DOCSLIB.ORG

Development of the Hybrid Sulfur Thermochemical Cycle

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Development of the Hybrid Sulfur Thermochemical Cycle Development of the Hybrid Sulfur Thermochemical Cycle William A. Summers and John. L. Steimke Savannah River National Laboratory Aiken, SC USA 3rd OECD Information Exchange Meeting on Nuclear Hydrogen Oarai, Japan October 5-7, 2005 Outline Hybrid Sulfur Cycle Description Process Design and System Performance Hydrogen Production Economics Electrolyzer Development and Testing Conclusions Thermochemical water-splitting Series of coupled chemical reactions Water consumption only; all intermediates regenerated Thermal input only (pure cycles) or thermal & electric (hybrid cycles) Extensively studied in 1970s Over 3000 potential cycles have been suggested with 115 cycles reported in literature Status of Thermochemical Cycles Major design challenges due to large material flows, corrosive chemicals, impurities, reactant separation, high temperature heat exchange, and costs Thermodynamic limitations require high temperature (800-900 ºC peak heat input) Currently in lab-scale development stage Three leading cycles: – Sulfur-Iodine (SI) process – Hybrid Sulfur (HyS) or Westinghouse process – Ca-Br process (ANL modification of UT-3 cycle) Sulfur Family of TC Cycles Common high temperature reaction to liberate oxygen Thermal decomposition of sulfuric acid: H2SO4 → H2O + SO2 + ½O2 Temperature > 900 °C Various lower temperature hydrogen production and regeneration steps Pure thermal cycles require minimum of 3 reaction steps Sulfur-Iodine (SI) is the most developed (or researched) thermochemical cycle Source: U.S. Department of Energy Hybrid Sulfur (HyS) Cycle is a simpler alternative All fluids, two-step hybrid process Chemistry involves only S-O-H species Developed by Westinghouse Electric in 1970’s Also known as Westinghouse Sulfur Cycle or Ispra Mark 11 Cycle Closed-loop 120 lph bench-scale demonstrated in 1978 Key development issues are performance and cost for electrochemical step HyS Reactions H2SO4 ↔ H2O + SO2 + ½O2 (1) (thermochemical; 800-900 °C) SO2 + 2 H2O → H2SO4 + H2 (2) (electrochemical; 80-120 °C) Net Reaction: H2O → H2 + ½O2 (3) HyS Electrolyzer Concept • Direct water electrolysis requires min. anode membrane cathode 1.23 volts and produces H2 and O2 H2SO4 H2O H2 • SO2 anode-depolarization reduces SO3 + reversible cell voltage to 0.17 Volts per 2H+ cell and produces H2 and H2SO4 SO2 + H2O • Practical cell voltages are 0.45 to 0.60 volts per cell at 80-120°C, requiring up SO2 (l) + H2SO4 H2SO4 Solution Solution to 75% less electricity than direct water (optional) electrolysis SO2 anode-depolarized electrolysis Hybrid Sulfur Block Process Schematic Requires electric & thermal input Electric Power High-temp Generation Heat Source High temperature (>900°C) heat Electric Power Thermal Energy source could be nuclear reactor >900°C H Product or solar thermal 2 Conc. H SO Thermochemical system has 2 4 Electrolyzer Sulfuric Acid and Auxiliaries Concentration & three main processing units Decomposition Dilute – SO2-depolarized electrolyzers H2SO4 – Sulfuric Acid concentration and SO2 SO2 Recycle O2 decomposition H2O Feed – SO2/O2 separation SO2 and O2 Separation O2 By-Product SRNL improvements to HyS process design Optimized overall system design and integration Improved efficiency of acid processing scheme Developed high-efficiency SO2/O2 separation system Conducted tradeoff studies to determine – electrolyzer acid feed concentration – sulfur dioxide conversion and recycle – cell temperature and pressure – acid