Search Results (38)

The surge in photovoltaic (PV) power generation has made it increasingly difficult to integrate the intermittent PV industry into the power grid while maintaining grid stability. The solution is to use the seasonal surplus of PV electricity to produce “green” hydrogen through water electrolysis and then use the hydrogen as an energy source or as a reactant in chemical processes in the chemical industry to produce value-added products. However, the development of advanced hydrogen storage technologies to ensure the safe handling, transportation, and distribution of H₂ is a major issue. The use of stable liquid organic hydrogen carriers (LOHCs) has emerged as a suitable technology for hydrogen storage. This review highlights prospective LOHC technologies based on reversible catalytic hydrogenation–dehydrogenation cycles of liquid organic molecules for hydrogen storage and release under mild temperature and pressure conditions. The state-of-the-art LOHC systems are critically reviewed, highlighting the most effective heterogeneous catalytic systems. Full article

This study assesses Queensland’s sugar industry potential for sustainable aviation fuel (SAF) production via biomass-to-liquids (BtL) processes. Using surplus sugarcane bagasse, preliminary estimates suggest that individual mills could support 60–130 MW_th gasifiers, while clustered approaches enable larger capacities. Annual BtL syncrude production could reach 440 mL, increasing to ~1000 mL with additional feedstocks. These findings highlight both the industrial-scale viability of SAF production and the logistical and engineering challenges that must be addressed to align with Australia’s renewable energy and fuel security goals. Full article

The HERMES project investigates the utilization of surplus wind and solar energy to produce renewable fuels such as hydrogen, methane, and methanol for seasonal storage, thereby supporting carbon neutrality and the energy transition. This initiative aims to create a closed-loop, zero-emission energy system with efficiencies of up to 65%, employing a low-pressure (≤30 bar) synthesis process—specifically, sorption-enhanced methanol synthesis—integrated into the power system. Excess renewable electricity is harnessed for chemical synthesis, beginning with electrolysis to generate hydrogen, which is then converted into methanol using CO₂ sourced from a biogas plant. This methanol, biomethane, or a hybrid fuel blend powers a supercritical gas turbine, providing a flexible and reliable energy supply. Optimization analysis indicates that a combined wind and photovoltaic system can meet 62% of electricity demand, while the proposed storage system can handle over 90%. Remarkably, liquid methanol storage requires a compact 313 m³ tank, significantly smaller than storage requirements for hydrogen or methane in gas form. The project entails a total investment of 105 M EUR and annual operation and maintenance costs of 3.1 M EUR, with the levelized cost of electricity expected to decrease by 43% in the short term and 69% in the long term as future investment costs decline. Full article

In Italy, watermelon cultivation spans 9510 hectares, with production levels largely influenced by seasonal market demand. As a result, surplus watermelon left unsold by September often remain in the fields, where they decompose naturally and go to waste. A chemical analysis of the watermelon liquid fraction waste (WW) indicates a high carbohydrate concentration, highlighting the potential for biotechnological valorization of this waste stream, converting it into lipids or exopolysaccharides (EPSs). This study investigates the feasibility of utilizing WW as an alternative growth substrate for microalgae, aligning with circular economy principles and advancing sustainable agricultural practices. By repurposing agricultural byproducts, this research supports biorefinery objectives, aiming to convert biomass into high-value secondary products, including biofuels, pigments, and nutraceuticals. Scenedesmus and Chlorella strains demonstrated promising growth and adaptability in WW, achieving biomass yields of 0.95 ± 0.07 g L⁻¹ and 0.37 ± 0.02 g L⁻¹, respectively, with a significant EPS production observed as medium gelation. Although lipid accumulation was limited in this case by the WW substrate, the lipid profiles of both strains were distinctively altered, notably lacking linolenic acid. Full article

Anaerobic digestion (AD), or biogas technology, is an optimal method for municipal organic waste (MOW) treatment, recovering both material and energy. This study takes a life cycle assessment perspective and examines the economic and environmental impacts of a BIO facility in Minamisanriku Town, Japan, which has utilized MOW (kitchen/food waste and surplus sludge from sewage) as local biomass resources since 2012. Stakeholder interviews were conducted to gather data on material flows and impacts. Scenario analysis considered various conditions, such as pre- and post-operation of the BIO facility, the use and non-use of digestate as liquid fertilizer, and the facility’s 100% operational efficiency. The results indicate that full operation of the BIO facility and marketing of value-added products, such as branded rice grown using liquid fertilizer, could significantly reduce greenhouse gas (GHG) emissions, lower integrated environmental costs, improve the regional economy, and increase net income. In the business as usual (BAU) scenario with a 56% operation rate of the BIO facility, there is an over 10% improvement in economic and environmental impacts compared to the pre-operation baseline. This study underscores the importance of maximizing biomass utilization to develop value-added uses by enhancing, extending, and expending stakeholder collaboration. Full article

