Search Results (119)

The advantages of torrefaction preheating, including the production of a hydrophobic solid product, improved particle size distribution, enhanced fuel properties with fewer environmental issues, decreased moisture content, and reduced volatile content. In order to meet the technical requirements of biomass oriented value-added and energy saving and emission reduction, pine sawdust (PS) was taken as the research object, and the physicochemical properties of the PS samples preheated at a low temperature were analyzed by synchronous thermal analysis (TG-DSC), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and organic element analyzer (EA). The effect of preheating at a lower temperature on the physicochemical properties of PS was discussed. The results showed that, under the preheating condition of 200 °C, compared with PS, the water content of PS-200 decreased by 3.23%, the volatile content decreased by 3.69%, the fixed carbon increased by 6.81%, the calorific value increased by 6.90%, the equilibrium water content decreases from 7.06% to 4.46%, and the hydrophobicity increases. This research, based on the improvement of the quality of agricultural and forestry waste and the promotion of the strategy of converting waste into energy, has contributed to the advancement of sustainable energy production. Full article

Low-carbon liquid fuels are needed for decarbonization of hard-to-decarbonize segments of the transportation sector. This decarbonization can be limited by the amount of renewable carbon. Thermochemical conversion of biomass/municipal solid waste (MSW) through gasification is a promising route for producing low-carbon fuels. There are two major opportunities for increasing the amount of low-carbon liquid fuel that can be produced from gasification in any region. One is to increase the amount of liquid fuel from a given amount of biomass/MSW, particularly by hydrogen-enhancement of gasification synthesis gas. Second is the potential for large expansion of use of biomass feedstocks from its present level. Such biomass feedstocks include agricultural waste, forestry waste, MSW, and specially grown biomass that does not interfere with food production. The use of MSW may provide advantages of an established network for pickup and transportation of feedstock to disposal sites and the avoidance of methane produced from landfilling of MSW. As a case study, we looked at potential expansion of US low-carbon fuel production, considering the recent projections of the 2024 USDOE report, which estimated potential production of a billion tons/yr of biomass/MSW feedstocks in the US. This report included an estimated potential for liquid biofuel production of 60 billion gallons/yr of diesel energy equivalent fuel without the use of hydrogen enhancement. By hydrogen-enhanced biomass/MSW gasification, this projection could be doubled to 120 billion gallons/yr of diesel energy equivalent fuel. Furthermore, the co-location potential of biomass/MSW resources with potential renewable energy generation sites is explored. This overlap of hydrogen production and biomass production in the US are located in regions such as the US Midwest, Texas, and California. This co-location strategy enhances logistical feasibility, reducing transport costs and optimizing energy system integration; and can be applied to other geographical locations. Hydrogen-enhanced biomass/MSW gasification offers a promising route to substantially increase low-carbon liquid fuel production (e.g., methanol) and support increased liquid fuel production and greenhouse gas reduction goals. Full article

Biogas produced from agricultural and forestry waste is emerging as a strategic and multifunctional solution to address climate change, inefficient waste management, and the need for renewable energy by transforming large volumes of biomass. Global estimates indicate that approximately 1.3 billion tons of waste is produced each year for these sectors; this waste is processed through anaerobic digestion, allowing it to be transformed into energy and biofertilizers. This reduces greenhouse gas emissions by up to 90%, promotes rural development, improves biodiversity, and prevents environmental risks, such as forest fires. However, despite its high global technical potential, which is estimated at 8000 TWh per year, its use remains limited as a result of its high initial costs, low efficiency in relation to lignocellulosic waste, and weak regulatory frameworks, especially in countries like Mexico, which use less than 5% of their available biomass. In response, emerging technologies, such as co-digestion with microalgae, integrated biorefineries, and artificial intelligence tools, are opening up new avenues for overcoming these barriers under a comprehensive approach that combines science, technology, and community participation. Therefore, biogas is positioned as a key pillar for a circular, fair, and resilient bioeconomy, promoting energy security and advancing toward a just and environmentally responsible future. Full article

