Growing demand for renewables and sustainable energy production contributes to a growing interest in producing high quality biomethane from biogas. Despite having methane (CH₄) as its main component, biogas may also present other noncombustible substances in its composition, i.e., carbon dioxide (CO₂), nitrogen (N₂) and hydrogen sulfide (H₂S). Contaminant gases, such as CO₂ and H₂S, are impurities known for being the main causes for the decrease of biogas calorific value and corrosion, wear of pipes, and engines, among others. Thus, it is necessary to remove these compounds from the biogas before it can be used in applications such as electricity production, thermal purposes, and replacement of conventional fossil fuels in vehicles, as well as injection into natural gas distribution networks. In this context, the present work aimed to present a systematic review of the literature using the multicriteria Methodi Ordinatio methodology and to describe processes and materials for H₂S removal. The discussion indicated new materials used, as well as the advantages and disadvantages observed and the limitations in industrial implementation. Full article

Building energy efficiency has grown strong in a context of soaring energy prices, especially in Europe. The use of energy-saving devices strongly influences its improvement, but in many cases, it is far from sufficient., especially if the energy comes from renewable sources with forced production. In the case of buildings, these are usually photovoltaic (PV) sources. For this reason, energy management systems (EMS) are becoming increasingly popular as they allow the increase in self-consumption and reduce the size of energy storage. This article presents analyses of historical energy consumption profiles in selected small- and medium-sized buildings powered by renewable energy sources. The implementation limitations of this type of systems, depending on the profile of the building, were identified and guidelines were presented to assess low-cost solutions dedicated to small buildings and considering the actual conditions of existing systems. Statistical analyzes were conducted for the energy demand profiles of 15 different buildings. The analyzes consisted of the preparation of box plots for each hour of working days and the calculation of the relative standard deviation (RSD) index for annual profiles of 60 min periods. The analyzes showed that the RSD index has low values for commercial buildings (e.g., hospital 7% and bank 15%) and very high values for residential buildings—even over 100%. On this basis, it can be concluded about the usefulness of energy profiles for demand forecasting. The novelty of the proposed method is to examine the possibility of using measurement data as data to forecast energy consumption based on statistical analysis, dedicated to low-cost EMS system solutions. Full article

This study addresses the problem of selecting the conductor sizes for medium-voltage distribution networks with radial configurations. The optimization model that represents this problem is part of the mixed-integer non-linear programming (MINLP) models, in which a power flow must be solved for each possible combination of conductor sizes. The main objective of this optimization problem is to find the best set of conductor sizes that minimize an economic objective function composed of the total costs of conducting materials added with the expected annual costs of the energy losses by proposing a new hybrid optimization methodology from the family of combinatorial optimization methods. To solve the MINLP model, a master–slave optimization method based on the modified version of the gradient-based metaheuristic optimizer (MGbMO) combined with the successive approximation power flow method for unbalanced distribution networks is presented. The MGbMO defines the set of conductor sizes assignable for each distribution line using an integer codification. The slave stage (three-phase power flow) quantifies the total power losses and their expected annual operating costs. Numerical results in the IEEE 8-, 27-, and 85-bus grids demonstrate the effectiveness of the proposed master–slave optimizer when compared with multiple combinatorial optimization methods (vortex search algorithm, the Newton-metaheuristic optimizer, the traditional and Chu and Beasley genetic algorithms, and the tabu search approaches). Two scenarios regarding the demand behavior were analyzed for the IEEE 8- and 27-bus grids: a peak load operation was considered, and, for the IEEE 85-bus grid, the daily demand behavior, including the presence of renewable generators, was considered. The 85-bus grid allowed showing that the most realistic operative scenario for selecting conductors is the case where a demand curve is implemented since reductions over 40% in the annual investment and operating costs were found when compared to the peak load operating condition. All numerical validations were performed in MATLAB software. Full article

Electric power systems have experienced the rapid insertion of distributed renewable generating sources and, as a result, are facing planning and operational challenges as new grid connections are made. The complexity of this management and the degree of uncertainty increase significantly and need to be better estimated. Considering the high volatility of photovoltaic generation and its impacts on agents in the electricity sector, this work proposes a multivariate strategy based on design of experiments (DOE), principal component analysis (PCA), artificial neural networks (ANN) that combines the resulting outputs using Mixture DOE (MDOE) for photovoltaic generation prediction a day ahead. The approach separates the data into seasons of the year and considers multiple climatic variables for each period. Here, the dimensionality reduction of climate variables is performed through PCA. Through DOE, the possibilities of combining prediction parameters, such as those of ANN, were reduced, without compromising the statistical reliability of the results. Thus, 17 generation plants distributed in the Brazilian territory were tested. The one-day-ahead PV generation forecast has been considered for each generation plant in each season of the year, reaching mean percentage errors of 10.45% for summer, 9.29% for autumn, 9.11% for winter and 6.75% for spring. The versatility of the proposed approach allows the choice of parameters in a systematic way and reduces the computational cost, since there is a reduction in dimensionality and in the number of experimental simulations. Full article

