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This paper aims to present an innovative approach to maritime transportation solutions and the need to minimize gas emissions and fuel consumption through green hydrogen research and substitution. Given its critical role in global commerce, maritime transportation has been a key factor for the past decades, specifically regarding the optimization of ship routing. The traditional focus on minimizing distance has been supplemented with modern, sustainability-driven objectives, including greater attention to fuel con...

The study-s aim is to assess the economic and environmental benefits of onshore power supply (OPS) implementation in port areas and to evaluate its cost-effectiveness under different energy price and emission trading scenarios. Specifically, the research investigates how OPS adoption impacts total annual costs, emissions of NOX, SO2, PM, and CO2, and overall cost-effectiveness expressed in euros per pollution unit. A quantitative simulation approach was employed using the OPS Calculation Tool, an Excel-based model...

Accurate, real-time characterization of drilling fluid rheological properties, such as plastic viscosity, yield stress, and gel strength, is vital for optimizing oil and gas drilling operations and advancing sustainable exploration. This study assesses advanced sensor technologies - ultrasonic sensors, inline viscometers, optical flow analyzers, and microfluidic sensors-for automated, real-time measurement of these properties in water-based, oil-based, and synthetic-based muds. Experiments utilized a closed-loop f...

Natural hydrogen (H2), produced through geological processes in the subsurface, is a potential energy source and is a substantial element of the global energy strategy for a smooth transition to carbon neutrality. The review of the published papers concerning the results of the natural hydrogen exploration, which have been carried out over the past few years, shows that the petroleum system concept could be transformed for the exploration of natural hydrogen. The present research is a case study for applying this ...

Global climate change and the need to transition to clean energy sources have brought green hydrogen to the forefront of regional and international energy strategies. Green hydrogen offers a low-carbon solution that can support decarbonization in the heavy industries, transportation, and industry sectors, and renewable energy sources can be integrated into its production. The Danube River is one of the primary hydrological axes in Central and Southeastern Europe, playing a strategic role in the region's energy and...

Mesoporous solids include metal oxides, silica, phosphates and other materials. They may contain various acidic and basic sites which are, in combination with metal nanoparticles, metal atoms, functional groups, etc., could be efficient multifunctional catalysts for cascade reactions. In this shot review, the most important aspects of such catalysts that furnish their catalytic activity and selectivity for cascade reactions in biomass processing discussed. A combination of one metal with another or with metal oxid...

The European Union-s (EU) ambition to accelerate the transition to renewable energies imposes the shift toward ecological mobility has become a key and very challenging task. High niche models of Battery Electric Vehicles (BEVs) are the flagmen in makers- competition but they are not accessible to the mass consumers. Mini and compact Battery Electric Vehicles (BEVs) are expected to play an increasing role in reducing urban congestion and emissions while promoting affordable and efficient transportation solutions. ...

Hydrogen is increasingly recognized as a promising energy carrier, but its storage poses significant safety challenges. One of the most common storage methods is the use of high-pressure Type I steel cylinders, where hydrogen is kept in gaseous form at variable pressures up to 1000 bar. Cylinders used in industrial processes are usually equipped with pressure or temperature-pressure relief devices, while transportation units often lack such protection. In accident scenarios, especially under fire exposure, cylinde...

This study investigates the propagation of hydrogen explosions in confined environments, focusing on the influence of geometry on explosion dynamics. Experimental models were developed to analyze the impact of spatial constraints on pressure rise and flame acceleration. Key parameters, including maximum pressure, flame front velocity, and pressure rise rate (dp/dt), were monitored and analyzed. The results highlight that changes in propagation direction significantly influence explosion behavior, leading to higher...

The decarbonization of the building sector and the recent disruption of energy markets has positioned Air Source Heat Pumps (ASHP) as a pivotal technology for reducing fossil fuel dependency and improving energy efficiency. However, their widespread deployment introduces challenges related to operational reliability, seasonal performance variability, and early fault detection. This study presents a data-driven approach for performance analysis and anomaly detection in real-world ASHP systems. Using five years of m...

Development of renewable energy systems can certainly contribute to climate change mitigation. In many regions initiatives can be noticed to succeed in increasing the efficient usage of renewable energy resources such as hydro power, solar and wind energy as well as bioenergy. From these resources the bioenergy and the hydro power by their storage possibilities have the potential to counterbalance the temporal variability of solar and wind energy. Anyway, by applying such renewable energy resources it is possible ...

Drilling fluid viscosity is a critical parameter influencing the efficiency and safety of drilling operations, yet real-time monitoring under dynamic conditions remains challenging due to varying temperature, pressure, and flow rates. This study develops algorithms for continuous, automated viscosity monitoring of drilling fluids to optimize drilling processes. The primary objective is to design robust algorithms capable of accurate viscosity predictions in real-time, addressing limitations of traditional manual m...

