scholarly journals Conceptual Design Development of a Fuel-Reforming System for Fuel Cells in Underwater Vehicles

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2000
Author(s):  
Seung-Kyo Jung ◽  
Won-Sim Cha ◽  
Yeong-In Park ◽  
Shin-Hyung Kim ◽  
Jungho Choi
Keyword(s):  
Fuel Cells ◽  
Separation Efficiency ◽  
Methanol Conversion ◽  
Underwater Vehicles ◽  
Hydrogen Yield ◽  
Design Development ◽  
Fuel Reforming ◽  
Aspen Hysys ◽  
Endothermic Reactions ◽  
High Separation

An air-independent propulsion system containing fuel cells is applied to improve the operational performance of underwater vehicles in an underwater environment. Fuel-reforming efficiently stores and supplies hydrogen required to operate fuel cells. In this study, the applicability of a fuel-reforming system using various fuels for underwater vehicles was analyzed by calculating the fuel and water consumptions, the amount of CO2 generated as a byproduct, and the amount of water required to dissolve the CO2 using aspen HYSYS (Aspen Technology, Inc., Bedford, MA, USA). In addition, the performance of the fuel-reforming system for methanol, which occupies the smallest volume in the system, was researched by analyzing performance indicators such as methanol conversion rate, hydrogen, yield and selectivity, and reforming efficiency under conditions at which pressure, temperature, steam-to-carbon ratio (SCR), and hydrogen separation efficiency vary. The highest reforming efficiency was 77.7–77.8% at 260 °C and 270 °C. At SCR 1.5, the reforming efficiency was the highest, which is 77.8%, and the CO2 generation amount was the lowest at 1.46 kmol/h. At high separation efficiency, the reforming efficiency increased due to the reduction of reactants, and a rate at which energy is consumed for endothermic reactions also decreased, resulting in a lower CO2 generation amount.

Structural and Compositional Analysis of a Ni/CeO2 Catalyst for Fuel Reforming in Solid Oxide Fuel Cells

2012 ◽  
Vol 18 (S2) ◽  
pp. 1398-1399
Author(s):  
R. Cavendish ◽  
P.A. Crozier
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Compositional Analysis ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Reforming

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

scholarly journals The Limitations in Current Studies of Organic Fouling and Future Prospects

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 922
Author(s):  
Xianghao Meng ◽  
Shujuan Meng ◽  
Yu Liu
Keyword(s):  
Membrane Fouling ◽  
Separation Efficiency ◽  
Deep Understanding ◽  
Support Vector ◽  
Feed Water ◽  
Source Water ◽  
Future Prospects ◽  
Surrogate Substances ◽  
High Separation ◽  
Selection Of

Microfiltration and ultrafiltration for water/wastewater treatment have gained global attention due to their high separation efficiency, while membrane fouling still remains one of their bottlenecks. In such a situation, many researchers attempt to obtain a deep understanding of fouling mechanisms and to develop effective fouling controls. Therefore, this article intends to trigger discussions on the appropriate choice of foulant surrogates and the application of mathematic models to analyze fouling mechanisms in these filtration processes. It has been found that the commonly used foulant surrogate (sodium alginate) cannot ideally represent the organic foulants in practical feed water to explore the fouling mechanisms. More surrogate foulants or extracellular polymeric substance (EPS) extracted from practical source water may be more suitable for use in the studies of membrane fouling problems. On the other hand, the support vector machine (SVM) which focuses on the general trends of filtration data may work as a more powerful simulation tool than traditional empirical models to predict complex filtration behaviors. Careful selection of foulant surrogate substances and the application of accurate mathematical modeling for fouling mechanisms would provide deep insights into the fouling problems.

Controllable Preparation of Silver Orthophosphate@Carbon Layer Core/Shell Heterostructure with Enhanced Visible Photocatalytic Properties and Stability

NANO ◽  
2015 ◽  
Vol 10 (02) ◽  
pp. 1550022 ◽  
Author(s):  
Yangcun Xie ◽  
Xiuwen Wang ◽  
Xu Wen
Keyword(s):  
High Stability ◽  
Separation Efficiency ◽  
Visible Region ◽  
Carbon Layer ◽  
Core Shell ◽  
Photogenerated Electrons ◽  
First Time ◽  
Fabrication Parameters ◽  
Controllable Preparation ◽  
High Separation

In this study, silver orthophosphate@carbon layer ( Ag 3 PO 4@ C ) core/shell heterostructure photocatalyst was prepared for the first time. The results showed that a uniform carbon layer was formed around the Ag 3 PO 4. By adjusting the hydrothermal fabrication parameters, the thickness of carbon layer could be easily controlled. Furthermore, the Ag 3 PO 4@ C had remarkable light absorption in the visible region. Photocatalytic tests displayed that the Ag 3 PO 4@ C heterostructures possessed a much higher degradation rate of phenol than pure Ag 3 PO 4 under visible light. The enhanced photocatalytic activity could be attributed to high separation efficiency of photogenerated electrons and holes based on the synergistic effect between carbon as a sensitizer and Ag 3 PO 4. Recycle tests showed that the Ag 3 PO 4@ C core/shell heterostructures maintained high stability over several cycles. The good stability could be attributed to the protection of insoluble carbon layer on the surfaces of Ag 3 PO 4 crystals in aqueous solution.

