1396results about "Calcium/strontium/barium oxides/hydroxides" patented technology

Hydrogen is produced from solid or liquid carbon-containing fuels in a two-step process. The fuel is gasified with hydrogen in a hydrogenation reaction to produce a methane-rich gaseous reaction product, which is then reacted with water and calcium oxide in a hydrogen production and carbonation reaction to produce hydrogen and calcium carbonate. The calcium carbonate may be continuously removed from the hydrogen production and carbonation reaction zone and calcined to regenerate calcium oxide, which may be reintroduced into the hydrogen production and carbonation reaction zone. Hydrogen produced in the hydrogen production and carbonation reaction is more than sufficient both to provide the energy necessary for the calcination reaction and also to sustain the hydrogenation of the coal in the gasification reaction. The excess hydrogen is available for energy production or other purposes. Substantially all of the carbon introduced as fuel ultimately emerges from the invention process in a stream of substantially pure carbon dioxide. The water necessary for the hydrogen production and carbonation reaction may be introduced into both the gasification and hydrogen production and carbonation reactions, and allocated so as transfer the exothermic heat of reaction of the gasification reaction to the endothermic hydrogen production and carbonation reaction.

A process for the production of ultrafine powders that includes subjecting a mixture of precursor metal compound and a non-reactant diluent phase to mechanical milling whereby the process of mechanical activation reduces the microstructure of the mixture to the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. The process also includes heat treating the mixture of nano-sized grains of the metal compound uniformly dispersed in the diluent phase to convert the nano-sized grains of the metal compound into a metal oxide phase. The process further includes removing the diluent phase such that the nano-sized grains of the metal oxide phase are left behind in the form of an ultrafine powder.

Polymer nanocomposite implants with nanofillers and additives are described. The nanofillers described can be any composition with the preferred composition being those composing barium, bismuth, cerium, dysprosium, europium, gadolinium, hafnium, indium, lanthanum, neodymium, niobium, praseodymium, strontium, tantalum, tin, tungsten, ytterbium, yttrium, zinc, and zirconium. The additives can be of any composition with the preferred form being inorganic nanopowders comprising aluminum, calcium, gallium, iron, lithium, magnesium, silicon, sodium, strontium, titanium. Such nanocomposites are particularly useful as materials for biological use in applications such as drug delivery, biomed devices, bone or dental implants.

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are prepared by polymer templated methods and are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to ethane and/or ethylene. Related methods for use and manufacture of the same are also disclosed.

Methods to manufacture nanoscale particles comprising metals, alloys, intermetallics, ceramics are disclosed. The thermal energy is provided by plasma, internal energy, heat of reaction, microwave, electromagnetic, direct electric arc, pulsed electric arc and/or nuclear. The process is operated at some stage above 3000K and at high velocities. The invention can be utilized to prepare nanopowders for nanostructured products and devices such as ion conducting solid electrolytes for a wide range of applications, including sensors, oxygen pumps, fuel cells, batteries, electrosynthesis reactors and catalytic membranes.

Methods and systems for processing metal oxides from metal containing solutions. Metal containing solutions are mixed with heated aqueous oxidizing solutions and processed in a continuous process reactor or batch processing system. Combinations of temperature, pressure, molarity, Eh value, and pH value of the mixed solution are monitored and adjusted so as to maintain solution conditions within a desired stability area during processing. This results in metal oxides having high or increased pollutant loading capacities and/or oxidation states. These metal oxides may be processed according to the invention to produce co-precipitated oxides of two or more metals, metal oxides incorporating foreign cations, metal oxides precipitated on active and inactive substrates, or combinations of any or all of these forms. Metal oxides thus produced are, amongst other uses; suitable for use as a sorbent for capturing or removing target pollutants from industrial gas streams or drinking water or aqueous streams or for personal protective respirators.

