EP0407471A4 - A catalytic method for concentrating isotopes - Google Patents
A catalytic method for concentrating isotopesInfo
- Publication number
- EP0407471A4 EP0407471A4 EP19890906628 EP89906628A EP0407471A4 EP 0407471 A4 EP0407471 A4 EP 0407471A4 EP 19890906628 EP19890906628 EP 19890906628 EP 89906628 A EP89906628 A EP 89906628A EP 0407471 A4 EP0407471 A4 EP 0407471A4
- Authority
- EP
- European Patent Office
- Prior art keywords
- deuterium
- hydrogen
- reaction
- catalyst
- deuteride
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B4/00—Hydrogen isotopes; Inorganic compounds thereof prepared by isotope exchange, e.g. NH3 + D2 → NH2D + HD
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D59/00—Separation of different isotopes of the same chemical element
- B01D59/28—Separation by chemical exchange
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B5/00—Water
Definitions
- the present invention relates to a catalytic method for concentrating isotopes.
- a more particular application of the method relates to concentrating deuterium using catalysts capable of selectively catalyzing a reaction with a deuterium-containing compound.
- the present invention finds particular utility in the production of heavy water.
- hydrogen-containing substances contain at least two isotopes of hydrogen, namely protium, having an approximate atomic weight of one, and deuterium, having an approximate atomic weight of two.
- the natural abundance of deuterium in hydrogen gas is given as 0.0150 percent in the "Handbook of Chemistry and Physics," 49th edition (1968-69), published by the Chemical Rubber Company, Cleveland, Ohio.
- the deuterium present in hydrogen gas is largely in the form of hydrogen deutride (HD) with a much smaller percentage occurring in the form of molecular deuterium (D 2 ).
- the deuterium content present in natural, untreated water is usually within the range of 0.012 to 0.016 percent depending on the source of the untreated water.
- the deuterium present in water is largely in the form of hydrogen deuterium oxide (HDO) with a much smaller percentage occurring in the form of deuterium oxide (D 2 O).
- Electrolysis was the first method used commercially to concentrate deuterium. When water is decomposed electrolytically into hydrogen and oxygen, the deuterium content at the cathode is substantially lower than that of the water remaining in the cell. As electrolysis continues, the remaining water becomes progressively enriched in deuterium.
- Fractional distillation was another of the early processes used to concentrate deuterium. This process uses differences in vapor pressures to separate deuterium oxide from water.
- Several processes have also been described for exchanging isotopes between a fluid and an isotope-containing gas.
- U.S. Pat. No. 2,690,379 to Urey et al. processes for accelerating deuterium exchange reactions between liquid water or water vapor and hydrogen gas are described using certain supported metal catalysts.
- the Urey et al. patent describes several counter-current and co-current hydrogen exchange systems which are promoted by those catalysts.
- the present invention overcomes the problems and disadvantages of the prior art by providing a catalytic method for concentrating an isotope using catalysts capable of selectively catalyzing a reaction with the isotope.
- the invention is particularly useful to concentrate deuterium from sources such as hydrogen rich gas.
- the invention can also be used to concentrate isotopes such as tritium, carbon-13, nitrogen-15, and others.
- the reaction process is much simpler than the prior art processes and requires only moderate energy input and limited processing equipment.
- the invention produces a concentrated product that, in the case of deuterium, can be further concentrated by conventional methods to produce heavy water at a significant savings over the prior art processes.
- an isotope may be concentrated from an admixture containing the isotope by contacting the admixture with a catalyst capable of selectively catalyzing a reaction with the isotope, and recovering the concentrated isotope from the reaction products.
- deuterium may be concentrated from an admixture containing a deuterium compound by reacting the admixture with a deuterium reactant in the presence of a catalyst capable of selectively catalyzing a reaction between the deuterium compound and the reactant, and recovering concentrated deuterium from the reaction products.
- deuterium may be concentrated from an admixture containing hydrogen deuteride by reacting the admixture with a source of oxygen in the presence of a catalyst capable of selectively catalyzing the oxidation of hydrogen deuteride, and recovering concentrated deuterium from the reaction products.
- deuterium may be concentrated from an admixture containing hydrogen deuteride by reacting the admixture with a reactant capable of undergoing hydrogenation in the presence of a catalyst capable of selectively catalyzing the reaction between hydrogen deuteride and the reactant to form a deuterated reaction product, reacting the deuterated reaction product with a source of oxygen, and recovering concentrated deuterium from the final reaction products.
