Search Results (3,498)

The present study aims to assess the sustainability of bioenergy potential from agriculture in the European Union in the period 2012–2021, with a particular focus on material flow and emissions management, bioenergy and recycling impacts, while assessing the potential of bioenergy from agriculture and analyzing the degree of self-sufficiency and import dependency in the biomass economy. While biomass has significant potential in the EU energy transition, its use is accompanied by challenges related to sustainability, carbon neutrality, efficiency and economic viability. Using a quantitative approach based on official statistical data, this research tracked the evolution of biomass imports, exports, domestic extraction and consumption, providing a comprehensive picture of the stability and adaptability of the biomass economy in the European Union. The results indicate a steady increase in domestic extraction and a stability in consumption, reflecting a high capacity of the European Union to manage biomass resources; thus, the degree of self-sufficiency has been high throughout the period, with a moderate dependence on imports, showing an adaptable economy. The conclusions suggest that in order to maintain this stability, the European Union must continue to develop balanced economic and environmental policies that support the sustainable use of biomass and contribute to the energy transition and environmental objectives. Full article

The worldwide population growth and its increasing affluence have led to an increase in global building energy consumption. Therefore, developing sustainable energy storage materials to mitigate this problem has become a high priority for many researchers. Organic phase change materials (PCMs), such as fatty acids, have been extensively studied for thermal energy storage in building applications due to their excellent performance in absorbing and releasing energy within the environment temperature ranges. However, issues related to their thermal conductivity, stability, and flammability could limit the potential and require addressing. In this review, organic PCMs, with a special focus on fatty acids, are discussed. This review covers recent studies related to PCM synthesis from bio-sources, methods for PCM incorporation in building materials, methods for enhancing organic PCM thermal properties, flammability challenges, and life cycle assessment. Finally, future opportunities are summarized. Full article

Hydrothermal liquefaction technology (HTL) is a promising thermochemical method to convert biomass into novel liquid fuels. The introduction of oxides and inorganic acids/bases during the hydrothermal process significantly impacts the yield and composition of bio-oil. However, systematic research on their effects, especially at lower temperatures, remains limited. In this paper, we examine the effects of acidity and alkalinity on cotton stalk hydrothermal bio-oil by introducing homogeneous acids and bases. Given the operational challenges associated with product separation using homogeneous acids and bases, this paper further delves into the influence of heterogeneous oxide catalysts (possessing varying degrees of acidity and alkalinity, as well as distinct microstructures and pore architectures) on the production of cotton stalk hydrothermal bio-oil. The effects of nanoscale oxides (CeO₂, TiO₂, ZnO, Al₂O₃, MgO and SiO₂) and homogeneous acid–base catalysts (NaOH, K₂CO₃, Na₂CO₃, KOH, HCl, H₂SO₄, HNO₃) on the quality of cotton stalk bio-oil under moderate hydrothermal conditions (220 °C, 4 h) were investigated. Characterization techniques including infrared spectroscopy, thermogravimetric analysis, elemental analysis, and GC-MS were employed. The results revealed that CeO₂ and NaOH achieved the highest bio-oil yield due to Ce³⁺/Ce⁴⁺ redox reactions, OH-LCC disruption, and ionic swelling effects. Nano-oxides enhanced the formation of compounds like N-ethyl formamide and aliphatic aldehydes while suppressing nitrogen-containing aromatics. The total pore volume and average pore width of oxides negatively correlated with their catalytic efficiency. CeO₂ with low pore volume and width exhibited the highest energy recovery. The energy recovery of cotton stalk bio-oil was influenced by both acid and base sites on the oxide surface, with a higher weak base content favoring higher yields and a higher weak acid content inhibiting them. The findings of this research are expected to provide valuable insights into the energy utilization of agricultural solid waste, such as cotton stalks, as well as to inform the design and development of highly efficient catalysts. Full article