Numerical evaluation of separation efficiency in the diverging T-junction for slug flow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Faheem Ejaz ◽  
William Pao ◽  
Hafiz Muhammad Ali
Keyword(s):  
Slug Flow ◽  
Design Methodology ◽  
Separation Efficiency ◽  
Fluid Model ◽  
Diameter Ratio ◽  
Maintenance Costs ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Practical Implications ◽  
High Separation

Purpose Offshore industries encounter severe production downtime due to high liquid carryovers in the T-junction. The diameter ratio and flow regime can significantly affect the excess liquid carryovers. Unfortunately, regular and reduce T-junctions have low separation efficiencies. Ansys as a commercial computational fluid dynamics (CFD) software was used to model and numerically inspect a novel diverging T-junction design. The purpose of diverging T-junction is to merge the specific characteristics of regular and reduced T-junctions, ultimately increasing separation efficiency. The purpose of this study is to numerically compute the separation efficiency for five distinct diverging T-junctions for eight different velocity ratios. The results were compared to regular and converging T-junctions. Design/methodology/approach Air-water slug flow was simulated with the help of the volume of the fluid model, coupled with the K-epsilon turbulence model to track liquid-gas interfaces. Findings The results of this study indicated that T-junctions with upstream and downstream diameter ratio combinations of 0.8–1 and 0.5–1 achieved separation efficiency of 96% and 94.5%, respectively. These two diverging T-junctions had significantly higher separation efficiencies when compared to regular and converging T-junctions. Results also revealed that over-reduction of upstream and downstream diameter ratios below 0.5 and 1, respectively, lead to declination in separation efficiency. Research limitations/implications The present study is constrained for air and water as working fluids. Nevertheless, the results apply to other applications as well. Practical implications The proposed T-junction is intended to reduce excessive liquid carryovers and frequent plant shutdowns. Thus, lowering operational costs and enhancing separation efficiency. Social implications Higher separation efficiency achieved by using diverging T-junction enabled reduced production downtimes and resulted in lower maintenance costs. Originality/value A novel T-junction design was proposed in this study with a separation efficiency of higher than 90%. High separation efficiency eliminates loss of time during shutdowns and lowers maintenance costs. Furthermore, limitations of this study were also addressed as the lower upstream and downstream diameter ratio does not always enhance separation efficiency.

PEM Fuel Cells, Materials and Design Development Challenges

Fuel Cells ◽  
2012 ◽  
pp. 341-367 ◽  
Author(s):  
Stephen J. Paddison ◽  
Hubert A. Gasteiger
Keyword(s):  
Fuel Cells ◽  
Pem Fuel Cells ◽  
Design Development

Amorphous colloidal photonic crystals assembled by mesoporous silica particles for thin layer chromatography with high separation efficiency and colorimetric recognition

2020 ◽  
Vol 8 (48) ◽  
pp. 17202-17210
Author(s):  
Xin Zhang ◽  
Yumei Ran ◽  
Qianqian Fu ◽  
Jianping Ge
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Mesoporous Silica ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Separation Efficiency ◽  
Colloidal Photonic Crystals ◽  
Crystal Film ◽  
Layer Chromatography ◽  
High Separation

A mesoporous SiO2 amorphous photonic crystal film was used to develop new thin-layer chromatography with high separation efficiency and simplified recognition.

scholarly journals Prediction of Reformed Gas Composition for Diesel Engines with a Reformed EGR System Using an Artificial Neural Network

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5886
Author(s):  
Jiwon Park ◽  
Jungkeun Cho ◽  
Heewon Choi ◽  
Jungsoo Park
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Alternative Fuels ◽  
Combustion Engine ◽  
Gas Production ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Fuel Reforming ◽  
Artificial Neural ◽  
Partial Oxidation Reforming

Facing the reinforced emission regulations and moving toward a clean powertrain, hydrogen has become one of the alternative fuels for the internal combustion engine. In this study, the prediction methodology of hydrogen yield by on-board fuel reforming under a diesel engine is introduced. An engine dynamometer test was performed, resulting in reduced particulate matter (PM) and NOx emission with an on-board reformer. Based on test results, the reformed gas production rate from the on-board reformer was trained and predicted using an artificial neural network with a backpropagation process at various operating conditions. Additional test points were used to verify predicted results, and sensitivity analysis was performed to obtain dominant parameters. As a result, the temperature at the reformer outlet and oxygen concentration is the most dominant parameters to predict reformed gas owing to auto-thermal reforming driven by partial oxidation reforming process, dominantly.

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