- deuterium may be concentrated from an admixture containing hydrogenn deuteride by reacting the admixture with a reactant selected from ethene, acetylene, and their homologues in the presence of a catalyst capable of selectively catalyzing the reaction between hydrogen deuteride and the reactant to form a deuterated reaction product, reacting the deuterated reaction product with source of oxygen, and recovering concentrated deuterium from the final reaction products.
- a reactant selected from ethene, acetylene, and their homologues
- a catalyst capable of selectively catalyzing the reaction between hydrogen deuteride and the reactant to form a deuterated reaction product, reacting the deuterated reaction product with source of oxygen, and recovering concentrated deuterium from the final reaction products.
- deuterium may be concentrated from an admixture containing hydrogen deuteride by contacting the admixture with a catalyst capable of selectively adsorbing hydrogen deuteride and capable of catalyzing the oxidation of hydrogen deuteride, reacting the adsorbed hydrogen deuteride with a source of oxygen, and recovering concentrated deuterium from the final reaction products.
- an admixture containing an isotope is first contacted with a catalyst capable of selectively catalyzing a reaction with the isotope.
- the isotope may be selected from any isotope capable of enrichment by this method, including both naturally occurring and artificially produced isotopes.
- the deuterium can be concentrated from any admixture of molecules and compounds that contains a deuterium compound.
- the deuterium compound may be any compound containing a deuterium atom.
- the admixture is a hydrogen rich gas containing hydrogen deuteride. Such an admixture will also contain traces of molecular deuterium and may contain other molecules and compounds as well. In some instances, it may be desireable to purify the hydrogen rich gas to avoid the production of impurities during the catalytic reaction.
- the admixture is a hydrogen rich gas such as the hydrogen stream used in the production of ammonia, the hydrogen produced by hydrogen generators, or the hydrogen process stream of oil refineries. Using the processes disclosed herein, the deuterium may be extracted from such hydrogen rich gas, and the hydrogen returned to the gas stream.
- the catalysts to be used are those catalysts capable of selectively catalyzing a reaction with an isotope within an admixture.
- a catalyst is capable of selectively catalyzing such a reaction when it enables a reaction with the isotope to proceed faster than reactions with other components of the admixture.
- Catalysts can be predicted according to the intermedion theory of adsorption by applying the hypothesis of R. R. Myers that "synchronization of vibration frequencies of molecules will facilitate their reaction.” According to the theory, reactants become associated with the metal such that their vibrational frequencies or energies are perturbed by proximity to the metal. A metal that perturbes the frequencies in a way that enables such synchronization of vibration frequencies acts as a catalyst.
- the first step in the catalyst prediction process is the identification of reactants for possible reaction mechanisms to achieve separation of the desired isotope.
- the next step in the catalyst prediction process is the development of equations describing intermedions of the reactants that relate the vibrational frequencies of intermedions to the number of their outer-shell electrons.
- An intermedion is a weakly bonded adsorbate (i.e., readily removed by evacuation at room temperature) that has a vibrational frequency corresponding to a non-integral number of electrons.
- the fraction of the non-integral number is the perturbation fraction of the metallic component of the adsorbant.
- the equations typically are a right hyperbola of the form:
- K is the curvature
- the vibrational frequency of the neutral carbon monoxide molecule with 10 valence electrons is 2143.27 cm -1 [Refs E.K. Plyler, L.R. Blaine, and W.S. Conner, J. Opt. Soc. Am., 45, 102 (1955)3 and the vibrational frequency of the positive ion of carbon monoxide with 9 valence electrons is 2183.90 cm -1 [Ref.: G. Herzberg, "Molecular Spectra and Molecular Structure I, Spectra of Diatomic Molecules," D.
- the third point is the number of electrons at which the vibrational frequency becomes zero--the point of dissociation of the molecule into ions.
- integers I A to I B range from two minus the number of electrons on the neutral molecule to one plus the number of electrons on the neutral molecule.
- integers for carbon monoxide are 8, 9, 10, 11; for oxygen, "O 2 ", 10, 11, 12, 13; for molecular hydrogen, "H 2 ", 0, 1; for ethene, 10, 11, 12, 13; for acetylene, 8, 9, 10, 11, for oxygen atoms, "0", 4, 5, 6, 7 etc.
- Fractions, "f” may, of course, range from 0-1.
- ⁇ is rewritten as "I + f" etc.
- the set of solutions, "f's,” are termed "optimum" fractions for the reaction. These are the fractions which make the vibrational frequencies of the two intermedions in synchronization, as required by the Myers Hypothesis as a criterion for reaction.