decomposition temperature and pressure Thermal Efficiency over 50% deemed likely 53.00 52.00 20% per-pass SO2 conversion 50% per-pass SO2 conversion 51.00 75% per-pass SO2 conversion 50.00 49.00 48.00 Net thermal efficiency, thermal Net % 47.00 Projected thermal efficiency is 46-53% 46.00 (HHV basis) 45.00 400 450 500 550 600 650 SO2 anode-depolarized cell potential, mV Target is high efficiency at reasonable reactor helium outlet temperatures 0.9 ideal efficiency He coolant ∆T: 0.8 ∆T = 250°C ∆T = 300°C ∆T = 350°C 0.7 ∆T = 400°C Target Operating Range 70% of ideal efficiency 0.6 0.5 2004 Hybrid Sulfur at 897°C 2005 Hybrid Sulfur at 900°C 2005 SI (GA calculation) Fractional thermal efficiency 2003 SI at 875°C (GA calculation) 0.4 1976 Hybrid Sulfur at 875°C 0.3 700 750 800 850 900 950 1000 1050 He-cooled reactor temperature, °C Commercial Plant Energy Balance 1,200 MW HT HT th 2 x 600 MWth HyS 952 MWth 576 MWe 341 MWe Process 2 x 600 MW GT GT 580 tpd H th (electrolyzers) 2 19 MWe (auxiliaries) Net thermal efficiency = 216 MWe Export Power 48.8% (HHV) HyS Energy Requirement: • 62% thermal energy • 38% heat value of electricity (48% efficiency) Higher efficiency projected with optimized flowsheets HyS hydrogen production costs may be somewhat lower than SI SI* HyS Plant Rating MWth 2400 2400 Plant Efficiency % (HHV basis) 52-42 48.8** Hydrogen Output Tonnes/Day 760-614 580 Electric Output MWe 0 216 Reactor System Cost $M 1,150 1,198 Electrolyzer Cost $ per m2 N/A 2000 Hydrogen Plant Cost $M 819 516 Electricity @ 3¢/kWh $M/yr N/A (51) Total Annual Cost $M/yr 413-399 306 Net Hydrogen Cost $ per kg 1.65-1.98 1.60 - with O2 credit 1.36-1.69 1.31 *W.A. Summers et al., US DOE NERI Topical Report, Project No. 02-160, 07/31/2004 **Current flowsheet; >50% expected. Delivered NuH2 is competitive with natural gas reforming at current fuel prices Breakeven Price for NG vs. NuH2 for Industrial H2 User 3 No CO2 Removal CO2 Sequestration Nuclear H2 2.5 2 1.5 1 April 2005 0.5 Hydrogen, $ per kg 0 024681012 Natural Gas Price, $ per MMB NG price real escalation = 2% per year SO2-depolarized Electrolysis + - Anode: SO2 (aq) + 2 H2O (aq) H2SO4 (aq) + 2 H + 2 e + - Cathode: 2 H + 2 e H2 (g) Sulfur dioxide is oxidized at the anode to form sulfuric acid Reversible cell voltage reduced to 0.17 volts per cell Practical cell voltages 0.5 – 0.6 volts (60-75% less than direct) Economic design requires high current density and low voltage Process design dictates electrolyzer operation at 100-120 °C and 20 bar with 50-60 wt% sulfuric acid Work in 1970’s Resulted in Test Electrolyzers With Reasonable Performance Current Density 200 mA/ cm2 H2SO4 Concentration 50 % Cell Temperature 49.4 °C Anode Potential 456 mV Cathode Potential 0 mV IR Drop 112 mV Total Cell Voltage 568 mV *Data taken after 140 hrs. of operation Westinghouse Laboratory Bipolar Cell Source: Westinghouse Electric Electrolyzer Development Program Original Westinghouse cells – Two compartment design with recirculating acid anolyte and catholyte – Carbon briquetted electrodes – Platinum electrocatalyst – Microporous rubber diaphragms – Positive flow of acid from cathode to anode Current design approach – Build on development of PEM fuel cells and electroyzers – Nafion or other proton-exchange-membrane – Gas diffusion carbon electrodes – Membrane-Electrode-Assembly (MEA) construction – Carbon flow fields – No acid catholyte required Ambient Pressure Testing of Electrolyzer Test Purposes – Verify reduced cell voltages based on SO2-depolarization – Verify applicability of MEA and PEM concepts – Examine issues of SO2 crossover and cell Modified