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Possible thermochemical cycle based on methanol. [Tetramethylphosphine]

Description: The production of hydrogen from methanol is of particular interest since the two reactions: CH/sub 4/ + H/sub 2/O + CO + 3H/sub 2/ and CO + 2H/sub 2/ = CH/sub 3/OH are individually well known industrial processes. Thus, if a method can be found to obtain the overall reaction: CH/sub 3/OH = CH/sub 4/ + 1/2 O/sub 2/ then, in total, a cyclic water splitting process is complete for which much of the industrial development is already known. A possible method is through the use of trimethylphosphine. This reacts with methanol to form a salt, tetramethyl phosphonium hydroxide: CH/sub 3/OH + (CH/sub 3/)/sub 3/P = (CH/sub 3/)/sub 4/POH. Tetramethylphosphonium hydroxide gives methane and trimethylphosphine oxide very readily: (CH/sub 3/)/sub 4/POH = CH/sub 4/ + (CH/sub 3/)/sub 3/PO. When anhydrous takes place readily at room temperature, but in the presence of water, the rate is retarded. In summary, the overall reaction can be written as: CH/sub 3/OH + (CH/sub 3/)/sub 3/P = CH/sub 4/ + (CH/sub 3/)/sub 3/PO. Thus, provided a way of removing oxygen from trimethylphosphine oxide can be found, (CH/sub 3/)/sub 3/PO = (CH/sub 3/)/sub 3/P + 1/2 O/sub 2/ is a simple method of converting methanol to methane and oxygen.
Date: January 1, 1982
Creator: Mason, C.F.V.
Partner: UNT Libraries Government Documents Department

Decomposition of hydrogen bromide using iron bromide and magnetite

Description: A means of thermochemically decomposing hydrogen bromide has been investigated experimentally using the reaction between magnetite and HBr as the bromine producing step. A high yield of Br/sub 2/ was formed in a short time (90% in 0.5 h). For the hydrogen producing step, the direct hydrolysis of ferrous bromide was confirmed as having an unfavorable equilibrium (3.61 x 10/sup -3/ at 849/sup 0/K). However, introduction of magnesium oxide into an aqueous solution of FeBr/sub 2/ and subsequent heating of the insoluble product gave H/sub 2/ and Fe/sub 3/O/sub 4/ in good yields. Further, Br/sub 2/ could be regenerated from this Fe/sub 3/O/sub 4/ by treatment with HBr. All the reactions were demonstrated to be fast, going to about 85% completion. The main drawback is the heat required to dry and dehydrate magnesium bromide in order to reform MgO by hydrolysis. These reactions are discussed within the framework of a thermochemical cycle.
Date: January 1, 1978
Creator: Mason, C.F.V.
Partner: UNT Libraries Government Documents Department

Oxidation of metal sulfites by iodine for use in thermochemical hydrogen cycles

Description: Thermochemical hydrogen cycles involving metal sulfates offer an alternative to sulfuric acid which is corrosion and has high energy requirements for drying prior to its thermal decomposition. The formation of such metal sulfates in conjunction with a low-temperature hydrogen formation step is discussed. The following reaction was studied: MgSO/sub 3/(c) + MgO(c) + I/sub 2/ (g) ..-->.. MgSO/sub 4/(c) + MgI/sub 2/(c). Although magnesium sulfite appears promising for this oxidation, a search was conducted for alternative metal sulfites which fit the following criteria for use: (a) sulfate must decompose in the temperature range available (< 1400/sup 0/K); (b) iodide must hydrolyze easily; and (c) salts must not be rare, toxic, or expensive. Lanthanum and titanium fit these criteria and will be investigated.
Date: January 1, 1981
Creator: Mason, C.F.V. & Bowman, M.G.
Partner: UNT Libraries Government Documents Department

Improved efficiency in thermochemical hydrogen cycles through decreasing the use of solvent water. Consideration of the sulfur dioxide: iodine cycle

Description: This paper considers the relationship between evaporation and efficiency and examines experimentally an adaptation of the sulfur dioxide-iodine cycle where little water needs to be evaporated or condensed.
Date: January 1, 1982
Creator: Mason, C.F.V. & Bowman, M.G.
Partner: UNT Libraries Government Documents Department

Cadmium-cadmium carbonate cycle for the thermochemical production of hydrogen

Description: A means of thermally decomposing water using cadmium, cadmium oxide and cadmium carbonate is described. Experimental emphasis is placed on the hydrogen producing step which consists of reacting cadmium with water and carbon dioxide to produce cadmium carbonate and hydrogen. The cycle is completed by decomposing the carbonate, first to the oxide, and then to the metal. Laboratory studies show that hydrogen is evolved slowly in relatively high yields (57 to 65%), but, when produced in the presence of ammonium chloride, both the yield and rate are increased (72% in 0.5 hr). The figure of merit of the cycle is 78% with a probability of some decrease resultant from the ammonium chloride reaction.
Date: January 1, 1980
Creator: Mason, C.F.V. & Bowman, M.G.
Partner: UNT Libraries Government Documents Department

Reactions for improving efficiencies in thermochemical cycles related to the sulfur dioxide-iodine process