The global increase in energy consumption, driven by population growth and improved living standards, has led to a heavy reliance on fossil fuels, causing significant environmental concerns. This has prompted a shift toward sustainable energy sources, with biomass, especially lignocellulosic forest biomass, emerging as a key alternative due to its abundance and carbon-neutral potential. Microwave-assisted pyrolysis (MAP) is an efficient method for converting forest biomass into valuable bioproducts and bioenergy with reduced energy use. This review introduces biomass types, focusing on forest biomass and its role in global energy production. It compares MAP to conventional pyrolysis, highlighting the benefits of rapid, uniform heating and improved product yields. Key operational conditions, such as temperature, microwave power, biomass size, and catalyst ratios, are discussed in relation to their impact on product quality and yield. Despite its advantages, MAP faces challenges, particularly in temperature control, which can affect bio-oil yield and quality. High temperatures may cause unwanted secondary reactions, while low temperatures can lead to incomplete decomposition. Research into biomass dielectric properties and process modeling is essential in order to optimize MAP and scale it up for industrial use. Addressing bio-oil quality issues through catalytic upgrading is also critical for broader adoption. Full article

Bio-oil produced via fast pyrolysis, irrespective of the biomass source, faces several limitations, such as high water content, significant oxygenated compound concentration (35–40 wt.%), a low heating value (13–20 MJ/kg), and poor miscibility with fossil fuels. These inherent drawbacks hinder the bio-oil’s desirable properties and usability, highlighting the necessity for advanced processing techniques to overcome these challenges and improve the bio-oil’s overall quality and applicability in energy and industrial sectors. To address the limitations of bio-oil, a magnetic bimetallic oxide catalyst supported on activated rice straw biochar (ZrO₂-Fe₃O₄/AcB), which has not been previously employed for this purpose, was developed and characterized for upgrading rice straw bio-oil in supercritical butanol via esterification. Furthermore, the silica in the biochar, combined with the Lewis acid sites provided by ZrO₂ and Fe₃O₄, offers Brønsted acid sites. This synergistic combination enhances the bio-oil’s quality by facilitating esterification, deoxygenation, and mild hydrogenation, thereby reducing oxygen content and increasing carbon and hydrogen levels. The effects of variables, including time, temperature, and catalyst load, were optimized using response surface methodology (RSM). The optimal reaction conditions were determined using a three-factor, one-response, and three-level Box-Behnken design (BBD). The ANOVA results at a 95% confidence level indicate that the results are statistically significant due to a high Fisher’s test (F-value = 37.07) and a low probability (p-value = 0.001). The minimal difference between the predicted R² and adjusted R² for the ester yield (0.0092) suggests a better fit. The results confirm that the optimal reaction conditions are a catalyst concentration of 1.8 g, a reaction time of 2 h, and a reaction temperature of 300 °C. Additionally, the catalyst can be easily recycled for four reaction cycles. Moreover, the catalyst demonstrated remarkable reusability, maintaining its activity through four consecutive reaction cycles. Its magnetic properties allow for easy separation from the reaction mixture using an external magnet. Full article

Land use regulations have played a critical role in the siting and operation of renewable energy technologies. While there is a growing literature on the siting of wind and solar technologies, less is known about the relationship between local codes and planning decisions and the development of wood-based bioenergy technologies, particularly in rural places. This research examines the relationship between local land use policies and the siting and operation of different types of wood-based bioenergy technologies in northern Michigan, USA. Land use codes including zoning laws and ordinances related to wood-burning devices from 506 cities, townships, and villages within 36 counties in northern Michigan were combined with US Census data in a GIS database. ArcGIS was used to examine geographical differences between communities and socioeconomic factors related to different regulatory approaches. We found that areas with greater population densities and higher income and education levels tended to have more nuanced land use codes related to all scales of wood-burning, including residential wood heating, commercial-scale heating, and power generation. This paper emphasizes the importance of local decision-making and land use policies in shaping the development of wood-based energy technologies, and suggests the need for greater attention to rural community dynamics in planning the shift to a lower-carbon economy. Full article

Real-world energy efficiency in the building sector is currently inadequate due to significant discrepancies between predicted and actual building energy performance. As operational energy is optimized through improved building envelopes, embodied energy typically increases, further exacerbating the problem. This gap underscores the critical need to re-evaluate current practices and materials used in energy-efficient building construction. It is well established that adopting a life cycle view of energy efficiency is essential to mitigate the building sector’s contribution to rising global energy consumption and CO₂ emissions. Therefore, this study aims to examine existing research on sustainable building materials for life cycle energy efficiency. Specifically, it reviews recent research to identify key trends, challenges, and suggestions from tested novel materials. A combination of theoretical analysis and narrative synthesis is employed in a four-stage framework discussing the challenges, context, concepts, and the reviewed literature. Key trends include the growing adoption of sustainable materials, such as bio-fabricated and 3D printed materials, which offer improved insulation, thermal regulation, and energy management capabilities. Multifunctional materials with self-healing properties are also emerging as promising solutions for reducing energy loss and enhancing building durability. The focus on reusing materials from the agricultural, food production, and paper manufacturing industries in building construction highlights the opportunity to facilitate a circular economy. However, the challenges are substantial, with more research required to ascertain long-term performance, show opportunities to scale the implementation of these novel materials, and drive market acceptance. Full article