PEM Water Electrolyzer degradation with time (84 cm2 active cell area) – Acquire data for modeling (Manufactured by Proton Energy Systems, Inc. with SRNL specified materials and and system scale-up changes) SO2-depolarzied Electrolyzer Test Facility Test Electrolyzer Designs Electrolyzer 1 procured from commercial PEM manufacturer – Based on standard water electrolyzer – Wetted parts changed to Teflon and Hastelloy B vs 316 SS – Pressure rated to 300 psig – Porous Titanium electrodes (could not be modified) Modified Commercial PEM Water – Nafion membrane; 4 mg/cm2 Pt loading Electrolyzer (84 cm2 active cell area) Electrolyzer 2 fabricated by Univ. of SC – Reseach type cell design – 50% smaller active cell area – Square plates; 60 psig rating – Carbon gas-diffusion electrodes – Pt on carbon electrocatalyst – Nafion membrane; 0.5 mg/cm2 Pt loading Research-type Electrolyzer (40 cm2) Test Results for Commercial-type Electrolyzer 2.0 1.5 Water only 1.0 SO2 + 30% H2SO4 SO2 + 70% H2SO4 Cell Voltage, V 0.5 0.0 0 200 400 600 800 Current Density, mA/cm2 Test Results for Research Electrolyzer 1.5 0.3 L/min, 1 bar 1.0 0.3 L/min/ 2 bar 0.9 L/min, 1 bar 0.9 L/min, 2 bar 1.5 L/min, 1 bar 0.5 Cell Voltage, V 1.5 L/min, 2bar Elect. No. 1 0.0 0 50 100 150 200 Current Density, mA/cm2 Test Result Summary Proof-of-concept for SO2-depolarized operation was confirmed Hydrogen generation observed at less than 0.5 volts per cell for low current density Severe corrosion measured in conventional PEM cell due to metal parts (titanium electrodes) Flow and mass transfer resistance in cell with gas diffusion electrodes limited operating current density Some sulfur formation observed at cathode Cell design and optimization program initiated Conclusions HyS Cycle is a viable thermochemical process – All major process steps and unit operations defined – Simplest known cycle with least equipment requirements – Plant thermal efficiency equals or exceeds other cycles – Hydrogen production costs are attractive Major technical issues associated with electrolyzer – High-temperature acid step common with S-I cycle – Proof-of-concept for PEM cell design established – Cell optimization and scale-up in progress Acknowledgements This work was sponsored by the U.S. Department of Energy under Contract No. DE-AC09-96SR18500 Funding provided by DOE Office of Nuclear Energy, Science and Technology under Nuclear Hydrogen Initiative Mr. David Henderson, technical program monitor.
Load more

Recommended publications
  • Solar Thermochemical Hydrogen Production Research (STCH)
    SANDIA REPORT SAND2011-3622 Unlimited Release Printed May 2011 Solar Thermochemical Hydrogen Production Research (STCH) Thermochemical Cycle Selection and Investment Priority Robert Perret Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. Approved for public release; further dissemination unlimited. Issued by Sandia National Laboratories, operated for the United States Department of Energy by Sandia Corporation. NOTICE: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government, nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, make any warranty, express or implied, or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represent that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government, any agency thereof, or any of their contractors or subcontractors. The views and opinions expressed herein do not necessarily state or reflect those of the United States Government, any agency thereof, or any of their contractors. Printed in the United States of America. This report has been reproduced directly from the best available copy.
