Search Results (141)

The investment estimation of the helium extraction project from natural gas is a crucial step in economically obtaining helium from both domestic and international projects. This article employs Aspen HYSYS to simulate the process and estimate the investment levels of Linde and Exxon Mobil integrated helium extraction processes. We investigate the influence of feed composition and processing capacity on investment costs and product returns. The results indicate that higher helium content of feed correlates with increased equipment investment costs and total capital cost (CAPEX), and that the Linde integrated process is significantly more sensitive to changes in helium content of feed than the Exxon Mobil integrated process. As the helium content of feed rises, the product returns of the two processes are evidently improved, leading to reduced investment payback periods. Both techniques exhibit favorable payback periods when the feed helium content exceeds 0.5 vol%. Nevertheless, elevated nitrogen content in the feed notably escalates the equipment investment costs and total capital costs. Furthermore, an increase in the processing capacity of feed gas leads to a nonlinear increase in total capital costs and annual operating costs. However, the cost per unit of helium extraction diminishes with increasing capacity. In general, the Linde integrated process requires higher separation energy consumption in comparison with the Exxon Mobil integrated process at similar processing capacities. Moreover, the sensitivity analysis shows that helium breakeven price is strongly affected by the price of both LNG and feed gas. Full article

Wastewater reuse is a proven strategy to mitigate water stress in drought-prone regions. However, this practice is still limited due to high implementation costs, regulatory hurdles, and limited public acceptance. In regions with low reclaim rates, a thorough evaluation of the potential for reuse is needed to support decision-making, focusing on opportunities that address both low-hanging fruit and high-leverage projects. This paper introduces a streamlined, data-centric methodology for assessing wastewater reuse potential, adaptable to various regional contexts. The methodology involves comprehensive data collection and processing to evaluate wastewater treatment plant (WWTP) capabilities and identify potential users, allowing the prioritisation of case studies based on demand alignment. Different treatment and distribution systems are analysed to match WWTP capabilities with user needs, considering volume, quality, and infrastructure requirements. Cost analysis incorporates capital expenditure (CAPEX), operational expenditure (OPEX) and unit costs using novel cost functions for treatment and distribution. Risk analysis adheres to WHO methodology to ensure safety and sustainability. A case study in the Lisbon and Oeste areas in Portugal validates this approach, revealing key insights into the potential and economic viability of water reuse. By comparing tariffs and costs associated with different reuse scenarios, this paper offers benchmarks for the economic feasibility of reuse projects. Full article

One of the main Frequently Asked Questions (FAQs) in project management for built environment or physical infrastructure projects is “How will this project scope be delivered on time and under budget, addressing health and safety in a sustainable way?” This article presents a parallel point of view summarised in a competing question: “Have you followed a systems engineering methodology to detail interfaces and integrations in the business case?” Megaprojects face multiple risks that incur project delays and cost overruns; hence, this article proposes a simple but nevertheless innovative model that incorporates a systems engineering framework at the start of the built environment or physical infrastructure project: the business case phase. This proposed approach seeks to derisk megaprojects composed of complex systems of systems (SoSs) in their earliest stage when financial decisions based on cost estimations have to be made. The scope of this article covers built environment and physical infrastructure projects and their associated ICT, digital, and technology programmes, rather than purely IT developments. The inconvenient truth is this additional systems engineering task embedded in the business case comes at a further project CAPEX cost that decision makers or stakeholders should be willing to accept as it provides a wider technical vision of the project and better quantifies the Return on Investment (ROI). Full article

In this paper, an optimisation framework is presented for planning a stand-alone microgrid for supplying EV charging (EVC) stations as a design and modelling approach for the FEVER (future electric vehicle energy networks supporting renewables) project. The main problem of the microgrid capacity sizing is making a compromise between the planning cost and providing the EV charging load with a renewable generation-based system. Hence, obtaining the optimal capacity for the microgrid components in order to acquire the desired level of reliability at minimum cost can be challenging. The proposed planning scheme specifies the size of the renewable generation and battery energy storage systems not only to maintain the generation–load balance but also to minimise the capital cost (CAPEX) and operational expenditures (OPEX). To study the impact of renewable generation and EV charging uncertainties, the information gap decision theory (IGDT) is used to include risk-averse (RA) and opportunity-seeking (OS) strategies in the planning optimisation framework. The simulations indicate that the planning scheme can acquire the global optimal solution for the capacity of each element and for a certain level of reliability or obtain the global optimal level of reliability in addition to the capacities to maximise the net present value (NPV) of the system. The total planning cost changes in the range of GBP 79,773 to GBP 131,428 when the expected energy not supplied (EENS) changes in the interval of 10 to 1%. The optimiser plans PV generation systems in the interval of 50 to 63 kW and battery energy storage system in the interval of 130 to 280 kWh and with trivial capacities of wind turbine generation. The results also show that by increasing the total cost according to an uncertainty budget, the uncertainties caused by EV charging load and PV generation can be managed according to a robustness radius. Furthermore, by adopting an opportunity-seeking strategy, the total planning cost can be decreased proportional to the variations in these uncertain parameters within an opportuneness radius. Full article