In view of rising global demand, energy is becoming a significant cost factor in industry and society. In addition to the global players China, India, and the USA, Africa will also become a driver of the world’s primary energy demand in the future due to the rapidly growing developing countries. In addition to the armed conflicts in Ukraine and the Middle East, global energy markets are tense and volatile due to inflation and higher borrowing costs. Because of society’s desire to phase out the use of fossil fuels, the use of renewable energies is increasingly taking center stage worldwide and especially in Germany. Rural areas and agriculture, especially energy-intensive livestock farms, are particularly affected by this development and are therefore faced with additional economic challenges. Additional energy can be generated by using photovoltaic systems on the roofs of farm buildings or by utilizing the liquid manure from livestock farming in biogas plants. For these farms, such alternative sources of energy could open previously untapped potential and additional synergies for using their own inexpensive energy on the farm or supplying surplus electricity directly to the public grid as a market participant. Agriculture could thus serve as an actor in a decentralized energy supply and thus build up regional energy networks. However, intelligent electricity storage concepts and a corresponding energy management system (EMS) are essential to be able to utilize the potential for renewable energy generation at all, to coordinate both internal production processes and the varying energy demand and supply on the electricity grid. As agricultural production processes differ greatly from farm to farm and region to region, the introduction of an energy management system is strongly dependent on user acceptance. The purpose of this study is to use the web-based software tool ADOPT (CSIRO 2018) to predict the level of acceptance and the duration of the market launch of an EMS based on the region of Bavaria. Individual important influencing factors for the subsequent regional marketing concept are also identified. Full article

The applications of liquid crystals in the field of renewable, clean and sustainable technologies of energy storage are of utmost importance at present. This paper delves into dielectric spectroscopic studies of a weakly polar nematic liquid crystal (NLC) enriched with an anthraquinone dye. The primary objective is to assess the impact of increasing dye concentrations on various properties. Anthraquinone dye has been found to increase the dielectric permittivity of weakly polar NLC, leading to a 4.7-fold increase in dielectric anisotropy. Simultaneously, a reduction of around 11% in threshold and operating voltages of the NLC has also been recorded after using dye as the guest material. The added dipolar contributions provided by dye molecules have been attributed to this surplus permittivity. The NLC has been found to have an approximately 54% faster response to the applied field. The intrinsic polarization field of dye molecules accelerates nearby LC molecule reorientation, leading to a 56.5% faster fall time and a 29.8% faster rise time in a 3.0 wt% dye-doped LC cell. These experimental results have been validated via computational studies as well. The simulation results about dipole moment and polarizability provide robust support for our experimental results. Such composites evince their potential for energy storage and 5G communication technologies with adjustable impedance and permittivity. Full article

Livestock digestate provides nutrients and organic matter to the soil while increasing agricultural sustainability. Nevertheless, nitrogen (N) losses due to the nutrient surplus in regions characterized by intensive animal farming activities still represent an unsolved issue. For this purpose, digestate needs proper treatment and management to avoid N losses in the environment. In the livestock farming context, anaerobic digestion (AD) can be accompanied by an ammonia stripping (AS) process for N recovery. This paper aims to investigate the feasibility AS prior to and after AD of the manure, focusing on two different livestock farms, representative of dairy cattle and pig breeding in southern Italy. AS was performed at a lab scale by injecting microbubbles of air, which allowed the pH to increase, and thus the removal of ammonia. The results show that treating a dairy raw slurry with high intermediate alkalinity (IA) (6707 mg CaCO₃ L⁻¹) with AS may not be convenient in terms of total ammonia nitrogen (TAN) reduction. As a matter of fact, the loss of buffering capacity during the stripping process resulted in a pH never exceeding the value of 9, which could not promote free ammonia volatilization, whereas integrating AD with AS allowed us to obtain a 34% higher TAN reduction under the same stripping conditions at a temperature (T) of 38 °C and a gas-to-liquid ratio (G/L) of 1:1. Therefore, the AS removal efficiency strongly depends on the characteristics (mainly IA) of the treated matrix. High IA values suggest a possible high concentration of volatile fatty acids, which hinders pH increases and, thus, enables ammonia stripping. Despite the initial matrix origin, a low IA compared to the total alkalinity (TA) (<20% of TA) ensures a greater ammonia removal efficiency, which could be similar between digestate and raw manure in the same operative process conditions. Nonetheless, the amount of ammonia stripped is related to the initial TAN concentration of the specific matrix. Full article

