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CRADA Final Report For CRADA NO. CR-12-006 [Operation and Testing of an SO{sub 2}-depolarized Electrolyzer (SDE) for the Purpose of Hydrogen and Sulfuric Acid Production]

Description: Over the past several years, Savannah River National Laboratory (SRNL) has led a team of collaborators under the Department of Energy’s (DOE) nuclear hydrogen production program to develop the Hybrid Sulfur (HyS) Process. HyS is a 2-step water-splitting process consisting of high temperature decomposition of sulfuric acid to generate SO{sub 2}, followed by the electrolysis of aqueous SO{sub 2} to generate hydrogen and sulfuric acid. The latter is fed back into the high temperature reactor. SRNL designed and built an SO{sub 2}-depolarized electrolyzer (SDE) and a test facility. Over 40 SDE’s were tested using different catalysts, membranes and other components. SRNL demonstrated that an SDE could be operated continuously for approximately 200 hours under certain conditions without buildup of sulfur at the SDE’s cathode, thus solving a key technical problem with SDE technology. Air Products and Chemicals, Inc. (APCI) is a major supplier of hydrogen production systems, and they have proprietary technology that could benefit from the SDE developed by SRNS, or some improved version thereof. However, to demonstrate that SRNL’s SDE is a truly viable approach to the electrolyzer design, continuous operation for far greater periods of time than 200 hours must be demonstrated, and the electrolyzer must be scaled up to greater hydrogen production capacities. SRNL and Air Products entered into a Cooperative Research and Development Agreement with the objective of demonstrating the effectiveness of the SDE for hydrogen and sulfuric acid production and to demonstrate long-term continuous operation so as to dramatically increase the confidence in the SDE design for commercial operation. SRNL prepared a detailed technical report documenting previous SDE development, including the current SDE design and operating conditions that led to the 200-hour sulfurfree testing. SRNL refurbished its single cell SDE test facility and qualified the equipment for continuous operation. A new membrane electrode assembly …
Date: February 24, 2014
Creator: Summers, W. A.; Colon-Mercado, H. R.; Steimke, J. L. & Zahn, Steffen
Partner: UNT Libraries Government Documents Department
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Report of the Selby Smelter Commission

Description: From Preface: "This bulletin presents the report of the commission and the papers, prepared by the various experts, which give the results of investigations undertaken by the commission and form the basis of its findings."
Date: 1915
Creator: Holmes, J. A.; Franklin, Edward C.; Gould, Ralph A. & Gould, Ralph A.
Partner: UNT Libraries Government Documents Department
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Soot-Catalyzed Oxidation of Sulfur Dioxide

Description: Experimental results are reviewed which demonstrate that combustion-generated soot particles can oxidize SO{sub 2} in both the absence ('dry' mechanism) and the presence ('wet' mechanism) of liquid water. The 'wet' mechanism is much more efficient than the 'dry' one, and is applicable to situations where the aerosol particles are covered with a liquid water layer. Calculations are presented which suggest that the soot-catalyzed oxidation of SO{sub 2} can be the dominant mechanism under realistic atmospheric conditions.
Date: May 1, 1978
Creator: Chang, S. G. & Novakov, T.
Partner: UNT Libraries Government Documents Department
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High SO2 Removal Efficiency Testing

Description: This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, "High Efficiency SO Removal Testing," for 2 the time period 1 October through 31 December 1996. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO removal efficiency. The upgrades being 2 evaluated mostly involve using performance additives in the FGD systems. The "base" project involved testing at the Tampa Electric Company�s Big Bend Station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy�s Merom Station (Option I), Southwestern Electric Power Company�s Pirkey Station (Option II), PSI Energy�s Gibson Station (Option III), Duquesne Light�s Elrama Station (Option IV), and New York State Electric and Gas Corporation�s Kintigh Station (Option V). The originally planned testing has been completed for all six sites. However, additional testing has been planned at the Big Bend Station, and that testing commenced during the current quarter. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the first quarter of calendar year 1996. Section 5 contains a brief acknowledgment.
Date: February 12, 1997
Creator: Blythe, Gary
Partner: UNT Libraries Government Documents Department
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High SO2 Removal Efficiency Testing

