|
|
- A Predictive Framework for Photovoltaic Waste Quantities and Recovery
Values: Insights and Application to the Italian Context
Abstract: The global surge in photovoltaic (PV) panel deployment since the 2000s has contributed to advancing the renewable energy sector. However, this proliferation raises concerns about the increasing number of PV modules that will end their operational life in the coming years, necessitating effective planning for their decommissioning and recovery. This paper addresses this imminent challenge by presenting a predictive model to estimate the volume of decommissioned PV modules from existing installations. To consider the variability associated with the operational life duration of PV panels, two different scenarios were considered: early loss and regular loss, both modelled through the Weibull function. Furthermore, the article proposes a methodology for the economic valorization of materials recovered from decommissioned PV modules, according to the different technologies employed. This approach encourages sustainable practices by assigning an economic value to recovered materials and promoting a circular economy in the renewable energy sector. The economic valuation methodology adds practicality to dismantling, emphasising responsible waste management’s potential economic benefits. To illustrate the applicability of the model, the study focuses on the Italian case, providing a detailed regional breakdown. The regional analysis not only improves the accuracy of the predictive model but also offers insights into localised PV module disposal patterns. By adapting the methodology to the individual Italian regions, the article serves as a concrete and valuable resource during the programming and planning phases, facilitating the implementation of a strategy to efficiently recover PV modules and minimising the environmental impact associated with decommissioning activities.
PubDate: Wed, 17 Jul 2024 00:00:00 GMT
- Modelling of Undular Jump Characteristics
Abstract: The article provides concise details about a hydraulic phenomenon known as the undular jump, that occurs under different conditions within different hydraulic constructions and can negatively influence on their operation and conditions. Therefore, the methods of modelling undular jump characteristics using physical and mathematical model are presented. Based on physical model of undular jump, the experimental data were obtained. Moreover, three mathematical models were considered and analyzed. The article gives the comparison of experimental data and data obtained by mathematical models. The advantages and disadvantages of considered mathematical models were specified. The novelty of work was in developing and improving mathematical model with taking into account the energy losses that are allowed to obtain the characteristics of undular jump with high accuracy.
PubDate: Sun, 30 Jun 2024 00:00:00 GMT
- Mapping of Energy Consumption for Cooling – Assessment of the Cooling
Demand Potential for the City of Riga
Abstract: Considering the global increase in mean air temperature and society’s demand for a comfortable indoor microclimate, cooling solutions in buildings will play an essential role in achieving global climate goals. Researchers estimate that global energy consumption will be significantly affected by the energy required for cooling. Assessment of cooling demand potential is an essential step to further analyse cooling options for buildings in certain areas. Within the framework of this study, mapping of energy consumption for cooling in the city of Riga (Latvia) is carried out. Mapping allows to assess the demand in a spatial perspective, identifying areas with a denser energy demand indicator, and, accordingly, a higher potential for implementation of district cooling and this method can be used in other countries and cities as well. Energy consumption for cooling at the building level was calculated and visualized using cadastral data and building energy certificate data. The results show that the potential energy consumption for cooling in the city of Riga can reach up to 397 GWh per year and the largest proportion of energy consumption for cooling is predicted in the category of multi – apartment buildings (up to 155 GWh per year), highlighting the need to pay particular attention how cooling demand is addressed in residential building sector. Results can be further used to evaluate the technical and economic feasibility of the district cooling implementation in parts of the city.
PubDate: Sun, 30 Jun 2024 00:00:00 GMT
- Integration of Acoustic Metamaterials Made of Plastic to Improve Building
Acoustics
Abstract: According to the Waste Management Policy of the European Union, the recycling and reuse of various wastes is considered the most environmentally friendly and advanced waste disposal technology that has the least impact on the environment. By applying the principles of the Circular Economy, plastic waste will extend its life cycle and will be used as secondary materials to create metamaterial structures with improved sound absorption and insulation properties. The aim of this study was to determine plastic potential for use in acoustic structures. Acoustic metamaterial resonators, created from plastic, were measured in an impedance tube according to standards ISO 10534-2 for their sound absorbing and ASTM E2611 for their insulating properties. Two types of plastic, PLA and recycled PET-G, were used in acoustic metamaterial 3D printing process. For sound insulation, combined resonator systems were used to control symmetrical wall sound resonance. Sound absorption of both PLA and PET-G metamaterials were peaking at 1600 Hz with 0.93 and 0.89 sound absorption coefficient, respectfully. The results showed that combined constructions with plastic metamaterials can be integrated into building structures and used as an alternative for improving building acoustics, reducing indoor noise and reverberation time.