Considering human influence and its negative impact on the environment, the world will have to transform the current energy system into a cleaner and more sustainable one. In residential as well as office buildings, there is a demand to minimize electricity consumption, improve the automation of electrical appliances and optimize electricity utilization. This paper describes the implementation of a smart switch with extended facilities compared to traditional switches, such as visual indication of evacuation routes in case of fire and acoustic alerts for emergencies. The proposed embedded system implements Modbus RTU serial communication to receive information from a fire alarm-control panel. An extension to the Modbus communication protocol, called Modbus Extended (ModbusE), is also proposed for smart switches and emergency switchboards. The embedded smart switch described in this paper as a scientific and practical contribution in this field, based on a performant microcontroller system, is integrated into the Building Internet of Things (BIoT) concept and uses the innovative ModbusE protocol. The proposed smart lighting system integrates building lighting access control for smart switches and sockets and can be extended to incorporate functionality for smart thermostats, access control and smart sensor-based information acquisition. Full article

This paper investigates bioethanol production from switchgrass, focusing on enhancement of efficiency through various pretreatment methods and comparing two bioethanol production processes: simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF). Physical, chemical, and biological pretreatment processes are applied to enhance the breakdown of switchgrass’s lignocellulosic structure. Effects of pretreatments, enzymatic hydrolysis, and fermentation on ethanol yield are discussed in detail. The comparative analysis reveals that SSF yields higher ethanol outputs within shorter times by integrating hydrolysis and fermentation into a single process. In contrast, SHF offers more control by separating these stages. The comparative analysis highlights that SSF achieves higher ethanol yields more efficiently, although it might restrict SHF’s operational flexibility. This study aims to provide a comprehensive overview of the current pretreatments, hydrolysis methods, and fermentation processes in bioethanol production from switchgrass, offering insights into their scalability, economic viability, and potential environmental benefits. The findings are expected to contribute to the ongoing discussions and developments in renewable bioenergy solutions, supporting advancing more sustainable and efficient bioethanol production techniques. Full article

The cultivation of perennial flowering wild plant species like common tansy (Tanacetum vulgare L.) seems promising for increasing biodiversity friendliness in rather monotonous bioenergy cropping systems in Central Europe, particularly on marginal sites. However, it is still unclear for which types of marginal agricultural land common tansy would be suitable and where; as a result, low-risk indirect land-use change biomass production through common tansy could be considered. Therefore, the aim of this study was to gather initial insights into the suitability of common tansy for sandy sites by means of a 6 L-pot experiment. For this purpose, five replicates of three substrates were prepared: Luvisol topsoil (control) from a field site near the University of Hohenheim, Germany; and admixtures of 50 and 83.4weight(wt)% of sand to the control (M1, and M2), respectively. This resulted in varying sand contents of the substrates of 4.7 (control), 53.3 (M1), and 83.0wt% (M2). In autumn 2021, common tansy seeds were collected from mother plants bearing the breeder’s indentifier ‘Z.8TAV 85/78’. These plants were part of a long-term field trial initiated at Hohenheim in 2014, where common tansy was grown as part of a wild plant mixture. In June 2022, 0.5 g of the seeds were sown in each pot. The pots were placed in outdoor conditions, arranged in a randomized complete block design and watered evenly as required. At harvest in July 2023, significant differences between the substrates in terms of the above- (shoots) and belowground (roots) development of the common tansy seedlings were observed. In M1, common tansy provided notable biomass growth of 56.6% of the control, proving to be potentially suitable for low-input cultivation under sandy soil conditions. However, an even higher share of sand and low nutrient contents in M2 resulted in minor plant development (14.4% of the control). Hence, field trials on sandy soils of about 50wt% of sand in the texture under tailored fertilization and various climatic conditions are recommended. Full article