- the next step in catalyst prediction process is the identification of perturbation fractions for various potential catalysts. These fractions for various metals are set forth in Table I. TABLE I . Perturbation Fractions and Corresponding
- the lower of the two oxidation states or the "ous" state corresponds to odd integers for even atoms or molecules, that is, atoms or molecules having an even number of protons and the higher of the two oxidation states or the "ic" state corresponds to even integers for even atoms or molecules; the reverse is true for atoms or molecules possessing an odd number of protons.
- the number of protons for a molecule is the combined total of protons of its constituent atoms.
- the "integers" referred to above are the integers corresponding to the vibrational frequency of the absorbate or reactant. It may be noted that the equations describing intermedions also contain the vibrational frequencies of the neutral molecule and positive and negative ions.
- the last step in the catalyst prediction process involves the comparison of optimum fractions with all known perturbation fractions of potential catalysts. If this comparison results in a match or agreement within about + 0.01 of a percent, more preferably within about +.0.002 of a percent, then it can be stated that the potential catalyst should catalyze the reaction between the reactants to form some appropriate product, providing that the free energy change is appropriate.
- vibrational frequencies of molecules vary as a function of changes in atomic mass.
- Isotopes by definition, are chemical entities that differ in atomic mass. If the atomic mass of two isotopes are sufficiently different to affect a variation in the vibrational frequencies of the pair, then each isotope may exhibit distinct chemical properties. This distinctiveness is not specific for neutral molecules; vibrational frequencies of isotopic intermdions, on a given adsorbent, will also be sufficiently different. Each isotopic adsorbate will be reactive toward other adsorbates, catalyzed by and dependent upon the metallic component of the adsorbent.
- isotopes with relatively small atomic mass can most easily be separated.
- Preferred isotopes that can be concentrated with particular effectiveness using this invention care those having an atomic weight less than about 22, including deuterium, tritium, carbon-13, and nitrogen-15.
- the ligands associated with the catalysts useful in this invention may be any ligands that are compatible with their catalytic action.
- Ligands as that term is used herein, are any atom or complex of atoms sufficiently closely associated with or attached to the particular metal or metals under consideration to alter or effect its chemical and/or catlaytic behavior. Thus in an alloy of two or more metals each metal acts as a ligand to the others.
- Preferred ligands include oxides, sulfides, and sufates, phosphates, chlorates, perchlorates, sulfites, thiosulfates, chlorides, bromides, iodides, fluorides, silicates, nitrates, as well as organic moieties which produce an organometallic compound, and intermetallic compouids, i.e. bimetallic compounds, and cluster compounds. Selection of a ligand will depend- upon the desired oxidation state of the catalyst and upon desired electron donor/acceptor properties to generate the appropriate intermedion for the desired reaction. Such selection will be a matter of routine for those skilled in the art.
- the catalyst may not only be in the form of a solid, a heterogeneous catalyst, but may also be a homogeneous catalyst, that is, soluble in a suitable solvent a colloidal suspension or an enzyme with its natural metallic component or "co-factor" or an altered enzyme containing a metal, synthetically replacing the natural metal.
- Catalysts in the +1 and +2 oxidation states may be stabilized in certian inorganic compounds, certain cluster compounds, and even on a metal surface, most appropriately a highly dispersed metal to afford a high surface area as is obtained in an aerogel of metal on a support such as silica or alumina.
- the catalysts useful in this invention may be conditioned prior to their use in any conventional manner that will facilitate the catalyst's activity.
- the catalyst is conditioned immediately prior to initiation of the reaction to a preferred oxidation state.
- a lower oxidation state may be obtained by exposing the catalyst to carbon monoxide.
- the catalyst is heated, and optionally exposed to nitrogen, to drive off any mixture before the reaction is initiated.
- deuterium may be concentrated from an admixture containing hydrogen deuteride by reacting the admixture with a source of oxygen in the presence of a catlayst capable of selectively catalyzing the oxidation of hydrogen deuteride to form hydrogen deuterium oxide. This reaction can be expressed as:
- the source of oxygen- used in the reaction with the hydrogen deuteride may be any molecule or compound capable of providing oxygen to the reaction, but is most preferably simply dry air.
- a similar reaction may be carried out with molecular deuterium to form deuterium oxide.
- the catalysts to be used in the reaction between the admixture containing hydrogen deuteride and oxygen can be any catalyst capable of selectively catalyzing the reaction between hydrogen deuteride and oxidation.
- Preferred catalyst are selected from vanadium in the +2 oxidation state, chromium in the +3 oxidation state, zinc in the +2 oxidation state, state, praesodymium in the +3 oxidation state, and compounds thereof.