PubDate: Mon, 24 Jun 2024 00:00:00 GMT
- Mechanical Properties and Lifecycle Assessment of a Green Alkali-Activated
Mortar Based on Biomass Wood Ash
Abstract: Portland cement (PC) is the most commonly used binder material for producing concrete. Nonetheless, increasing concerns have been attached to its manufacture which is highly energy-intensive and generates a large quantity of greenhouse gases. Developing alkali-activated materials as eco-binders is a sustainable replacement for PC and many investigations have been reported successfully utilizing industrial wastes as precursors. However, owing to the low reactivity, studies regarding biomass wood ashes (BWA) are still limited. To produce a green cementless alkali-activated mortar material, in this study, biomass fuel by-products – biomass wood bottom ash and biomass wood fly ash – were binarily used as precursors. Sodium hydroxide NaOH at 10 mol/L and calcium hydroxide Ca(OH)2 at 20 % by binder mass were applied as alkali activators. Recycled sand, substituting natural sand, was adopted as fine aggregate with an aggregate/binder ratio of 2 to reduce the consumption of non-renewable natural resources. Compressive and flexural strength were tested to evaluate the mechanical performance. A cradle-to-gate lifecycle assessment was conducted to analyse the environmental impacts. The results reveal that the alkali-activated mortar has less environmental impact compared to the traditional PC mortar. NaOH solution is the primary source of environmental influence and BWA only contributes to very limited impacts. The usage of Ca(OH)2 effectively improves the mechanical strength and compared to NaOH, it leads to decreased energy demand, requires fewer preparation steps and is less dangerous for operation.
PubDate: Sat, 22 Jun 2024 00:00:00 GMT
- The Impact of RED III Directive on the Use of Renewable Fuels in Transport
on the Example of Estonia
Abstract: Over the past two decades, there has been an increasing use of biofuels worldwide, especially in Europe. The main objective is to reduce greenhouse gas emissions, particularly carbon dioxide (CO2), from transportation. The regulation of fuels produced from biomass and other renewable sources at the EU level is primarily governed by the Renewable Energy Directive (RED). As of today, RED III directive has come into effect, significantly altering the EU fuel market by 2030. The main change involves an increase in the share of renewable fuels in transport and the non-use of first-generation fuels. Since all EU member states are obliged to comply with the RED III directive, it is essential to assess the current status of each member state in meeting the requirements for transport fuels. Therefore, the aim of this article is to analyse the impact of the RED III directive on the use of renewable fuels in the transport sector. Specifically, it provides an overview of various RED directives’ requirements, analyses the shares of renewable fuels in fossil diesel in Estonia under different RED III compliance scenarios, and presents an overview of the situation regarding the use of renewable fuels in Estonia. The article is based on a literature review, and fuel share calculations are based on RED III directive calculation methodologies. The results of the study indicate that if the requirement for the share of renewable energy used in transport is 29 %, using only HVO (Hydrotreated Vegetable Oil) to achieve this goal would require replacing 30.3 % of diesel with HVO. In cases where there is a requirement to reduce the greenhouse gas emission intensity of fuels in the transport sector by at least 14.5 % by 2030, the volumetric share of HVO fuel must meet certain criteria based on the raw material. For example, fuel produced from residues must contain a minimal amount of biocomponents. In this context, biologically derived oil is initially used, such as in food preparation. Subsequently, after its use in food preparation, it is processed into fuel. The article also addresses cases where biogas is introduced as a renewable component in replacing diesel.