This work is aimed at the search of optimal conditions of selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) to 2-methyl-3-buten-2-ol (MBE). The main question was if the common slurry reactors are suitable for this reaction under ambient hydrogen pressure with the use of environmentally friendly solvents. Thus, we investigated the effect of the reactor type (shaker-type or slurry), temperature and solvent nature (isopropanol, n-butanol or toluene were used) on the behavior of a palladium catalysts (1 wt.% of P...

The urgent need to combat climate change has driven the search for sustainable transportation solutions. Electric vehicles (EVs) and hydrogen fuel cell vehicles (FCVs) have emerged as promising alternatives to traditional fossil fuel-powered cars, offering the potential to significantly reduce carbon emissions. This article provides a detailed analysis and comparison of these two technologies, focusing on their technical, economic, and environmental aspects. EVs rely on batteries to store electrical energy, which ...

The energy security of the Czech Republic (CR) and the European Union (EU) has become a key strategic issue over the past decade, as highlighted by the recent energy crisis caused by dependence on energy imports from geopolitically unstable regions. The field of energy security is a complex and strategic issue influenced by numerous factors. Technological advances, digitalisation, electromobility, the development of AI, geopolitical upheavals and the drive for decarbonisation are all increasing the demand for a st...

The article discusses the advantages of using cryogenic technology in the production of gravel filter elements. A method for calculating the main components for the production of temporarily monolithic annular gravel elements is described. An approach has been developed for the strength analysis of annular gravel filter bits, taking into account installation conditions and the effect of water flow in the aquifer. An analytical calculation was performed to determine the distribution of gravel packing in the behind-...

The charging time of Electric Vehicles (EVs) is an important parameter that greatly affects their operation. Its evaluation helps to estimate the distance traveled. The paper derives an analytical relationship that helps estimate the charging time of the remaining capacity of the EV battery. The relationship is based on a quadratic approximation of charging times for several categories of batteries with different capacities and charging stations with different power levels.

The transition to a sustainable energy system is one of the European Union's key strategic directions, in line with achieving climate neutrality by 2050, as outlined by the European Green Deal. The Black Sea region has considerable potential for renewable energy sources, particularly offshore wind, solar, and biomass. Due to this potential, the area has become a hub for European initiatives focused on increasing the share of renewable sources in the regional energy mix, and consequently, on energy security and red...

This paper focuses on analyzing the behavior of a photovoltaic system installed on a selected building, using the PVcase software to evaluate the influence of temperature on energy performance. The study simulates a typical summer day, comparing the operation of photovoltaic panels during two distinct periods: in the morning, when the ambient temperature is lower, and at midday, when the temperature reaches its peak. Through these simulations, variations in voltage, current, and generated power are determined, as ...

Hydrogen is considered the energy source which can ensure the global transition to sustainable low-carbon energy systems. Municipalities can become more eco-friendly by adopting and implementing hydrogen-based energy systems. At the beginning of the transition toward carbon neutrality, the municipalities can use the hydrogen mixed with natural gas in the existing natural gas network for food and domestic hot water preparation, and heating and electricity generation, and the hydrogen stored as compressed gas, cryo-...

Energy remains a key driver of human development and economic growth. The projected increase in the global population to 8.5 billion by 2030 will intensify energy demand and dependence on fossil fuels, the main source of CO2 emissions. This highlights the urgent need for renewable and sustainable energy solutions. Hydrogen is considered a promising clean energy carrier; however, most hydrogen is still produced from natural gas via steam reforming, releasing significant amounts of CO2. Growing attention is therefor...

The disadvantage of generating electricity from renewable sources is the need for its simultaneous consumption afterwards or distribution to other consumers over long distances, which is accompanied by significant energy losses in networks with increasing transportation distances. In addition, there is a discrepancy between the seasonal maximum volumes of electricity generation and consumption. Thus, imbalances arise between the demand and supply of electricity on the market. This problem can be solved by converti...

Solar thermal energy is a widely established source for Domestic Hot Water (DHW) production. However, standard DHW systems rely on external electrical energy to power auxiliary components such as circulation pumps and automation controls. This paper aims to demonstrate the feasibility of a self-sustaining system capable of simultaneous thermal energy recovery and electrical generation, thereby enhancing overall energy efficiency and reducing the carbon footprint. Experimental investigations were conducted on a cus...

In previous studies, when conducting a geospatial analysis of 297 degraded territories in Latvia, it was found that 6.7% of them would be suitable for electricity production with renewable energy resources and approximate calculations of the possible electricity production potential were made. The task of the study was to conduct an in-depth study of the degraded territory found in the previous analysis in an area of 11.0 ha, taking into account the location of the territory in relation to the daily movement and a...

