Search Results (1,234)

Using waste biomass as a raw material for the combined production of electricity and heat offers corresponding energy, economic, environmental and resource efficiency benefits. The study examines both the performance of a system for combined energy production based on the Organic Rankine Cycle (ORC) utilizing wood biomass and the market interest in its deployment within Bulgaria. Its objective is to propose a technically and economically viable solution for the recovery of waste biomass through the combined production of electricity and heat while simultaneously assessing the readiness of industrial and municipal sectors to adopt such systems. The cogeneration plant incorporates an ORC module enhanced with three additional economizers that capture residual heat from flue gases. Operating on 2 t/h of biomass, the system delivers 1156 kW of electric power and 3660 kW of thermal energy, recovering an additional 2664 kW of heat. The overall energy efficiency reaches 85%, with projected annual revenues exceeding EUR 600,000 and a reduction in carbon dioxide emissions of over 5800 t/yr. These indicators can be achieved through optimal installation and operation. When operating at a reduced load, however, the specific fuel consumption increases and the overall efficiency of the installation decreases. The marketing survey results indicate that 75% of respondents express interest in adopting such technologies, contingent upon the availability of financial incentives. The strongest demand is observed for systems with capacities up to 1000 kW. However, significant barriers remain, including high initial investment costs and uneven access to raw materials. The findings confirm that the developed system offers a technologically robust, environmentally efficient and market-relevant solution, aligned with the goals of energy independence, sustainability and the transition to a low-carbon economy. Full article

Industrial catalysts are accelerating the global transition toward renewable energy, serving as enablers for innovative technologies that enhance efficiency, lower costs, and improve environmental sustainability. This review explores the pivotal roles of industrial catalysts in hydrogen production, biofuel generation, and biomass conversion, highlighting their transformative impact on renewable energy systems. Precious-metal-based electrocatalysts such as ruthenium (Ru), iridium (Ir), and platinum (Pt) demonstrate high efficiency but face challenges due to their cost and stability. Alternatives like nickel-cobalt oxide (NiCo₂O₄) and Ti₃C₂ MXene materials show promise in addressing these limitations, enabling cost-effective and scalable hydrogen production. Additionally, nickel-based catalysts supported on alumina optimize SMR, reducing coke formation and improving efficiency. In biofuel production, heterogeneous catalysts play a crucial role in converting biomass into valuable fuels. Co-based bimetallic catalysts enhance hydrodeoxygenation (HDO) processes, improving the yield of biofuels like dimethylfuran (DMF) and γ-valerolactone (GVL). Innovative materials such as biochar, red mud, and metal–organic frameworks (MOFs) facilitate sustainable waste-to-fuel conversion and biodiesel production, offering environmental and economic benefits. Power-to-X technologies, which convert renewable electricity into chemical energy carriers like hydrogen and synthetic fuels, rely on advanced catalysts to improve reaction rates, selectivity, and energy efficiency. Innovations in non-precious metal catalysts, nanostructured materials, and defect-engineered catalysts provide solutions for sustainable energy systems. These advancements promise to enhance efficiency, reduce environmental footprints, and ensure the viability of renewable energy technologies. Full article

In the present work, six biochars were produced from the pyrolysis of poultry manure at 400 °C and 600 °C (PM-B-400 and PM-B-600), and their post-modification with, respectively, iron chloride (PM-B-400-Fe and PM-B-600-Fe) and potassium permanganate (PM-B-400-Mn and PM-B-600-Mn). First, these biochars were deeply characterized through the assessment of their particle size distribution, pH, electrical conductivity, pH at point-zero charge, mineral composition, morphological structure, and surface functionality and crystallinity, and then valorized as biofertilizer to grow spring barley at pot-scale for 40 days. Characterization results showed that Fe- and Mn-based nanoparticles were successfully loaded onto the surface of the post-modified biochars, which significantly enhanced their structural and surface chemical properties. Moreover, compared to the control treatment, both raw and post-modified biochars significantly improved the growth parameters of spring barley plants (shoot and root length, biomass weight, and nutrient content). The highest biomass production was obtained for the treatment with PM-B-400-Fe, owing to its enhanced physico-chemical properties and its higher ability in releasing nutrients and immobilizing heavy metals. These results highlight the potential use of Fe-modified poultry manure-derived biochar produced at low temperatures as a sustainable biofertilizer for soil enhancement and crop yield improvement, while addressing manure management issues. Full article