PubDate: Wed, 19 Jun 2024 00:00:00 GMT
- Numerical Evaluation of Harmful Consequences after Accidental Explosion at
a Hydrogen Filling Station
Abstract: This study aims to present computational technology that can be used to evaluate numerically the harmful environmental consequences caused by an accidental hydrogen release from failed high-pressure dispensing cylinders and its explosion at a vehicle hydrogen filling station. A coupled problem of a hydrogen explosion products expansion in the atmospheric ground layer and a harmful explosion pressure wave shock impact on service personnel and infrastructure buildings at an accident site is solved by means of computer experiment simulation series. A spatial time-dependent model of compressible hydrogen-air mixture flow is used to obtain pressure history in calculation area in order to assess maximum overpressure in control points of human possible locations and on building surfaces exposed to hydrogen blast wave impact. A deterministic impact consequences model is based on comparing maximum overpressure values extracted from the mathematical model with threshold ranges corresponding to certain degrees of human damage and infrastructure destruction. The presented computer technology allows safety experts to identify potentially dangerous zones by means of mathematical modelling and recommend effective protection measures to mitigate negative consequences of explosions.
PubDate: Wed, 19 Jun 2024 00:00:00 GMT
- Application of Synthesized Hydrates in the National Economy
Abstract: The article analyses the thermodynamic conditions for long-term storage of hydrates and proposes a methodology for calculating the main thermodynamic parameters that ensure long-term stability of the structure of gas hydrates. A criterion for optimizing thermodynamic parameters and heat and mass transfer parameters for effective introduction of new technology
PubDate: Tue, 23 Apr 2024 00:00:00 GMT
- Effectiveness of Water-Amine Combined Process for CO Extraction from
Biogas
Abstract: The EU countries are implementing biomethane production projects from biogas, supplying it to the natural gas distribution grid, or using it as motor fuel. It is also extremely relevant for Ukraine, supposing the problems with gas import due to Russian aggression. Biogas production from landfills, agriculture waste, and sewage is already implemented in Ukraine, so the next step must be biomethane production on an industrial scale and the selection of biogas separation technology is important. Using 11 years of industrial experience in biogas production from landfills, wide experience of the different methane-containing gases separations, and small companies’ industrial possibilities, the most applicable separation technologies for Ukraine were selected: amine, water, and combined water amine carbon dioxide separation. These technologies had compared using computer simulation with real landfill biogas flow rate debt. Results of a software simulation of the most applicable water-amine absorption technology were verified using a laboratory setup. For carbon dioxide concentration in biogas at 32–42 % vol., the specific energy consumption when using water absorption is on average 2 times less compared to amine absorption, but at the same time, the loss of methane due to its solubility in water during water absorption amounted to 7.1–7.6 %, with practically no losses in amine absorption, and minor losses at 0.17–2.8 % in combined water-amine technology. The energy consumption of combined water-amine absorption is comparable to that of water absorption due to: a) reduction of heat losses for the regeneration process of saturated amine absorbent, as part of carbon dioxide has already been removed with water technology; b) using the methane excess to compensate power consumption of the biogas compressor during the preliminary water absorption of carbon dioxide and/or to compensate heat costs of the saturated amine absorbent regeneration
PubDate: Mon, 25 Mar 2024 00:00:00 GMT
- Research of Insertion Loss of Multilayered Construction with Devulcanized
Waste Rubber
Abstract: In this study, the insertion loss of devulcanized waste rubber baffles were evaluated. Acoustic baffles are suitable to reduce noise from the devices or machines by interfering with their emitting sound waves. Knowledge of the acoustic properties of the material used is of significant importance in ensuring the effectiveness of the acoustic properties of the baffle. Basic properties include airborne sound insulation, which is usually determined during laboratory tests. Baffles consists of sound absorbing and sound insulating materials. In this study, plasterboards were used as sound insulating material and devulcanized waste rubber as sound absorbing material. During the devulcanization process, porous granules are obtained, which can be used as an acoustic material. In this study, two types of rubber granules were devulcanized by grinding method and one other type was chemically devulcanized. Three types of rubber granules were mixed together in increasing 25 % proportion steps and glued with patented polyurethane glue. A total of 15 different composition devulcanized waste rubber granule boards were made. Rubber boards were attached together with the plasterboards. Insertion loss of the different composite baffles was measured in semi-anechoic chamber in a purposefully designed stand in 1/3rd octave bands. The results showed that the insertion loss of the baffles was mostly dependent on the rubber granule board density. When the density of the rubber board increased, the insertion loss also increased. The 5–6 dB insertion loss difference was measured between the most and least dense rubber granule board baffles.