- catalysts are Cr 2 O 3 and ZnO, both of which are commercially available from Harshaw/Filtrol Partnership in Cleveland, Ohio, and United Catalysts Inc. of Louisville, Kentucky, respectively.
- the reaction conditions under which the reaction between hydrogen dueteride and oxygen takes place may be any reaction conditions under which the reaction proceeds and the reaction with hydrogen deuteride takes place faster than the reaction with other components of the admixture, notably hydrogen (protium).
- the reaction temperature is less than 700oF. At temperatures greater than 700oF, it has been found that the rate of reaction between hydrogen (protium) and oxygen increases faster than the rate of reaction between hydrogen deuteride and oxygen, and the concentration of hydrogen deuterium oxide in the reaction products decreases. In a most preferred embodiment, the temperature is between 500o and 600oF.
- the pressure at which the reaction between the admixture of hydrogen and hydrogen deuteride with oxygen takes place may be atmospheric pressure, but is preferably a pressure greater than atmospheric pressure. It will be understood by those skilled in the art that temperature and pressure are interrelated and that temperatures optimum for production hydrogen deuterium oxide may vary with pressures and vice versa.
- the products of the reaction between the admixture containing hydrogen deuteride and oxygen will include compounds in addition to hydrogen deuterium oxide.
- the admixture most commonly will contain large quantities of hydrogen (protium). Although the reaction is selective for hydrogen deuteride, some hydrogen (protium) will react with the oxygen to form water. In addition, if there are impurities in the admixture, there may be impurities among the reaction products as well. In the most preferred embodiment, however, the reaction conditions are chosen so that light water production and impurities are minimized.
- concentrated deuterium principally in the form of hydrogen deuterium oxide
- the reaction products are condensed by cooling, such as in a dry ice/acetone bath.
- the condensate contains hydrogen deuterium oxide and light water.
- the condensate will contain deuterium oxide as well.
- deuterium may be concentrated by reacting an admixture containing hydrogen deuteride with a reactant capable of undergoing hydrogenation in the presence of a catalyst capable of selectively catalyzing the reaction between hydrogen deuteride and the reactant to form a deuterated reaction product, reacting the deuterated reaction product with a source of oxygen to form hydrogen deuterium oxide, and recovering concentrated deuterium from the final reaction products.
- the compounds capable of undergoing hydrogenation may be any unsaturated organic compound containing a double or a triple bond, such as alkenes, alkynes, benzenes, aldehydes, ketones, esters, and nitriles.
- the compounds capable of undergoing hydrogenation are selected from ethene and its homologues, such as propene, butene, pentene, hexene, etc., and from acetylene and its homologues, such as propyne, 1-butyne, 2-butyne, 1-pentyne, 2-pentyne, 3-methly-1-butyne, etc.
- the compounds are selected from ethene and acetylene.
- the reaction with hydrogen deuteride is believed to form deuterated ethane and can be expressed ass
- the catalysts to be used in the reaction between an admixture containing hydrogen deuteride and ethene or its homologues can be any catalyst capable of selectively catalyzing the reaction hydrogen deuteride and ethene.
- Preferred catalyst are selected from compounds of chromium in the +2, +3, and +6 oxidation states, yttrium in the +1 oxidation state, zirconium in the +4 oxidation state, and gadolinium in the +1 oxidation state.
- the catalysts are Cr 2 O 3 and ZrO 2 , both of which are commercially available from Harshaw/Filtrol Partnership in Cleveland, Ohio.
- the deuterated ethene can then be reacted with oxygen, and the reaction can be expressed as:
- the deuterated ethene can be further reacted with hydrogen deuteride to form C 2 H 4 D 2 , and then reacted with oxygen.
- the catalysts to be used in the reaction between an admixture of hydrogen deuteride and acetylene or its homologues can be any catalyst capable of selectively catalyzing the reaction between hydrogen deuteride and acetylene.
- Preferred catalysts are selected from compounds of calcium in the +2 oxidation state, titanium in the +2 oxidation state, and lanthanum in the +3 oxidation state.
- the reaction conditions under which a reaction between an admixture containing hydrogen deuteride and a reactant capable of undergoing hydrogenation takes place may be any reaction conditions under which the reaction proceeds and the reaction with hydrogen deuteride proceeds faster than the reaction which with other components of the admixture, notably hydrogen (protium).
- the reaction temperture is less than 500oF.
- the temperature is between ambient and 300 oF.
- the pressure at which the reaction takes place may be atmospheric pressure, but is preferably a pressure greater than atmospheric pressure.