Frequency, tie-line power, and the terminal voltages of synchronized generators must all be kept within prescribed limits to ensure the stability of an interconnected power grid through combined automatic generation control (AGC) and automatic voltage regulator (AVR) loops. Thermal power plants, electric vehicles, and renewable energy sources—including solar and wind, geothermal, and solar thermal power plants—form the two-area integrated power system in present research. A new cascade controller named the cascaded proportional integral derivative (PID) and fractional-order PID (CPID-FOPID) controller is proposed for the first time, whose performance is compared with the PID and FOPID controller. The results show that the proposed cascade controller outperforms PID and FOPID in delivering superior dynamic characteristics, including short settling times and low oscillation amplitudes. A new metaheuristic algorithm named the coot algorithm was applied to optimize the parameters of these controllers. The suggested controller outperforms FOPID in the combined AGC and AVR problem under uncertain conditions (random load disturbance, variable input of solar irradiation, and wind power). Robustness of the controller is tested with significant variation in the turbine time constant of the thermal and geothermal power plant. In this study, authors also investigated the best possible coordination between the superconducting magnetic energy storage (SMES) and gate-controlled series capacitor (GCSC) devices to control both voltage and frequency simultaneously. The effect of communication time to the power system is analyzed in this study. Additionally, the obtained results are satisfactorily validated using OPAL-RT real-time digital simulator. Full article

The growing importance of creative knowledge workers as a resource of particular significance for the growth of organizations is becoming one of the greatest challenges of the knowledge-based economy. Thus, the growing role of creative organizations contributes to building the economic potential of cities, regions, countries, but also of various organizations operating in the market. The development of civilization at its current stage has always been a source of this type of activity. Hence, the issue of understanding how creative knowledge workers operate has been and continues to be addressed by researchers around the world in recent years. The topic presented in this article on the knowledge and creativity of employees and their impact on the growth of creative organizations to a certain extent responds to this demand. The aim of the article is to clarify and extend the conceptualization in terms of creative activities performed by knowledge workers and the correlations with their characteristics and with knowledge initiatives. Achieving the set aim would allow to indicate that modern development depends on the proper generation of knowledge and creativity and the resources offered by an organization to facilitate its absorption in terms of growth prospects. The article reviews the research on cognitive, theoretical, methodological, and empirical issues regarding the development of creative knowledge workers employed in creative organizations as well as characteristics of workers and knowledge initiatives introduced in organizations. The analysis of the literature allowed to establish a research framework and indicate which knowledge initiatives are important and which characteristics of selected employees may be related to creative activities. Empirical verification was carried out through the analysis of basic descriptive statistics with Spearman’s ρ rank correlation and the relationship between nominal and ordinal variables using chi-square tests. The results of the study revealed significant relationships between the performance of creative activities and certain characteristics of knowledge workers as well as between the performance of creative activities and the introduction of knowledge initiatives. It turned out that the knowledge of the nature of the connections between the mentioned activities and knowledge initiatives is the basis for determining which knowledge initiatives in the case of a given creative organization will bring the best results in the form of taking effective creative activities by knowledge workers. Moreover, a person who performs creative activities has only some of the characteristics presented in this article. The research results are particularly relevant to the development of creative knowledge workers employed in creative organizations. Setting out guidelines aimed at changing this state of affairs and the research conducted allowed the identification of areas for improvement in order to ensure that they develop more effectively and meet the demands of competitiveness, generating more innovative ideas. Full article

Only recently, smart cities are taking shape, thanks to the rapid development of Internet of Things (IoT), cloud computing, and other similar technologies. Given the high demands placed on advanced technologies such as autonomous driving, cloud data services, and high-precision sensors, smart cities are creating an intelligent transportation environment conducive to the introduction of autonomous vehicles (AVs). In this context, the use of AVs in transportation is also considered a form of transportation innovation. As a result, AVs are considered more favorable to people interested in new technologies because they appear to be technologically superior. Their association with the most up-to-date technology can serve as a symbol for those who wish to demonstrate their interest in new technologies through their appearance. The positive image of technological innovation projected by AVs may influence their acceptance among technology enthusiasts to a significant degree. In this context, this study investigates the effects of perceived advantage, perceived risk, and perceived safety on the intention to use autonomous vehicles. For this purpose, data were collected from vehicle users living in Turkey by survey method. Secondly, factor analyses and regression analyses were performed with the data set obtained from 611 participants. As a result of the analyses, it has been determined that the perceived advantage and perceived security increase the intention to use autonomous vehicles. In contrast, the perceived risk reduces this intention to use. According to these results, recommendations were made to the companies about the level of acceptance of this technology by the users to assess their investments in autonomous vehicles better. Full article