PubDate: Sat, 09 Mar 2024 00:00:00 GMT
- Hydrothermal Conversion of Fly Ash into Monomineralic Zeolite Synthesis
for Biodiesel Production
Abstract: Fly ashes as a residue from combustion processes of coal in coal-fired power stations can be applied for zeolite formation. The zeolite synthesis has considerable effect on their structure following further catalytic use. The formation of analcime is guided by the operation of the silicate framework in the company of Na+, [Al(OH)4]−, [H2SiO4]2− species, coming from fly ash processing. Here, we have highlighted the importance of conducting the coal fly ash waste management towards monomineralic zeolite synthesis, in the form of powder analcime. It is the first report on powder analcime production without fly ash residues, confirmed by SEM and XRD analysis. The obtained analcime-zeolite was further explored as biodiesel catalyst based on base-catalyzed transesterification process. The effect of analcime catalyst usage on the biodiesel yield was determined with observed 97.2 % conversion efficiency under the concentration of 4%wt at 230 °C, with three times reusable analcime catalysts. Coal fly ash-derived monominerals on a large scale can significantly contribute to the sustainability goals and efficient waste management.
PubDate: Sat, 02 Mar 2024 00:00:00 GMT
- Optimization Study of Carbon Emissions in Wind Power Integrated Systems
Based on Optimal Dispatch Algorithm
Abstract: With the integration of wind power into the power system, dispatch becomes more complex and existing algorithms are no longer applicable. This paper focuses on optimizing carbon emissions in wind farm generation while considering issues related to wind power integration and carbon trading. An optimal dispatch algorithm was designed with the objective of minimizing total costs, which was then solved using the cuckoo search (CS) algorithm. Additionally, an adaptive improvement was made to the CS algorithm to obtain the improved cuckoo search (ICS) algorithm. An analysis was conducted on a case study with 10 units. The ICS algorithm obtained higher quality solutions, with a total cost of $ 632 719 and a calculation time of 0.51 minutes, which was superior to the solutions obtained by the particle swarm optimization and CS algorithms. Fluctuations in the confidence level of system rotation reserve capacity could lead to variations in the final system cost, which needs to be adjusted according to actual conditions. The dispatch scheme obtained by the ICS algorithm showed reduced carbon emissions, total costs, and better performance when compared with the optimal dispatch algorithm in different scenarios. The results show that the proposed methods are reliable and practical.
PubDate: Sat, 02 Mar 2024 00:00:00 GMT
- MSW Management in Two Italian Mountainous Areas
Abstract: Two case studies are reported in the present work. They regard municipal solid waste (MSW) management trends in the last decades in two Italian provinces selected to analyse some issues of waste management in mountainous areas. The first case study refers to a selective collection (SC) rate expected to reach 80 % soon. This scenario assumes SC mainly in kerbside mode. The scenario is based on specific local conditions: the absence of a thermo-chemical plant in the territory (but with a part of the residual MSW burnt in a neighbour province), the presence of local plant of anaerobic, and a sanitary landfill for pre-treated residual MSW. The adopted tariff helped increasing the SC rate: indeed, since 2013, a tariff calculated at user level, depending on the behaviour of each user, has been adopted. This is called punctual tariff. The second case study concerns an area where SC reached about 75 %. The punctual tariff has been recently introduced. In this scenario, an incineration plant and a Solid Recovered Fuel (SRF) plant allow implementing an industrial symbiosis solution in conjunction with a cement factory. The work demonstrates that SC can be the core of a correct MSW management and that kerbside collection is fully compatible with mountainous area. However, other issues remain to be optimized yet: the low density of mountain areas makes difficult to implement enhanced solutions of SC (e.g. for diapers) and increases costs for light packaging collection; moreover, the presence of tourist fluxes can significantly affect SC efficiency.