- the products of a reaction between an admixture containing hydrogen deuteride and a reactant capable of undergoing hydrogenation may include compounds in addition to deuterated reaction products. Although the reaction is selective for hydrogen deuteride, some hydrogen (protium) may react with the reactant. In addition, if there are impurities in the hydrogen stream, there may be impurities among the reaction products as well. In the most preferred embodiment, however, the reaction conditions are chosen so that production of the deuterated reaction product is maximized and impurities are minimized.
- the deuterated reaction product is reacted with a source of oxygen.
- the deuterated reaction product is first recovered by a suitable means, such as condensation by cooling in liquid nitrogen.
- the deuterated reaction product is then mixed with air and reacted in the presence of any oxidation catalyst, which, in some cases, may be the same catalyst used for the hydrogenation reaction.
- the reaction conditions under which a reaction between a deuterated reaction product and oxygen takes place may be any reaction conditions under which hydrogen deuterium oxide is formed.
- the reaction temperature is less than 700oF. In a most preferred embodiment, the temperature is between 500o and 600oF.
- the reaction between the deuterated reaction product and oxygen may take place at any pressure.
- the products of the reaction between the deuterated reaction product and oxygen will include compounds in addition to hydrogen deuterium oxide.
- some of the hydrogen (protium) atoms in the deuterated reaction product may react with the oxygen to form water.
- reactants with a small number of hydrogen atoms such as ethene and acetylene, are preferred.
- homologues of ethene and acetylene are used in the reaction, more ater will be produced because of the presence of additional hydrogen (protium) atoms.
- concentrated deuterium principally in the form of hydrogen deuterium oxide
- the reaction products are condensed by cooling, such as in a dry ice/acetone bath.
- the condensate contains hydrogen deuterium oxide, water, and a small percentage of deuterium oxide in equilibrium with the hydrogen deuterium oxide.
- deuterium may be concentrated from an admixture containing hydrogen deuteride by reacting the admixture with a source of oxygen in the presence of a catalyst capable of selectively adsorbing hydrogen deuteride and capable of catalyzing the oxidation of hydrogen deuteride.
- the catalysts to be used in this reaction can be any catalyst capable of selectively adsorbing hydrogen deuteride and capable of catalyzing the oxidation of hydrogen deuteride.
- the catalyst is Cr 2 O 3 . The adsorption of hydrogen deuteride onto the catalyst takes place as a first reaction step.
- the reaction conditions under which the adsorption takes place may be any reaction conditions under which hydrogen deuteride is selectively adsorbed onto the catalyst. Most importantly, where the admixture contains a large quantity of hydrogen (protium), the hydrogen deuteride is adsorbed preferentially over hydrogen (protium). In a preferred embodiment, the reaction temperature is between ambient and 300oF.
- the catalyst is exposed to a source of oxygen.
- the hydrogen deuteride reacts with oxygen and is desorbed.
- the source of oxygen is dry air.
- the reaction conditions under which the reaction with oxygen and desorbtion takes place may be any condition under which these reactions take place.
- the reaction between adsorbed hydrogen deuteride with a source of oxygen is carried out at temperature of between 500 oC and 900oF.
- reaction products of this hydrogen deuteride oxidation and desorption will include hydrogen deuterium oxide. Although the reaction is selective for hydrogen deuteride, some hydrogen (protium) will react with oxygen to form water.
- concentrated deuterium principally in the form of hydrogen deuterium oxide
- the reaction products are condensed by cooling.
- the condensate contains hydrogen deuterium oxide and water as well as a small percentage of deuterium oxide in equilibrium with the hydrogen deuterium oxide.
- the concentration of deuterium recovered according to the invention may have a concentration at least ten times, and more preferably at least fifteen times, greater than the concentration of deuterium in the admixture before the reaction.
- the concentrated deuterium may then be further concentrated or purified by any conventional means such as electrolysis or fractional distillation. The cost of these purification processes, however, will be greatly reduced by starting with a concentrated product.
- Reactant tank 4 foot long, 4 inch diameter, internal volume of 1,000 cubic inches, carbon steel construction
- Pressure Regulator for regulating the flow of reactants from the reactant tank;
- Critical Flow Orifices two critical flow orifices for smoothing the flow, rate;
- Glass Reactor internal volume 700cc, bottom inlet, top outlet on side, wrapped with a heating tape and fiberglass tape;
- Power Supply to heat the glass reactor;
- Variac to vary the voltage from the power supply to the heating tapes and control temperature;
- Thermocouple attached to the glass reactor through a rubber stopper in the top with LED readout;
- Condenser consisting of a tube condenser and a Dewar Flask
- the reactant tank was flushed six times with hydrogen gas and vented.