Hydrogen integration represents a promising strategy for decarbonizing Floating Production, Storage and Offloading (FPSO) operations, which traditionally rely on gas turbines and diesel generators. This study proposes a hybrid FPSO concept combining renewable energy generation with onboard hydrogen production, storage, and utilization. The system emphasizes green hydrogen produced by renewable-powered electrolysis of desalinated seawater, supported by blue hydrogen from associated gas reforming with carbon capture...

Rapid growth of world population and economic activities continue to cause the increase of anthropogenic greenhouse gases (GHG) emissions. To mitigate GHG emissions and limit global warming, researchers and practitioners around the globe search for clean energy solutions. Many researchers believe that hydrogen (H2), with its high energy density, has a promising potential. Yet, practical implementation of H2-based energy generation faces technical and economic challenges. So far, over 95% of global hydrogen product...

This paper analyses the current development status of hydrogen production technologies and projects global demand growth through 2050. Production costs and CO2 emissions per kilogram of hydrogen are identified as key factors influencing the adoption of hydrogen technologies. While fossil-based methods currently offer cost advantages, electrolysis and biological processes demonstrate superior performance regarding CO2 emissions. Provided that sufficient investments are made, the cost of renewable energy production ...

Levulinic acid (LA) obtained by processing of plant biomass is used to synthesize many important compounds, among which is gamma-valerolactone (GVL) - a platform chemical. At present, bifunctional catalysts based on inorganic supports are the most widespread in the reaction of selective hydrogenation of LA to GVL. Polymers can serve as promising alternative to inorganic supports. In the framework of the presented study, the series of amorphous aromatic polymers was synthesized using different monomers: phenanthren...

This paper analyses the implementation of recent geospatial technologies to map and model underground natural gas networks in three dimensions, with a focus on the use of mobile LiDAR scanning systems. The research focuses on the Subcetate area in the municipality of Arad, a representative example for the technical-urban networks in western Romania. The main objective is to create a geospatial database (GIS) with a high degree of accuracy, which would include the information collected from the site about the route...

The Heat Transfer Coefficient (HTC, h) is critical for evaluating the thermal performance of Trombe Walls (TW), passive solar heating systems that utilize solar energy for space heating. This study analyzes convective and radiative HTC mechanisms on a TW absorber surface, emphasizing factors such as airflow patterns, surface roughness, temperature gradients, emissivity, and environmental conditions (solar radiation, ambient temperature, wind speed). Experimental and numerical methods were applied to quantify HTC f...

Global climate and ecological crisis urge to decarbonazation of EU through sustainable low carbon alternatives to achieve carbon neutrality by 2050. Within this context, Power-to-Hydrogen-to-Power (P2H2P) technologies are playing an essential role in the energy transitions boosting the energy system flexibility, facilitating the integration of renewable energy sources and providing a promising pathway for long-term energy storage and clean fuel supply. Driving forces behind this research are the imperative raise t...

The article presents directions for improving diamond drill bits designed for drilling in hard abrasive rocks. The first direction involves the development of multilayer tools in which impregnated diamond layers are separated by soft, non-diamond interlayers of the same configuration. Additionally, ring-shaped bits have been developed with diamond-bearing layers placed on the concave surface of the matrix. This design enables the use of a weakened rock zone beneath the working elements, enhancing rock-breaking eff...

This paper presents the modeling and simulation of an electrical energy management system that integrates a 300 V, 8 Ah lithium-ion battery, a DC shunt machine, and a variable DC load using NEPLAN simulation software. The main purpose of this work is to investigate the performance and control behavior of a hybrid electrical system where the power flow is automatically regulated according to the State of Charge (SOC) of the battery. The DC machine alternates between motor and generator modes depending on the SOC le...

This study presents a multicriteria evaluation for the integration and development of the Limberg Pumped Storage Hydropower Plant (PSHP) in Austria. The research aims to identify the most sustainable and efficient solution to enhance energy storage capacity and operational flexibility within the national energy system. Three development scenarios were analyzed using a Multicriteria Decision Analysis (MCDA) based on the Analytic Network Process (ANP) implemented in Super Decisions (SD) software. Scenario 1 involves...

One of the directions towards a green energy transition is the spread of electric vehicles in the transportation sector. This necessitated the installation of electric charging stations, but as their number increases, so do the problems with their management and the increasing consumption of electricity. In this regard, there is a need to search for intelligent management solutions in the transition to alternative energy sources. This research is related to the development of a project to build a smart system for ...

Complex energy systems, in the current period of transition to a climate-neutral society, comprise two fully functional subsystems, that of fossil fuel-based production and that of production from renewable energy sources. The functional coexistence of these subsystems is achieved due to the capture of the CO2 component from flue gases through the energy vector represented by green H2. This takes on both the role of energy accumulation and the role of transforming the CO2 component, captured during the combustion ...

