The decision-making process behind the selection of a gas turbine engine (GT) is crucial and must be made in accordance with economic, environmental, and technical requirements. This paper presents the relevant economic, exergoeconomic and exergoenvironmental analyses for four GT engines with different compressor configurations. The GT engine configurations are identified according to the type of compressor: axial, axial-centrifugal, two-stage centrifugal, and centrifugal-centrifugal. The performances of the four GT engines were validated against manufacturer supplied data using specialized software. The economic analysis, a detailed life cycle costing considering the cost to be paid per unit net power obtained from the GT, and subsequent shortest payback period showed that the GT with centrifugal-centrifugal compressor was most economically feasible. This was followed, in order, by the GT-axial, GT-axial-centrifugal, and finally the GT-two-stage centrifugal configuration, where the co... [more]

Electronic goods are a major consumer of many critical metals, including copper, nickel, tin, zinc, lead, and precious metals. The processing of end-of-life electronic equipment (E-Scrap) is becoming increasingly important to maintain the supply of the critical metals required globally, and to reduce environmental pollution. Currently, the dominant route for E-Scrap processing is pyrometallurgical processing, with the first stage of processing being reductive smelting to produce a black copper and a ‘clean’ discard slag. The management of the slag in this first step is central to the success of the E-Scrap recycling process. The E-Scrap ISASMELT™ furnace has a highly turbulent bath, providing conditions that generate high rates of zinc fuming and allow a wide range of operable slag conditions. This enables efficient E-Scrap smelting to occur, whilst overcoming the challenges associated with alternative technologies. Operable slag compositions and high zinc fuming are heavily influenced... [more]

In this study, Zn(NO3)2·6H2O was selected as the metal source, and ZIF-7-modified magnetic graphene-based matrix materials (MRGO@ZIF-7) were prepared by in situ growth. ZIF-7 modified magnetic graphene-based molecular imprinting complexes (MRGO@ZIF7-MIP) were successfully synthesized by a surface molecular imprinting technique using bisphenol A (BPA) as the template molecule. The obtained experimental materials were characterized by X-ray diffraction (XRD), Brunner−Emmet−Teller (BET) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS). The proper adsorption and selective recognition ability of the MRGO@ZIF7-MIP were studied by an equilibrium adsorption method. The obtained MRGO@ZIF7-MIP showed significant molecular recognition of bisphenol A (BPA) and good selectivity and reproducibility for BPA in different aqueous environments such as drinking water, river water, and lake... [more]

Landslide susceptibility analysis has become a necessary means of pre-disaster portal positioning and scientific early warning. How can an effective zoning model of landslide susceptibility be established to examine the important factors affecting landslide development in coal mine areas? Focusing on the need for a reliability analysis of landslide susceptibility in coal mine areas, landslide cataloging and environmental factor data were used as objects, combined with the knowledge of landslide mechanisms, disaster environmental factors and the spatial correlation of landslide disasters, the frequent landslide area of Jiumine in the main part of Xishan Coalfield was selected as the research area, and more than 50 influencing factors were collected and calculated. Eighteen factors with correlation coefficients of less than 0.3 were selected, and a landslide susceptibility analysis method combining the spatial characteristics of landslide factors and the heuristic fuzzy logic model was p... [more]

Second-generation biodiesel, which is produced from essential oil plants, has important advantages, including a high yield of biofuels and the potential to reduce greenhouse gas emissions. The goal of this research was to examine the profile of original and review articles on biodiesel production from essential oils using bibliometric analysis. The search strategy identified 186 relevant and available peer-reviewed publications from 1981 to 2023, which were downloaded from the Web of Science (WoS) database. The retrieved documents were analyzed using VOSviewer. China was the predominant country publishing those documents, followed by the United States, India, Australia, and France. The keyword cluster analysis indicated the presence of 10 main research topics: diesel, fuel, and engine performance; extraction of lipids from microalgae; biofuel production from essential oils; green chemistry; the pyrolysis process; bioethanol production from renewable raw materials; obtaining biodiesel f... [more]