With the rapid growth of the global population, increasing per capita energy demands, and waste generation, the need for innovative strategies to mitigate greenhouse gas emissions and effective waste management has become paramount. Pyrolysis, a thermochemical conversion process, facilitates the transformation of diverse biomass feedstocks, including agricultural biomass, forestry waste, and other carbonaceous wastes, into valuable biofuels such as bio-oil, biochar, and producer gas. The article reviews the benefits of pyrolysis as an effective and scalable technique for biofuel production from waste biomass. The review describes the different types of pyrolysis processes, such as slow, intermediate, fast, and catalytic, focusing on the effects of process parameters like temperature, heating rate, and residence time on biofuel yields and properties. The review also highlights the configurations and operating principles of different reactors used for pyrolysis, such as fixed bed, fluidized bed, entrained flow, plasma system, and microwaves. The review examines the factors affecting reactor performance, including energy consumption and feedstock attributes while highlighting the necessity of optimizing these systems to improve sustainability and economic feasibility in pyrolysis processes. The diverse value-added applications of biochar, bio-oil, and producer gas obtained from biomass pyrolysis are also discussed. Full article

It is crucial to clarify the relationship between ecological industry development and ecological civilization construction, as well as their driving forces, to promote high-quality local development. The ecological environment of the karst region is fragile, and it faces a contradiction between ecological preservation and economic advancement. Coordinating the relationship between economic development and ecological protection is crucial for achieving sustainable development in rural karst regions. This study identified karst characteristics in Guizhou province, China, by constructing an index system for ecological industry development and civilization construction. It employed the entropy weight method to calculate a comprehensive score and utilized a coupling coordination model to analyze interactions and symbiotic coordination. Finally, a linear regression analysis model was employed to analyze the impact of ecological industrial development on the construction of ecological civilization. The results indicate the following: (1) The ecological industry and ecological civilization construction levels exhibited a relatively stable growth trajectory across three research areas from 2011 to 2021, with the ecological civilization construction index outperforming the ecological industry development index. (2) The correlation analysis indicated a relationship between the two indices in the research areas, and the divergence trend among the three research areas rose in a uniform direction, indicating a strong positive correlation between the two indices. From the perspective of the coupling degree (C), the degree of coupling between ecological industry and ecological civilization construction in the three research areas exceeded 0.9, indicating a high level of coordination. This suggests that ecological civilization construction and ecological industry in these research areas are effectively coordinated and exist in a state of harmonious co-promotion. There were differences from the coupling coordination degree (D) perspective, but they increased in the three research areas. (3) The regression analysis results indicate that the per capita agricultural output value, per capita forestry output value, per capita forage industry output value, industrial solid waste utilization rate, energy consumption per unit of GDP, tourism income, rocky desertification level, and proportion of the labor force population with a high school education or higher significantly contribute to the development of ecological civilization. The per capita forestry output value greatly advances ecological civilization, significantly enhancing ecological culture and security. The coefficients are 0.0354 and 0.0393, respectively, indicating that a 1% rise in the per capita forestry output value results in increases of 0.0354% and 0.0393% in the ecological culture and security indices. Full article

With the increasing scarcity of traditional hardwood sawdust resources, developing sustainable substrates for edible fungi cultivation has become an urgent industrial priority. This study systematically evaluated the effects of bamboo sawdust substitutions (20%, 30%, 40%, and 50%) on mycelial growth, fruiting body development, and nutritional quality of Auricularia heimuer, while elucidating the underlying molecular mechanisms through transcriptome sequencing. The results demonstrated that bamboo substitution of ≤30% maintained normal mycelial growth and fruiting body differentiation, with 20% and 30% substitutions increasing yields by 5.30% and 3.70%, respectively, compared to the control. However, 50% substitution significantly reduced yield by 9.49%. Nutritional analysis revealed that 20–40% bamboo substitution significantly enhanced the contents of crude protein, polysaccharides, and essential minerals (calcium, iron, and selenium) in fruiting bodies. Transcriptome analysis identified upregulation of glycosyl hydrolase family genes and downregulation of redox-related genes with increasing bamboo proportions. Biochemical assays confirmed these findings, showing decreased oxidative substances and increased reductive compounds in mycelia grown with high bamboo content, which indicate disrupted cellular redox homeostasis. This study provides both a practical solution to alleviate the “edible mushrooms derived from lignicolous fungi–forest conflict” and fundamental insights into fungal adaptation mechanisms to non-wood substrates, thus establishing a theoretical foundation for the valorization of agricultural and forestry wastes. Full article