    [Show full text]
  • Optimization of the Hybrid Sulfur Cycle for Nuclear Hydrogen Production Using Unisim Design
    Transactions of the Korean Nuclear Society Spring Meeting Jeju, Korea, May 22, 2009 Optimization of the Hybrid Sulfur Cycle for Nuclear Hydrogen Production Using UniSim Design Yong Hun Jung a∗, Yong Hoon Jeong a aKAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Korea *Corresponding author: [email protected] 1. Introduction 2. Simulation The sulfur-based thermochemical cycles are A simple Hybrid Sulfur Cycle flow sheet was considered as the most promising methods to produce developed and described on the UniSim Design as hydrogen. The Hybrid Sulfur (HyS) Cycle is a mixed shown in Fig. 2. PR-Twu equation of state model is thermochemical cycle with the sulfur-aided electrolysis selected among the fluid packages provided by basis as depicted in the Fig. 1. Hydrogen is produced from environment of UniSim Design [3]. Electrolyzer unit is water by oxidizing sulfur dioxide in the low not described. Instead, the experimental data of the temperature electrolysis step and the sulfuric acid which required electrode potentials for the various acid is also produced in the electrolyzer proceeds to the high concentrations is inputted in the linked spread sheet of temperature thermochemical step. The sulfuric acid is the UniSim Design [2]. The thermochemical step: the concentrated in the concentrator first and then cycle except the electrolyzer is adjusted to produce decomposed into steam and sulfur trioxide, which is 1kgmole/h of sulfur dioxide and this is equivalent to further decomposed into sulfur dioxide and oxygen at 1kgmole/h of hydrogen from the whole cycle assuming high temperature (;1100 K) in the decomposer. After that all the sulfur dioxide are consumed in the separated with oxygen in the separator, the sulfur electrolyzer.
    [Show full text]
  • Hybrid Sulfur (Westinghouse) V0.Pub
    IEA/HIA TASK 25 : HIGH TEMPERATURE HYDROGEN PRODUCTION PROCESS Hybrid Sulfur cycle Process principle H2 ½ O2 H2 + H2SO4 ½ O2 (1) 2 H2O + SO2 —> H2SO4 + H2 S + H SO (2) SO2 (2a) H2SO4 —> H2O + SO3 (1) Circulation 2 4 2 H2O + SO2 + 2 H O (2b) SO —> SO + ½ O Electrolysis 80°C 2 3 2 2 850°CH2O Heat H2O Electrical Energy Current status : Hybrid Sulfur The Hybrid Sulfur (Westinghouse) Cycle is a Process description : two-step thermochemical cycle for decomposing (1) SO electrolysis at 80° C water into hydrogen and oxygen. Sulfur oxides 2 (2) H2SO4 decomposition : (2a) Starts at 450° C serve as recycled intermediates within the system. (2b) Starts at 800° C • Significant research activity for nuclear Heat source : and solar. Nuclear or Solar heat source • Chemical reactions all demonstrated. Materials : Electrodes : carbon-supported platinum catalysts Advantages : H2SO4 Decomposition : Ceramics such as silicon • Uses common / inexpensive chemicals. carbide, silicon nitride and cermets • Cycle has the potential for achieving high thermal efficiencies. Efficiency : • Only one intermediary species (oxides of The cycle efficiency is 42 % which has the potential sulfur). to be increased to 48.8 % 1. Challenges : Cost evaluation : • Requires high temperature. Between 4.4 and 6.8 $/kg for a nuclear heat source12 • Corrosion by H SO . 2 4 Between 1.6 and 5.6 €/kg for a solar heat source13,14 Version 1 1 IEA/HIA TASK 25: HIGH TEMPERATURE HYDROGEN PRODUCTION PROCESS Flow-sheet The Hybrid Sulphur cycle, also named Ispra Mark 11 cycle or Westinghouse Sulphur cycle was developed in the 70’s by Westinghouse Electric corporation.