Description: This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, "High Efficiency SO2 Removal Testing", for the time period 1 April through 30 June 1997. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO2 removal efficiency. The upgrades being evaluated mostly involve using performance additives in the FGD systems. The "base" project involved testing at the Tampa Electric Company�s Big Bend Station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy�s Merom Station (Option I), Southwestern Electric Power Company�s Pirkey Station (Option II), PSI Energy�s Gibson Station (Option III), Duquesne Light�s Elrama Station (Option IV), and New York State Electric and Gas Corporation�s Kintigh Station (Option V). The originally planned testing has been completed for all six sites. However, additional testing is being conducted at the Big Bend Station. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the third quarter of calendar year 1997. Section 5 contains a brief acknowledgment.
Date: July 29, 1997
Creator: Blythe, Gary
Partner: UNT Libraries Government Documents Department
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Removal of H2S and SO2 by CaCO3-Based Sorbents at High Pressure

Description: The theoretical and experimental investigation of the mechanism of SO2 and H2S removal by CaCO3 -based sorbents (limestones and dolomites) in pressurized uidized-bed coal combustors (PFBC) and high pressure gasi#12;ers, respectively, is the main objective of this study. It is planned to carry out reactivity evolution experiments under simulated high pressure conditions or in high pressure thermogravimetric and, if needed, uidized- bed reactor (high pressure) arrangements. The pore structure of fresh, heat-treated, and half-calcined solids (dolomites) will be analyzed using a variety of methods. Our work will focus on limestones and dolomites whose reaction with SO2 or H2S under atmospheric conditions has been studied by us or other research groups in past studies. Several theoret- ical tools will be employed to analyze the obtained experimental data including a variable di#11;usivity shrinking-core model and models for di#11;usion, reaction, and structure evolution in chemically reacting porous solids. During the six months of this reporting period, work was primarily done on the study of the behavior of the sul#12;dation of limestones under sequential calcination conditions in the presence of small amounts of oxygen and the development of a stochastic simulation code for determining the extent of pore volume trapping (formation of inaccessible pore space) in gas-solid reactions accompanied by pore volume reduction such as the sulfation and sul#12;dation of calcined limestones and dolomites. The incentive for carrying out sul#12;dation experiments in the presence of oxygen was provided by the observation that some sul#12;dation experiments that were conducted as oxygen was accidentally leaking into the feed mixture of the reactor showed completely di#11;erent behavior from that obtained in the absence of oxygen. Experiments were carried out in the thermogravimetric analysis system that we developed for studying gas-solid reactions at atmospheric or subambient pressures. The two CaCO3 solids (Greer limestone and Iceland spar) that we …
Date: February 1, 1998
Creator: Sotirchos, Stratis V.
Partner: UNT Libraries Government Documents Department
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High SO2 Removal Efficiency Testing

Description: This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, "High Efficiency SO2 Removal Testing", for the time period 1 January through 31 March 1997. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO2 removal efficiency. The upgrades being evaluated mostly involve using performance additives in the FGD systems. The "base" project involved testing at the Tampa Electric Company�s Big Bend Station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy�s Merom Station (Option I), Southwestern Electric Power Company�s Pirkey Station (Option II), PSI Energy�s Gibson Station (Option III), Duquesne Light�s Elrama Station (Option IV), and New York State Electric and Gas Corporation�s (NYSEG) Kintigh Station (Option V). The originally planned testing has been completed for all six sites. However, additional testing is planned at the Big Bend Station. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the second quarter of calendar year 1997. Section 5 contains a brief acknowledgement.
Date: April 23, 1997
Creator: Blythe, Gary
Partner: UNT Libraries Government Documents Department
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Theoretical studies of collisional relaxation of highly excited SO{sub 2} in an Ar bath

