scholarly journals Thermodynamic Considerations for Thermal Water Splitting Processes and High Temperature Electrolysis

2008 ◽  
Author(s):  
J. E. O’Brien
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Thermal Water ◽  
Nuclear Reactor ◽  
Operating Conditions ◽  
Thermodynamic Efficiency ◽  
Temperature Ranges ◽  
Reactor Types ◽  
High Temperature Electrolysis

A general thermodynamic analysis of hydrogen production based on thermal water splitting processes is presented. Results of the analysis show that the overall efficiency of any thermal water splitting process operating between two temperature limits is proportional to the Carnot efficiency. Implications of thermodynamic efficiency limits and the impacts of loss mechanisms and operating conditions are discussed as they pertain specifically to hydrogen production based on high-temperature electrolysis. Overall system performance predictions are also presented for high-temperature electrolysis plants powered by three different advanced nuclear reactor types, over their respective operating temperature ranges.

scholarly journals Economic Analysis of a Nuclear Reactor Powered High-Temperature Electrolysis Hydrogen Production Plant

2008 ◽  
Author(s):  
E. A. Harvego ◽  
M. G. McKellar ◽  
M. S. Sohal ◽  
J. E. O’Brien ◽  
J. S. Herring
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Economic Analysis ◽  
Nuclear Reactor ◽  
Primary System ◽  
Production Plant ◽  
Operating Pressure ◽  
System Pressure ◽  
Reference Design ◽  
High Temperature Electrolysis

A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled nuclear reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540°C and 900°C, respectively. The electrolysis unit used to produce hydrogen includes 4,009,177 cells with a per-cell active area of 225 cm2. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating-current (AC) to direct-current (DC) conversion efficiency is 96%. The overall system thermal-to-hydrogen production efficiency (based on the lower heating value of the produced hydrogen) is 47.1% at a hydrogen production rate of 2.356 kg/s. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.23/kg of hydrogen was calculated assuming an internal rate of return of 10%.

Hydrogen production by high temperature electrolysis with nuclear reactor

2008 ◽  
Vol 50 (2-6) ◽  
pp. 422-426 ◽  
Author(s):  
Seiji Fujiwara ◽  
Shigeo Kasai ◽  
Hiroyuki Yamauchi ◽  
Kazuya Yamada ◽  
Shinichi Makino ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Nuclear Reactor ◽  
High Temperature Electrolysis

scholarly journals System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

2012 ◽  
Author(s):  
Edwin A. Harvego ◽  
James E. O’Brien ◽  
Michael G. McKellar
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Cost Analysis ◽  
Average Cost ◽  
Operating Conditions ◽  
System Evaluation ◽  
Production Plant ◽  
Plant Design ◽  
Commercial Scale ◽  
High Temperature Electrolysis

Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimized of the design using a detailed process flow sheet and realistic operating conditions specified the analyst. The lifecycle cost analysis was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.

System Evaluation and Economic Analysis of a Nuclear Reactor Powered High-Temperature Electrolysis Hydrogen-Production Plant

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
E. A. Harvego ◽  
M. G. McKellar ◽  
M. S. Sohal ◽  
J. E. O’Brien ◽  
J. S. Herring
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Economic Analysis ◽  
Production Efficiency ◽  
Nuclear Reactor ◽  
Primary System ◽  
Production Plant ◽  
System Pressure ◽  
Reference Design ◽  
High Temperature Electrolysis

A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen-production concepts. The reference plant design is driven by a high-temperature helium-cooled nuclear reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540°C and 900°C, respectively. The electrolysis unit used to produce hydrogen includes 4,009,177 cells with a per-cell active area of 225 cm2. The optimized design for the reference hydrogen-production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that has evolved on the anode (oxygen) side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating current to direct current conversion efficiency is 96%. The overall system thermal-to-hydrogen-production efficiency (based on the lower heating value of the produced hydrogen) is 47.1% at a hydrogen-production rate of 2.356 kg/s. This hydrogen-production efficiency is considerably higher than can be achieved using current low-temperature electrolysis techniques. An economic analysis of this plant was performed using the standardized hydrogen analysis methodology developed by the Department of Energy Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen-production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.23/kg of hydrogen was calculated assuming an internal rate of return of 10%.

Economic and environmental competitiveness of high temperature electrolysis for hydrogen production

2021 ◽  
Author(s):  
Kavan Motazedi ◽  
Yaser Khojasteh Salkuyeh ◽  
Ian J. Laurenzi ◽  
Heather L. MacLean ◽  
Joule A. Bergerson
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
High Temperature Electrolysis

An Air-Brayton Nuclear-Hydrogen Combined-Cycle Peak- and Base-Load Electric Plant

2007 ◽  
Author(s):  
Charles Forsberg
Keyword(s):  
High Temperature ◽  
Power Output ◽  
Nuclear Reactor ◽  
Peak Load ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Electricity Production ◽  
Spinning Reserve ◽  
High Temperature Reactor ◽  
Base Load

A combined-cycle power plant is proposed that uses heat from a high-temperature nuclear reactor and hydrogen produced by the high-temperature reactor to meet base-load and peak-load electrical demands. For base-load electricity production, air is compressed; flows through a heat exchanger, where it is heated to between 700 and 900°C; and exits through a high-temperature gas turbine to produce electricity. The heat, via an intermediate heat-transport loop, is provided by a high-temperature reactor. The hot exhaust from the Brayton-cycle turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, after nuclear heating of the compressed air, hydrogen is injected into the combustion chamber, combusts, and heats the air to 1300°C—the operating conditions for a standard natural-gas-fired combined-cycle plant. This process increases the plant efficiency and power output. Hydrogen is produced at night by electrolysis or other methods using energy from the nuclear reactor and is stored until needed. Therefore, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the hydrogen and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the grid.

scholarly journals An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

2014 ◽  
Author(s):  
Shannon Bragg-Sitton ◽  
Richard Boardman ◽  
Robert Cherry ◽  
Wesley Deason ◽  
Michael McKellar
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Fast Reactor ◽  
High Temperature Electrolysis
Sign in / Sign up

Export Citation Format

Share Document