    [Show full text]
  • Click to Add Title SOL2HY2 Solar to Hydrogen Hybrid Cycles
    SOL2HY2 Solar To Hydrogen Hybrid Cycles Michael Gasik Aalto University Foundation sol2hy2.eucoord.com Coordinator email: [email protected] to add title Programme Review Days 2016 Brussels, 21-22 November PROJECT OVERVIEW Project Information Call topic SP1-JTI-FCH.2012.2.5 – Thermo-electrical- chemical processes with solar heat sources Grant agreement number 325320 Application area (FP7) Hydrogen Production Start date 01/06/2013 End date 30/11/2016 Total budget (€) 3,701,300 FCH JU contribution (€) 1,991,115 Other contribution (€, source) 214,000 (Tekes, FI) Stage of implementation 99% project months elapsed vs total project duration, at date of November 1, 2016 Partners Enginsoft (IT), Aalto (FI), ENEA (IT), DLR (DE), Outotec (FI), Erbicol (CH), Woikoski (FI) PROJECT SUMMARY • The project focuses on applied R&D and demo of the relevant-scale key components of the solar-powered, CO2-free hybrid water splitting cycles, complemented by their advanced modeling and process simulation and site-specific optimization • Solar-powered thermo-chemical cycles are capable to directly transfer concentrated sunlight into chemical energy. Of these, hybrid-sulfur (HyS) cycle was identified as the most promising, but its challenges remain in materials and the whole flowsheet optimization, tailored to specific solar input and plant site location. • In the project, consortium developed solutions for the SO2-depolarized electrolyser, sulfuric acid handling and for the BoP. • The on-Sun demo has proven the said concepts and a new software tool were created, allowing the tailoring of such flexible plant at any worldwide location, leading to H2 plants and technology “green concepts” commercialization.
    [Show full text]
  • SO2 - an Indirect Source of Energy
    Downloaded from orbit.dtu.dk on: Dec 15, 2017 SO2 - An indirect source of energy Kriek, R.J.; Van Ravenswaay, J.P.; Potgieter, M.; Calitz, A.; Lates, V.; Björketun, Mårten; Siahrostami, Samira; Rossmeisl, Jan Published in: Southern African Institute of Mining and Metallurgy. Journal Publication date: 2013 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Kriek, R. J., Van Ravenswaay, J. P., Potgieter, M., Calitz, A., Lates, V., Björketun, M., ... Rossmeisl, J. (2013). SO2 - An indirect source of energy. Southern African Institute of Mining and Metallurgy. Journal, 113(8), 593- 604. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. SO2 – an indirect source of energy by R.J. Kriek*, J.P. van Ravenswaay*, M. Potgieter*, A. Calitz*, V. Lates*, M.E. Björketun†, S. Siahrostami†, and J. Rossmeisl† Around the mid-1970s SO2 emissions peaked, subsequently declining as a direct Synopsis result of the implementation of focused abatement technologies.
    [Show full text]
  • Method for Evaluation of Thermochemical and Hybrid Water-Splitting Cycles
    Ind. Eng. Chem. Res. 2009, 48, 8985–8998 8985 Method for Evaluation of Thermochemical and Hybrid Water-Splitting Cycles Miguel Bagajewicz,* Thang Cao, Robbie Crosier, Scott Mullin, Jacob Tarver, and DuyQuang Nguyen Department of Chemical, Biological and Materials Engineering, The UniVersity of Oklahoma, Norman, Oklahoma This paper presents a methodology for the preliminary evaluation of thermochemical and hybrid water-splitting cycles based on efficiency. Because the method does not incorporate sufficient flowsheet details, the efficiencies are upper bounds of the real efficiencies. Nonetheless, they provide sufficient information to warrant comparison with existing well-studied cycles, supporting the decision to disregard them when the bound is too low or continuing their study. In addition, we add features not present in previous works: equilibrium conversions as well as excess reactants are considered. The degrees of freedom of each cycle (temperatures, pressures, and excess reactants) were also considered, and these values were varied to optimize the cycle efficiency. Ten cycles are used to illustrate the method. I. Introduction species entering the process is water, and the only products of the process are hydrogen and oxygen. Heat and work are also Declining volumes of fossil fuel reserves and an increase in transferred across the system boundaries for the heating and their demand has caused a recent rise in the cost of energy. cooling of process streams, the separation of reactive species, Similarly, nations across the globe are aspirating to become less and to drive the chemical reactions. dependent on foreign resources for the fulfillment of energy requirements. Furthermore, a steady increase in greenhouse gas Many studies have been performed in previous years to emissions over the past decades has brought about the reality evaluate water-splitting cycles as a means to produce hydrogen.