Pholiota adiposa is a macrofungi that is rich in nutrients and has a delicious taste. Eating more can improve human immunity and inhibit cancer. However, the P. adiposa yield is low and cannot meet market demand. Therefore, strain improvement was carried out by exploring the mechanism of stress adaptation in P. adiposa. In addition, fermentation of the four common grains by P. adiposa mycelia increased their nutrient content and improved their antioxidant capacity. The results revealed that the growth of the mycelium was greatest when sucrose was used as the carbon source at 25 °C. At 35 °C, the MDA content and cellulase enzyme activity of the mycelia decreased by 27.6% and 40.8%, respectively, from 2 to 4 days, and the SOD, CAT, and GR enzyme activities increased by 31.6%, 49.2%, and 1.2%, respectively. The fermentation results revealed that the soluble protein content, reducing sugar content, and DPPH free radical scavenging ability of the fermented grains were significantly greater than those of the unfermented grains. This study can be used to cultivate macrofungi with environmental adaptability and provides a basis for the utilization of biological waste and increased food nutrition. Full article

Linear low-density polyethylene (LLDPE) waste presents a major environmental concern due to its high and widespread use. This study explores the potential of fungal mycelium as a bioremediation solution for LLDPE degradation, by evaluating on mycelial growth efficiency, ligninolytic enzyme activity, weight loss, surface morphology changes, and economic feasibility. Among the tested fungal species, Schizophyllum commune WE032, Lentinus sajor-caju TBRC6266, and Trametes flavida AM011, S. commune demonstrated the most vigorous mycelial expansion (20.53 mm/day) and highest biomass accumulation (276.87 mg). Screening for ligninolytic enzymes revealed significant laccase (Lac) and manganese peroxidase (MnP) activity in all three species indicating their potential in polymer degradation. Weight loss analysis showed that S. commune achieved the greatest LLDPE degradation (1.182% after 30 days), highlighting its enzymatic and metabolic efficiency in breaking down synthetic polymers. Surface morphology studies supported these findings, revealing substantial erosion was observed in LLDPE sheets treated with S. commune and L. sajor-caju, confirming their effectiveness in polymer disruption. FTIR analysis indicated the formation of new functional groups and alterations in the carbon backbone, suggesting active depolymerization processes. Economic evaluation demonstrated that fungal biodegradation is a cost-effective and environmentally sustainable strategy, aligning with circular economy principles by enabling the generation of value-added products from plastic waste. Additionally, fungal-based waste treatment aligns with circular economy principles, generating value-added products while mitigating plastic pollution. These findings highlight fungal mycelium’s potential for plastic waste management, advocating for further research on optimizing growth conditions, enhancing enzyme expression, and scaling industrial applications. Future research will focus on integrating fungal bioremediation with biomass residues from agricultural and forestry sectors, offering a comprehensive solution for waste management and environmental sustainability. Full article

Agroforestry residues are a promising source of organic matter and energy. These organic wastes are often poorly managed by incineration or open-air composting, resulting in the emission of greenhouse gases. Solid-state anaerobic digestion has recently attracted considerable attention to converting organic waste with a high total solids content, such as agroforestry residues, into renewable energy. However, the complex structure of these residues is still a defiance to this technology. Their degradation requires a long period, resulting in low heat and mass transfer. In addition, the process is often inhibited by the accumulation of toxic compounds. An efficient management process has remained under development. Comprehending the challenges faced when treating agroforestry waste is necessary to create practical applications. This review provides essential information for more effective management of complex agricultural and forestry residues using the SS-AD process. It covers the different parameters and experiments that have successfully managed these residues for renewable energy production. Various solutions have been identified to overcome the drawbacks encountered. These include co-digestion, which brings together different residues for better sustainability, and the strategies used to improve energy production from these residues at different levels, involving efficient pretreatments and appropriate operational reactor designs. Full article