The aim of this study is to provide a comprehensive analysis of the outcome of two separate techno-economic studies that were conducted for the scaled-up and industrially relevant processes of a) synthetic natural gas (SNG) production from captured (cement-based) CO₂ and green-H₂ (via renewable-assisted electrolysis) and b) combined electricity and crude biofuel production through the integration of biomass pyrolysis, gasification, and solid oxide fuel cells. As was found, the SNG production process seems more feasible from an economic perspective as it can be comparable to current market values. Full article

This study presents a novel approach to address these challenges by introducing automobile platinum honeycomb catalysts into biomass combustion systems. The study employed a dual methodology, combining experimental investigations and a Life Cycle Assessment (LCA) case study, to comprehensively evaluate the catalyst’s performance and environmental impacts. The catalyst’s ability to facilitate combustion without open flame formation and its operational efficiency throughout combustion phases position it as a promising avenue for reducing gaseous and particulate matter emissions. The LCA considers multiple impact categories, employing the ReCiPe 2008 Hierarchist midpoint and endpoint perspective to assess environmental effects. The experimental results show that the catalyst effectively reduced CO, SO₂, and particulate emissions. Temperatures below 400 °C diminished the catalyst’s performance. The catalyst achieved a 100% CO conversion rate at specific temperatures of 427.4–490.3 °C. The findings highlight the potential for a 34% reduction in environmental impacts when replacing conventional rice husk combustion with the catalyst-integrated system. Notably, the study emphasizes the significance of sustainable catalyst manufacturing processes and cleaner electricity sources in maximizing environmental benefits. In conclusion, the integration of platinum honeycomb catalysts into biomass combustion systems, exemplified by rice husk combustion, emerges as a promising strategy for achieving more sustainable and environmentally friendly bioenergy production. Full article

Small reservoirs have important functions, such as water resource guarantee, flood control and drought resistance, biological habitat and maintaining regional economic development. In order to better clarify the impact of agricultural activities on the nutritional status of water bodies in small reservoirs, zooplankton were quantitatively collected from four small reservoirs in the Jiuxianshan agricultural area of Qufu, Shandong Province, in March and October 2023, respectively. The physical and chemical parameters in sampling points were determined simultaneously. Meanwhile, water samples were collected for nutrient salt analysis, and the eutrophication of water bodies in four reservoirs was evaluated using the comprehensive nutrient status index method. The research found that the species richness of zooplankton after farming (100 species) was significantly higher than that before farming (81 species) (p < 0.05). On the contrary, the dominant species of zooplankton after farming (7 species) were significantly fewer than those before farming (11 species). The estimation results of the standing stock of zooplankton indicated that the abundance and biomass of zooplankton after farming (92.72 ind./L, 0.13 mg/L) were significantly higher than those before farming (32.51 ind./L, 0.40 mg/L) (p < 0.05). Community similarity analysis based on zooplankton abundance (ANOSIM) indicated that there were significant differences in zooplankton communities before and after farming (R = 0.329, p = 0.001). The results of multi-dimensional non-metric sorting (NMDS) showed that the communities of zooplankton could be clearly divided into two: pre-farming communities and after farming communities. The Monte Carlo test results are as follows (p < 0.05). Transparency (Trans), pH, permanganate index (COD_Mn), electrical conductivity (Cond) and chlorophyll a (Chl-a) had significant effects on the community structure of zooplankton before farming. Total nitrogen (TN), total phosphorus (TP) and electrical conductivity (Cond) had significant effects on the community structure of zooplankton after farming. The co-linearity network analysis based on zooplankton abundance showed that the zooplankton community before farming was more stable than that after farming. The water evaluation results based on the comprehensive nutritional status index method indicated that the water conditions of the reservoirs before farming were mostly in a mild eutrophic state, while the water conditions of the reservoirs after farming were all in a moderate eutrophic state. The results show that the nutritional status of small reservoirs in agricultural areas is significantly affected by agricultural activities. The zooplankton communities in small reservoirs underwent significant changes driven by alterations in the reservoir water environment and nutritional status. Based on the main results of this study, we suggested that the use of fertilizers and pesticides should be appropriately reduced in future agricultural activities. In order to better protect the water quality and aquatic ecology of the water reservoirs in the agricultural area. Full article