    [Show full text]
  • Dynamic Simulation of a Solar Powered Hybrid Sulfur Process for Hydrogen Production Satwick Boddu University of South Carolina
    University of South Carolina Scholar Commons Theses and Dissertations 2018 Dynamic Simulation of a Solar Powered Hybrid sulfur Process for Hydrogen Production Satwick Boddu University of South Carolina Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Chemical Engineering Commons Recommended Citation Boddu, S.(2018). Dynamic Simulation of a Solar Powered Hybrid sulfur Process for Hydrogen Production. (Master's thesis). Retrieved from https://scholarcommons.sc.edu/etd/4820 This Open Access Thesis is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Dynamic Simulation of a Solar Powered Hybrid sulfur Process for Hydrogen Production by Satwick Boddu Bachelor of Technology, Indian Institute of Technology - Guwahati, 2014 Submitted in Partial Fulfillment of the Requirements For the Degree of Master of Science in Chemical Engineering College of Engineering and Computing University of South Carolina 2018 Accepted by: Edward P. Gatzke, Director of Thesis Stanford G. Thomas, Reader John W. Weidner, Reader Cheryl L. Addy, Vice Provost and Dean of the Graduate School Abstract The Hybrid Sulfur process is a thermo-electrochemical cycle used to produce hydrogen from water. The process requires a high temperature energy source for H 2SO 4 decomposition with temperature reaching 800°C. This step is followed by SO 2 - depolarized water electrolysis. Using solar energy as the high temperature energy source allows for efficient environmentally friendly production of hydrogen. This method is an alternative to traditional photovoltaic electrolysis for hydrogen production.
    [Show full text]
  • Planet Hydrogen
    FOCUS ENEA_ Splitting water with renewable heat: green hydrogen beyond electrolysis In view of a diversification of energy sources and technologies for green hydrogen production, ENEA, since 2005, has been working on the development of water splitting thermochemical cycles powered by concen- trated solar energy, participating in several research projects within National and European programs. Par- ticularly ENEA has developed a unique expertise on materials and components with the aim of identifying critical aspects and defining innovative solutions to bring this challenging technology to an industrial maturi- ty. To this end, within the Electric System Research programme, ENEA is currently investigating a “modified Sulphur – Iodine” thermochemical cycle, to increase both the thermal efficiency of the hydrogen production route and the technical feasibility of its integration with the solar technology. Innovative materials are under study and the preliminary results show that the use of intermediate solid reactants can be the key to reduce the maximum operating temperatures and the energy consumption of the separation steps. In un'ottica di diversificazione delle fonti energetiche e delle tecnologie per la produzione di idrogeno verde, l'ENEA, dal 2005, si occupa dello sviluppo di cicli termochimici di scissione dell'acqua alimentati da energia solare concen- trata, partecipando a diversi progetti di ricerca nell'ambito di programmi nazionali ed europei. In particolare ENEA ha sviluppato una competenza unica su materiali e componenti con l'obiettivo di identificare gli aspetti critici e defi- nire soluzioni innovative per portare questa sfidante tecnologia ad una maturità industriale. A tal fine, all'interno del programma di Ricerca sul Sistema Elettrico, l'ENEA sta attualmente studiando un ciclo termochimico “Zolfo - Iodio modificato”, per aumentare sia l'efficienza termica del percorso di produzione dell'idrogeno, sia la fattibilità tecnica della sua integrazione con la tecnologia solare.