Description: A modification of the sulfur dioxide-iodine cycle which uses magnesium oxide, magnesium sulfite and magnesium iodide is examined with particular emphasis on decreasing the amount of water employed and thereby increasing the efficiency. The key reaction is that of iodine with magnesium oxide and magnesium sulfite hexahydrate with no additional water. This produces 77% of the total possible sulfate as well as magnesium iodide, hydrogen iodide and hydrogen at 523/sup 0/K. The efficiency of this cycle varies between 58% and 39% depending on the amount of heat that can be recovered. This is the first example of a cycle where there is no large energy burden due to evaporation.
Date: January 1, 1982
Creator: Mason, C.F.V. & Bowman, M.G.
Partner: UNT Libraries Government Documents Department

Metal sulfite/sulfate reactions in thermochemical hydrogen cycles

Description: The thermochemical cycles which have been most extensively developed all involve the thermal decomposition of sulfuric acid which is corrosive. Metal sulfate cycles have been studied as a means of circumventing handling corrosive mixtures at high temperatures. However, these metal sulfate cycles still use an electrochemical step to produce H/sub 2/. Alternate H/sub 2/ producing steps to be used in conjunction with metal sulfates are examined.
Date: January 1, 1980
Creator: Mason, C.F.V. & Bowman, M.G.
Partner: UNT Libraries Government Documents Department

Improved efficiency in the sulfur dioxide-iodine hydrogen cycle through the use of magnesium oxide

Description: The reaction of iodine with dry magnesium oxide and magnesium sulfite hexahydrate was studied experimentally as a possible means of improving the efficiency of the sulfur dioxide-iodine cycle. When no extra water was introduced, the maximum product yield was 67% obtained at 423 K. With excess water vapor, a nonporous plug was formed which prevented complete reaction. In the second case, maximum yield was 62% measured at 433 K showing that added water does not increase reaction products. This reaction gives an alternate route for producing hydrogen from water via the sulfur dioxide-iodine process.
Date: January 1, 1981
Creator: Mason, C.F.V. & Bowman, M.G.
Partner: UNT Libraries Government Documents Department

Studies on the LASL cadmium-cadmium carbonate cycle

Description: The following results were obtained from studies on the cadmium-cadmium carbonate cycle. A new lower limit for the heat of formation of CdO(g) has been estimated ..delta..H/sup 0//sub f,298/ > 113.8 kJ/mol. Hydrogen production is subject to catalysis. While Pd is an effective catalyst, NH/sub 4/Cl shows greater catalytic activity. Seventy-two percent of the total available H/sub 2/ is formed in one-half hour at 523/sup 0/K using NH/sub 4/Cl as a catalyst. Four to five moles of water must be removed from CdCO/sub 3/ prior to its thermal decomposition.
Date: January 1, 1980
Creator: Mason, C.F.V.; Bowman, M.G. & Behrens, R.G.
Partner: UNT Libraries Government Documents Department

Characterization and immobilization of cesium-137 in soil at Los Alamos National Laboratory

Description: At Los Alamos National Laboratory, cesium-137 ({sup 137}Cs) is a major contaminant in soils of Technical Area 21 (TA-21) and is mainly associated with soil particles {<=}2.00 mm. Cesium-137 was not leached by synthetic groundwater or acid rainwater. Soil erosion is a primary mechanism of {sup 137}Cs transport in TA-21. The methodology that controls soil particle runoff can prevent the transport of {sup 137}Cs.
Date: June 1, 1996
Creator: Lu, Ningping; Mason, C.F.V. & Turney, W.R.J.R.
Partner: UNT Libraries Government Documents Department

Sorption Behavior of Strontium-85 Onto Colloids of Silica and Smectite

Description: Strontium-90 is one of the sizable radioactive contaminants found in DP Canyon at Los Alamos, New Mexico. Radioactive surveys found the {sup 90}Sr is present in surface and groundwater in DP Canyon and Los Alamos Canyon. Colloids may influence the transport of this radionuclide in surface water and groundwater environments in both canyons. In this study, we investigated the sorption/desorption behavior of Sr on colloids of smectite and silica. Laboratory batch sorption experiments were conducted using {sup 85}Sr as a surrogate to {sup 90}Sr. Groundwater, collected from DP Canyon and from Well J-13 at Yucca Mountain, Nevada, and deionized water were used in this study. Our results show that 92% to 100% of {sup 85}Sr was rapidly adsorbed onto smectite colloids in all three waters. The concentrations of Ca{sup 2+} significantly influence the adsorption of {sup 85}Sr onto silica colloids. Desorption of {sup 85}Sr from smectite colloids is much slower than the sorption process. Desorption of {sup 85}Sr from silica colloids was rapid in DP groundwater and slow using J-13 groundwater and deionized water.
Date: November 10, 1998
Creator: Lu, N.; Triay, I.R.; Mason, C.F.V. & Longmire, P.A.
Partner: UNT Libraries Government Documents Department