In this study, we investigated the changing characteristics of climatic scale (monthly) tropical extreme precipitation in warming climates using the Energy Exascale Earth System Model (E3SM). The results are from Atmospheric Model Intercomparison Project (AMIP)-type simulations driven by (a) a control experiment with the present-day sea surface temperature (SST) and CO₂ concentration, (b) P4K, the same as in (a) but with a uniform increase of 4K in the SST globally, and (c) the same as in (a), but with an imposed SST and CO₂ concentration from the outputs of the coupled E3SM forced by a 4xCO₂ concentration. We found that as the surface warmed under P4K and 4xCO₂, both convective and stratiform rain increased. Importantly, there was an increasing fractional contribution of stratiform rain as a function of the precipitation intensity, with the most extreme but rare events occurring preferentially over land more than the ocean, and more so under 4xCO₂ than P4K. Extreme precipitation was facilitated by increased precipitation efficiency, reflecting accelerated rates of recycling of precipitation cloud water (both liquid and ice phases) in regions with colder anvil cloud tops. Changes in the vertical profiles of clouds, condensation heating, and vertical motions indicate increasing precipitation–cloud–circulation organization from the control and P4K to 4xCO₂. The results suggest that large-scale ocean warming, that is, P4K, was the primary cause contributing to an organization structure resembling the well-known mesoscale convective system (MCS), with increased extreme precipitation on shorter (hourly to daily) time scales. Additional 4xCO₂ atmospheric radiative heating and dynamically consistent anomalous SST further amplified the MCS organization under P4K. Analyses of the surface moist static energy distribution show that increases in the surface moisture (temperature) under P4K and 4xCO₂ was the key driver leading to enhanced convective instability over tropical ocean (land). However, a fast and large increase in the land surface temperature and lack of available local moisture resulted in a strong reduction in the land surface relative humidity, reflecting severe drying and enhanced convective inhibition (CIN). It is argued that very extreme and rare “record-breaking” precipitation events found over land under P4K, and more so under 4xCO₂, are likely due to the delayed onset of deep convection, that is, the longer the suppression of deep convection by CIN, the more severe the extreme precipitation when it eventually occurs, due to the release of a large amount of stored surplus convective available potential energy in the lower troposphere during prolonged CIN. Full article

The literature suggests two forms of flow slides: breaching and liquefaction. Both forms of failure have comparable ultimate circumstances, but the progression and sand movement mechanisms of breaching failure diverge from those of liquefaction. The first type, breaching, occurs in densely packed sand and is characterized by slow sand grain discharge throughout the dilation of the failing soil particles and negative excess pore pressures. The latter form, known as liquefaction, is the process by which a mass of soil abruptly begins to behave like a flowing liquid, and as a result, it can flow out across overly mild slopes. The process begins in compacted sand and is linked to positive surplus pore water pressures that are caused by the compaction of the sand. Despite the available literature on flow slide failures, our understanding of the mechanisms involved remains limited. Since flow slides often begin below the water surface, they can go undetected until the collapse reaches the bank above ground. The complexity of flow slides requires the use of cutting-edge technological instruments, diving equipment, advanced risk assessment, and a variety of noteworthy probabilistic and sensitivity analyses. Hence, we developed a new sensitivity index to identify the risk of breach failure and vulnerable coastal areas to this risk. In addition, we developed a sophisticated hybrid model that allows for all possibilities of flow slides in sync with random variables used in this new sensitivity index. In this new hybrid model, three distinctive models exist. The 3D Hydrodynamic Model addresses waves, wind, current, climate change, and sediment transport. The Monte Carlo Simulation is responsible for sensitivity analysis, and the Bayesian Network focuses on joint probabilities of coastal flow slide parameters of this new index that incorporates all environmental parameters, including climate change. With the assistance of these three models, researchers aim to: (a) expand the application scope by presenting a method on coastal flow slides; (b) consider different particle diameters corresponding to critical angle slope failure; (c) analyze variables that can play a pivotal role in the flow slides; and (d) present a methodology for coupling coastal flow slide projections with reliable outcomes. The hybrid model incorporates random variables of retrogressive breach failures, and the new risk index considers their ranges to control the simulation. The use of such a hybrid model and risk index offers a robust and computationally efficient approach to evaluating coastal flow slides. Full article