    [Show full text]
  • Hydrogen Production by the Solar-Powered Hybrid Sulfur Process: Analysis of the Integration of the CSP and Chemical Plants in Selected Scenarios
    Hydrogen production by the solar-powered hybrid sulfur process: Analysis of the integration of the CSP and chemical plants in selected scenarios Cite as: AIP Conference Proceedings 1734, 120006 (2016); https://doi.org/10.1063/1.4949208 Published Online: 31 May 2016 Raffaele Liberatore, Michela Lanchi, and Luca Turchetti ARTICLES YOU MAY BE INTERESTED IN Integration of photovoltaic and concentrated solar thermal technologies for H2 production by the hybrid sulfur cycle AIP Conference Proceedings 1850, 100013 (2017); https://doi.org/10.1063/1.4984470 Solar hydrogen production with cerium oxides thermochemical cycle AIP Conference Proceedings 1850, 100002 (2017); https://doi.org/10.1063/1.4984459 Modeling of a CeO2 thermochemistry reduction process for hydrogen production by solar concentrated energy AIP Conference Proceedings 1734, 120008 (2016); https://doi.org/10.1063/1.4949210 AIP Conference Proceedings 1734, 120006 (2016); https://doi.org/10.1063/1.4949208 1734, 120006 © 2016 Author(s). Hydrogen Production by the Solar-powered Hybrid Sulfur Process: Analysis of the Integration of the CSP and Chemical Plants in Selected Scenarios Raffaele Liberatore1, Michela Lanchi1 and Luca Turchetti1, a) 1ENEA - Italian National Agency for New Technologies, Energy and Sustainable Economic Development, via Anguillarese 301 - 00123 Rome, Italy. a)Corresponding author: [email protected] Abstract. The Hybrid Sulfur (HyS) is a water splitting process for hydrogen production powered with high temperature nuclear heat and electric power; among the numerous thermo-chemical and thermo-electro-chemical cycles proposed in the literature, such cycle is considered to have a particularly high potential also if powered by renewable energy. SOL2HY2 (Solar to Hydrogen Hybrid Cycles) is a 3 year research project, co-funded by the Fuel Cells and Hydrogen Joint Undertaking (FCH JU).
    [Show full text]
  • Detailed Analysis of the Hydrogen Sulfide Production Step in a Sulfur-Sulfur Thermochemical Water Splitting Cycle
    1 AN ABSTRACT OF THE DISSERTATION OF Kevin R. Caple for the degree of Doctor of Philosophy in Chemical Engineering presented on January 24, 2014. Title: Detailed Analysis of the Hydrogen Sulfide Production Step in a Sulfur-Sulfur Thermochemical Water Splitting Cycle Abstract approved: _________________________________________ Alexandre F.T. Yokochi The production of hydrogen has been one of the most heavily studied, energy related fields over the past half century, yet few methods are commercially or economically viable and none are currently sustainable. Of those aiming at the sustainable production of hydrogen using renewable resources, perhaps the most widely studied are those attempting to thermochemically split water via various chemical intermediates. These provide an attractive conceptual alternative to other methods due to lower energy input requirements and to the production of the targeted hydrogen and oxygen in separate reaction steps. One of the most widely studied thermochemical cycles is the Sulfur-Iodine cycle, the development of which has recently slowed due to the difficulty in the separation of hydrogen iodine from a hydrogen iodide-iodine-water azeotrope, material compatibility issues, and the perceived need use large amounts of iodine in the process. A modification of the Sulfur-Iodine thermochemical cycle that attempts to avoid those issues along with mitigating the need to process large amounts of water in the cycle was developed, in a cycle we describe as the Sulfur-Sulfur cycle. This new thermochemical cycle can