The increasing market share of electric vehicles and the politically intended phase-out of the internal combustion engine require reliable and realistic predictions for future consumption and greenhouse gas emissions as a function of technological solutions. This also includes the consumption- and emission-intensive transport of goods. We consider both passenger vehicles and commercial vehicle traffic in our study and have investigated whether there are drive alternatives to the battery electric vehicle that enable uninterrupted trips with a long range, especially for regional delivery services and internationally active freight forwarders. To this end, we have analysed three system architectures and their expected technological progress until 2050: battery electric vehicles (BEV), fuel cell electric vehicles (FCEV), and internal combustion engine vehicles (ICEV) running on compressed natural gas (CNG). The latter case serves as a best-practice reference from a combustion technology pe... [more]

Auxiliary diesel heaters are commonly used in all types of vehicles in cold climates and conditions around the world. Electric buses used in public transport utilise diesel-burning auxiliary heaters to provide thermal comfort for passengers under cold weather conditions while maintaining the operational range otherwise reduced by electric heating. However, the downside of utilising diesel burners is that they cause similar exhaust pollutants to conventional diesel vehicles. Because the emission control for auxiliary heaters is lax, the diesel burners typically lack any exhaust aftertreatment (EAT), resulting in potentially high local emissions. As the public transport sectors around the world seem to transit from traditional internal combustion engine-vehicles to battery electric applications, the significance of the emissions caused by diesel auxiliary heaters is continuously increasing. EVs are generally considered zero-emission vehicles but the implementation of diesel burners is ev... [more]

While hydro turbines generate over 40% of the world’s total renewable energy, these traditional turbines present a great environmental concern due to the potential of their sharp blades to damage aquatic lives and ecology, along with their harmful noise and vibration during operation. One effective solution to these environmental issues is to substantially increase the skew of these blades, which would result in a much safer blade operation for aquatic animals (such as fish, etc.) and a substantial reduction in noise and vibration. Adding skew to turbine rotors is known to reduce cavitation and noise, and hence, to mitigate the environmental impact on underwater fauna and flora. However, adding skew will compromise the power performance of the turbines. This study aimed to identify the effect of rotor skew on the hydrodynamic power performance of a series of horizontal-axis turbine rotors that were manufactured using 3D printing technology and tested in a towing tank. The diameter of t... [more]

Fines migration is a common cause of permeability and, consequently, injectivity and productivity decline in subterranean reservoirs. Many practitioners implement prevention or remediation strategies to reduce the impact of fines migration on field productivity and injectivity. These efforts rely on careful modelling of the underlying physical processes. Existing works have demonstrated the ability to predict productivity decline by quantifying the extent of particle decline at different fluid velocities. Fluid flows in porous media often involve multiple phases, which has been shown in laboratory experiments to influence the extent of particle detachment. However, no theory has directly accounted for this in a particle detachment model. In this work, a new model for fine particle detachment, expressed through the critical retention function, is presented, explicitly accounting for the immobile fines trapped within the irreducible water phase. The new model utilises the pore size distr... [more]

Upgrades in building energy efficiency codes led to differences between buildings designed according to outdated codes and those with most recent requirements. In this context, our study investigates the influence of external wall thermal transmittance, thermal inertia, and orientation on energy demand (heating, cooling) and occupant thermal comfort. Simulation models of an office building were designed, varying (i) the thermal transmittance values (0.20 and 0.60 W/(m2K)), (ii) the room orientation (four cardinal directions), and (iii) the wall thermal inertia (approximately 60 kJ/(m2K) for low and 340 kJ/(m2K) for high thermal inertia. The energy demand for heating and cooling seasons was calculated for Ljubljana using EnergyPlus 9.0.0 software. The reduction of the external wall thermal transmittance value from 0.6 W/(m2K) to 0.2 W/(m2K) contributes to significant energy savings (63% for heating and 37% for cooling). Thermal inertia showed considerable potential for energy savings, e... [more]