Description: This paper describes molecular dynamics studies of collisional relaxation of highly excited SO{sub 2} in an Ar bath. Most of the calculations use a newly developed global ab initio potential surface for SO{sub 2} that correctly describes the superoxide (SOO) and ring isomers of SO{sub 2} that occur as secondary minima on the ground state potential surface at high energies (about 75% of the dissociation energy) above the C{sub 2v} minimum. Rate constants for the S + O{sub 2} and O + SO reactions are calculated to test this surface, and to examine the importance of electronically excited states in the O + SO recombination. The Ar + SO{sub 2} collisions are described by summing the ab initio potential with empirical intermolecular potentials. The resulting average vibrational energy transfer <{Delta}E> per collision is in good agreement with direct measurements (done at energies where the secondary minima are not populated) at 1000K, but the agreement is poorer at 300K. The agreement is significantly better than was obtained in a previous theoretical study, and our results indicate that the use of improved intramolecular and intermolecular potentials is crucial to obtaining the better results. The energy dependence of <{Delta}E> is found to be much stronger at energies where the secondary minima on the potential surface are accessible, however much of this effect is reproduced using a potential that has the same dissociation energy but not the secondary minima.
Date: December 31, 1995
Creator: Lendvay, G.; Schatz, G. C. & Harding, L. B.
Partner: UNT Libraries Government Documents Department
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Determination of the Optimum Concentration of Sulfur Dioxide to be Used in Sweet Potato Dehydration

Description: The object of this paper is to determine the optimum concentration of sulfur dioxide to be used in the commercial dehydration of the sweet potato by this process. Attention has been given to two aspects of the problem, (1) the effect of sulfur dioxide upon the extraction of water from the sweet potato by mechanical means, and (2) the effect of sulfur dioxide upon the stability of the carotene in the sweet potato over a period of several months.
Date: 1941
Creator: Kearby, Howard Raymond
Partner: UNT Libraries
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SO2 REMOVAL FROM FLUE GASES USING UTILITY SYNTHESIZED ZEOLITES

Description: It is well known that natural and synthetic zeolites (molecular sieves) can adsorb gaseous SO<sub>2</sub> from flue gas and do it more efficiently than lime based scrubbing materials. Unfortunately their cost ($500-$800 per ton) has deterred their use in this capacity. It is also known that zeolites are easy to synthesize from a variety of natural and man-made materials. The overall objective of the current work has been to evaluate the feasibility of having a utility synthesize its own zeolites, on-site, from fly ash and other recycled materials and then use these zeolites to adsorb SO<sub>2</sub> from their flue gases. Work to date has shown that the efficiency of the capture process is related to the degree of crystallinity and the type of zeolite that forms in the samples. Normally, those samples cured at 150°C contained a greater proportion of zeolite and as such were more SO<sub>2</sub> adsorptive than their low-temperature counterparts. However, in order for the project to be successful, on site synthesis must remain an option, i.e. _100°C synthesis. In light of this, the experimental focus now has two aspects. First, compositions of the starting materials are being altered by blending the current suite of fly ashes with other fly ashes, ground glass cullet and silica fume to promote the formation and growth of well crystallized and highly adsorptive zeolites. Second, greater degrees of reaction at significantly lower temperatures are being promote by ball milling the fly ash prior to use, by the use of more concentrated caustic solutions, and by the addition of zeolite seeds to the reactants. In all cases studies will focus on the effect of structure type and degree of conversion on SO<sub>2</sub> adsorption. Future work will concentrate on the study of the effect of weathering on the suitability of converting fly ash into …
Date: October 31, 1998
Creator: GRUTZECK, MICHAEL
Partner: UNT Libraries Government Documents Department
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Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results

Description: A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.
Date: January 25, 2004
Creator: Smith, Steven J.; Andres, Robert; Conception , Elvira & Lurz, Joshua
Partner: UNT Libraries Government Documents Department
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Fundamentals of Mercury Oxidation in Flue Gas

