Solar energy is one of the most promising energy sources, and its effective use has been continuously attracting widespread attention. Here, a solar-power thermoelectric system with self-cleaning ...capability was introduced based on a hydrogel. The hydrogel is formed through the polymerization of acrylic acid and acrylamide, resulting in the formation of compact ion channels within its structure. The mixed solvent of dimethyl sulfoxide and ethylene glycol plays a crucial role in this process by generating a significant number of hydrogen bonds, which enables the hydrogel to retain water and possess exceptional strength. Based on the coupling effect of the aforementioned two characteristics, the hydrogel exhibits a stable and remarkable electrochemical reaction facilitated by the synergistic action of NaCl and Fe(CN)6 3–/4–. By leveraging the unique reaction mechanism within the hydrogel, we achieved significant improvements in multiple aspects of the system, including high Seebeck coefficient (2.1 mV K–1), excellent thermoelectric figure of merit (9.84 × 10–3), good electrical conductivity (1.6 S m–1), and low thermal conductivity (0.251 W m–1 K–1). Furthermore, the integration of superhydrophobicity using fluoridated carbon nanotubes endows the system with photothermal and self-cleaning capability simultaneously. Particularly, the power density can reach 3.3 mW m–2, which could lit the LED easily. Thus, this self-cleaning thermoelectric system represents a promising option for solar-energy-dependent outdoor solar energy utilization.
The development of low-cost, highly durable alkaline oxygen evolution reaction (OER) catalysts with competitive activity comparable to that of noble metals is crucial for addressing energy and ...environmental challenges. In this study, the Co + HNO3 electrode prepared by a more industrial thermal decomposition coating method has a porous surface structure and stronger Co–O hybrid. The electrode showed a high electrocatalytic intrinsic activity, which greatly improved its alkaline OER performance. Under 0.1 M KOH and 10 mA cm–2 conditions, the Co + HNO3 electrode demonstrated a remarkably low overpotential of 280 (mV vs RHE), outperforming commonly used pure Ni plate electrodes, commercial IrO2 electrodes, as well as several reported Co-based catalysts. Furthermore, the Co + HNO3 electrode maintained its superior activity without noticeable degradation during continuous operation for 40,000 s at 0.1 M KOH and 10 mA cm–2. In the harsh environment of 1 M KOH, 1 A cm–2, and 60 °C, the accelerated life of the electrode is as long as 312 h, showing good electrochemical long-term stability. This approach of achieving porous structure and stronger Co–O hybridization by precursor solvent induction in this study provides a new idea for the preparation of efficient OER catalysts.
Natural gas hydrate (NGH) has the advantages of wide distribution and large reserves, and has attracted extensive attention from the international community. Researchers have conducted quantitative ...microscopic pore-scale simulations, exploitation surveys, laboratory tests, and numerical simulations, but commercial development is still a long way off. In view of the existing problem of insufficient productivity, enlarged permeable well wall technology is studied in this paper, which is a method to improve reservoir productivity by changing well conditions. There is a free gas zone in the Class 1 reservoir and no free gas zone in the Class 3 reservoir; the structural differences lead to different multiphase seepage processes, and the mechanisms of stimulation are also different. In order to further improve productivity and understand the production difference between the two reservoirs, this paper selects Class 1 and Class 3 reservoirs, establishes the numerical simulation model of NGH extraction by the depressurization method, analyzes the influence of well radius and permeability on productivity, and compares the influence of this technology on the two reservoirs. The results show that (1) the productivity of Class 1 and Class 3 reservoirs is significantly increased under this technology. The same well adjustment has a better effect on Class 3 reservoirs. (2) When the radius is 1 m, the best stimulation effect is shown; the radius enlarges from 0.1 to 1 m, and the V P of Class 1 and Class 3 reservoirs is increased by 19.70 and 17.06%, respectively. (3) When permeability is 1 × 10–7 m2, the best stimulation effect is shown; the permeability is increased from 1 × 10–9 to 1 × 10–7 m2, and V P is increased by 35.50 and 115.35%, respectively. (4) Changing the radius and permeability at the same time can better improve the productivity of the two reservoirs, and has a synergistic effect on Class 3 reservoirs.
One of the key parameters in assessing the production potential of unconventional oil and gas reservoirs is the quantification of organic matter, which is generally determined by pyrolysis. ...Laboratory nuclear magnetic resonance (NMR) is widely used in the oil industry; being a nondestructive method, it enables the possibility to perform several analyses on the same sample, which is desirable due to the heterogeneity of these types of geological formations. 13C spectra provide much information, from speciation to maturity determination. The main drawback of this technique is the inherently low signal obtained for these nuclei, rendering extremely long experimental times. A solution is using cross-polarization schemes that transfer the high polarization of nearby 1H nuclei to 13C ones, with the penalty that quantification is a priori not feasible. In this work, we analyze the cross-polarization evolution and conclude that quantifying the total organic content (TOC) is possible for a wide range of organic matter content and maturities for rock samples corresponding to the Neuquén and Cuyo basins in Argentina.