Gasification of municipal solid waste and other biogenic residues (e.g., biomass and biowaste) is increasingly recognized as a promising thermochemical pathway for converting non-recyclable fractions into valuable energy carriers, with applications in electricity generation, district heating, hydrogen production, and synthetic fuels. This paper provides a comprehensive analysis of major gasification technologies, including fixed bed, fluidized bed, entrained flow, plasma, supercritical water, microwave-assisted, high-temperature steam, and rotary kiln systems. Key aspects such as feedstock compatibility, operating parameters, technology readiness level, and integration within circular economy frameworks are critically evaluated. A comparative assessment of incineration and pyrolysis highlights the environmental and energetic advantages of gasification. The valorization pathways for main product (syngas) and by-products (syngas, ash, tar, and biochar) are also explored, emphasizing their reuse in environmental, agricultural, and industrial applications. Despite progress, large-scale adoption in Europe is constrained by economic, legislative, and technical barriers. Future research should prioritize scaling emerging systems, optimizing by-product recovery, and improving integration with carbon capture and circular energy infrastructures. Supported by recent European policy frameworks, gasification is positioned to play a key role in sustainable waste-to-energy strategies, biomass valorization, and the transition to a low-emission economy. Full article

The development of multifunctional conductive hydrogels with rapid self-healing capabilities and powerful sensing functions is crucial for advancing wearable electronics. This study designed and prepared a polyvinyl alcohol (PVA)–borax hydrogel incorporating carbon nanotubes (CNTs) and biomass carbon nanospheres (CNPs) as dual-carbon fillers. This hydrogel exhibits excellent conductivity, mechanical flexibility, and self-recovery properties. Serving as a highly sensitive piezoresistive sensor, it efficiently converts mechanical stimuli into reliable electrical signals. Sensing tests demonstrate that the CNT/CNP/PVA–borax hydrogel sensor possesses an extremely fast response time (88 ms) and rapid recovery time (88 ms), enabling the detection of subtle and rapid human motions. Furthermore, the hydrogel sensor also exhibits outstanding cyclic stability, maintaining stable signal output throughout continuous loading–unloading cycles exceeding 3200 repetitions. The hydrogel sensor’s characteristics, including rapid self-healing, fast-sensing response/recovery, and high fatigue resistance, make the CNT/CNP/PVA–borax conductive hydrogel an ideal choice for multifunctional wearable sensors. It successfully monitored various human motions. This study provides a promising strategy for high-performance self-healing sensing devices, suitable for next-generation wearable health monitoring and human–machine interaction systems. Full article

The amount of waste generated by society is constantly increasing. Consequently, there is a need to develop new and better methods of treating it. A significant part of municipal waste is biowaste, which can be treated as a source of valuable resources such as nutrients, organic matter, and energy. The present work aims to determine the properties of the tested household biowaste and the possibility of using it as feedstock in slow pyrolysis to obtain biochar. The slow pyrolysis process of the biowaste was carried out in an electrically heated Horizontal Tube Furnace (HTF) at temperatures of 400 °C, 500 °C, and 600 °C in a nitrogen atmosphere. The analysis showed that depending on the type and composition of the biowaste, its properties are different. All the biowaste tested has a high moisture content (between 63.51% and 81.53%), which means that the biowaste needs to be dried before the slow pyrolysis process. The characteristics of kitchen biowaste are similar to those of food waste studied by other researchers in different regions of the world. In addition, the properties of kitchen biowaste are similar to those of the typical biomasses used to produce biochar via slow pyrolysis, such as wood, almond shells, and rice husks. Both kinds of garden biowaste tested may have been contaminated (soil, rocks) during collection, which affected the high ash content of spring (17.75%) and autumn (43.83%) biowaste. This, in turn, affected all the properties of the garden biowaste, which differed significantly from both the literature data of other garden wastes and from the properties of typical biomass feedstocks used to produce biochar in slow pyrolysis. For all biowaste tested, it was shown that as the pyrolysis temperature increases, the yield of biochar decreases. The maximum mass yield of biochar for kitchen, spring garden, and autumn garden biowaste was 36.64%, 66.53%, and 66.99%, respectively. Comparing the characteristics of biowaste before slow pyrolysis, biochar obtained from kitchen biowaste had a high carbon content, fixed carbon, and a higher HHV. In contrast, biochar obtained from garden biowaste had a lower carbon content and a lower HHV. Full article

