scholarly journals Evolution of fuel cells powered by H2S-containing gases

2008 ◽  
Vol 14 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Karl Chuang ◽  
Jingli Luo ◽  
Alan Sanger
Keyword(s):  
Elemental Sulfur ◽  
Electrical Power ◽  
Operating Conditions ◽  
Composite Anode ◽  
Operating Environment ◽  
Optimal Process ◽  
Anode Catalysts ◽  
Power Densities ◽  
Sustainable Power ◽  
Thermodynamic Basis

The development of the process and electrochemical materials for conversion of H2S in a fuel cell to co-generate electrical power and benign products is outlined. While the thermodynamic basis for the process was clear, it was necessary to perform extensive research into the development of materials as catalysts and electrolytes, and to determine the optimal process and operating conditions. Through the use of composite anode catalysts and compatible new protonic electrolytes that are both chemically and thermally stable in the operating environment, we have achieved good and sustainable power densities. The only products are power, elemental sulfur and steam.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

Introduction of the Taurus™ 65 Industrial Gas Turbine for Power Generation

2008 ◽  
Author(s):  
George Rocha ◽  
Simon Reynolds ◽  
Theresa Brown
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Electrical Power ◽  
Field Evaluation ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Liquid Fuels ◽  
Operating Cycle ◽  
Product Experience ◽  
Exhaust Heat

Solar Turbines Incorporated has combined proven technology and product experience to develop the new Taurus 65 gas turbine for industrial power generation applications. The single-shaft engine is designed to produce 6.3 megawatts of electrical power with a 33% thermal efficiency at ISO operating conditions. Selection of the final engine operating cycle was based on extensive aerodynamic-cycle studies to achieve optimum output performance with increased exhaust heat capacity for combined heat and power installations. The basic engine configuration features an enhanced version of the robust Centaur®50 air compressor coupled to a newly designed three-stage turbine similar to the Taurus 70 turbine design. Advanced cooling technology and materials are used in the dry, lean-premix annular combustor, consistent with Solar’s proven SoLoNOx™ combustion technology, capable of reducing pollutant emissions while operating on standard natural gas or diesel liquid fuels. Like the Titan™ 130 and Taurus 70 products, a traditional design philosophy has been applied in development of the Taurus 65 gas turbine by utilizing existing components, common technology and product experience to minimize risk, lower cost and maximize durability. A comprehensive factory test plan and extended field evaluation program was used to validate the design integrity and demonstrate product durability prior to full market introduction.

scholarly journals Simulation Models of Skidder Conventional and Hybrid Drive

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 921
Author(s):  
Juraj Karlušić ◽  
Mihael Cipek ◽  
Danijel Pavković ◽  
Juraj Benić ◽  
Željko Šitum ◽  
...  
Keyword(s):  
Storage System ◽  
Electrical Power ◽  
Simulation Models ◽  
Energy Storage System ◽  
Management Control ◽  
Operating Conditions ◽  
Hybrid Drive ◽  
Power Generator ◽  
Working Cycle ◽  
Battery Energy

The paper presents a hypothetical conversion of a conventional cable skidder powertrain to its hybrid version. Simulations of skidder operation were made for two existing forest paths, based on the technical characteristics of the engine, transmission system and the characteristics of the winch. Fuel and time consumption were calculated per working cycle considering the operating conditions (slope, load mass). The model was then converted to a hybrid version by adding a battery energy storage system in parallel with the electrical power generator and by employing an energy management control strategy. The dimensions of the battery and the power generator were chosen based on the characteristics of the existing winch with the aim of completely taking over its operation. The management strategy was selected using the specific fuel consumption map. All simulations were repeated for the hybrid drive under the same operating conditions. The results show that fuel savings of around 13% can be achieved with the selected hybrid drive and steering strategy.

Model-Based Calibration of a Biogas Engine Control System

2012 ◽  
Author(s):  
Michael Flory ◽  
Joel Hiltner ◽  
Clay Hardenburger
Keyword(s):  
Control System ◽  
Natural Gas ◽  
Electrical Power ◽  
Engine Performance ◽  
Operating Conditions ◽  
High Quality ◽  
Model Based ◽  
Crank Angle ◽  
Short Period ◽  
Exhaust Gas Emission