PubDate: Fri, 23 Feb 2024 00:00:00 GMT
- Effects of Temperature, pH, and Agitation on Growth and Butanol Production
of , , and
Abstract: Butanol is a promising alternative to fossil-derived fuels. Clostridium genus bacteria are known for their ability to produce butanol as one of the metabolites, however, at the moment this solution is not economically viable. To solve it, the process of butanol production should be optimized. While ABE fermentation has been extensively studied, information about the optimal growth conditions for specific microorganisms often differs from one study to another. Therefore, this study aims to search for optimal growth conditions in sealed serum bottle tests for three widely used strains in ABE fermentation. In this study effects of temperature, pH, and agitation were tested on Clostridium acetobutylicum, Clostridium beijerinckii, and Clostridium saccharoperbutylacetonicum. The optimal temperature for C. beijerinckii growth and butanol production was 32 °C, the optimal agitation speed for growth was 0 rpm, but for butanol production, it was 200 rpm. For C. saccharoperbutylacetonicum growth and butanol production pH 7.5, 30 °C temperature and an agitation rate of 100 rpm were optimal, however, this effect was slight. For C. acetobutylicum cultivation optimal temperature, pH, and agitation rate were respectively 37 °C, 6.5, and 200 rpm.
PubDate: Mon, 19 Feb 2024 00:00:00 GMT
- Development of New Bio-Based Building Materials by Utilising Manufacturing
Waste
Abstract: Over the last decade, research has increasingly focused on reducing the use of natural resources and improving waste management in the construction industry. Various possibilities exist for reducing waste in this sector, ranging from using waste as filler materials to developing new binders and building materials. This study focuses on the development of bio-based building materials using waste from the manufacturing of wood-wool cement boards. The binder and filler materials were obtained from the manufacturing waste and used in this research. The developed materials were tested for their visual appearance, macrostructure, material density, thermal conductivity coefficient and compressive strength. The results showed promising data for the self-bearing bio-based building materials, which had similar thermal properties to other bio-based materials and could be used as thermal insulation materials with a thermal conductivity coefficient of 0.0827–0.1172 W/(mK). The material density of the developed bio-based composites was found to be 430–617 kg/m3. By incorporating manufacturing waste into the production process of bio-based building materials, it becomes evident that overall waste from manufacturing plants can be significantly reduced, and the sustainability aspect of wood-cement board manufacturers can be enhanced.
PubDate: Mon, 12 Feb 2024 00:00:00 GMT
- The Influence of Young People on Household Decisions on Energy Efficiency
in Latvia
Abstract: Young people are the future members of the energy communities, who play a role in shaping a climate-responsible society. However, in the context of the geopolitical and economic events of 2022, the awareness of young people in Latvia about energy efficiency issues and the readiness to engage in climate change mitigation processes, as well as the influence of their attitude on the decisions of adult household members in the field of energy efficiency have not been sufficiently studied. The issue is crucial within the framework of the European Green Deal, where various serious games for building energy communities are being developed, and young people are the ones who can influence the decision-making process. The purpose of the study is to provide serious game developers with an insight into young people's knowledge of energy efficiency issues, associations with a climate responsible society, attitudes towards daily habits in the field of energy efficiency, as well as whether climate change issues are discussed in families and whether young people believe that they can influence views and habits of their family members. 71 participants from four contrasting geographical regions in Latvia took part in the study. The study was conducted using qualitative research methods, including questionnaires and interviews. The results have shown that young people in the regions of Latvia are aware of energy efficiency measures, and the answers provide an insight into the various experiences they have had in their households. The research also highlighted negative aspects, such as young people’s unwillingness to strongly support household comfort level reduction in the name of climate change – only a little more than half would be willing to live in cooler rooms. Young people believe that they can influence the attitude and behaviour of other household members in an energy resource management matter. The results of the study lead to the conclusion that more attention should be paid to messages addressed to young people in public spaces, so that they associate themselves as an existing and future part of energy communities. They should be given examples and explanations regarding the importance of their actions in reducing climate change. Developers of serious games are encouraged to integrate aspects related to youth as participants in decision-making into the content of simulation tools, based on the results of the study.