    [Show full text]
  • Hybrid Metal Oxide Cycle Water Splitting Richard B
    Bucknell University Bucknell Digital Commons Other Faculty Research and Publications Faculty Scholarship 2016 Hybrid metal oxide cycle water splitting Richard B. Diver Jr Robert D. Palumbo Nathan P. Siegel Bucknell University James E. Miller Follow this and additional works at: https://digitalcommons.bucknell.edu/fac_pubs Part of the Energy Systems Commons, and the Thermodynamics Commons Recommended Citation Diver, Richard B. Jr; Palumbo, Robert D.; Siegel, Nathan P.; and Miller, James E., "Hybrid metal oxide cycle water splitting" (2016). Other Faculty Research and Publications. 137. https://digitalcommons.bucknell.edu/fac_pubs/137 This Other is brought to you for free and open access by the Faculty Scholarship at Bucknell Digital Commons. It has been accepted for inclusion in Other Faculty Research and Publications by an authorized administrator of Bucknell Digital Commons. For more information, please contact [email protected]. US009279188B2 (12) United States Patent (10) Patent No.: US 9.279,188 B2 Diver, Jr. et al. (45) Date of Patent: Mar. 8, 2016 (54) HYBRD METAL OXDE CYCLE WATER (58) Field of Classification Search SPLITTING CPC ......................................................... C25B 1/04 USPC .......................................................... 205/637 (75) Inventors: Richard B. Diver, Jr., Albuquerque, NM See application file for complete search history. (US); Robert D. Palumbo, Valparaiso, IN (US); Nathan P. Siegel, Lewisburg, (56) References Cited PA (US); James E. Miller, Albuquerque, NM (US) U.S. PATENT DOCUMENTS 3,807,090 A 4, 1974 Moss (73) Assignee: Sandia Corporation, Albuquerque, NM 4,192,726 A 3/1980 Pangbornet al. (US) 4,202,744. A * 5/1980 Pan et al. ...................... 205/339 4,256,549 A * 3/1981 Divisek et al.
    [Show full text]
  • Hydrogen Production Via a Sulfur-Sulfur Thermochemical Water-Splitting Cycle
    AN ABSTRACT OF THE DISSERTATION OF Nicholas J. AuYeung for the degree of Doctor of Philosophy in Chemical Engineering presented on October 14, 2011. Title: Hydrogen Production via a Sulfur-Sulfur Thermochemical Water-Splitting Cycle Abstract approved: ____________________________________________________ Alexandre F.T. Yokochi Thermochemical water splitting cycles have been conceptualized and researched for over half a century, yet to this day none are commercially viable. The heavily studied Sulfur-Iodine cycle has been stalled in the early development stage due to a difficult HI- H2O separation step and material compatibility issues. In an effort to avoid the azeotropic HI-H2O mixture, an imidazolium-based ionic liquid was used as a reaction medium instead of water. Ionic liquids were selected based on their high solubility for SO2, I2, and tunable miscibility with water. The initial low temperature step of the Sulfur-Iodine cycle was successfully carried out in ionic liquid reaction medium. Kinetics of the reaction were investigated by I2 colorimetry. The reaction also evolved H2S gas, which led to the conceptual idea of a new Sulfur-Sulfur thermochemical cycle, shown below: 4I2(l)+4SO2(l)+8H2O(l) ↔4H2SO4(l) + 8HI(l) 8HI(l) +H2SO4(l) ↔H2S(g)+4H2O(l) +4I2(l) 3H2SO4(g)↔3H2O(g)+3SO2(g)+1½O2(g) H2S(g)+2H2O(g)↔SO2(g)+3H2(g) The critical step in the Sulfur-Sulfur cycle is the steam reformation of H2S. This highly endothermic step is shown to successfully occur at temperatures in excess of 800˚C in the presence of a molybdenum catalyst. A parametric study varying the H2O:H2S ratio, temperature, and residence time in a simple tubular quartz reactor was carried out and Arrhenius parameters were estimated.
    [Show full text]