Alternate thermochemical cycles for advanced hydrogen production

Description: Experimental studies have validated three classes of thermochemical cycles (Bismuth sulfate-sulfuric acid, magnesium sulfate-magnesium iodide, and oxide-based) based on high temperature solids decomposition as an endothermic step. Such cycles offer the possibility of high efficiency when coupled with high temperature isothermal heat sources. Methods for handling solids in high temperature decomposition reactions have been tested. The results suggest that efficient and practical cycles can be based on such reactions.
Date: January 1, 1982
Creator: Bowman, M.G.; Hollabaugh, C.M.; Jones, W.M. & Mason, C.F.V.
Partner: UNT Libraries Government Documents Department

Migration of Sr-20, Cs-137, and Pu-239/240 in Canyon below Los Alamos outfall

Description: Technical Area-21 (TA-21) of Los Alamos National Laboratory (LANL) is on a mesa bordered by two canyons DP Canyon and Los Alamos (LA) Canyon. DP Canyon is a small semiarid watershed with a well defined channel system where the stream flow is ephemeral. TA-21 has had a complex history of waste disposal as research to determine the chemical and metallurgical properties of nuclear materials occurred here from 1945-1978. Due to these operations, the TA-21 mesa top and bordering canyons have been monitored and characterized by the LANL Environmental Restoration Program. Results identify radionuclide values at outfall. 21-011 (k) which exceed Screening Action Levels, and points along DP Canyon which exceed regional background levels. The radiocontaminants considered in this study are strontium-90, cesium-137, and plutonium-239. This research examines sediment transport and speciation of radionuclide contaminant migration from a source term named SWMU 21-011 (k) down DP Canyon. Three dimensional surface plots of data from 1977-1994 are used to portray the transport and redistribution of radioactive contaminants in an alluvial stream channel. An overall decrease in contamination concentration since 1983 has been observed which could be due to more stringent laboratory controls and also to the removal of main plutonium processing laboratories to another site.
Date: April 1, 1996
Creator: Murphy, J.M.; Mason, C.F.V.; Boak, J.M. & Longmire, P.A.
Partner: UNT Libraries Government Documents Department

A complete remediation process for a uranium-contaminated site and application to other sites

Description: During the summer of 1996 the authors were able to test, at the pilot scale, the concept of leaching uranium (U) from contaminated soils. The results of this pilot scale operation showed that the system they previously had developed at the laboratory scale is applicable at the pilot scale. The paper discusses these results, together with laboratory scale results using soil from the Fernald Environmental Management Project (FEMP), Ohio. These FEMP results show how, with suitable adaptations, the process is widely applicable to other sites. The purpose of this paper is to describe results that demonstrate remediation of uranium-contaminated soils may be accomplished through a leach scheme using sodium bicarbonate.
Date: December 31, 1998
Creator: Mason, C.F.V.; Lu, N.; Kitten, H.D.; Williams, M. & Turney, W.R.J.R.
Partner: UNT Libraries Government Documents Department

Strontium-85 and plutonium-239 sorption in rock samples from the Semipalatinsk Test Site, Kazakhstan

Description: The adsorption and desorption of strontium and plutonium were studied as a function of rock type and simulated ground waters from the Semipalatinsk Test Site (STS). Seven different rock types were obtained from the Balapan Region of the STS and were subjected to x-ray diffraction analyses. Two different ground waters were simulated using data supplied by the National Nuclear Center. The results indicate the sorption of strontium is strongly dependent on the minerals present in the rock species and on the total ionic strength of the ground water whereas, in all cases, plutonium was strongly irreversibly sorbed.
Date: March 1, 1999
Creator: Mason, C.F.V.; Lu, N.; Marusak, N.L.; Scheber, B.; Chipera, S.; Daukeyev, D. et al.
Partner: UNT Libraries Government Documents Department

A comparison of the design of Russian and US containers for plutonium oxide storage.

Description: The safe storage of plutonium in the form of plutonium oxide (Pu02) is a major concern in countries with significant plutonium inventories . The goal is to stabilize and package oxide in such a way that the possibility of leaks and failures are unlikely. Currently in Russia, Pu02 is stored 1 at the Mining and Chemical Combine (MCC, Zheleznogorsk) and at the Siberian Chemical Combine (SCC, former Tomsk-7). (Plutonium metal is stored at PA 'Mayak' and is not addressed here) . Current storage containers for Russian Pu02 do not meet modern safety requirements . Further, every three years the gaskets have to be replaced . The containers can become over pressurized due to radiation processes and this results in possible container failures 1 . In the US, Pu02 is present at several Department of Energy (DOE) sites 2 . US reports of long time storage of Pu02 show a few cases of storage container failures 2 among thousand of intact cases. Major causes of malfunction are metal oxidation in non-airtight packages and gas pressurization from inadequately stabilized oxide . Because of these failures the US DOE adopted a standard 3 for stabilization, packaging and storage of plutonium-bearing material that addresses these vulnerabilities .
Date: January 1, 2003
Creator: Mason, C. F. V. (Caroline F. V.); Zygmunt, Stanley J.; Wedman, Douglas E.; Eller, P. G. (Phillip Gary); Erickson, R. M. (Randall M.); Hansen, W. J. (Walter J.) et al.
Partner: UNT Libraries Government Documents Department