 86.63%) compared to BC alone (22.23% to 42.93%) under 1 and 5 min contact time. The observed effect was mainly attributed to the acidification properties of BC/PS system due to the release of H⁺ during the adsorption process. Also, BC-PS adsorbent exhibited almost twice the sorption capacity (15.981 mg/g) as compared to 9.037 mg/g of BC for F⁻ removal. The isotherm model reveals that the process follows Langmuir isotherm (R² = 0.999) with process kinetics defined by a pseudo-second-order model (R² = 0.996). Thermodynamic analysis of F⁻ adsorption on BC-PS indicates an endothermic physisorption (∆H° = 1.70 kJ/mol) and non- spontaneous (∆G° ˃ 0) process. Overall, the study revealed that PS treatment of BC can enhance the adsorption efficiency of the absorbent, making it a sustainable sorbent alternative.

Second-generation bioethanol derived from rice straw faces several challenges, including complex processing stages that involve pretreatment, hydrolysis, and fermentation. Physical, chemical, and physicochemical pretreatments require significant energy, generate chemical waste, and are not environmentally friendly. Current methods for second-generation bioethanol production, such as separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and simultaneous saccharification and co-fermentation (SSCF), remain inefficient due to the separation of enzyme production from hydrolysis and fermentation. This study aims to enhance the efficiency of the production process by integrating fungal pretreatment using Pleurotus ostreatus and consolidated bioprocessing (CBP) using a consortium of Trichoderma reesei and Saccharomyces cerevisiae via a one-pot system. Response surface methodology (RSM) using central composite design (CCD) was employed to optimize bioethanol production. The lignin, cellulose, and hemicellulose contents of rice straw decreased by 31.80%, 6.75%, and 11.65%, respectively, after pretreatment for 21 days. The solids concentration of 34.7% produced the highest bioethanol yield of 27.51 mg/g whole pretreated rice straw (WPRS) at 38 °C for 192 h. Integrating fungal pretreatment and CBP using a microbial consortium resulted in a bioethanol yield of 92.17 mg/g rice straw for 29 days. This study introduces a novel method for producing second-generation bioethanol from rice straw that is both more efficient and environmentally friendly. These findings provide a foundation for further research on the industrial-scale development of second-generation bioethanol from rice straw.

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Response surface methodology (RSM) is crucial in optimizing complex processes like reducing sugar production, offering a systematic approach to parameters, and analyzing the intricate interactions between multiple factors to maximize sugar yield. The current study focuses on enhancing sugar production from corn stover biomass using the nanotechnology-based pretreatment. Corn stover was pretreated with photocatalytic aluminum-doped zinc oxide (Al-ZnO) nanoparticles under ultraviolet irradiation. This was followed by dilute acid (H₂SO₄) and basic (NaOH) hydrolysis to measure the formation of sugars (glucose, arabinose, galactose, mannose, and xylose). A Box-Behnken design within RSM was used to optimize operating parameters such as ultraviolet irradiation time, Al-ZnO nanoparticles concentration, and H₂SO₄ and NaOH concentrations. The results showed that longer UV irradiation exposure had an inverse effect on sugar production, while nanoparticle concentration had a direct and positive effect on sugar production. In photocatalytic acid hydrolysis, the sugars yield reached up to 19.02 g/L at 75 UV time, 1 g/L Al-ZnO nanoparticles, and H₂SO₄ concentration of 2mmnM. For basic hydrolysis, a higher sugar yield of 15.76 (g/L) was achieved at 75 UV time, 1 g/L Al-ZnO nanoparticles, and NaOH concentration of 1.25 M.

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