PubDate: Mon, 12 Feb 2024 00:00:00 GMT
- Analysing Metal Melting Methods for Green Transformation of Scrap Metal:
Case Study of Latvia using MCDA and SWOT Analysis
Abstract: Metal is one of the most widely used materials in the world. It was a crucial driving force in technological development since the industrial age and continues to push us forward to this day. As metal consumption grows, so does the amount of scrap metal generated. Proper utilization of this waste is crucial in mitigating the negative environmental impacts of the metalworking industry. The processing and use of raw materials is often associated with high resource consumption and high emissions. The utilisation of scrap metal instead of raw metal can lead to up to 10 times less electricity consumption and up to 30 times fewer CO2 emissions. However, selecting the most suitable scrap metal processing technology is crucial, particularly in the case of the metal melting furnace which is the backbone of the industry. The efficiency of this process determines the environmental indicators for the entire scrap metal melting process. This paper conducts an analysis of 8 types of metal melting furnaces based on 11 environmental criteria. Furthermore, a SWOT analysis is conducted to evaluate the efficiency of the metal smelting process in Latvian metalworking enterprises and the potential for future expansion.
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
- Case Study of EPS Aggregate Insulation Material Used in Construction Sites
Abstract: Thermal insulation materials used in civil engineering have been developing throughout time. One of the latest thermal insulation used in construction sites with gained popularity is EPS aggregate and mineral binder-based composite. Waste recycling potential, low cost, and ease of installation have brought popularity to the material. This research investigates such material which is formulated by EPS aggregates and pure Portland cement binder thus making EPS aggregate concrete (EAC). Many contractors use such untested and uncertified EAC material due to the low cost of the raw materials. In this research, EAC was taken directly from the construction site. Material physical and mechanical properties are evaluated and compared to commercial counterparts. The drying of the material was investigated, following the practice in the construction sites where upper covering layers are built according to the time schedule ignoring material drying process. Results were compared with commercial EAC. Results indicate that rapid construction schedule with layer-to-layer covering of wet EAC results in dramatically slow drying of such composites, which is one of the main problems for safe use in civil engineering. EAC density from 113 to 169 kg/m3 was measured with an average compressive strength of 49 kPa. The thermal conductivity of the tested EAC was from 0.050 to 0.055 W/(mK).
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
- Supercritical CO Extraction of Fish Roe
Abstract: Seafood is rich in omega-3 polyunsaturated fatty acids, and the good emulsifying properties of phospholipids make them suitable for use in the food, pharmaceutical and cosmetic industries. This study attempted to evaluate different fish species obtained using supercritical carbon dioxide without and with and ethanol as co-solvent extraction and organic solvent (ethanol) extraction. Supercritical CO2 extraction was performed at 30–50 °C and at different pressures (17.7–33.0 MPa), maintaining a CO2 flow rate of 0.6 mL/min for 3 hours. Gas chromatography and Bligh & Dyer methods were used to analyze the extracts. The results showed that only one species of fish roe (rainbow trout) produced oil, but it was concluded that improvements were needed to be able to extract oil from African catfish roe using supercritical CO2 extraction. Rainbow trout roe contains the most monounsaturated fatty acids (44 %).
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
- Assessing the Sustainability Impact of Improving Secondary Steel
Production: Lessons Learned from an Italian Plant
Abstract: This work presents a sustainability assessment approach to evaluate technological innovations in secondary steel production making use of Electric Arc Furnace (EAF) technology. The assessment covers the environmental, social, and economic dimensions of sustainability by combining different tools (Life Cycle Assessment and Analytic Hierarchy Process), and also provides an integrated assessment of the overall sustainability. The approach, which can also be used to support decision-making, has been applied to a real case study of a steel plant located in Northern Italy. In the case study, environmental sustainability is positively impacted mainly by increased metal yield and reduced furnace energy consumption. The greatest social sustainability benefits are mainly related to improved ergonomic and safety conditions for workers (reduced demand for physical effort, manual handling and repetitiveness, and lower risk of accidents), as a consequence of the introduction of Industry 4.0 technologies. Regarding economic sustainability, a positive impact related to reduced cycle time, increased metal yield and quality yield, reduced maintenance and quality control costs was observed. The integrated assessment of the overall sustainability has proven to be a viable approach to manage trade-offs between the different dimensions of sustainability.
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
|
Open Access journal