This study combines convolutional neural network (CNN) recognition technology, Greenwich engineering software, and statistical yearbook methods to evaluate rural solar, wind, and biomass energy resources in pilot cities in China, respectively. The CNN method enables the rapid identification of the available roof area, and Greenwich software provides wind resource simulation with local terrain adaptability. The results show that the capacity of photovoltaic power generation reaches approximately 15.63 GW, the potential of wind power is 458.3 MW, and the equivalent of agricultural waste is 433,900 tons of standard coal. The city is rich in wind, solar, and biomass resources. By optimizing the hybrid power generation system through genetic algorithms, wind energy, solar energy, biomass energy, and coal power are combined to balance the annual electricity demand in rural areas. The energy trends under different demand growth rates were predicted through the LEAP model, revealing that in the clean coal scenario of carbon capture (WSBC-CCS), clean coal power and renewable energy will dominate by 2030. Carbon dioxide emissions will peak in 2024 and return to the 2020 level between 2028 and 2029. Under the scenario of pure renewable energy (H_WSB), SO₂/NO_x will be reduced by 23–25%, and carbon dioxide emissions will approach zero. This study evaluates the renewable energy potential, power system capacity optimization, and carbon emission characteristics of pilot cities at a macro scale. Future work should further analyze the impact mechanisms of data sensitivity on these assessment results. Full article

An increasing number of soils, including those in EU countries, are affected by organic matter deficiency and the deterioration of nutrients, and using mineral fertilizers is often associated with negative environmental impacts. One of the basic recommendations for sustainable agriculture is to increase the proportion of organic fertilizers in crop production and preserve soil biodiversity. An increasingly common organic fertilizer is biogas plant digestate, the physical and chemical properties of which depend primarily on the waste material used in biogas production. However, the fertilizer value of this additive and its effects on the soil environment, including beneficial organisms, remain insufficiently studied. Soil macrofauna, particularly earthworms, play a crucial role in soil ecosystems, because they significantly impact the presence of plant nutrients, actively participate in forming soil structures, and strongly influence organic matter dynamics. The present study was undertaken to determine the effects of fertilizing a silt loam soil with the solid fraction of digestate in monoculture crop production on earthworm community characteristics and the resulting changes in selected soil physicochemical properties. The research was conducted at a single site, so the original soil characteristics across the experimental plots were identical. Plots were treated annually (for 3 years; 2021–2023) with different levels of digestate: DG100 (100% of the recommended rate; 30 t ha⁻¹), DG75 (75% of the recommended rate; 22.5 t ha⁻¹), DG50 (15 t ha⁻¹), DG25 (7.5 t ha⁻¹), and CL (a control plot without fertilizer). An electrical method was used to extract earthworms. Those found at the study site belonged to seven species representing three ecological groups: Dendrodrilus rubidus (Sav.), Lumbricus rubellus (Hoff.), and Dendrobaena octaedra (Sav.) (epigeics); Aporrectodea caliginosa (Sav.), Aporrectodea rosea (Sav.), and Octolasion lacteum (Örley) (endogeics); and Lumbricus terrestris (L.) (anecics). Significant differences in the abundance and biomass of earthworms were found between the higher level treatments (DG100, DG75, and DG50), and the lowest level of fertilization and the control plot (DG25 and CL). The DG25 and CL plots showed an average of 24.7% lower earthworm abundance and 22.8% lower biomass than the other plots. There were no significant differences in the earthworm metrics between the plots within each of the two groups (DG100, DG75, and DG50; and DG25 and CL). The most significant influence on the average abundance and average biomass of Lumbricidae was probably exerted by soil moisture and the annual dosage of digestate. A significant increase in the abundance and biomass of Lumbricidae was shown at plots DG100, DG75, and DG50 in the three successive years of the experiment. The different fertilizer treatments were found to have different effects on selected soil parameters. No significant differences were found among the values of the analyzed soil traits within each plot in the successive years of the study. Full article

This research paper provides new insights into the impact of accelerated mineralization of alkaline waste materials on the physical and mechanical behavior of low-carbon cement-based mortars. Standardized eco-cement mortars were prepared by replacing Portland cement with 7% and 20% proportions of three alkaline waste materials (white ladle furnace slag, biomass ash, and fine concrete waste fraction) that had been previously carbonated in a static reactor at predefined humidity and CO₂ concentration. The mortars’ physical (total/capillary water absorption, electrical resistivity) and mechanical properties (compressive strength up to 90 d of curing) were analyzed, and their microstructures were examined using mercury intrusion porosimetry and computed tomography. The results reveal that carbonated waste materials generate a greater heat of hydration and have a lower total and capillary water absorption capacity, while the electrical resistivity and compressive strength tests generally indicate that they behave similarly to mortars not containing carbonated minerals. Mercury intrusion porosimetry (microporosity) indicates an increase in total porosity, with no clear refinement versus non-carbonated materials, while computed tomography (macroporosity) reveals a refinement of the pore structure with a significant reduction in the number of larger pores (>0.09 mm³) and intermediate pores (0.001–0.09 mm³) when carbonated residues are incorporated that varies depending on waste material. The construction and demolition waste (CCDW-C) introduced the best physical and mechanical behavior. These studies confirm the possibility of recycling carbonated waste materials as low-carbon supplementary cementitious materials (SCMs). Full article