Polymer flocculants are used to promote solid–liquid separation processes in wastewater treatment technologies, and bio-based flocculants possess many advantages over conventional synthetic polymers. Potato starch microgranules were chemically modified and mechanically sheared to produce modified starch flocculants. The effectiveness of produced cationic starch (CS) and cross-linked cationic starch (CCS) flocculants in the thickening and dewatering of surplus activated sewage sludge was evaluated and compared with that of synthetic cationic flocculants (SCFs) The flocculation efficiency of SCF, CS, and CCS in sludge thickening was determined by measuring the filtration rate of treated surplus activated sludge. Comparing the optimal dose of SCFs and CCS flocculants needed for thickening, the CCS dose was more than 10 times higher, but a wide flocculation window was determined. The impact of used flocculants on the dewatering performance of surplus activated sludge at optimal dose conditions was investigated by measuring capillary suction time. The filtration efficiencies (dewaterability) of surplus activated sludge using SCF, CS, and CCS were 69, 67, and 72%, respectively. The study results imply that mechanically processed cross-linked cationic starch has a great potential to be used as an alternative green flocculant in surplus activated sludge thickening and dewatering operations in municipal sewage sludge treatment processes. Full article

The “Green Revolution” (GR) technology-induced agricultural intensification has transformed India from food scarcity to a food surplus country. However, this has also resulted into several adverse repercussions. Increased application of chemical fertilizers and pesticides with stagnating/declining crop productivity has dovetailed with uncertain market conditions and climate change effects which has resulted in un-remunerative agriculture. Consequently, farmers have fallen into the debt trap due to the rising cost of crop production apart from health hazards due to serious exposure to harmful chemical pesticides. Natural Farming (NF), an agro-ecological approach to farming is believed to be an effective way to counter some of these challenges. The present paper presents field-level farmers’ experiences of NF adoption in three states of India—Andhra Pradesh, Karnataka, and Maharashtra. The study was conducted during February–March 2019 by surveying 295 NF adopted and 170 non-NF adopted farmers. It was found that NF practice has been followed by some farmers for more than 10 years but others have adopted during the recent past. There is variation in the practice followed by the NF farmers. There are farmers who are using Farm Yard Manure (FYM). A solid form of jeevamritha (liquid concoction of microbial inoculants) called as ghanajeevamritha was also found to be used by farmers in Andhra Pradesh. It was observed that non-NF yields are superior to NF yield without FYM. In most crops, however, NF with FYM had a greater yield than NF without FYM and non-NF farms. There has been a decrease in the variable cost and a marginal increase in the market price of NF produce. The study suggests that natural farming may be seen as one of the alternative practices which has potential to rejuvenate the agro-ecosystem, besides cost saving for the individual farmers. Full article

Precision fertilization is a promising mitigation strategy to reduce environmental impacts of N-fertilization, but the effective benefits of variable-rate fertilization have not yet been fully demonstrated. We evaluated the short-term response (23 days) of GHGs emissions following variable-rate fertilization on barley. Yields, biomass (grains + straw) and different N-use indicators (N uptake, grain protein concentration, recovery efficiency, physiological efficiency, partial factor productivity of applied nutrient, agronomic efficiency and N surplus) were compared. Four N fertilization treatments were performed: (i) conventional– 150 kg ha⁻¹; (ii) variable with granular fertilizer; (iii) variable with foliar liquid supplement; (iv) no fertilization. According to proximal sensing analysis (Greenseeker Handheld) and crop needs, both variable-rate treatments accounted for 35 kg N ha⁻¹. Cumulative GHGs emissions were not significantly different, leading to the conclusion that the sensor-based N application might not be a GHGs mitigation strategy in current experimental conditions. Results showed that both site-specific fertilizations ensured the maintenance of high yields with a significant N rate reduction (approximately by 75%) and a N use improvement. Variable-rate N fertilization, due to similar yields (~6 tons ha⁻¹) than conventional fertilization and higher protein content in foliar treatment (14%), confirms its effectiveness to manage N during the later phases of growing season. Full article