In the last century human society has registered huge development in all human-related fields, fact that has been possible without doubt by designing technological applications with the usage of diverse natural resources, especially energy ones. Anyway, recorded progress, especially in technological fields, was feasible because of using fossil fuels for electric and thermal energy supply, which resulted besides positive impacts in undesired environmental pollution. Currently most debated effect by CO2 emissions is...

Industrial Control Systems (ICS) are foundational to critical national infrastructure, operating vital processes in sectors such as water treatment, power generation, oil and gas, and manufacturing. As these systems become increasingly integrated with information technology through the Industrial Internet of Things (IIoT), they face growing risks from cyber threats. As Bulgaria accelerates the integration of renewable energy infrastructure, particularly solar, wind, and gas-to-power systems, the cybersecurity of t...

In these article, we discusses the analysis of the profitability of investments in energy storage batteries, in the context of injection policies in the grid in Romania. The study compares the compensation and energy sale regimes for prosumers and producers depending on the installed capacity, thus showing the impact of market prices and tax regulations on the return of investment (ROI). The case study has three scenarios, each with specific formulas for calculating ROI depending on the price of the stored energy ...

All nuclear power plants in Slovakia can effectively prevent emergencies caused by technical or human error. Before commissioning, they must demonstrate to the Nuclear Supervisory Authority that the plant can respond to even extremely unlikely events. The design of the plant has safety systems that will prevent damage to nuclear fuel and the release of radioactive substances so as not to endanger human health and the environment. The maximum design accident for a WWER-440 reactor is a rupture of the main circulati...

Achieving efficient energy systems has become a challenge for researchers, as many engineering applications combine convective heat transfer in fluid saturated porous media, such as nuclear reactors, hydrogen production and storage, underground disposal of waste, food processing and storage, solar power collectors or geothermal systems. For this purpose, it is essential to calculate energy losses and identify methods that involve minimal costs. The paper presents a problem of free convection for a fluid flow throu...

The significant growth of the global population that has happened in the last years strains even more the present fragile balance between the produced and consumed resources, if the current rate of development is to be maintained without change the harmful and the negative effects caused by the global warming will only amplify.The increase of the water level, the desertification of fertile lands and the greenhouse gas effects are only a few of the problems we already need to resolve, because of this the transition...

The transition to renewable energy sources is a key strategy for reducing carbon emissions and ensuring energy sustainability. This study explores the integration of photovoltaic (PV) systems for hydrogen production and storage in Constan?a County, Romania. The region benefits from high solar potential, making it an optimal location for implementing solar energy solutions. The proposed system converts solar energy into electricity through photovoltaic panels, which is then used to power an electrolyzer for hydroge...

As the offshore oil and gas industry faces mounting pressure to reduce its carbon footprint, Floating Production, Storage and Offloading (FPSO) units are emerging as critical platforms for implementing clean energy innovations. This paper explores the potential for integrating renewable energy sources such as offshore wind, solar photovoltaic, and wave energy with advanced energy storage technologies, including lithium-ion batteries and hydrogen-based systems, within FPSO operations. The hybridization of power gen...

The maritime industry represents a significant contributor to global greenhouse gas emissions, primarily through the combustion of fossil fuels used by ship engines. As international regulations tighten and environmental awareness grows, reducing global greenhouse gas emissions from ships has become an important objective. This study explores the potential for emission reduction on passenger ships through the implementation of a hybrid propulsion system. The study methodology involves solving the following aspects...

During the process of adapting renewable energy and ensuring national energy security in the current geopolitical context, technological progress in the field of green energy has received increased attention. This has led to the development of updated policies on investment in onshore renewable energy (which uses wind and solar energy through wind turbines and photovoltaic parks) and offshore renewable energy (which uses tidal, wave, solar, and wind energy through floating photovoltaic parks and wind turbines that...

In this paper, we present some practical considerations regarding the design of power voltage stabilizer equipment. Nowadays, technologies for raising and/or lowering the voltage to a level required by the power line or a consumer are increasingly used (in wind or solar power generation systems, or in energy conversion systems with a direct current intermediate circuit). Our study refers to a conversion solution consisting of two converter stages. The first stage consists of two boost converters operating in antip...

Mannitol is an important raw material in the production of resins, lubricants, coatings, surfactants, explosives, cosmetics and drugs. One of the promising ways to obtain it is the catalytic conversion of inulin, a natural polyfructosan found in large quantities in some agricultural crops. In this study a Ru-containing magnetic catalyst was proposed for the process of hydrolytic hydrogenation of inulin to mannitol. Under optimal reaction conditions a high mannitol selectivity of 44.3 % was obtained 100 % conversio...