An indoor climate impacts human comfort, well-being, and safety. Therefore, it remains an important topic since, nowadays, people spend a significant amount of time indoors. Additionally, as tropical geographical zones become more populated, urbanised, and industrialised, the energy demand for air conditioning will rise significantly. In terms of the indoor climate, hospitals are particularly demanding due to the special needs of their occupants, however there is a paucity of studies about the tropics. Through a systematic analysis of accessible data and peer-reviewed articles, this study performed a quantitative and qualitative review of the scientific studies selected by the defined inclusion and exclusion parameters. A total of 65 tropics-related scientific publications, 28 on indoor thermal comfort and 37 on indoor air quality published between 2000 and 2023, were systematically reviewed. This study’s findings corroborated those from the previous studies, alluding that there is a p... [more]

High-quality managerial decision-making is crucial for improving the resource efficiency of production companies in the context of digitalization. Currently, the use of modern methods and tools to manage the consumption and supply of resources of companies should consider the principles of a circular economy. This study focused on the development of a mechanism to manage resource efficiency in the fuel and energy sector. It used the methodological tools developed by the authors, including a comprehensive integral assessment of resource efficiency and a practice-oriented research methodology adapted for fuel and energy enterprises. Having analyzed the existing state of resource consumption, the authors discovered a disparity of indicators, methods and means in the applied assessment of the accounting, control and expenditure of energy resources. Using the analytic hierarchy process as a foundation, the authors applied a technique for identifying inefficient production processes at the f... [more]

In order to solve the problem that the dual Mach Zehnder (M-Z) interferometer system is easily affected by external environmental noise, a data signal-processing scheme based on Hilbert−Huang transform (HHT) is proposed to achieve high-precision location with distributed optical fibers. The polarization compensation module has a built-in dual Sagnac interferometer system which is used to stabilize the polarization state of the Sagnac interferometer. The eigenmode function is obtained by empirical mode decomposition of the received two optical signals, and then the Hilbert spectrum is obtained by superimposing the Hilbert transform, so that the high-similarity curve caused by the vibration signal can be clearly and intuitively extracted. The optical signal information can be calculated based on the cross-correlation and delay estimation algorithm to accurately obtain the vibration position information. The experimental results show that the positioning accuracy can reach ±11 m, with a s... [more]

Space heating is a necessity in Alaska; however, the use of heating fuels carries both economic and environmental costs. In the Fairbanks North Star Borough (FNSB), Alaska, most households utilize heating fuel oil as a primary source for home heating and firewood as a secondary source. In the FNSB, wood-burning devices are the principal source of fine particulate matter with a size of 2.5 microns or less, (PM2.5), but firewood is less expensive when compared to heating fuel oil. The FNSB has been designated as a nonattainment area for PM2.5, which has been linked to negative cardiopulmonary impacts and other adverse health consequences. Electric thermal storage heaters (ETSH) could help solve the PM2.5 problem by displacing firewood used for residential space heating. We use dichotomous choice contingent valuation (DC-CV) to estimate willingness to pay (WTP) for an ETSH program which would allow FNSB residents to offset 100 gallons of heating fuel oil annually. Certainty correction is... [more]

The aim of this review was to analyze to what extent the relationship between corporate social responsibility (CSR), environment and energy has been addressed in the specialized literature and which are the deficient segments in this regard. VOSviewer was used for data extraction, mapping and grouping the articles from journals that have been indexed in Web of Science (WOS). A total of 102 papers were found approaching the topic of corporate social responsibility, environment and energy policy, 5192 research papers for CSR and the environment and 320 on CSR and energy policy. Following the bibliometric analysis, we can conclude that we are facing a shortage of works that analyze the relationship between the three fields together. The number of published articles was reduced to establish the direction of influence between the three variables, as well as the impact between them. However, the advantage that emerges from this lack of works is that there are many opportunities to find news... [more]