This study presents an integrated approach to sustainable soil and crop management by evaluating the individual and combined effects of cow manure (CM), rice husk biochar (RHB), and potassium humate (KH)—three underutilized, low-cost organic amendments derived from agricultural byproducts. Uniquely, it investigates how these amendments simultaneously affect soil physical and chemical properties, plant growth, and the accumulation of bioactive compounds in sunflower sprouts, thereby linking soil health to crop nutritional quality. The application of 2% w/w KH alone resulted in the greatest increases in macroaggregation (+0.51), soil pH (from 6.8 to 8.6), and electrical conductivity (+298%). The combination of 1% w/w CM and 2% KH led to the highest increases in soil organic carbon (OC, +62.9%) and soil respiration (+56.4%). Nitrate and available phosphorus (P) peaked with 3% w/w RHB + 2% KH (+120%) and 1% w/w CM + 0.5% KH (+35.5%), respectively. For plant traits, 0.5% w/w KH increased the total leaf area by 61.9%, while 1% w/w CM enhanced shoot and root biomass by 60.8% and 79.0%, respectively. In contrast, 2% w/w KH reduced chlorophyll content (−43.6%). Regarding bioactive compounds, the highest total phenolic content (TPC) was observed with 1% w/w KH (+21.9%), while the strongest DPPH antioxidant activity was found under 1% w/w CM + 1% w/w KH (+72.6%). A correlation analysis revealed that biomass production and secondary metabolite accumulation are shaped by trade-offs arising from resource allocation under stress or nutrient limitations. Potassium, P, soil microbial respiration, and OC emerged as key integrators connecting soil structure, fertility, and plant metabolic responses. Overall, the combination of 1% w/w CM with 0.5–1% w/w KH proved to be the most effective strategy under the tested conditions. Full article

Continuous growth in energy demand is observed throughout the world, with simultaneous rapid consumption of fossil fuels. New effective technologies and systems are needed that allow for a significant increase in the use of renewable energy sources, such as the sun, wind, biomass, and sea tides. Currently, one of the main research challenges refers to thermal energy management, taking into account the discontinuity and intermittency of both energy supply and demand. Phase change materials (PCMs) are a useful solution in the design and manufacturing of multifunctional materials for energy storage technologies such as solar cells and photovoltaic systems. In order to design efficient PCM-based systems for energy applications, ideas and behaviors from nature should be taken account as it has created over millions of years a plethora of unique structures and morphologies in complex hierarchical materials. Inspirations for nature have been applied to improve and adjust the properties of materials for energy conversion and storage as well as in the design of advanced energy systems. Therefore, this review presents recent developments in biomimetic and bio-inspired multifunctional phase change materials for the energy storage and conversion of different types of renewable energy to thermal or electrical energy. Future outlooks are also provided to initiate integrated interdisciplinary bio-inspired efforts in the field of modern sustainable PCM technologies. Full article

The imperative to decarbonize global energy systems and enhance energy security necessitates a transition towards ecofuels, broadly classified as biofuels, waste-derived fuels, and electrofuels (e-Fuels). The primary goal of this review is to provide a holistic and comparative evaluation of these three pivotal ecofuel pillars under a unified framework, identifying their strategic niches in the energy transition by critically assessing their interconnected technical, economic, and policy challenges. It offers a comparative dissection of inherent resource constraints, spanning biomass availability, the immense scale of renewable electricity required for e-Fuels, sustainable carbon dioxide (CO₂) sourcing, and the complexities of utilizing non-biodegradable wastes, identifying that true feedstock sustainability and holistic lifecycle management are paramount, cross-cutting limitations for all pathways. This review critically highlights how the current global reliance on fossil fuels for electricity production (approx. 60%) and the upstream emissions embodied in renewable energy infrastructure challenge the climate neutrality claims of ecofuels, particularly e-Fuels, underscoring the necessity for comprehensive well-to-wheels (WtW) lifecycle assessments (LCAs) over simpler tank-to-wheels (TtW) approaches. This perspective is crucial as emerging regulations demand significant greenhouse gas (GHG) emission reductions (70–100%) compared to fossil fuels. Ultimately, this synthesis argues for a nuanced, technologically neutral deployment strategy, prioritizing specific ecofuels for hard-to-abate sectors, and underscores the urgent need for stable, long-term policies coupled with robust and transparent LCA methodologies to guide a truly sustainable energy transition. Full article