This study presents a novel approach that integrates hydrothermal carbonization (HTC) technology with circular economy principles to optimize the management of nitrogen and phosphorus in agricultural wastewater. Given the increasing global resource scarcity and continuous ecological degradation, the valorization of biomass wastewater has become a critical pathway for the promotion of sustainable development. Biomass wastewater, which contains crop residues, forestry leftovers, and food processing byproducts, has long been regarded as useless waste. However, this wastewater contains abundant organic matter and possesses significant renewable energy potential. The valorization of biomass wastewater can significantly reduce environmental pollution. Through the optimization of the HTC process parameters, we achieved an improvement in the quality and yield of carbonized products, facilitating the efficient recycling and utilization of resources. This research demonstrates that HTC technology can transform agricultural wastewater into valuable biofertilizers, biomass energy, and organic feed, while simultaneously reducing the reliance on fossil fuels, decreasing greenhouse gas emissions, and mitigating the environmental impact of agricultural activities. This paper provides a comprehensive exploration of the application of HTC technology in agricultural ecosystems, highlighting its beneficial role in nitrogen and phosphorus management, resource utilization efficiency, and environmental pollution reduction. The findings of this study suggest that HTC technology holds significant potential in optimizing agricultural wastewater treatment, promoting resource recycling, and advancing sustainable agricultural development. Furthermore, this research offers theoretical support and practical guidance for the implementation of HTC technology in agricultural ecosystems, which is of paramount importance in fostering circular economic development and achieving sustainable agriculture. Full article

Converting agricultural and forestry waste into high-value-added bio-oil via hydrothermal liquefaction (HTL) reduces incineration pollution and alleviates fuel oil shortages. Current research focuses on adjusting HTL parameters like temperature, time, catalyst, and pretreatment. Few studies explore raw material composition and its interactions with bio-oil properties, limiting guidance for future multi-material hydrothermal co-liquefaction. In view of the above problems, the lignocellulosic model in this paper used cellulose, hemicellulose, lignin, and protein as raw materials. At a low hydrothermal temperature (220 °C), the yield and properties of hydrothermal bio-oil were used as indicators to explore the influence of the proportional content of different model components on the interaction in the hydrothermal process through its simple binary blending and multivariate blending. Then, compared with the hydrothermal liquefaction process of cotton stalk, the interaction between components in the hydrothermal process of real lignocellulose was explored. The results demonstrated significant interactions among cellulose, lignin, and hemicellulose in cotton stalks. The relative strength of component interactions was ranked by yield (wt.%) and property modulation as follows: cellulose–lignin (C-L, 6.82%, synergistic enhancement) > cellulose–hemicellulose (C-X, 1.83%, inhibitory effect) > hemicellulose–lignin (X-L, 1.32%, non-significant interaction). Glycine supplementation enhanced bio-oil yields, with the most pronounced effect observed in cellulose–glycine (C-G) systems, where hydrothermal bio-oil yield increased from 2.29% to 4.59%. Aqueous-phase bio-oil exhibited superior high heating values (HHVs), particularly in hemicellulose–glycine (X-G) blends, which achieved the maximum HHV of 29.364 MJ/kg among all groups. Meanwhile, the characterization results of hydrothermal bio-oil under different mixing conditions showed that the proportion of model components largely determined the composition and properties of hydrothermal bio-oil, which can be used as a regulation method for the synthesis of directional chemicals. Cellulose–lignin (C-L) interactions demonstrated the strongest synergistic enhancement, reaching maximum efficacy at a 3:1 mass ratio. This study will deepen the understanding of the composition of lignocellulose raw materials in the hydrothermal process, promote the establishment of a hydrothermal product model of lignocellulose, and improve the yield of bio-oil. Full article

This study compares the methane emission estimates from the Intergovernmental Panel on Climate Change with satellite-based measurements from Sentinel-5P to assess trends in global methane emissions and concentrations. Focusing on the countries listed in Annex I of the United Nations Framework Convention on Climate Change and the key sectors of Agriculture, Energy, industrial processes and product use, land use, land use change, forestry, and Waste, this analysis uses data from 1990 to 2021, evaluated through the Mann–Kendall trend test. The findings reveal a decline in methane emissions reported by the IPCC, particularly in the Energy and Waste sectors, driven by stricter environmental regulations and technological advancements in these regions. However, the satellite data from the TROPOspheric Monitoring Instrument for 2019–2024 indicate an increasing trend in atmospheric methane concentrations, suggesting that the reductions reported in the inventories may be insufficient to offset ongoing or previously accumulated emissions. The discrepancies between the IPCC inventories and the satellite observations highlight the challenges in methane source attribution and the limitations of relying solely on inventory-based methods. This study demonstrates the potential of integrating high-resolution satellite data with the traditional methodologies to improve the accuracy of methane emission estimates. Such an approach provides a more comprehensive understanding of methane dynamics, particularly in regions where natural and anthropogenic sources overlap. The findings of this study contribute to a better understanding of global methane emission trends and their implications for climate change. Integrating satellite observations into national inventories has practical applications for enhancing methane monitoring, improving emission reporting, and supporting global climate goals through the more effective and sustainable management of methane emissions. Full article