- the reactant tank was then charged with deuterium to 6.1 psig, subsequently with oxygen to 15.1 psig, and finally with hydrogen to 120 psig.
- the catalyst was then prepared by exposing the catalyst to carbon monoxide to condition the catalyst to the +2 oxidation state and by heating the catalyst to a temperature of about 571oF to drive off any moisture.
- the reactant feed to the glass reactor was then turned on and held constant. A flow rate 210 cc/min was maintained until the tank pressure was insuffcient to maintain this flow. Flow was continued until all the flow ceased. Initial temperature of the glass reactor was 565oF and increased to 577oF during the reaction. Pressure was atmospheric pressure.
- the condensate in the condenser was analyzed at the conclusion of the experiment with an FTIR infrared spectrometer (Analect Instruments Model No. FX6260 with computer and color CRT).
- the concentration of deuterium atoms in the condensate was measured in five samples and found to average 15%. This corresponds to a 30% efficiency in extracting the deuterium atoms from the reactant admixture.
- Example 2 A continuous flow experiment with the same experimental apparatus used in Example 1 was performed with the exception that the outlet gas from the condenser was bubbled through a column of mercury of 27.6 inches to create an operating pressure of approximately two atmospheres.
- the reactant tank was flushed with hydrogen and then charged with deuterium to 6.0 psig, subsequently with oxygen to 15.0 psig, and finally with hydrogen to 120 psig. This produced an admixture having a ratio of hydrogen:deuterium:oxygen (H:D:O) of approximately 20:1:3.
- Zinc oxide catalyst identical to that used in example 1 was prepared by exposing the catalyst to hydrogen to condition the zinc to the +2 oxidation state and by heating the catalyst to a temperature of 588 oF to drive off any moisture. The reactant feed to the glass reactor was then turned on and held constant. A flow rate of 147 cc/min was maintained until pressure in the reactant tank was insufficient to maintain this flow. Flow was continued until all flow ceased. Initial temperature of the glass reactor was 598oF and decreased to 572oF during reaction.
- Example 2 The reaction products that exited the reactor were condensed and analyzed as in Example 1. Condensate yield was 11.25g. The concentration of deuterium atoms in the condensate was found to be 21%. This corresponds to a 52.9% efficiency in extraction of the deuterium atoms from the reactant admixture.
- EXAMPLE 3 A continuous flow experiment with the same experimental apparatus used in Example 1 was performed. The reactant tank was flushed with hydrogen and then charged with deuterium to 6.0 psig, subsequently with oxygen to 15.0 psig, and finally with hydrogen to 120 psig. This produced an admixture having a ratio of hydrogen:deuterium:oxygen (H:D:O) of approximately 20:1:3.
- the catalyst was prepared by exposing the catalyst to carbon monoxide for approximately 200 minutes to condition the chromium to the +3 oxidation state and by heating the catalyst to a temperature of 594oF to drive off any moisture.
- the reactant feed to the glass reactor was then turned on and held constant. A flow rate of 142 cc/min was maintained until pressure in the tank was insufficient to maintain this flow. Flow was continued until all flow ceased. Initial temperature of the glass reactor was 590 oF and decreased to 575oF during the reaction.
- Example 2 A continuous flow experiment with the same experimental apparatus used in Example 1 was performed.
- the reactant tank was flushed with hydrogen and then charged with deuterium to 6.0 psig, subsequently with ethene to 9.0 psig, and finally with hydrogen to 100 psig. This produced an admixture having a ratio of hydrogen:deuteriumsethene of approximately 20:1:0.5.
- chromium oxide catalyst identical to that used in example 3 was added to the glass reactor.
- the catalyst was prepared by exposing the catalyst to carbon monoxide for 16 hours to condition the chromium to the +3 oxidation state and by heating the catalyst to a temperature of 530oF to drive off any moisture.
- the reactant feed to the glass reactor was turned on and held constant. A flow rate of 30 cc/min was maintained for three hours and then increased to 50 cc/min until a sufficient amount of product for analysis was produced. At this time, the flow rate was shut off, and the reactant tank pressure was noted to be 90 psig. Initial temperature of the glass reactor was 300 oF and decreased to 239oF during the reaction.
- reaction products that exited the reactor were condensed in liquid nitrogen.
- a vacuum was then pulled on a second reactant tank.
- the condensate was removed from the liquid nitrogen and vaporized into the second reactant tank.
- the second reactant tank was then charged with dry air to 75 psig.
- the catalyst in the glass reactor was heated to a temperature of 575oF.
- the feed from the second reactant tank was then turned on and held constant. A flow of approximately 200 cc/min was maintained until the pressure in the reactant tank was insufficient to maintain this flow. Flow continued until all flow ceased.