This review highlights recent innovations in food packaging, emphasizing the shift from conventional petroleum-based materials to bio-based alternatives and smart packaging systems. Bio-based materials, such as starch, cellulose, and polyhydroxyalkanoates (PHA), offer sustainable solutions due to their biodegradability and reduced environmental impact. These materials are positioned as eco-friendly alternatives to traditional plastics but face challenges related to production costs and scalability. Additionally, advancements in smart packaging technologies, including sensor and indicator systems, provide real-time food quality monitoring, enhancing food safety and reducing waste. Active packaging technologies, incorporating natural antioxidants and moisture control, extend product shelf life and improve food preservation. Furthermore, these biopolymers typically present a lower CO₂ footprint, energy costs, and water consumption during production, compared to traditionally used synthetic plastics. The review identifies challenges, such as regulatory barriers and technological limitations, but also outlines significant opportunities for future research and innovation in the food packaging sector, aiming for more efficient, safer, and environmentally sustainable packaging solutions. Full article

According to most energy demand forecasts, woody biomass has the potential to become an important source of renewable energy, especially during the transitional period of energy transition. The aim of this article was to estimate the energy potential of the biomass from the forest and the biomass generated by the mechanical processing of wood raw material and also to show the spectrum of possibilities for the potential use of the biomass for energy production in Poland. This research used available statistical and literature data on the species structure of harvested wood and the qualitative and assortment structures of woody biomass. The basic parameters of the raw material were evaluated in accordance with the EU classification of energy wood. This study confirmed the relationship between the energy potential of woody biomass and energy demand in Poland. The correlation coefficient for these variables was r = 0.984. This correlation was reflected in the significant shares of biomass in the production of electricity (more than 9%) or heat (almost 14%). Energy wood resources in Poland are smaller than in other European Union countries, which affects the scale of the potential use of woody biomass for energy purposes. Nevertheless, the use of such a biomass is fully justified from the point of view of possible development. Full article

The equilibrium swelling test was employed to determine the swelling response of Nitrile Butadiene Rubber (NBR) with various acrylonitrile (ACN) contents, and the three-dimensional solubility parameter (HSP) and modified Flory–Huggins interaction parameter (χ_HSP) were used to establish the prediction model of the oil-resistant property. The results indicate that the energy difference (Ra) between NBR and solvents calculated by HSP values can be correlated with the swelling response qualitatively with an inversed “S-shape”, and high swelling response occurs at Ra < 8 MPa^1/2 for NBR. For the purpose of establishing the prediction model, the new modified χ_HSP value has been calculated and fitted with the swelling response using exponential and logarithmic fittings, respectively. Two prediction models considering all the possible influencing factors have been obtained to determine the swelling response and oil resistance of NBR-based rubber products in bio-fuels, represented by the bio-diesel and IRM 903 test oil in this work. The swelling response of NBR can be evaluated precisely, and high swelling regions can be predicted and avoided in the new emerging fuels through the prediction models. Thus, the oil resistance of NBR-based rubber products, such as seals, holes and gaskets can be well predicted now. Full article

In this research, the effect of change in stacking sequences on the impact performance of bio-hybrid fiber-reinforced polymer (bio-HFRP) composite materials was analyzed and evaluated. The methodology was developed, based on the mechanical testing and utilization of tree-based machine learning regression models. Low-velocity impact (LVI) testing was performed on five distinct stacking sequences of carbon/flax bio-HFRP at energies ranging from 15 J to 90 J. For all tests, peak impact force was recorded and compared. Symmetric configurations with a uniform distribution of flax layers across the composite laminate exhibited better impact performance. Additionally, two tree-based machine learning (ML) algorithms were used: random forest (RF) and decision tree (DT). The performance metrics used to assess and compare the efficiency were the coefficient of determination (R²), mean square error (MSE), and mean absolute error (MAE). The most accurate model for the prediction of peak impact force was DT with the R² training and test dataset values of 0.9920 and 0.9045, respectively. Furthermore, lower MSE and MAE values were attained using the DT model as compared to the RF model. The developed methodology and the model serve as powerful tools to predict the damage-induced properties of bio-HFRP composite laminates utilizing minimal resources and saving time as well. Full article