China
Africa
Explore chapters and articles related to this topic
Energy and the Environment
Published in Marc J. Assael, Geoffrey C. Maitland, Thomas Maskow, Urs von Stockar, William A. Wakeham, Stefan Will, Commonly Asked Questions in Thermodynamics, 2022
Marc J. Assael, Geoffrey C. Maitland, Thomas Maskow, Urs von Stockar, William A. Wakeham, Stefan Will
A fuel cell is an electrochemical energy conversion device which can capture and use the power of hydrogen very efficiently. It directly converts the chemical energy inherent in hydrogen into electricity and is essentially pollution-free, producing only water and heat, which can also be used for other applications such as combined heat and power CHP (Breeze 2017). As we shall see, fuel cells combine this clean electricity generation with efficiencies two to three times those of traditional fossil fuel power plants and engines. The first fuel cell was, in fact, invented a long time ago, in 1839 by William Grove who developed what he called a “gas voltaic battery” (Grove 1839; Sella 2020). It was Ludwig Mond and Charles Langer who first used the term “fuel cell” some 50 years later (Mond and Langer 1889; Appleby 1990).
Fuel Cells
Published in Sergio C. Capareda, Introduction to Renewable Energy Conversions, 2019
A fuel cell is an electrochemical energy conversion device. It converts the chemical energy of a fuel (e.g., hydrogen) directly into electrical energy. The fuel and an oxidizing agent (usually oxygen from air) are continuously but separately supplied to the two electrodes of the cell, at which they undergo a reaction. Figure 8.1 shows the typical schematic and structure of a fuel cell that uses hydrogen gas and oxygen from the air. This is a typical proton exchange membrane fuel cell (PEM). The hydrogen fuel is channeled through the field flow plates to the anode on one side. The oxygen from the air is channeled to the cathode on the other side of the cell. A platinum catalyst is used at the anode, causing the hydrogen to split into positive hydrogen ions (protons) and negatively charged electrons. This PEM allows only the positively charged ions to pass through to the cathode. The negatively charged electrons must travel along the external circuit to the cathode, creating an electrical current. The electrons and positively charged hydrogen ions combine with oxygen at the cathode to form water, which then flows out of the cell.
Energy Storage for PV Applications
Published in Majid Jamil, M. Rizwan, D. P. Kothari, Grid Integration of Solar Photovoltaic Systems, 2017
Majid Jamil, M. Rizwan, D. P. Kothari
Fuel cells are similar to a battery in that it is also an electrochemical energy conversion device, but there is a major difference in that fuel cells are designed for continuous replenishment of the reactants consumed, which means it needs an external source such as oxygen and fuel to produce electricity, unlike a battery, which has limited energy storage capacity. Also the electrodes of fuel cells are catalytic, which means it will never discharge permanently and are stable, whereas in batteries, electrodes are changed during charging or discharging reactions.
Integrative technology hubs for urban food-energy-water nexuses and cost-benefit-risk tradeoffs (I): Global trend and technology metrics
Published in Critical Reviews in Environmental Science and Technology, 2021
Ni-Bin Chang, Uzzal Hossain, Andrea Valencia, Jiangxiao Qiu, Qipeng P. Zheng, Lixing Gu, Mengnan Chen, Jia-Wei Lu, Ana Pires, Chelsea Kaandorp, Edo Abraham, Marie-Claire ten Veldhuis, Nick van de Giesen, Bruno Molle, Severine Tomas, Nassim Ait-Mouheb, Deborah Dotta, Rémi Declercq, Martin Perrin, Léon Conradi, Geoffrey Molle
Hydrogen fuel cell (EE3-HFC) technology is an electrochemical energy conversion process used to convert chemical potential energy into electrical energy. In this system, hydrogen gas (H2) and oxygen gas (O2) are used as fuel through a proton exchange membrane cell. It is considered a nontoxic and renewable source of energy, provided H2 and O2 are obtained from renewable energy, and is applicable for transportation and other activities in various FEW systems. However, the presence of impurities, even trace elements in fuel, air streams, or fuel cell systems, could severely affect the anode, membrane, and cathode, which could dramatically reduce the performance (Cheng et al., 2007). Descriptions of other emerging energy technologies in evolving FEW nexus systems such as CO2 plume geothermal power (EE1-CPG), bacteria-powered solar cell (EE4-BPSC), molecular solar thermal energy storage (EE5-MSTES), tidal lagoon (EE6-TL), molten salt battery (EE7-MSB), low head hydro-turbine system (EE8-LHH), and gravity storage (EE9-GS) are given in Supplementary Information (S2.1). Most of the emerging energy technologies are associated with higher investment costs, but are highly efficient. For example, EE1-CPG is about 10 times more efficient than the traditional system. Many of these are still unproven technologies in terms of long term efficiency, and technological and environmental risks, but researchers are working to resolve such issues (Supplementary Information Table S10).