Pipeline natural gas composition is monitored and controlled in order to deliver high quality, relatively consistent gas quality in terms of heating value and detonation characteristics to end users. The consistency of this fuel means gas-fired engines designed for electrical power generation (EPG) applications can be highly optimized. As new sources of high quality natural gas are found, the demand for these engines is growing. At the same time there is also an increasing need for EPG engines that can handle fuels that have wide swings in composition over a relatively short period of time. The application presented in this paper is an engine paired with an anaerobic digester that accepts an unpredictable and varying feedstock. As is typical in biogas applications, there are exhaust stream contaminants that preclude the use of an oxygen or NOx sensor for emissions feedback control. The difficulty with such a scenario is the ability to hold a given exhaust gas emission level as the fuel composition varies. One challenge is the design of the combustion system hardware. This design effort includes the proper selection of compression ratio, valve events, ignition timing, turbomachinery, etc. Often times simulation tools, such as a crank-angle resolved engine model, are used in the development of such systems in order to predict performance and reduce development time and hardware testing. The second challenge is the control system and how to implement a robust control capable of optimizing engine performance while maintaining emissions compliance. Currently there are limited options for an OEM control system capable of dealing with fuels that have wide swings in composition. Often times the solution for the engine packager is to adopt an aftermarket control system and apply this in place of the control system delivered on the engine. The disadvantage to this approach is that the aftermarket controller is not calibrated and so the packager is faced with the task of developing an entire engine calibration at a customer site. The controller must function well enough that it will run reliably during plant start-up and then eventually prove capable of holding emissions under typical operating conditions. This paper will describe the novel use of a crank-angle resolved four-stroke engine cycle model to develop an initial set of calibration values for an aftermarket control system. The paper will describe the plant operation, implementation of the aftermarket controller, the model-based calibration methodology and the commissioning of the engine.

Impact of Transient Operating Conditions on Electrical Power System and Component Reliability

2014 ◽  
Vol 7 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Marco Amrhein ◽  
Jason Wells ◽  
Eric Walters ◽  
Seana McNeal ◽  
Brett Jordan ◽  
...  
Keyword(s):  
Power System ◽  
Electrical Power ◽  
Operating Conditions ◽  
Electrical Power System ◽  
Component Reliability

Numerical Investigations on the Power Generation of Turbo-Expander During the Propane De-Hydrogenation Process

2019 ◽  
Author(s):  
Hwabhin Kwon ◽  
Heesung Park
Keyword(s):  
Power Generation ◽  
Rotational Speed ◽  
Mechanical Energy ◽  
Pressure Ratio ◽  
Electrical Power ◽  
Operating Conditions ◽  
Hydrogenation Process ◽  
Operation Conditions ◽  
Turbo Expander ◽  
Discharge Pressure

Abstract A turboexpander for the propane de-hydrogenation process with blade and splitter has been numerically investigated. Since the turboexpander expands fluid from higher inlet pressure to lower discharge pressure, the kinetic energy of fluid is converted into useful mechanical energy. The efficiency and power generation with the designed turboexpander have been simulated with different operating conditions. The pressure ratio between inlet and outlet and rotational speed are varied to characterize the performance of the turboexpander as an electrical power generator. The numerical simulations have shown the vortex at the trailing edges of blade and splitter which decreases the efficiency. The rotational speed and the pressure ratio are parameterized to obtain operation conditions which achieve high power generation and efficiency. Consequently, the generated power from 614.12 kW to 693.45kW is obtained at the normal rotational speed and the pressure ratio between 1.75 to 2.22.

scholarly journals Performance Assessment of Turbocharged PEM Fuel Cell Systems for Civil Aircraft Onboard Power Production

2007 ◽  
Author(s):  
Stefano Campanari ◽  
Giampaolo Manzolini ◽  
Andrea Beretti ◽  
Uwe Wollrab
Keyword(s):  
Fuel Cell ◽  
Environmental Control ◽  
Electrical Power ◽  
Pem Fuel Cell ◽  
Operating Conditions ◽  
Partial Substitution ◽  
Continuous Increase ◽  
System Architectures ◽  
Civil Aircraft ◽  
Air Compression

In recent years, civil aircraft projects are showing a continuous increase in the demand of onboard electrical power, both for the partial substitution of hydraulic or pneumatic controls and drives with electrical ones, and for the consumption of new auxiliary systems developed in response to flight safety and environmental control issues. Aiming to generate on-board power with low emissions and better efficiency, several manufacturers and research groups are considering the possibility to produce a relevant fraction of the electrical power required by the aircraft by a fuel cell system. The first step would be to replace the conventional auxiliary power unit (APU, based on a small gas turbine) with a Polymer Membrane fuel cell type (PEM), which today is favored with respect to other fuel cell types thanks to its higher power density and faster start-up. The PEM fuel cell can be fed with an hydrogen rich gas coming from a fuel reformer, operating with the same jet fuel used by the aircraft, or relying on a dedicated hydrogen storage onboard. The cell requires also an air compression unit, where the temperature, pressure and humidity of the air stream feeding the PEM unit during land and in-flight operation strongly influence the performance and the physical integrity of the fuel cell. In this work we consider different system architectures, where the air compression system may exploit an electrically driven compressor or a turbocharger unit. The compressor type and the system pressure level are optimized according to a fuel cell simulation model which calculates the cell voltage and efficiency as a function of temperature and pressure, calibrated over the performances of real PEM cell components. The system performances are discussed under different operating conditions, covering ground operation, intermediate and high altitude cruise conditions. The optimized configuration is selected, presenting energy balances and a complete thermodynamic analysis.