Building better batteries Tarascon, J.-M; Armand, M
Nature (London),
02/2008, Letnik:
451, Številka:
7179
Journal Article
Recenzirano
If a new energy economy is to emerge, it must be based on a cheap and sustainable energy supply. One of the most flagrantly wasteful activities is travel, and here battery devices can potentially ...provide a solution, especially as they can be used to store energy from sustainable sources such as the wind and solar power.
Extreme weather events have a significant impact on the aging and outdated power distribution infrastructures. These high-impact low-probability events often result in extended outages and loss of ...critical services, thus, severely affecting customers' safety. This calls for the need to ensure the resilience in distribution networks by quickly restoring the critical services during a disaster. This paper presents an advanced feeder restoration method to restore critical loads using distributed energy resources (DERs). A resilient restoration approach is proposed that jointly maximizes the amount of restored critical loads and optimizes the restoration times by optimally allocating grids available DER resources. The restoration problem is modeled as a mixed-integer linear program with the objective of maximizing the resilience to postrestoration failures while simultaneously satisfying grids critical connectivity and operational constraints and ensuring a radial operation for a given open-loop feeder configuration. Simulations are performed to demonstrate the effectiveness of the proposed approach using the IEEE 123-node feeder with five DERs supplying 11 critical loads and the IEEE 906-bus feeder with three DERs supplying 17 critical loads. The impacts of DER availability and fuel reserve on restored networks are assessed and it is shown that the proposed approach is successfully able to restore a maximum number of critical loads using available DERs.
In this study, we conducted physical modeling to investigate the effectiveness of nanodispersed catalysts, specifically pure magnetite and magnetite with nickel oxide, for in situ upgrading of ...high-viscosity Ashal′cha heavy oil through thermal steam treatment (TST). The reactions were carried out at 250 °C for different treatment durations (24, 48, and 72 h). The aquathermolysis reactions with Fe3O4 + NiO catalyst exhibited remarkable results, achieving an optimum viscosity reduction of 2000 mPa·s through thermal cracking, which converted heavy high-molecular-weight compounds into lighter compounds. Furthermore, the presence of the catalyst contributed to increased levels of light-saturated compounds and aromatic compounds, while significantly decreasing asphaltenes and resins. Hydrogen donors were introduced to prevent hydrocarbon polymerization. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that increasing the treatment duration did not adversely affect the reaction compared to the absence of the catalyst. Notably, the magnetite catalyst demonstrated high efficiency due to its availability, cost-effectiveness, and small nanosize, facilitating penetration into reservoir rock pores when injected into the reservoir medium. These findings underscore the potential of nanodispersed catalysts for in situ heavy oil upgrading, offering viscosity reduction and the conversion of heavy compounds into valuable light compounds.
Rising energy costs, losses in the present-day electricity grid, risks from nuclear power generation, and global environmental changes are motivating a transformation of the conventional ways of ...generating electricity. Globally, there is a desire to rely more on renewable energy resources (RERs) for electricity generation. RERs reduce greenhouse gas emissions and may have economic benefits, e.g., through applying demand side management with dynamic pricing so as to shift loads from fossil fuel-based generators to RERs. The electricity grid is presently evolving toward an intelligent grid, the so-called smart grid (SG). One of the major goals of the future SG is to move toward 100% electricity generation from RERs, i.e., toward a 100% renewable grid. However, the disparate, intermittent, and typically widely geographically distributed nature of RERs complicates the integration of RERs into the SG. Moreover, individual RERs have generally lower capacity than conventional fossil fuel-based plants, and these RERs are based on a wide spectrum of different technologies. In this article, we give an overview of recent efforts that aim to integrate RERs into the SG. We outline the integration of RERs into the SG along with their supporting communication networks. We also discuss ongoing projects that seek to integrate RERs into the SG around the globe. Finally, we outline future research directions on integrating RERs into the SG.
•A Li-ion BESS market overview of Europe, the Middle East and Africa is presented.•Existing Li-ion BESS use-cases are analyzed.•Key drivers enabling the implementation of Li-ion BESS projects are ...discussed.•Requirements and associated risk factors are evaluated.•The future relevant technological developments and market trends are assessed.
Large-scale Lithium-ion Battery Energy Storage Systems (BESS) are gradually playing a very relevant role within electric networks in Europe, the Middle East and Africa (EMEA). The high energy density of Li-ion based batteries in combination with a remarkable round-trip efficiency and constant decrease in the levelized cost of storage have led to the recent boom of the technology. However, many of the potential applications of large-scale battery systems are not economically viable at this point in time. As a result, several BESS projects are being pushed by the industry towards specific niches which are based on revenue streams that can be rather complex than straightforward. The aim of this paper is to provide an overview of how large-scale Li-ion BESS are currently being implemented in the EMEA region, giving an answer to the following questions: what are the main use-cases of large-scale Li-ion batteries that are being implemented? What are the key factors that are enabling the deployment of BESS projects in the present markets? How can current tendencies be extrapolated to the future outlook of Li-ion BESS implementations? The large-scale energy storage market is evolving at a very fast pace, hence this review paper intends to contribute to a better understanding of the current status of Li-ion battery systems focusing on the economic feasibility that is driving the realization of Li-ion BESS projects in the EMEA region.
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