- Initial temperature of the glass reactor was 575oF and increased to 680oF during the reaction.
- the reaction products that exited the reactor were condensed in dry ice. Since only the ethene and deuterated ethane were condensed in the liquid nitrogen, only a few drops of the oxidation products (condensate) were needed for analysis.
- the condensate was then analyzed with an FTIR infrared spectrometer as in Example 1.
- the concentration of deuterium atoms in the condensate was found to be 9.5%.
- Deuterium concentration in deuterated ethane containing five protiums and one deuterium atom is 16.67%.
- a 9.5% deuterium concentration equates to a 57% (9.5/16.67) extraction efficiency of deuterium from the available ethene.
- Example 3 A continuous flow experiment with the same experimental apparatus used in Example 3 was performed.
- the reactant tank was flushed with hydrogen and then charged with deuterium to 6.0 psig, subsequently with ethene to 6.0 psig, and finally with hydrogen to 120 psig. This produced an admixture having a ratio of hydrogentdeuterium: ethene of approximately 20:1:1.
- zirconium oxide catalyst Approximately 115 cc (207.85g) of zirconium oxide catalyst was added to the glass reactor.
- the catalyst was obtained from Harshaw/Filtrol and is identified as zirconia catalyst/Zr-0304 T 1/8/E149-1-16-2. This particular catalyst was custom made and has been discontinued by the manufacturer.
- the catalyst was prepared by exposing the catalyst to carbon monoxide for approximately 12 hours to condition the zirconium to the +4 oxidation state and by heating the catalyst in the presence of nitrogen to a temperature of 503 oF to drive off any moisture.
- the reactant feed to the glass reactor was turned on and held constant. A flow rate of 17 cc/min was maintained for two and a half hours. Temperature of the glass reactor was 270 oF during the reaction.
- reaction products that exited the reactor were condensed in a condensor submersed in liquid nitrogen.
- a vacuum was then pulled on a second reactant tank.
- the condensate was removed from the liquid nitrogen and vaporized into the second reactant tank.
- the second reactant tank was then charged with dry air to 80 psig.
- Chromium catalyst in the another glass reactor was reconditioned by exposing the catalyst to carbon monoxide and then heated to a temperature of 565oF.
- the feed from the second reactant tank was then turned on and held constant.
- a flow of 300 cc/min was maintained until the pressure in the reactant tank was insufficient to maintain flow. Flow continued until all flow ceased.
- Initial temperature of the glass reactor was 575oF during the reaction.
- the reaction products that exited the reactor were condensed in dry ice. Condensate yield was 1.175g.
- the condensate was then analyzed with an FTIR infrared spectrometer as in Example 1.
- the average concentration of deuterium atoms in four samples of the condensate was found to be 10.9%. This corresponds to a 65% efficiency in extraction of the deuterium atoms.
- Example 2 A continuous flow adsorption experiment with the same experimental apparatus as in Example 1 was performed.
- the reactant tank was flushed with hydrogen, and then charged with hydrogen to 3 psig, subsequently with deuterium to 5.8 psig, and finally with hydrogen to 46 psig. This produced an admixture having a ratio of hydrogen:deuterium of approximately 22:1.
- Approximately 125 cc of chromium oxide catalyst was added to the glass reactor.
- the catalyst was obtained from Harshaw and is identified as Cr-0211-T, 5/32".
- the manufacturer's specification for this catalyst was the same as the catalyst used in Example 3.
- the catalyst was then prepared by exposing the catalyst to carbon monoxide and then heating the catalyst to a temperature of 610oF to drive off any moisture.
- the reactant feed to the glass reactor was turned on and held constant. A flow rate of 300 cc/min was maintained until the pressure in the reactant tank was insufficient to maintain this flow. Flow continued until all flow ceased. The temperature of the glass reactor ws 275oF during the reaction. The reactant products that exited the glass reactor were passed through the condenser cooled in dry ice/acetone bath, but no condensate was obtained.
- a stream of dry air from a second reactant tank was then fed to the glass reactor and held constant.
- a flow rate of 150 cc/min was maintained until condensation ceased to be observed.
- a temperature of 580 oF was maintained during the reaction.
- Example 6 A continuous flow adsorption experiment with the same experimental apparatus as in Example 6 was performed.
- the reactant tank was flushed with hydrogen, then charged with hydrogen to 2 psig., subsequently with deuterium to 2.5 psig, and finally with hydrogen to 350 psig. This produced an admixture having a ratio of hydrogen:deuterium of approximately 700:1.
- chromium oxide catalyst identical to that used in example 6 was added to the glass reactor.