Parallel Inductor Multilevel Current Source Inverter for Input Ripple Current Reduction in PEM Fuel Cell Applications
Published in IETE Journal of Research, 2020
Nik Fasdi Nik Ismail, Nasrudin Abd. Rahim, Siti Rohani Sheikh Raihan, Yusuf Al-Turki
However, storing this energy is problematic and challenging: batteries or storage units perform well over short timescales, but over periods of months or year different methods are necessary, making storage units not attractive options for utility companies and consumers [1]. Energy storage in the form of hydrogen offers a possible alternative. This energy storage or a fuel cell is a direct electrochemical energy conversion device. Through electrochemistry, fuel cell directly converts chemical energy into electrical energy. Unlike a battery which can be depleted, a fuel cell will continue to produce electricity as long as hydrogen is supplied. The potential for highly reliable and long-lasting systems can be achieved [2]. Nevertheless, fuel cell technology is still new and faces challenges and barriers to its implementation such as the cost of the fuel cell, power density and performance, hydrogen storage and fuel cell durability under start-stop cycling [2,3].
Effect of air supply on the performance of an active direct methanol fuel cell (DMFC) fed with neat methanol
Published in International Journal of Green Energy, 2018
Qian Xu, Weiqi Zhang, Jian Zhao, Lei Xing, Qiang Ma, Li Xu, Huaneng Su
A direct methanol fuel cell (DMFC) is an electrochemical energy conversion device that directly converts the chemical energy stored in methanol into electricity. The market opportunity for DMFCs as portable power source of mobile electronic devices is promising as compared with conventional batteries, because DMFCs have several distinct advantages, e.g. system simplicity, easy refueling, and high energy density (Dillon, Srinivasan, and Arico 2004; Kamarudin, Daud, and Ho 2007; Munjewar, Thombre, and Mallick 2017). Nevertheless, the overall cell performance has not reached to the expected level although great efforts have been involved during past decades. The main technological issues are: sluggish and complicate kinetics of the methanol oxidation reaction (MOR) (Liu et al. 2006; Sun, Xing, and Scott 2010; Wang 2004; Xing et al. 2016) and the permeation of methanol from the anode through electrolyte membrane to the cathode, which is called ‘methanol crossover (MCO)’ (Heinzel and Barragan 1999; Shironita et al. 2014). MCO not only causes a mixed potential at cathode, but also leads to a waste of fuel, lowering the overall efficiency of fuel cells (Li and Faghri 2013). The MCO rate is associated with the methanol concentration in anode catalyst layer (ACL). The conventional way to alleviate the impact of MCO is to feed a diluted methanol solution (i.e. 1–2 M for active fuel supply systems and 3–5 M for passive DMFC) to the anode (Bae et al. 2006; Chan et al. 2008; Liu et al. 2005; Mallick, Thombre, and Shrivastava 2016). However, this method would also cause a large decrease in system specific energy, hence loses the most attractive feature of DMFC–high energy density.