Due to climate change risks, the public, regulators, and investors require solid actions to minimize the greenhouse gas (GHG) emissions of mineral extraction and metals production. The mining sector considers alternatives to reduce its carbon footprint by transforming the business and adopting new technologies into operations. Given the capital intensity, technical characteristics, and business structure involved, a shift in the mining industry necessitates impartial insights into the trade-offs and risks. Considering the low-carbon transition trade-offs and risks in mining, this study presents the application of system dynamics modeling (SDM) in mining projects to analyze the impact of decarbonization alternatives with respect to carbon footprint and costs. A system dynamics model of an open-pit copper mine is developed to quantify greenhouse gas (GHG) emissions, as well as capital and operational costs, during the project life cycle. The change in GHG emissions in the business-as-usual scenario with diesel equipment haulage versus the alternative scenario with electric overland conveyor haulage is compared concerning GHG emissions and associated costs. The results unequivocally demonstrated that electrifying material mobility offers significant decarbonization in open-pit mining if the on-site electricity has a low emission factor. The findings also indicate that the substantial cost difference between electrification and diesel alternatives is another major obstacle to implementing electrification in an open-pit copper mine. This research proves that implementing SDM in the mining industry can offer impartial insights into decision-making and enable a thorough evaluation of options using quantitative criteria. It effectively assesses and communicates the trade-offs and risks of transitioning to low-carbon alternatives because it analyzes project variables quantitatively and holistically and is easy to run. Full article

This survey of predominantly middle–high-income owner-occupier households in the Kingdom of Saudi Arabia (KSA) assessed household perspectives to residential photovoltaics (PVs) (n = 268). Higher-income households were statistically more likely to (i) accept financial payback times of more than 12 months for the CAPEX cost of a PV system, and (ii) be prepared to contribute up to SAR 10,000 (USD 2666) towards the CAPEX cost of a system. A multiple logistic regression analysis indicated that a high household education level and the dwelling tenure (owner) are key variables that positively influence PV acceptability. Median apartment and villa households in this survey had annual electricity demands of 22,969 kWh and 48,356 kWh, respectively. The available roof area per apartment and villa was assessed, considering parapet shading and roof furniture limitations (the presence of AC units, etc.), at 20 m² and 75 m², respectively. This would accommodate either a 4 kWp apartment system or a 10 kWp villa system mounted horizontally. Time-of-use tariffs or grant subsidies towards the cost of a PV system will be required to enable the surveyed households to meet their stated economic conditions for purchasing a PV system. This indicates that PV policies in KSA will need to be adapted to encourage the uptake of PVs. Full article

Forecasting the actual cost of the implementation of a construction project is of great importance in the case of technical management and enables financial resources to be initially maintained in a controlled manner and in a way that is as close as possible to the actual state. Based on the analysis of the developed knowledge base, which contains data from 612 reports of the Bank Investment Supervision regarding 45 construction projects from 2006 to 2023 with a total value of over PLN 1,300,000,000, best-fit curves were determined, and the expected area of the cumulative actual cost of selected construction projects was specified. The obtained polynomial functions and graphs of real areas of cost curves (in the form of nomograms) constitute a reliable graphical representation that enables the application of research results in typologically similar groups/sectors of the construction industry. The elaborated course of the cumulative cost curve (CCCC) as a method of CAPEX prediction in selected construction projects stands for a combined approach of the S-curve, polynomial functions, and the best-fit area of cumulative earned cost. The research used scientific tools that can be practically and easily used by both managers and participants of the investment process. Full article

This paper presents simulations of different concentration plants that use Inert Construction and Demolition Waste as feed to generate coarse aggregates from old concretes. Different feed materials were studied: CDW generated in Spain; low-strength concretes, C16/20, which are ordinary concrete used in civil construction; and high-strength concretes, C50/60, from specific demolitions, such as old viaducts and bridges. Granulometric and densimetric analyses were performed, and the composition of the granulometric fractions of the proposed concretes were analyzed based on previous studies carried out, to understand the materials that can be recovered and considered for reinvestment in the market. Investment analysis considering the CAPEX, OPEX, revenue, IRR, MIRR, NPV, and DPP of the different concentrating plants with varying streams of concentration to recover the materials of interest (coarse aggregates) are presented and discussed. The results of the analyses indicate greater viability in plants that use mobile plants and the use of water jigs. Full article