A reaction-based process has been developed for the selective removal of carbon dioxide (CO₂) from a multicomponent gas mixture to provide a gaseous stream depleted in CO₂ compared to the inlet CO₂ concentration in the stream. The proposed process effects the separation of CO₂ from a mixture of gases (such as flue gas/fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO₂ (CaRS-CO₂) process consists of contacting a CO₂ laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO₂ by the formation of calcium carbonate (CaCO₃). Once “spent”, CaCO₃ is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO₂. The “regenerated” CaO is then recycled for the further capture of more CO₂. This carbonation-calcination cycle forms the basis of the CaRS-CO₂ process. This process also identifies the application of a mesoporous CaCO₃ structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles.

A process of treating metal oxide nanoparticles that includes mixing metal oxide nanoparticles, a solvent, and a surface treatment agent that is preferably a silane or siloxane is described. The treated metal oxide nanoparticles are rendered hydrophobic by the surface treatment agent being surface attached thereto, and are preferably dispersed in a hydrophobic aromatic polymer binder of a charge transport layer of a photoreceptor, whereby π—π interactions can be formed between the organic moieties on the surface of the nanoparticles and the aromatic components of the binder polymer to achieve a stable dispersion of the nanoparticles in the polymer that is substantially free of large sized agglomerations.

The present invention includes a method of producing a crystalline metal oxide nanostructure. The method comprises providing a metal salt solution and providing a basic solution; placing a porous membrane between the metal salt solution and the basic solution, wherein metal cations of the metal salt solution and hydroxide ions of the basic solution react, thereby producing a crystalline metal oxide nanostructure.

A process to produce mixed metal oxides and metal oxide compounds. The process includes evaporating a feed solution that contains at least two metal salts to form an intermediate. The evaporation is conducted at a temperature above the boiling point of the feed solution but below the temperature where there is significant crystal growth or below the calcination temperature of the intermediate. The intermediate is calcined, optionally in the presence of an oxidizing agent, to form the desired oxides. The calcined material can be milled and dispersed to yield individual particles of controllable size and narrow size distribution.

Wet-chemical methods involving the use of water-soluble hydrolytically stable metal-ion chelate precursors and the use of a nonmetal-ion-containing strong base can be used in a coprecipitation procedure for the preparation of ceramic powders. Examples of the precipitants used include tetraalkylammonium hydroxides. A composition-modified barium titanate is one of the ceramic powders that can be produced. Certain metal-ion chelates can be prepared from 2-hydroxypropanoic acid and ammonium hydroxide.

Nanoparticles comprising titanium, such as nanoscale doped titanium metal compounds, inorganic titanium compounds, and organic titanium compounds, their methods of manufacture, and methods of preparation of products from nanoparticles comprising titanium are provided.

A low-temperature hydrothermal reaction is provided to generate crystalline perovskite nanotubes such as barium titanate (BaTiO₃) and strontium titanate (SrTiO₃) that have an outer diameter from about 1 nm to about 500 nm and a length from about 10 nm to about 10 micron. The low-temperature hydrothermal reaction includes the use of a metal oxide nanotube structural template, i.e., precursor. These titanate nanotubes have been characterized by means of X-ray diffraction and transmission electron microscopy, coupled with energy dispersive X-ray analysis and selected area electron diffraction (SAED).

The present invention is directed to novel sol-gel methods in which metal oxide precursor and an alcohol-based solution are mixed to form a reaction mixture that is then allowed to react to produce nanosized metal oxide particles. The methods of the present invention are more suitable for preparing nanosized metal oxide than are previously-described sol-gel methods. The present invention can provide for nanosized metal oxide particles more efficiently than the previously-described sol-gel methods by permitting higher concentrations of metal oxide precursor to be employed in the reaction mixture. The foregoing is provided by careful control of the pH conditions during synthesis and by ensuring that the pH is maintained at a value of about 7 or higher.

Disclosed is an additive for a plastic, comprising fine particles obtained by calcination and slaking of a dolomite which exhibits two endothermic peaks in the differential thermal analysis, said fine particles containing calcium carbonate, magnesium carbonate, magnesium oxide, calcium hydroxide and magnesium hydroxide as main chemical components and also containing an ignition loss component in an amount of 10 to 40% by weight based on the weight of said fine particles. A plastic hating hydrogen chloride scavenging properties and antimicrobial properties imparted by incorporating the additive for a plastic is also disclosed.