The use of low-cost agricultural and forestry waste for the preparation of modified phenolic foam (MPF) has attracted widespread attention and has shown promising prospects. This study proposes a novel method for producing MPF using pine sawdust. The full components of pine wood powder and its liquefied products were used as raw materials, and the resin was modified with a silane coupling agent (KH560), triethylene glycol (TEG), and nylon 66 (PA66). Subsequently, three novel MPFs were successfully fabricated using a transplanted core foaming technique, and their material properties were subsequently investigated. The results showed that all three MPFs exhibited excellent compressive strength and flame retardancy, with compressive strength ranging from 5.93 MPa to 12.22 MPa and oxygen index values between 36.2% and 41.5%. In terms of water resistance, the MPFs significantly outperformed traditional phenolic foam (PF); in particular, the addition of 4% KH560 and PA66 reduced the water absorption rate to as low as 2.5%. Furthermore, the powdering rate and thermal conductivity of all MPFs were significantly reduced, with chalking rates decreasing by 28.57% to 50%. This research presents a novel method for preparing MPF using agroforestry waste as a partial replacement for phenol. This approach achieves high-value utilization of pine sawdust while maintaining the performance of the MPF, thus broadening the avenues for MPF production. Full article

Selenium (Se)-enriched microalgae are emerging as new food or agricultural resources. Thus far, the microalgae tested for Se accumulation or biofortification are still very limited. Here, we investigated the effects of selenite on the growth of three terrestrial microalgae (Vischeria sp. WL1, Chlorella sp. WL1, and Nostoc flagelliforme) and their total Se accumulation levels. The three microalgae were previously collected at the same location and show great application potential but differ in classification and growth speed. Three concentrations (10, 20, and 40 mg/L) of selenite were used for treatment. The former two species could resist 40 mg/L selenite but the last one could not. At the relatively optimal concentration (20 mg/L selenite), their specific growth rates were 0.09, 0.10, and 0.05 μ day⁻¹, respectively. Vischeria sp. WL1 could accumulate 3.3 mg/g dry weight (DW) Se after 16 days of cultivation; N. flagelliforme could accumulate 5.6 mg/g DW Se after 24 days of cultivation. Chlorella sp. WL1 accumulated a relatively lower amount of Se, being 0.74 mg/L DW after 18 days of cultivation, but its more rapid growth would be beneficial to saving production costs. These results indicate that three microalgae are capable of functioning as excellent carriers for Se nutrients. This study will contribute to enriching the microalgal resource pool for Se biofortification in food and agricultural areas. Full article

Slow-release nitrogen fertilizer technology is essential for sustainable agriculture, reducing field pollution and enhancing fertilizer efficiency. Lignin, a natural polymer derived from agricultural and forestry waste, offers unique benefits for slow-release fertilizers due to its biocompatibility, biodegradability and low cost. Unlike conventional biochar-based fertilizers that often rely on simple pyrolysis, this study employs hydrothermal activation to create a lignin-based slow-release nitrogen fertilizer (LSRF) with enhanced nutrient retention and controlled release capabilities. By incorporating porous carbon derived from industrial alkaline lignin, this LSRF not only improves soil fertility, but also reduces nitrogen loss and environmental contamination, addressing key limitations in existing fertilizer technologies. We studied the hydrothermal carbonization and chemical activation of IAL, optimizing the conditions for producing LSRF by adjusting the ratios of PC, IAL and urea. Using BET, SEM and FT-IR analyses, we characterized the PC, finding a high specific surface area of 1935.5 m²/g. A selected PC sample with 1923.51 m²/g surface area and 0.82 cm³/g pore volume and yield (37.59%) was combined with urea via extrusion granulation to create the LSRF product. Soil column leaching experiments showed that LSRF effectively controls nutrient release, reducing nitrogen loss and groundwater contamination, ensuring long-term crop nutrition. This research demonstrates LSRF’s potential in improving fertilizer efficiency and promoting sustainable agriculture globally. Full article