Fuel Cells最新文献

The treatment of high concentration and low C/N ratio of nitrate wastewater is a promising and challenging research topic. Combining electrochemical reduction and anammox is a technology with great development potential for nitrogen removal from wastewater. In this work, Cu─Ag─Co cathode materials were prepared by two-step electrodeposition method. The effect of current density and initial pH value on nitrate reduction efficiency was investigated in a single chamber electrolytic cell equipped with Cu─Ag─Co cathode and Ti/RuO₂─IrO₂ anode. The results showed that under the conditions of initial NO₃⁻─N concentration of 500 mg L⁻¹, Na₂SO₄ concentration of 0.125 mol L⁻¹, current density of 10 mA cm⁻², initial pH value of 7, and treatment time of 5 h, NO₃⁻─N removal ratio was 84.5%, the concentration of NO₂⁻─N and NH₄⁺─N was 180.2 mg L⁻¹ and 173.2 mg L⁻¹. Wastewater with a concentration ratio of NO₂⁻─N and NH₄⁺─N of 1.04:1 meets the influent requirements for anaerobic ammonia oxidation. Through the combination process, the final NO₃⁻─N removal ratio was 82.6%, the NO₂⁻─N concentration was 3.2 mg L⁻¹, and the NH₄⁺─N concentration was 26.4 mg L⁻¹. It provided a reference for the treatment of wastewater with low C/N ratio nitrate by combining electrochemical reduction and anammox.

Solid oxide fuel cell (SOFC) systems have become a research focus because of their clean and high-efficiency properties. Control of output voltage and fuel utilization is critical to the energy management for multi-energy systems incorporating SOFC energy supply. However, maintaining precise control of the system's voltage in the presence of perturbations can be challenging. Moreover, the system's voltage control process can lead to fuel utilization fluctuations, which may affect the economy and safety. The design of the controller must meet both of these requirements. The stringent control requirements lead to poor parameter adaptability of existing controllers. This paper designs a nonlinear function and adopts a nonlinear/linear active disturbance rejection controller (ADRC) based on state switching to solve the output voltage tracking control problem of SOFC and maintain the fuel utilization rate in the ideal range. The simulation experimental results show that the proposed method has the advantages of strong and superior parameter adaptability with less control effort, which provides theoretical guidance for the design of the output voltage controller of the actual SOFC system.

Fuel cell technology is a promising alternative to traditional internal combustion engines in various applications, especially in transportation applications. This paper proposes a framework of strategic energy management for fuel cell electric vehicles (FCEVs), which is developed to safeguard the dual vehicle energy sources, that is, fuel cells and power batteries. This is accomplished by applying an energy management strategy (EMS) from a prognostic perspective. A fuzzy energy management approach is used to manage the power flow in the FCEV, enabling safe and predefined operation at multiple degradation points. To guarantee reliable and continuous energy source functioning, prognostics algorithms are incorporated into the EMS to identify energy source degradation. The prediction results are integrated into the controller by refining the controller parameters geometrically. Simulation outcomes show that the proposed EMS offers efficient use the dual energy sources, which improves the durability of the energy sources.

In a polymer electrolyte membrane (PEM) fuel cell, the following degradation mechanisms are associated with the catalyst particles and their support: carbon support corrosion triggered by carbon and platinum oxidation, platinum dissolution with redeposition, and particle detachment with agglomeration. In this work, an electrochemical model for those degradation effects is presented as well as its coupling with a three-dimensional computational fluid dynamics PEM fuel cell performance model. The overall model is used to calculate polarization curves and current density distributions of a PEM fuel cell in a fresh and aged state as well as the degradation process during an accelerated stress test with 30 000 voltage cycles. The obtained simulation results are compared to measurements on a three-serpentine channel PEM fuel cell with an active area of 25 cm² under various temperatures and humidities. The experimental data are obtained with a segmented test cell using respective degradation protocols and test conditions proposed by the United States Department of Energy. In addition to the temperature and humidity changes, the influence of geometry and material parameters on the degree of degradation and the resulting fuel cell performance is explored in detail.

Microbial electrolysis cells (MECs) can effectively treat sulfate-containing wastewater, but biocathode microorganisms, such as sulfate-reducing bacteria (SRB), are susceptible to environmental influences. In practical wastewater treatment, the flow of water in the reactor generates shear forces that directly impact the growth and structure of the biofilm, which leads to changes in MEC efficacy. However, the sulfate reduction efficacy and biofilm community structure changes in MEC reactors under flow conditions have yet to be adequately evaluated. In this study, two-chamber SRB biocathode MECs were constructed under flow conditions (experimental group [EG]) and stationary conditions (control group [CG]). The sulfate reduction rates of CG and EG were stable and reached 88.9% and 84.45%, respectively. The output voltage and current density of EG were similar to those of CG, indicating that the MEC could operate stably under flow conditions. The community structure of the biocathode indicated a high relative abundance of Desulfomicrobium from EG, which promoted the dissimilatory sulfate reduction pathway. This information reveals the potential of flow in improving the performance of MECs in treating sulfate-containing wastewater.

The efficient cathode material helps to improve the removal of antibiotics in the electro-Fenton (EF) system. The simultaneous doping of transition metals and heterogeneous non-metallic elements in biochar electrodes can enhance the performance of EF systems, but the catalytic mechanism for EF needs to be further explored. In this study, novel Fe/S-doped biochar cathodes derived from marine algae (MA) were prepared to investigate the removal rate of ceftriaxone sodium (CS) and the underlying mechanisms. The results indicated that the Fe/S modified MA (Fe/S/MA) biochar cathode showed the highest CS removal rate (71.23%) in the EF system when treating 20 mg/L CS solution containing 8 mg/L Fe²⁺ at pH 4. Scanning electron microscopy and X-ray photoelectron spectroscopy analyses revealed that this cathode provided more iron and sulfur active sites for catalyzing the oxygen reduction reaction to produce H₂O₂, enhanced surface porosity, and improved CS removal rate. Electrochemical tests demonstrated this cathode possessed high electrocatalytic capacity, rapid charge transfer capability, and low electrode resistance. This suggested that it can provide more oxygen reduction reaction sites to promote ∙OH generation and enhance Fe²⁺ regeneration for improving CS removal. This study demonstrates the Fe/S/MA biochar cathode in the EF system shows great potential for the removal of antibiotics.

Traditional wastewater treatment plants (WWTPs) consume a significant amount of energy to clean wastewater. However, for medium- and small-scale WWTPs, it is crucial to have an energetically self-sustained treatment. In this regard, novel low-energy demand treatment systems, such as nature-based solutions (NBS), are highly suitable alternatives. Constructed wetlands coupled with microbial fuel cells (MFC), referred to as electrowetlands (EWs), are NBS able to treat wastewater while recovering electricity. In this study, initially, various granular carbon materials were tested as anode materials in laboratory-scale MFCs, and anthracite was selected due to its higher electrochemical activity. Then, pre-pilot scale tests were conducted, evaluating different EW configurations. The one consisting in a horizontal anode yielded the best wastewater treatment efficiencies (chemical oxygen demand [COD] degradation greater than 90%) and electricity production (11 mW m⁻²; 260 mWh day⁻¹ m⁻²). Finally, a 50 m² pilot was constructed in Valladolid, studying its performance under real conditions for 1 year. The pilot showed robust and stable performance, achieving high wastewater treatment efficiencies (COD degradation >85%, outflow COD of 100 ppm) and generating 115 Wh in 1 year (power density of 0.4 mW m⁻²).