In an attempt to effectively utilize a multitude of surplus sludge from sewage treatment plants, ordinary Portland cement was used to solidify the dry surplus sludge as a building material. The dry surplus sludge and cement were mixed at different proportions with a certain dosage of water and then cured for 3–60 days at room temperature. The unconfined compression strength (R_C) of solidified blocks was investigated with respect to the effects of the ratio of liquid to solid (R_l/S), surplus sludge dosage (D_S), the dosage of sodium silicate (D_Na2SiO3), and the proportion of fly ash (W_F). The fabricated solidified blocks were characterized by scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray Diffraction Analysis (XRD). The results demonstrated that R_C at 60 days reduced obviously with the increase in R_l/s when Ds was given, whereas R_C reduced with D_S increased to 15.0 wt% from 5.0 wt% for solidified blocks. When D_S was 5.0 wt%, R_C of 28 days was reduced from 20.87 MPa to 14.50 MPa, with an increase in R_l/s from 0.35 to 0.55. For the given R_l/s, such as R_l/s = 0.35, R_C at 60 days was 23.75 MPa, 2.80 MPa, and 2.50 MPa when D_S were 5.0 wt%, 10.0 wt%, and 15.0 wt%, respectively, which were relatively lower in comparison to that of Portland cement solidified blocks without surplus sludge (51.40 MPa). In addition, the addition of Na₂SiO₃ and fly ash was favorable in terms of improving the R_C for solidified blocks. R_C of 60 days increased initially and then reduced with the increase in D_Na2SiO3 from 0.0 wt% to 9.0 wt% at R_l/s = 0.45 and D_S = 5.0 wt%. At D_Na2SiO3 = 7.5 wt%, R_l/s = 0.45, and D_S = 5.0 wt%, the highest R_C value of 34.70 MPa was achieved after being cured for 60 days. Furthermore, R_C of 60 days increased initially and then reduced with W_F increasing from 0.0 wt% to 25.0 wt%, and the highest R_C value of 34.35 MPa was achieved at W_F = 10.0 wt%, R_l/s = 0.45, and D_S = 5.0 wt%. At the ratio of D_Na2SiO3 = 7.50 wt%, R_l/S = 0.35, W_F = 20 wt%, D_S = 15.0 wt% and M = 1.00, R_C of 28 days reached 26.70 MPa. With these values, the utilization of sludge utilized (D_S = 15.0 wt%) was increased by double compared with D_S = 5.0 wt% (20.87 MPa). To investigate the effect of environmental temperature on the mechanical properties and mass of solidified blocks, the freeze-thaw cycling experiment was carried out. The R_C of 28 days and the mass of the solidified block reduced with the number of freeze-thaw cycles, increasing for solidified blocks with D_S of 5.0 wt%, 10.0 wt%, and 15.0 wt%, manifesting a decrease of 25.60%, 32.30%, and 40.60% for R_C and 3.40%, 4.10%, and 4.90% for mass, respectively. This work provides sufficient evidence that surplus sludge has a huge potential application for building materials from the perspective of improving their mechanical properties. It provides an important theoretical basis for the disposal as well as efficient utilization of sludge. Full article

There are increasing international efforts to tackle climate change by reducing the emission of greenhouse gases. As such, the use of electrolytic hydrogen as an energy carrier in decentralised and centralised energy systems, and as a secondary energy carrier for a variety of applications, is projected to grow. Required green hydrogen can be obtained via water electrolysis using the surplus of renewable energy during low electricity demand periods. Electrolysis systems with alkaline and polymer electrolyte membrane (PEM) technology are commercially available in different performance classes. The less mature solid oxide electrolysis cell (SOEC) promises higher efficiencies, as well as co-electrolysis and reversibility functions. This work uses a bottom-up approach to develop a viable business model for a SOEC-based venture. The broader electrolysis market is analysed first, including conventional and emerging market segments. A further opportunity analysis ranks these segments in terms of business attractiveness. Subsequently, the current state and structure of the global electrolyser industry are reviewed, and a ten-year outlook is provided. Key industry players are identified and profiled, after which the major industry and competitor trends are summarised. Based on the outcomes of the previous assessments, a favourable business case is generated and used to develop the business model proposal. The main findings suggest that grid services are the most attractive business sector, followed by refineries and power-to-liquid processes. SOEC technology is particularly promising due to its co-electrolysis capabilities within the methanol production process. Consequently, an “engineering firm and operator” business model for a power-to-methanol plant is considered the most viable option. Full article