Description: The objective of this project is to understand the importance of and the contribution of gas-phase and solid-phase coal constituents in the mercury oxidation reactions. The project involves both experimental and modeling efforts. The team is comprised of the University of Utah, Reaction Engineering International, and the University of Connecticut. The objective is to determine the experimental parameters of importance in the homogeneous and heterogeneous oxidation reactions; validate models; and, improve existing models. Parameters to be studied include HCl, NO{sub x}, and SO{sub 2} concentrations, ash constituents, and temperature. This report summarizes Year 3 results for the experimental and modeling tasks. Experiments have been completed on the effects of chlorine. However, the experiments with sulfur dioxide and NO, in the presence of water, suggest that the wet-chemistry analysis system, namely the impingers, is possibly giving erroneous results. Future work will investigate this further and determine the role of reactions in the impingers on the oxidation results. The solid-phase experiments have not been completed and it is anticipated that only preliminary work will be accomplished during this study.
Date: July 31, 2006
Creator: Lighty, JoAnn S.; Silcox, Geoffrey; Fry, Andrew; Helble, Joseph & Krishnakumar, Balaji
Partner: UNT Libraries Government Documents Department
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State-of-the-Art Review of Materials-Related Problems in Flue Gas Desulfurization Systems

Description: This report characterizes the chemical and mechanical environments to which the structural components used in flue-gas desulfurization (FGD) are exposed. It summarizes the necessary background information pertinent to various FGD processes currently in use, with particular emphasis on lime/limestone scrubbing technology, so that the materials problems and processing variables encountered in FGD systems can be better defined and appreciated. The report also describes the materials currently used and their performance to date in existing wet scrubbers. There is little doubt that with more extensive use of coal and flue-gas scrubbers by utilities and other segments of private industry, a better understanding of the material failure mechanisms, performance limitations, and potential problem areas is required for the design of more reliable and cost-effective FGD systems.
Date: October 1980
Creator: Maiya, P. S.
Partner: UNT Libraries Government Documents Department
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An historic global SO2 emissions inventory for climate detection studies FY97 report to NOAA

Description: It has become apparent that anthropogenic aerosols exert radiative influence on the climate. This influence is comparable in magnitude but opposite in sign to that of greenhouse gases. The modeling effort here at LLNL has been designed to provide data and information for climate detection studies in order to help understand the role of anthropogenic aerosols over the interannual and decadal time scales.
Date: July 1, 1997
Creator: Dignon, J.
Partner: UNT Libraries Government Documents Department
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Assessing historical global sulfur emission patterns for the period 1850--1990

Description: Anthropogenic sulfur dioxide emissions from energy-producing and metal production activities have become an important factor in better understanding the relationship between humans and the environment. Concerns about (1) acid rain effects on the environment and (2) anthropogenic aerosols affecting possible global change have prompted interest in the transformation and fate of sulfur in the environment. One step in assessing the importance of sulfur emissions is the development of a reliable regional emission inventory of sulfur as a function of time. The objective of this research effort was to create a homogeneous database for historical sulfur emission estimates for the world. The time from 1850--1990 was selected to include the period of industrialization form the time the main production of fuels and minerals began until the most recent year for which complete production data exist. This research effort attempts to correct some of the deficiencies associated with previous global sulfur emission estimates by (1) identifying those production activities that resulted in sulfur emissions by country and (2) calculating historical emission trends by country across years. An important component of this study was the comparison of the sulfur emission results with those of previous studies.
Date: July 19, 1996
Creator: Lefohn, A.S.; Husar, J.D.; Husar, R.B. & Brimblecombe, P.
Partner: UNT Libraries Government Documents Department
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Test Plan for Characterization Testing of SO2-depolarized Electrolyzer Cell Designs

Description: SRNL received funding in FY 2005 to test the Hybrid Sulfur (HyS) Process for generating hydrogen. This technology employs an electrolyzer that uses a sulfur dioxide depolarized anode to greatly reduce the electrical energy requirement. The required current is the same as for conventional electrolysis of water, but the required cell voltage is reduced. The electrolyzer is a key part of HyS technology. Completing the material loop for HyS requires a high temperature decomposition of sulfuric acid to regenerate the sulfur dioxide gas needed for the anode reaction. Oxygen is also produced and could be sold. The decomposition of sulfuric acid is being studied by others in a separately funded task. It is not included in this SRNL task.
Date: February 15, 2006
Creator: Steimke, J. L.
Partner: UNT Libraries Government Documents Department
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