An oil recovery technique, different composition waterflooding (DCW), dependent on the varying injected water composition has been the subject of various research work in the past decades. Research work has been carried out at the lab, well and field scale whereby the introduction of different injection water composition vis-a-vis the connate water is seen to bring about improvements in the oil recovery (improvements in both macroscopic and microscopic recoveries) based on the chemical reactions, while being sustainable from ease of implementation and reduced carbon footprint points of view. Although extensive research has been conducted, the main chemical mechanisms behind the oil recovery are not yet concluded upon. This research work performs a data analysis of the various experiments, identifies gaps in existing experimentation and proposes a comprehensive experimentation measurement reporting at the system, rock, brine and oil levels that leads to enhanced understanding of the und... [more]

Conventional techniques for hydrate production may cause the deconstruction of hydrate, changing the geomechanical stresses of the reservoir, which could trigger the subsidence of the seafloor. A new method for replacing CH4 from the hydrate lattice by CO2, without damaging the mechanical structure of sediment, has been proposed. This approach can achieve both the objectives of long-term CO2 sequestration and the safe production of CH4 from hydrates. By coupling the Chen-Guo model into Tough+Hydrate V1.5, an updated simulator CO2-EGHRSim V.10 (CO2 Enhanced Gas Hydrate Recovery simulator) was developed in this work to describe the replacing processes of CH4 from the hydrate lattice by CO2 and to evaluate the storage potential of CO2 and the recovery efficiency of CH4 from the hydrate-bearing reservoirs. The developed simulator was verified using measured data obtained from laboratory experiments. The verification suggested that CO2-EGHRSim performed well in predicting the replacing proc... [more]

Gas hydrates, being promising energy sources, also have good prospects for application in gas separation and capture technologies (e.g., CO2 sequestration), as well as for seawater desalination. However, the widespread use of these technologies is hindered due to their high cost associated with high power consumption and the low growth rates of gas hydrates. Previous studies do not comprehensively disclose the combined effect of several surfactants. In addition, issues related to the kinetics of CO2 hydrate dissociation in the annealing temperature range remain poorly investigated. The presented review suggests promising ways to improve efficiency of gas capture and liquid separation technologies. Various methods of heat and mass transfer enhancement and the use of surfactants allow the growth rate to be significantly increased and the degree of water transformation into gas hydrate, which gives impetus to further advancement of these technologies. Taking the kinetics of this into acco... [more]

This paper presents a life cycle assessment (LCA) analysis of a new, high-concentration photovoltaic (HCPV) technology developed as part of the HIPERION project of hybrid photovoltaics for efficiency record using an integrated optical technology. In the LCA calculations, the production stage of a full module was adopted as a functional unit. SimaPro version 9.00.49, the recent Ecoinvent database (3.8), and the IPCC 2021 GWP 100a environmental model were applied to perform the calculations. The environmental impact of the HCPV panel was determined for constructional data and for recycling of the main elements of the module. The results of the calculations show that recycling of PMMA, rubber, and electronic elements reduced the total carbon footprint by 17%, from 240 to 201 kg CO2-eq. The biggest environmental load was generated by the PV cells: 99.9 kg CO2eq., which corresponds to 49.8% (41.7% without recycling) of the total environmental load due to the large number of solar cells used... [more]

The role of interzonal airflows is especially pronounced in naturally ventilated buildings. In such buildings, reversed airflows in the ventilation stacks might occur as well. This affects the air exchange rate and contaminant distribution in buildings. A significant increase in carbon dioxide concentration is a characteristic phenomenon for poorly ventilated rooms. This paper demonstrates the application of metabolic carbon dioxide concentration measurements for interzonal airflow estimation in naturally ventilated buildings. The presented method is based on the continuous measurements of CO2 concentration at one point in each zone. These measurements are used to estimate airflow pattern in a multizone building by applying an inverse analysis. The developed methodology employs an iterative Levenberg-Marquardt procedure to maximise the nonlinear likelihood function. The validity of the method was verified against measurements carried out in a single naturally ventilated room. Further,... [more]

