摘要:
Disclosed are methods and apparatus for providing an ammonia feed for a low-temperature process. The process includes two defined stages, gasification and hydrolysis. In a first stage thermal reactor, an aqueous urea solution is fed to a gasification chamber and heated gases are controlled in response to demand from a low temperature process requiring ammonia. The heated gases and aqueous urea are introduced into the gasification chamber upstream to fully gasify the solution of aqueous urea to a first stage gas stream comprising ammonia and isocyanic acid. The first stage gas stream is withdrawn and maintained hot enough to prevent solids formation. All amounts of urea feed, water and heated gases fed into the first stage thermal reactor are monitored and adjusted as necessary to achieve efficient hydrolysis in the second stage hydrolysis reactor. The second stage gas stream is withdrawn from the second stage reactor responsive to demand from a low temperature process requiring ammonia.
摘要:
An adsorbent comprising a zeolite having a pore diameter of not less than 4.5 angstroms and not more than 7.3 angstroms as a principal component, which can adsorb xenon under ordinary temperatures and pressures or under ordinary temperatures and low xenon partial pressures. In addition, a xenon adsorbing device comprising an adsorbent, a container of a vapor poorly-permeating material, which houses the adsorbent, and a joint part which joins the container to a xenon enclosure space, in which the adsorbent is communicated with the xenon enclosure space. Thereby, the present invention provides an adsorbent which recovers xenon directly from the used equipment in which xenon is enclosed with efficiency under ordinary temperatures and pressures or under ordinary temperatures and low xenon partial pressures, and a xenon adsorbing device using the adsorbent.
摘要:
This gas purifying process removes trace constituents from a mixed gas that includes a rare gas and nitrogen as main components, and at least one from among hydrogen, nitrogen and hydrogen reaction products, and water vapor as the trace constituent. This process sequentially carries out an adsorbing step for removing water vapor and nitrogen and hydrogen reaction products; a hydrogen oxidation step for converting the hydrogen into water vapor by means of a hydrogen oxidation catalytic reaction in the presence of oxygen; and a drying step for removing water vapor generated in the hydrogen oxidation step. When nitrogen oxides are included as a trace constituent, then a denitration step is carried out prior to the adsorbing step, to convert nitrogen oxides into nitrogen and water vapor by means of a catalytic denitration reaction in the presence of a reducing substance.
摘要:
The invention relates to a process for the production of oxygen using novel membranes, formed from perovskitic or multi-phase structures, with a chemically active coating which demonstrate exceptionally high rates of fluid flux. The process uses membranes that are conductors of oxygen ions and electrons, which are substantially stable in air over the temperature range of 25° C. to the operating temperature of the membrane.
摘要:
This invention relates to gas-impermeable, solid state materials fabricated into membranes for use in catalytic membrane reactors. This invention particularly relates to solid state oxygen anion- and electron-mediating membranes for use in catalytic membrane reactors for promoting partial or full oxidation of different chemical species, for decomposition of oxygen-containing species, and for separation of oxygen from other gases. Solid state materials for use in the membranes of this invention include mixed metal oxide compounds having the brownmillerite crystal structure.
摘要:
Metal oxides particularly useful for the manufacture of catalytic membranes for gas-phase oxygen separation processes having the formula: AxAnullxnullByFeynullBnull2-(ynullynull)O5nullzwhere: x and xnull are greater than 0; y and ynull are greater than 0; xnullxnull is equal to 2; ynullynull is less than or equal to 2; z is a number that makes the metal oxide charge neutral; A is an element selected from the lanthanide elements and yttrium; Anull is an element selected from Be, Mg, Ca, Sr, Ba and Ra; B is an element selected from the group consisting of Al, Ga, In or mixtures thereof and Bnull is Co or Mg, with the exception that when Bnull is Mg, Anull and Anull are not Mg. The metal oxides are useful for preparation of dense membranes which may be formed from dense thin films of the mixed metal oxide on a porous metal oxide element. The invention also provides methods and catalytic reactors for oxygen separation and oxygen enrichment of oxygen deficient gases which employ mixed conducting metal oxides of the above formula.
摘要翻译:特别适用于制备气相氧分离方法的催化膜的金属氧化物,具有下列结构式:其中式(1)代入式中AxA'x'ByFey'B''2-(y + y')O5 + z in-line-formula>其中:x和x'大于0; y和y'大于0; x + x'等于2; y + y'小于或等于2; z是使金属氧化物电荷中性的数字; A是选自镧系元素和钇的元素; A'是选自Be,Mg,Ca,Sr,Ba和Ra的元素; B是选自Al,Ga,In或其混合物中的元素,B“是Co或Mg,但是当B”是Mg时,A'和A“不是Mg。 金属氧化物可用于制备可由多孔金属氧化物元件上的混合金属氧化物的致密薄膜形成的致密膜。 本发明还提供了使用上述式的混合导电金属氧化物的氧气分离和缺氧气体的富氧的方法和催化反应器。
摘要:
The present invention relates to an electrochemical cell comprising a solid electrolyte conductive for O.sup.2- anions in contact with an anode and a cathode of identical or different composition, the electrolyte solid being comprised of a composition derived from Bi.sub.4 V.sub.2 O.sub.11 of which at least one of the cationic constituent elements is substituted by at least one substituting element chosen such that the gamma phase structural type of Bi.sub.4 V.sub.2 O.sub.11 is maintained, as well as the equilibrium of charges, at least one of the anode or the cathode including two parts, a first part being of a mixed electronic and ionic conductive material in contact with the solid electrolyte, the second part being an electronic conductive material superposed on the first part. The invention equally relates to the use of the electrochemical cell with a view towards the separation or the extraction of oxygen.
摘要:
An electrocatalytic process is described for producing unsaturated hydrocarbon compounds from saturated hydrocarbon compounds. The process is conducted in an electrogenerative cell and generally comprises the steps of(A) providing a fuel cell comprising a solid electrolyte having a first surface coated with conductive metal, metal oxide or mixtures thereof capable of catalyzing the reduction of oxygen to oxygen ions, and a second surface coated with metal, metal oxide or mixtures thereof, the two conductive coatings being connected by an external circuit,(B) passing an oxygen-containing gas in contact with the first conductive coating while,(C) passing the saturated hydrocarbon compound-containing feed gas in contact with the second conductive coating, and(D) recovering unsaturated hydrocarbons.In a preferred embodiment, the conductive metal coating on the first and second surfaces comprises a silver-containing metal composition. In another preferred embodiment, the invention comprises a continuous process for the oxidative dehydrogenation of ethane to ethylene and acetylene while generating electricity in an electrogenerative reactor.
摘要:
Sulfur dioxide and nitrogen oxides are removed from inert gases by contacting the gaseous mixture with petroleum of coal tar pitches at 400.degree.-600.degree. F.