Use of a Heat Pump to Supply Energy to the Iodine-Sulphur Thermochemical Cycle for Hydrogen Production

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Yohann Dumont ◽  
Patrick Aujollet ◽  
Jean-Henry Ferrasse
Keyword(s):  
Hydrogen Production ◽  
Energy Distribution ◽  
Heat Pump ◽  
Production Efficiency ◽  
Nuclear Reactor ◽  
Distribution Network ◽  
Thermochemical Cycle ◽  
Total Energy Consumption ◽  
Important Place ◽  
Energy Needs

The hydrogen world consumption should increase significantly to progressively replace hydrocarbons. Due to its high power density, nuclear reactor should take an important place in this production. This paper focuses on the hydrogen production by thermochemical cycle using the heat available at 900°C of a new generation nuclear reactor. The chosen thermochemical cycle for this study is the iodine-sulphur thermochemical cycle water splitting.The process flowsheet under consideration has high total energy consumption. It has also many local energy needs unevenly distributed over a wide temperature range. The raw distribution of this energy gives a hydrogen production efficiency of 14.0%. To improve this, the proposed coupling is built using an energy distribution network with a coolant to meet the safety requirements. In this simple case, the efficiency of hydrogen production comes to 21.9%. By integrating a heat pump into the energy distribution network, the efficiency of production increases to 42.0%. The exergetic efficiency, increases from 59.3% to 85.8%.

Reactive Pellets for Improved Solar Hydrogen Production Based on Sodium Manganese Ferrite Thermochemical Cycle

2008 ◽  
Author(s):  
Carlo Alvani ◽  
Mariangela Bellusci ◽  
Aurelio La Barbera ◽  
Franco Padella ◽  
Marzia Pentimalli ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Sodium Carbonate ◽  
Production Efficiency ◽  
Manganese Carbonate ◽  
Reactive System ◽  
Thermochemical Cycle ◽  
Manganese Ferrite ◽  
Oxide Mixture

Hydrogen production by water-splitting thermochemical cycle based on manganese ferrite /sodium carbonate reactive system is reported. Two different preparation procedures for manganese ferrite/sodium carbonate mixture were adopted and compared in terms of materials capability to cyclical hydrogen production. According to the first procedure conventionally synthesized manganese ferrite, i. e. high temperature (1250 °C) heating in Ar of carbonate/oxide precursors, was mixed with sodium carbonate. The blend was tested inside a TPD reactor using a cyclical hydrogen production/material regeneration scheme. After few cycles the mixture resulted rapidly passivated and unable to further produce hydrogen. An innovative method that avoids the high temperature synthesis of manganese ferrite is presented. This procedure consists in a set of consecutive thermal treatments of a manganese carbonate/sodium carbonate/iron oxide mixture in different environments (inert, oxidative, reducing) at temperatures not exceeding 750 °C. Such material, whose observed chemical composition consists in manganese ferrite and sodium carbonate in stoichiometric amount, is able to evolve hydrogen during 25 consecutive water-splitting cycles, with a small decrease in cyclical production efficiency.

Reactive Pellets for Improved Solar Hydrogen Production Based on Sodium Manganese Ferrite Thermochemical Cycle

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Carlo Alvani ◽  
Mariangela Bellusci ◽  
Aurelio La Barbera ◽  
Franco Padella ◽  
Marzia Pentimalli ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Sodium Carbonate ◽  
Production Efficiency ◽  
Manganese Carbonate ◽  
Reactive System ◽  
Thermochemical Cycle ◽  
Manganese Ferrite ◽  
Oxide Mixture

Hydrogen production by water-splitting thermochemical cycle based on manganese ferrite/sodium carbonate reactive system is reported. Two different preparation procedures for manganese ferrite/sodium carbonate mixture were adopted and compared in terms of material capability to cyclical hydrogen production. According to the first procedure, conventionally synthesized manganese ferrite, i.e., high temperature (1250°C) heating in Ar of carbonate/oxide precursors, was mixed with sodium carbonate. The blend was tested inside a temperature programed desorption reactor using a cyclical hydrogen production/material regeneration scheme. After a few cycles, the mixture resulted rapidly passivated and unable to further produce hydrogen. An innovative method that avoids the high temperature synthesis of manganese ferrite is presented. This procedure consists in a set of consecutive thermal treatments of a manganese carbonate/sodium carbonate/iron oxide mixture in different environments (inert, oxidative, and reducing) at temperatures not exceeding 750°C. Such material, whose observed chemical composition consists of manganese ferrite and sodium carbonate in stoichiometric amounts, is able to evolve hydrogen during 25 consecutive water-splitting cycles, with a small decrease in cyclical production efficiency.

