• Energy Research

The sudden increase in the concentration of carbon dioxide (CO2) in the atmosphere due to the high dependency on fossil products has created the need for an urgent solution to mitigate this challenge. Global warming, which is a direct result of excessive CO2 emissions into the atmosphere, is one major issue that the world is trying to curb, especially in the 21st Century where most energy generation mediums operate using fossil products. This investigation considered a number of materials ideal for the capturing of CO2 in the post-combustion process. The application of aqueous ammonia, amine solutions, ionic liquids, and activated carbons is thoroughly discussed. Notable challenges are impeding their advancement, which are clearly expatiated in the report. Some merits and demerits of these technologies are also presented. Future research directions for each of these technologies are also analyzed and explained in detail. Furthermore, the impact of post-combustion CO2 capture on the circular economy is also presented.

AbstractThis research investigates the development of a digital twin (DT) for ground heat exchangers (GHEs) and its potential to enhance the efficiency and sustainability of shallow geothermal energy systems. It introduces an innovative approach for building a GHE‐DT that connects the physical and digital systems to monitor key parameters, predict issues, and optimize energy efficiency. The process involves several phases including implicit knowledge codification, data‐driven analysis, model construction, and system design. The study emphasizes real‐time monitoring of the effective parameters: ground temperature and fluid conditions (flow rate, temperature, and pressure). The GHE‐DT's digital system mainly comprises three sections, namely, data storage, mathematical modeling, and data‐driven modeling. The role of the presented mathematical model is to simulate the GHE's behavior and assess its performance characteristics, such as the heat exchanger's effectiveness and efficiency. Additionally, the data‐driven model used in the proposed DT utilizes formal concept analysis and relation concept analysis to identify connections and associations among parameters for a better understanding of the GHE functioning. The GHE‐DT provides useful services including trend analysis, problem prediction, and correlation analysis. These services provide engineers and operators with the opportunity to increase dependability, save maintenance costs, and optimize GHE performance.

Despite that the Proton Exchange Membrane Fuel Cell (PEMFC) is considered to be an efficient power device; around half of the energy produced from the electrochemical reaction is dissipated as heat due to irreversibility of the cathodic reaction, Ohmic resistance, and mass transport overpotentials. Effective heat removal from the PEMFC, via cooling, is very important to maintain the cell/stack at a uniform operating temperature ensuring the durability of the device as excessive operating temperature may dry out the membrane and reduces the surface area of the catalyst hence lowering the performance of the cell. In addition to cooling, capturing the produced heat and repurposing it using one of the Waste Heat Recovery (WHR) technologies is an effective approach to add a great economic value to the PEMFC power system. Global warming, climate change, and the high cost of energy production are the main drivers to improve the energy efficiency of PEMFC using WHR. This paper presents an overview of the recent progress concerning the cooling strategies and WHR opportunities for PEMFC. The main cooling techniques of PEMFCs are described and evaluated with respect to their advantages and disadvantages. Additionally, the potential pathways for PEMFC-WHR including heating, cooling, and power generation are explored and assessed. Furthermore, the main challenges and the research prospects for the cooling strategies and WHR of PEMFCs are discussed.

Living organisms' energy conversion is considered as an essential and sustainable green energy source and future bio-hybrid technologies. Recently, plants were used after harvesting as biomass in bio-fermentation as an energy source. In bio-electrochemical systems, microorganisms work with plants to generate electricity, hydrogen, or methane. This work discusses the simultaneous pollutant removal and electricity generation in plant-based bio-electrochemical systems (P-BES). Factors affecting the P-BES performance and the removal efficiencies of the different organic and inorganic pollutants were illustrated. Furthermore, the plant-based bioelectrochemical systems' role in achieving the sustainable development goals (SDGs) was discussed. The SDGs contribution of plant-based bioelectrochemical systems were presented and discussed to evaluate such systems' ability to achieve the three pillars of sustainable development, i.e., economic, environmental, and social.

This paper outlines the key components necessary to develop a digital twin (DT) for a wind turbine, aiming to provide a detailed methodology and guidelines for building this system, which facilitates optimization during operation and helps prevent system failures. It presents the four major systems required to construct the DT: the physical, digital, connection, and service systems. This study also presents the critical design, measured, and calculated parameters of a wind turbine, which are essential to the development of the DT. The physical system of the wind turbine and its critical components were examined, including the rotor, blades, shaft, generator, tower, and nacelle. The paper also explores the digital system of the DT, including data storage, digital models, and mathematical modeling. The problems that may occur during the operation were presented in addition to the possible solutions that the service system must suggest. According to the project's needs and requirements, it was found that the DT of a wind turbine can employ various connection systems such as supervisory control and data acquisition, wireless sensor networks, smart grids, Internet of Things, and cloud-based systems.

Supercapacitors (SCs) are recognized by high power densities and significantly higher cyclic stability compared to batteries. However, the energy density in SCs should be improved for better applications and commercialization. This could be achieved by developing materials characterized by such porous structures as metal-organic frameworks (MOFs) and metal chalcogenides in the electrodes’ materials. Herein, the recent advances in MOF derived from metal sulfides and selenides as electrode materials for SCs are reviewed and discussed. Strategies such as adopting core-shell structures, carbon-coating, and doping, which are used to promote the electrochemical performances of these MOF-based materials, are presented. Additionally, the progress in developing S-doped MOF-derived catalysts for the oxidation-reduction reaction (ORR) in the cathode of fuel cells is also reviewed. In addition, the challenges and future research trends are summarized in this minireview.

The rapid growth in the consumption of fossil fuels resulted in climate change and severe health issues. Among the different proposed methods to control climate change, carbon capture technologies are the best choice in the current stage. In this study, the various membrane technologies used for carbon capture and their impact on achieving sustainable development goals (SDGs) are discussed. Membrane-based carbon capture processes in pre-combustion and post-combustion, which are known as membrane gas separation (MGS) and membrane contactor (MC), respectively, along with the process of fabrication and the different limitations that hinder their performances are discussed. Additionally, the 17 SDGs, where each representing a crucial topic in the current global task of a sustainable future, that are impacted by membrane-based carbon capture technologies are discussed. Membrane-based carbon capture technologies showed to have mixed impacts on different SDGs, varying in intensity and usefulness. It was found that the membrane-based carbon capture technologies had mostly influenced SDG 7 by enhancement in the zero-emission production, SDG 9 by providing 38-42% cost savings compared to liquid absorption, SDG 3 through reducing pollution and particulate matter emissions by 23%, and SDG 13, with SDG 13 being the most positively influenced by membrane-based carbon capture technologies, as they significantly reduce the CO2 emissions and have high CO2 capture yields (80-90%), thus supporting the objectives of SDG 13 in combatting climate change.