Fuel Cells for Aircraft Application

2009 ◽  
Author(s):  
Kaspar Andreas Friedrich ◽  
Josef Kallo ◽  
Johannes Schirmer
Keyword(s):  
Fuel Cell ◽  
Electrical Power ◽  
Cell System ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Fuel Cell System ◽  
System Architectures ◽  
Cell Systems ◽  
Research Aircraft ◽  
Aircraft Application

Although air transport is responsible for only about 2% of all anthropogenic CO2 emissions, the rapidly increasing volume of air traffic leads to a general concern about the environmental impact of aviation. Future aircraft generations have to face enhanced requirements concerning productivity, environmental compatibility and higher operational availability, thus effecting technical, operational and economical aspects of in-flight and on-ground power generation systems. Today’s development in aircraft architecture undergoes a trend to a “more electric aircraft” which is characterised by a higher proportion of electrical systems substituting hydraulically or pneumatically driven components, and, thus, increasing the amount of electrical power. Fuel cell systems in this context represent a promising solution regarding the enhancement of the energy efficiency for both cruise and ground operations. For several years the Institute of Technical Thermodynamics of the German Aerospace Center (Deutsches Zentrum fu¨r Luft- und Raumfahrt, DLR) in Stuttgart is engaged in the development of fuel cell systems for aircraft applications. The activities of DLR focus on: • Identification of fuel cell applications in aircraft in which the properties of fuel cell systems, namely high electric efficiency, low emissions and silent operation, are capitalized for the aircraft application. • Design and modeling of possible system designs. • Experimental investigations regarding specific aircraft relevant operating conditions. • Qualification of airworthy fuel cell systems. • Set up and full scale testing of fuel cell systems for application in research aircraft. In cooperation with Airbus several fuel cell applications within the aircraft for both ground and cruise operation could be identified. In consequence, fuel cell systems capable to support or even replace existing systems have been derived. In this context, the provision of inert gas for the jet fuel (kerosene) tank and electrical cabin power supply including water regeneration represent the most promising application fields. The contribution will present the state of development discussing the following points: • Modeling of different system architectures and evaluation of promising fuel cell technologies (PEFC vs. SOFC). • Experimental evaluation of fuel cell systems under relevant conditions (low-pressure, vibrations, reformate operation, etc.). • Fuel cell system demonstrator Hyfish (hydrogen powered model aircraft). • Fuel cell test in DLR’s research aircraft ATRA (A320) including the test of an emergency system based on hydrogen and oxygen with 20 kW of electrical power. The fuel cell system was integrated into an A320 aircraft and tested up to a flight altitude of 25 000 feet under several acceleration and inclination conditions.

Characterizing Performance of a PEM Fuel Cell for a CMET Balloon

2011 ◽  
Author(s):  
Denise A. McKahn ◽  
Whitney McMackin
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Mass Density ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Cell Polarization ◽  
Operating Conditions ◽  
Design Parameters ◽  
Design System ◽  
Power Densities

We present the design of a multi-cell, low temperature PEM fuel cell for controlled meteorological balloons. Critical system design parameters that distinguish this application are the lack of reactant humidification and cooling due to the low power production, high required power mass-density and relatively short flight durations. The cell is supplied with a pressure regulated and dead ended anode, and flow controlled cathode at variable air stoichiometry. The cell is not heated and allowed to operate with unregulated temperature. Our prototype cell was capable of achieving power densities of 43 mW/cm2/cell or 5.4 mW/g. The cell polarization performance of large format PEM fuel cell stacks is an order of magnitude greater than for miniature PEM fuel cells. These performance discrepancies are a result of cell design, system architecture, and reactant and thermal management, indicating that there are significant gains to be made in these domains. We then present design modifications intended to enable the miniature PEM fuel cell to achieve power densities of 13 mW/g, indicating that additional performance gains must be made with improvements in operating conditions targeting achievable power densities of standard PEM fuel cells.

scholarly journals Sustainable Power Generation in Continuous Flow Microbial Fuel Cell Treating Actual Wastewater: Influence of Biocatalyst Type on Electricity Production

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Zainab Z. Ismail ◽  
Ali Jwied Jaeel
Keyword(s):  
Bacillus Subtilis ◽  
Microbial Fuel Cells ◽  
Electrical Power ◽  
Domestic Wastewater ◽  
Electricity Production ◽  
Biofilm Growth ◽  
Power Outputs ◽  
Electrical Power Output ◽  
Sustainable Power

Microbial fuel cells (MFCs) have the potential to simultaneously treat wastewater for reuse and to generate electricity. This study mainly considers the performance of an upflow dual-chambered MFC continuously fueled with actual domestic wastewater and alternatively biocatalyzed with aerobic activated sludge and strain ofBacillus Subtilis. The behavior of MFCs during initial biofilm growth and characterization of anodic biofilm were studied. After 45 days of continuous operation, the biofilms on the anodic electrode were well developed. The performance of MFCs was mainly evaluated in terms of COD reductions and electrical power output. Results revealed that the COD removal efficiency was 84% and 90% and the stabilized power outputs were clearly observed achieving a maximum value of 120 and 270 mW/m2obtained for MFCs inoculated with mixed cultures andBacillus Subtilisstrain, respectively.

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