The Coupling of Nuclear Heat and Hydrogen Production Thermochemical Cycles

2009 ◽  
Author(s):  
Zhaolin Wang ◽  
Greg Naterer ◽  
Kamiel S. Gabriel ◽  
Rob Gravelsins ◽  
Venkata Daggupati
Keyword(s):  
Hydrogen Production ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Heat Extraction ◽  
Working Fluid ◽  
Thermochemical Cycle ◽  
Thermochemical Cycles ◽  
Maximum Heat ◽  
Nuclear Heat

The technology to use nuclear heat to thermally split water into hydrogen and oxygen attracts more and more attentions at present. This paper discusses some challenges to couple nuclear heat with thermochemical hydrogen production cycles. The challenges include matching the maximum heat grade of thermal chemical cycles and nuclear reactors, and extracting heat from nuclear reactors. Sulfur-iodine and copper-chlorine cycles are taken as typical examples for analysis and discussion. The heat grade and quantity required by each step of the cycles are discussed. The maximum heat grade of sulfur-iodine cycle is higher than 800°C which cannot be easily coupled by GenIV nuclear reactor and other sources of heat must be provided. In comparison, the maximum heat grade of copper-chlorine cycle is 530°C which can be coupled by more nuclear reactors such as advance Gen-III and future Gen-IV nuclear reactor. It is concluded that thermochemical cycles with lower temperature requirement are easier to couple with present and future generations of reactors. Low temperature thermochemical cycles such as copper-chlorine cycles are recommended to match the heat grade of most nuclear reactors. Some methods are proposed to couple heat between a thermochemical cycle and nuclear power generating station. Several heat extraction methods such as using working fluid of nuclear reactor to provide heat to thermochemical cycles are proposed in this paper.

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%.

Physical-Chemical and Thermodynamic Analyses of Ethanol Steam Reforming for Hydrogen Production

2006 ◽  
Vol 3 (3) ◽  
pp. 346-350 ◽  
Author(s):  
Antonio Carlos Caetano de Souza ◽  
José Luz-Silveira ◽  
Maria Isabel Sosa
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Production Efficiency ◽  
Physical Chemical ◽  
Steam Reforming Of Ethanol ◽  
Thermodynamic Conditions ◽  
High Production ◽  
Exergetic Analysis ◽  
Global Reaction ◽  
Technical Features

Steam reforming is the most usual method of hydrogen production due to its high production efficiency and technological maturity. The use of ethanol for this purpose is an interesting option because it is a renewable and environmentally friendly fuel. The objective of this article is to present the physical-chemical, thermodynamic, and exergetic analysis of a steam reformer of ethanol, in order to produce 0.7Nm3∕h of hydrogen as feedstock of a 1kW PEMFC. The global reaction of ethanol is considered. Superheated ethanol reacts with steam at high temperatures producing hydrogen and carbon dioxide, depending strongly on the thermodynamic conditions of reforming, as well as on the technical features of the reformer system and catalysts. The thermodynamic analysis shows the feasibility of this reaction in temperatures about 206°C. Below this temperature, the reaction trends to the reactants. The advance degree increases with temperature and decreases with pressure. Optimal temperatures range between 600 and 700°C. However, when the temperature attains 700°C, the reaction stability occurs, that is, the hydrogen production attains the limit. For temperatures above 700°C, the heat use is very high, involving high costs of production due to the higher volume of fuel or electricity used. The optimal pressure is 1atm., e.g., at atmospheric pressure. The exergetic analysis shows that the lower irreversibility is attained for lower pressures. However, the temperature changes do not affect significantly the irreversibilities. This analysis shows that the best thermodynamic conditions for steam reforming of ethanol are the same conditions suggested in the physical-chemical analysis.

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