European islands have been leading the charge in renewable energy innovation. Yet, the intermittent nature of sources like solar and wind poses challenges such as grid saturation and frequency variations. Limited interconnection with mainland grids exacerbates these issues, necessitating backup from conventional power sources during low-production periods. Until 2021, Crete operated independently, but new infrastructure now integrates it with the Greek mainland grid, facilitating swift energy transfers. This integration enables surplus power from Crete’s solar and wind systems to be transmitted to the mainland and vice versa. However, reliance on remote power production exposes the island to market fluctuations and distant disruptions, impacting electricity production. Storage technologies offer a solution, enhancing renewable energy penetration while reducing carbon emissions. Green hydrogen, a rising storage method, shows promise in offsetting carbon emissions. Its clean-burning nature minimizes environmental impact and reduces reliance on costly and harmful conventional sources. This study aims to evaluate the feasibility of achieving carbon-neutral electricity production in Crete, Greece, using hydrogen storage to offset annual carbon emissions in a financially viable and sustainable manner. Hydrogen’s clean-burning properties reduce environmental impact and lessen dependence on expensive and environmentally harmful conventional sources. The methodology prioritizes the independence of the Cretan electricity system, utilizing electrolysis to produce green hydrogen and proton-exchange membrane (PEM) fuel cells for energy generation. It investigates the optimal expansion of renewable energy systems, including photovoltaic (PV) and wind turbine (WT) parks, alongside the installation of hydrogen storage, under specific assumptions. This proposed installation aims to achieve both island independence and profitability, requiring an additional expansion in PV capacity of 2.13 GW, WT capacity of 3.55 GW, and a hydrogen system with electrolyzer and fuel cell capacities totaling 278.83 MW each, along with a hydrogen tank capacity of 69.20 MWh. The investment entails a capital expenditure (CAPEX) of 6,516,043,003.31 EUR for a nearly zero net present value (NPV) over 20 years. However, carbon neutrality cannot be attained through this optimal solution alone, as relying solely on carbon sequestration from olive groves, the primary crop cultivated on the island, is insufficient as a carbon sink method. The annual net carbon emissions from electricity production, island transport, residential heating, and carbon sequestration are estimated at 94,772.22 tCO₂. Full article

Smart cities like Neom require efficient and reliable transportation systems to support their vision of sustainable and interconnected urban environments. High-speed trains (HSTs) play a crucial role in connecting different areas of the city and facilitating seamless mobility. However, to ensure uninterrupted communication along the rail lines, advanced communication systems are essential to expand the coverage range of each base station (BS) while reducing the handover frequency. This paper presents the dual transceiver free space optical (FSO) communication system as a solution to achieve these objectives in the operational environment of HSTs in Neom city. Our channel model incorporates log-normal (LN) and gamma–gamma (GG) distributions to represent channel impairments and atmospheric turbulence in the city. Furthermore, we integrated the siding loop model, providing valuable insights into the system in real-world scenarios. To assess the system’s performance, we formulated the received signal-to-noise ratio (SNR) of the network under assumed fading conditions. Additionally, we analyzed the system’s bit error rate (BER) analytically and through Monte Carlo simulation. A comparative analysis with reconfigurable intelligent surfaces (RIS) and relay-assisted FSO communications shows the superior coverage area and efficiency of the dual transceiver model. A significant reduction of up to 76% and 99% in the number of required BSs compared to RIS and relay, respectively, is observed. This reduction leads to fewer handovers and lower capital expenditure (CAPEX) costs. Full article

Battery cell finalization is a crucial process chain in battery manufacturing, contributing to a significant share of CAPEX and OPEX. Thus, there is a high cost-saving potential by improving the process chain. This research paper investigates various crucial facets of the cell finalization process in battery cell production through an expert survey. These include investment cost allocation, potential cost savings in sub-processes, reject generation, early detection of faulty cells, quality measurement techniques, and the utilization of inline data for early quality determination and real-time process control during the formation process. A solution approach for the implementation of electrochemical impedance spectroscopy for inline early quality determination is given. The results yield valuable insights for optimizing the formation process and enhancing product quality. Full article