The goal of reducing the climate impact of shipping requires many different activities. To reduce greenhouse gas emissions, the International Maritime Organization prepared some proposals to meet and fulfill the requirements. It sets out the provisions of the International Convention for the Prevention of Pollution from Ships 73/78 Annex 6—Prevention of the Air Pollution from Ships (1997) with the amendments and the future objectives set. The main objective is to achieve climate neutrality from shipping by 2050. One method is the decarbonization of marine fuels. The types of fuels that are transient fuels, with the final target fuel being hydrogen, are shown. Carbon dioxide emissions depend on the chemical composition of the fuel, its Lower Heating Value and the engine efficiency. The aim of the manuscript is to demonstrate that the use of fuels with lower carbon content is a transitional process enabling the hydrogen era to take place. An analysis of this problem is presented as a review of the subject along with the author’s comments and observations. The development of technologies for adapting potential fuels to combustion requirements in marine diesel engines and gas turbines, together with their storage and bunkering capabilities, are the main barriers to their limited use. The efficiency of marine diesel engines reaches a value of about 50%, while that of fuel cells are close to 100%. It seems that hydrogen will be the fuel of the future, including in shipping. Its basic use is in fuel cells, the efficiency of which is almost twice that of current thermal internal combustion engines. Full article

This research tackles effective and functional management practices in energy consumption using advanced technological solutions to mitigate unexpected events. This study specifically focuses on the recent COVID-19 pandemic that led to a reduction in energy consumption and therefore meddled with the project management’s status quo for the energy sources. Moreover, this research analyzes the role of information and communication technology (ICT) solutions in energy management before and after the recent coronavirus pandemic turmoil. This study also examined the role and place of sustainable energy resources in the effective management of energy consumption during the COVID-19 pandemic. The main purpose of this research is to demonstrate how the recent coronavirus pandemic affected energy consumption and energy prices in many countries and how it paved the way for the new ICT in managing energy consumption. This study elaborated a model to show how these changes evolved in selected European Union (EU) Member States. It turns out that adjusted electricity consumption, as well as the average daily spot electricity prices for the baseload power in the EU countries, declined, and this trend is likely to continue in the next years to come. Due to the COVID-19 pandemic, substantial changes in the economy led to reduced office space usage, cutting commuting and business trips, and bringing commercial travel almost to a halt, further shifting the energy balance towards renewable energy sources (RES). Besides, it becomes apparent that ICT solutions used in maintaining and superintending the energy balance are gaining popularity and wide recognition worldwide and will help pave the way towards modern and smart high-renewables grids. Full article

Fuel and oil spills during the exploration, refining, and distribution of oil and petrochemicals are primarily responsible for the accumulation of organic pollutants in the environment. The reduction in contamination caused by hydrocarbons, heavy metals, oily effluents, and particulate matter generated by industrial activities and the efficient recovery of oil at great depths in an environmentally friendly way pose a challenge, as recovery and cleaning processes require the direct application of surface-active agents, detergents, degreasers, or solvents, often generating other environmental problems due to the toxicity and accumulation of these substances. Thus, the application of natural surface-active agents is an attractive solution. Due to their amphipathic structures, microbial surfactants solubilize oil through the formation of small aggregates (micelles) that disperse in water, with numerous applications in the petroleum industry. Biosurfactants have proven their usefulness in solubilizing oil trapped in rock, which is a prerequisite for enhanced oil recovery (EOR). Biosurfactants are also important biotechnological agents in anti-corrosion processes, preventing incrustations and the formation of biofilms on metallic surfaces, and are used in formulations of emulsifiers/demulsifiers, facilitate the transport of heavy oil through pipelines, and have other innovative applications in the oil industry. The use of natural surfactants can reduce the generation of pollutants from the use of synthetic detergents or chemical solvents without sacrificing economic gains for the oil industry. Therefore, investments in biotechnological processes are essential. It is predicted that, in the not-too-distant future, natural surfactants will become viable from an economic standpoint and dominate the world market. The application of biosurfactants in these settings would lead to industrial growth and environmental sustainability. The main goal of this paper is to provide an overview of diverse applications of biosurfactants on environmental remediation, petroleum biotechnology, and the oil industry through a scientific literature review. Full article