- the catalyst was then preparerd by exposing the catalyst to air and then heating the catalyst to a temperature of 582oF.
- the reactant feed to the glass reactor was turned on and held constant. A flow ratio of 200 cc/min. was maintained until the pressure in the reactant tank was insufficient to maintain flow. Flow continued until all flow ceased.
- the temperature of the glass reactor was 265oF during the reaction.
- the reactant products that exited the glass reacted were passed through a condenser cooled in dry ice, but no condensate was obtained.
- a stream of dry air from a second reactant tank was then fed to the glass reactor and held constant. A flow rate of 100 cc/min was maintained until condensation ceased to be observed. A temperature of 582oF was maintained during the reaction.
- a static experiment was performed in a 300 ml autoclave. Approximately 200 cc of chromium oxide catalyst identical to that used in example 3 was conditioned and placed in the autoclave. The autoclave was evacuated and pressured to 4 psig with an admixture having a ratio of hydrogen:deuterium: ethene of approximately 20:1:0.5. The autoclave was pressured with pure hydrogen resulting in a hydrogen to deuterium ratio of 2000:1 and heated to reaction temperature resulting in a reaction pressure of 1600 psig.
- tritium is a problem contaminant in water and heavy water used to cool nuclear reactors. Using the processes of this invention, tritium may be selectively reacted from such contaminated water to form that a product that can then be more readily removed from the water.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US17624888A | 1988-03-31 | 1988-03-31 | |
US176248 | 1988-03-31 |
Publications (2)
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EP0407471A1 EP0407471A1 (en) | 1991-01-16 |
EP0407471A4 true EP0407471A4 (en) | 1992-03-11 |
Family
ID=22643590
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19890906628 Ceased EP0407471A4 (en) | 1988-03-31 | 1989-03-29 | A catalytic method for concentrating isotopes |
Country Status (5)
Country | Link |
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EP (1) | EP0407471A4 (en) |
JP (1) | JPH03503521A (en) |
AU (1) | AU3736189A (en) |
WO (1) | WO1989009182A1 (en) |
ZA (1) | ZA892389B (en) |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2690380A (en) * | 1944-05-04 | 1954-09-28 | Hugh S Taylor | Production of deuterium oxide |
US2780526A (en) * | 1951-04-12 | 1957-02-05 | Union Oil Co | Isotope separation process |
DE1263717B (en) * | 1965-01-15 | 1968-03-21 | Degussa | Process for the conversion of hydrogen and / or deuterium with oxygen |
CH477361A (en) * | 1966-01-19 | 1969-08-31 | Ceskoslovenska Akademie Ved | Process for compressing the heavier isotopes of hydrogen, deuterium and tritium |
FR1593961A (en) * | 1968-12-03 | 1970-06-01 | ||
US4178350A (en) * | 1973-08-27 | 1979-12-11 | Engelhard Minerals & Chemicals Corp. | Removal of tritium and tritium-containing compounds from a gaseous stream |
US4196176A (en) * | 1978-08-03 | 1980-04-01 | The United States Of America As Represented By The United States Department Of Energy | Method and apparatus for controlling accidental releases of tritium |
US4331522A (en) * | 1981-01-12 | 1982-05-25 | European Atomic Energy Commission (Euratom) | Reprocessing of spent plasma |
DE3123860C2 (en) * | 1981-06-16 | 1984-08-09 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | Method and device for the gradual enrichment of deuterium and / or tritium by isotope exchange |
US4673547A (en) * | 1982-05-24 | 1987-06-16 | Kernforschungsanlage Julich Gesellschaft Mit Beschrankter Haftung | Process for separation of hydrogen and/or deuterium and tritium from an inert gas flow and apparatus for effectuation of process in the cooling gas circuit of a gas-cooled nuclear reactor |
-
1989
- 1989-03-29 JP JP1506246A patent/JPH03503521A/en active Pending
- 1989-03-29 AU AU37361/89A patent/AU3736189A/en not_active Abandoned
- 1989-03-29 WO PCT/US1989/001215 patent/WO1989009182A1/en not_active Application Discontinuation
- 1989-03-29 EP EP19890906628 patent/EP0407471A4/en not_active Ceased
- 1989-03-31 ZA ZA892389A patent/ZA892389B/en unknown
Also Published As
Publication number | Publication date |
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AU3736189A (en) | 1989-10-16 |
ZA892389B (en) | 1989-12-27 |
JPH03503521A (en) | 1991-08-08 |
EP0407471A1 (en) | 1991-01-16 |
WO1989009182A1 (en) | 1989-10-05 |
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