CO2 injection to enhance shale oil recovery provides a win-win solution to meet the global fuel shortage and realize ultimate carbon neutrality. When shale reservoirs contain high salinity water, CO2 injection can result in salt precipitation to block the nanometer pores in the shale, causing undesirable formation damage. Understanding salt precipitation and dissolution dynamics at the nanoscale are fundamental to solving this practical challenge. In this work, we developed a shale micromodel to characterize salt precipitation and dissolution based on nanofluidic technology. By directly distinguishing different phases from 50 nm to 5 μm, we identified the salt precipitation sites and precipitation dynamics during the CO2 injection. For the salt precipitation in the nanometer network, we identified two precipitation stages. The ratio of the precipitation rates for the two stages is ~7.9 times that measured in microporous media, because of the slow water evaporation at the nanoscale. For... [more]

Against the backdrop of China’s carbon emission reduction targets and the promotion of the construction of a unified domestic market, what kind of carbon emission effect has market integration had in weakening regional barriers and optimizing resource allocation? This paper adopts a two-way fixed effects analysis based on China’s provincial panel data from 2003 to 2019. It uses a mediation model to explore the relationship between market integration and carbon emissions. Furthermore, industrial rationalization and upgrade are the basis for examining whether a competitive or cooperative relationship exists between the carbon emission effects generated and promoting market integration between regions. The study finds a negative relationship between market integration and carbon emissions. In addition, there is significant heterogeneity in the effect of market integration on carbon emissions, and the influence effect is mainly in central China; industrial rationalization can play an enhan... [more]

Since the COVID-19 outbreak, special attention has been paid to proper ventilation and building management systems. The indoor air CO2 concentration level is still used as an effective indicator to evaluate indoor air quality. Many different sensors have appeared on the market in the last two years. However, calibration procedures and guidance on proper installation have not been well described by manufacturers. The research method is based on a review of technical parameters. The practical measurements of CO2 concentration were taken using different sensors. For these purposes three different premises were selected. It was found that CO2 measurement failure happened in residential buildings without mechanical ventilation. Meanwhile, in well ventilated buildings all sensors have shown similar results and the difference between sensors located in different zones was minimal.

The injection performance of carbon dioxide (CO2) for oil recovery depends upon its injection capability and the actual injection rate. The CO2−rock−water interaction could cause severe formation damage by plugging the reservoir pores and reducing the permeability of the reservoir. In this study, a simulator was developed to model the reactivity of injected CO2 at various reservoir depths, under different temperature and pressure conditions. Through the estimation of location and magnitude of the chemical reactions, the simulator is able to predict the effects of change in the reservoir porosity, permeability (due to the formation/dissolution) and transport/deposition of dissoluted particles. The paper also presents the effect of asphaltene on the shift of relative permeability curve and the related oil recovery. Finally, the effect of CO2 injection rate is analyzed to demonstrate the effect of CO2 miscibility on oil recovery from a reservoir. The developed model is validated against t... [more]

The aim of this research is to investigate the effects of a direct current (DC) electric field on the combustion behavior of a co-flow propane diffusion flame. The flame length and NOx emission were observed and measured. The electric field enhances the combustion process of propane diffusion flame by causing the movement of ions and molecules in the flame, resulting in a change in the shape of the flame. The flame heights decrease with an increase in the applied voltage and polarity, a more dominant effect to be observed with a positive DC electric field. However, for the applied negative polarity, the inner-cone of the propane diffusion flame is shifted by the electric field. Drastic reduction in the NOx emission is observed with an increase in the applied DC voltage and polarity. In the existing system, the reduction percentage of NOx is within the range of 55 to 78%.