As the LCOE for photovoltaics has decreased several times, it is once again gaining popularity. The intensification of the development of PV installations is contributing to the duck curve phenomenon in an increasing number of countries and, consequently, affecting current electricity prices. Decisions on new investments in large-scale PV sources are driven by potential economic and environmental effects, and these, in turn, are subject to locational considerations, both as to the country and its region. In calculating the economic impact of locating a 1 MWp PV farm, it was assumed that the electricity generated by the farm would be fed into the national grid, and that the life of the PV farm would be 20 years. Poland was considered as an example country for the placement of a photovoltaic farm. The authors of this paper proposed that the main verification parameter is the availability of connection capacities to feed the produced electricity into the country’s electricity grid. The methodology proposed by the authors for the selection of the location of a PV farm consists of four steps: step (i) identification and selection of the administrative division of a given country; step (ii) verification of available connection capacities; step (iii) (two stages) verification of other factors related to the location of the PV farm (e.g., information on land availability and the distance of the land from the substation), and analysis of productivity at each potential location and electricity prices achieved on the power exchange; step (iv) economic analysis of the investment—analyses of PV farm energy productivity in monetary terms on an annual basis, cost analysis (CAPEX, OPEX) and evaluation of economic efficiency (DPP, NPV, IRR). The greatest impact on the economic efficiency of a PV project is shown by the value of land (as part of CAPEX), which is specific to a given location, and revenues from energy sales, which are pretty similar for all locations. Full article

Plasma technology has emerged as a very helpful tool in a variety of sectors, notably metallurgy. Innovators and scientists are focused on the problem of finding a more ecologically friendly way of extracting titanium and iron metal from natural ilmenite concentrate for industrial applications. A direct current (DC) plasma torch operating at atmospheric pressure is used in this study to describe a decarbonization process for reducing an ilmenite concentrate. The plasma gases employed in this torch are CO₂ and CH₄. The molar ratio of the gases may be crucial for achieving a satisfactory reduction of the ilmenite concentrate. As a result, two molar ratios for CO₂/CH₄ have been chosen: 1:1 and 2:1. During torch operation, a thin layer of graphite is formed on the cathode to establish a protective barrier, prolonging the cathode’s life. The material was analyzed using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The output gases were analyzed using mass spectrometry (MS). In addition, a thermodynamic analysis was performed to predict the development of thermodynamically stable phases. An economic assessment (including capital expenditures (CAPEX) and operating expenditures (OPEX)) and a carbon balance were developed with the feasibility of the piloting in mind. Full article

Traditional hypervisor-assisted virtualization is a leading virtualization technology in data centers, providing cost savings (CapEx and OpEx), high availability, and disaster recovery. However, its inherent overhead may hinder performance and seems not scale or be flexible enough for certain applications, such as microservices, where deploying an application using a virtual machine is a longer and resource-intensive process. Container-based virtualization has received attention, especially with Docker, as an alternative, which also facilitates continuous integration/continuous deployment (CI/CD). Meanwhile, LXD has reactivated the interest in Linux LXC containers, which provides unique operations, including live migration and full OS emulation. A careful analysis of both options is crucial for organizations to decide which best suits their needs. This study revisits key concepts about containers, exposes the advantages and limitations of each container technology, and provides an up-to-date performance comparison between both types of containers (applicational vs. system). Using extensive benchmarks and well-known workload metrics such as CPU scores, disk speed, and network throughput, we assess their performance and quantify their virtualization overhead. Our results show a clear overall trend toward meritorious performance and the maturity of both technologies (Docker and LXD), with low overhead and scalable performance. Notably, LXD shows greater stability with consistent performance variability. Full article

In this study, real voyage data and ship specifications of a general cargo ship are employed, and it is assumed that diesel generators are replaced with hydrogen proton exchange membrane fuel cells. The effect of the replacement on CO₂, NO_X, SO_X, and PM emissions and the CII value is calculated. Emission calculations show that there is a significant reduction in emissions when hydrogen fuel cells are used instead of diesel generators on the case ship. By using hydrogen fuel cells, there is a 37.4% reduction in CO₂ emissions, 32.5% in NO_X emissions, 37.3% in SO_X emissions, and 37.4% in PM emissions. If hydrogen fuel cells are not used instead of diesel generators, the ship will receive an A rating between 2023 and 2026, a B rating in 2027, a C rating in 2028–2029, and an E rating in 2030. On the other hand, if hydrogen fuel cells are used, the ship will always remain at an A rating between 2023 and 2030. The capital expenditure (CAPEX) and operational expenditure (OPEX) of the fuel cell system are USD 1,305,720 and USD 2,470,320, respectively, for a 15-year lifetime, and the hydrogen fuel expenses are competitive at USD 260,981, while marine diesel oil (MDO) fuel expenses are USD 206,435. Full article