|
Copper–chlorine Cycle
The copper–chlorine cycle (Cu–Cl cycle) is a four-step thermochemical cycle for the production of hydrogen. The Cu–Cl cycle is a hybrid process that employs both Thermochemistry, thermochemical and electrolysis steps. It has a maximum temperature requirement of about 530 degrees Celsius. The Cu–Cl cycle involves four chemical reactions for water splitting, whose net reaction decomposes water into hydrogen and oxygen. All other chemicals are recycled. The Cu–Cl process can be linked with nuclear plants or other heat sources such as solar and industrial waste heat to potentially achieve higher efficiencies, lower environmental impact and lower costs of hydrogen production than any other conventional technology. The Cu–Cl cycle is one of the prominent thermochemical cycles under development within the Generation IV reactor, Generation IV International Forum (GIF). Through GIF, over a dozen countries around the world are developing the next generation of nuclear reactor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper - Chlorine Cycle
Copper is a chemical element with the Symbol (chemistry), symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductility, ductile metal with very high thermal conductivity, thermal and electrical conductivity. A freshly exposed surface of pure copper has a Copper (color), pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material#Metal, building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be Smelting, smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercritical Water Reactor
The supercritical water reactor (SCWR) is a concept Generation IV reactor, designed as a light water reactor (LWR) that operates at supercritical pressure (i.e. greater than 22.1 MPa). The term ''critical'' in this context refers to the critical point of water, and must not be confused with the concept of criticality of the nuclear reactor. The water heated in the reactor core becomes a supercritical fluid above the critical temperature of 374 °C, transitioning from a fluid more resembling liquid water to a fluid more resembling saturated steam (which can be used in a steam turbine), without going through the distinct phase transition of boiling. In contrast, the well-established pressurized water reactors (PWR) have a primary cooling loop of liquid water at a subcritical pressure, transporting heat from the reactor core to a secondary cooling loop, where the steam for driving the turbines is produced in a boiler (called the steam generator). Boiling water reactor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Production
Hydrogen production is the family of industrial methods for generating hydrogen gas. As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming of natural gas and other light hydrocarbons, partial oxidation of heavier hydrocarbons, and coal gasification. Other methods of hydrogen production include biomass gasification, zero-CO2-emission methane pyrolysis, and electrolysis of water. The latter processes, methane pyrolysis as well as water electrolysis can be done directly with any source of electricity, such as solar power. The production of hydrogen plays a key role in any industrialized society, since hydrogen is required for many essential chemical processes. In 2020, roughly 87 million tons of hydrogen was produced worldwide for various uses, such as oil refining, and in the production of ammonia (NH3) (through the Haber process) and methanol (CH3OH) (through reduction of carbon monoxide O, and also as a fuel in transportation. The glo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Reactions
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation. Some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, etc.), carbon monoxide, carbon dioxide, carbides, and the following salts of inorganic anions: carbonates, cyanides, cyanates, and thiocyanates. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it does not occur within living things. History Friedrich Wöhler's conversion of ammonium cyanate into urea in 1828 is often cited as the starting point of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reactions
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course of acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc–zinc Oxide Cycle
For chemical reactions, the zinc–zinc oxide cycle or Zn–ZnO cycle is a two step thermochemical cycle based on zinc and zinc oxide for hydrogen production with a typical efficiency around 40%. Process description The thermochemical two-step water splitting process uses redox systems: *Dissociation: ZnO → Zn + 1/2 O2 *Hydrolysis: Zn + H2O → ZnO + H2 For the first endothermic step concentrating solar power is used in which zinc oxide is thermally dissociated at into zinc and oxygen. In the second non-solar exothermic step zinc reacts at with water and produces hydrogen and zinc oxide. The temperature level is realized by using a solar power tower and a set of heliostats to collect the solar thermal energy. See also * Cerium(IV) oxide–cerium(III) oxide cycle * Copper–chlorine cycle * Hydrosol-2 * Hybrid sulfur cycle * Iron oxide cycle * Sulfur–iodine cycle The sulfur–iodine cycle (S–I cycle) is a three-step thermochemical cycle used to produce hydrogen. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur–iodine Cycle
The sulfur–iodine cycle (S–I cycle) is a three-step thermochemical cycle used to produce hydrogen. The S–I cycle consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. All other chemicals are recycled. The S–I process requires an efficient source of heat. Process description The three reactions that produce hydrogen are as follows: # I2 + SO2 + 2 H2O 2 HI + H2SO4 (); Bunsen reaction #*The HI is then separated by distillation or liquid/liquid gravitic separation. #2 H2SO4 2 SO2 + 2 H2O + O2 () #*The water, SO2 and residual H2SO4 must be separated from the oxygen byproduct by condensation. #2 HI I2 + H2 () #*Iodine and any accompanying water or SO2 are separated by condensation, and the hydrogen product remains as a gas. : : Net reaction: 2 H2O → 2 H2 + O2 The sulfur and iodine compounds are recovered and reused, hence the consideration of the process as a cycle. This S–I process is a chemical heat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Oxide Cycle
For chemical reactions, the iron oxide cycle (Fe3O4/FeO) is the original two-step thermochemical cycle proposed for use for hydrogen production. It is based on the reduction and subsequent oxidation of iron ions, particularly the reduction and oxidation between Fe3+ and Fe2+. The ferrites, or iron oxide, begins in the form of a spinel and depending on the reaction conditions, dopant metals and support material forms either Wüstites or different spinels. Process description The thermochemical two-step water splitting process uses two redox steps. The steps of solar hydrogen production by iron based two-step cycle are: : \begin \ce &\ce \\ \ce & \ce \end Where M can by any number of metals, often Fe itself, Co, Ni, Mn, Zn or mixtures thereof. The endothermic reduction step (1) is carried out at high temperatures greater than , though the "Hercynite cycle" is capable of temperatures as low as . The oxidative water splitting step (2) occurs at a lower ~ temperature which prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid Sulfur Cycle
The hybrid sulfur cycle (HyS) is a two-step water-splitting process intended to be used for hydrogen production. Based on sulfur oxidation and reduction, it is classified as a hybrid thermochemical cycle because it uses an electrochemical Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outco ... (instead of a thermochemical) reaction for one of the two steps. The remaining thermochemical step is shared with the sulfur-iodine cycle. The Hybrid sulphur cycle (HyS)was initially proposed and developed by Westinghouse Electric Corp. in the 1970s, so it is also known as the "Westinghouse" cycle. Current development efforts in the United States are being led by the Savannah River National Laboratory. Process description The two reactions in the HyS cycle are as follows: # H2SO4 → H2O + SO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerium(IV) Oxide–cerium(III) Oxide Cycle
The cerium(IV) oxide–cerium(III) oxide cycle or CeO2/Ce2O3 cycle is a two-step thermochemical process that employs cerium(IV) oxide and cerium(III) oxide for hydrogen production. The cerium-based cycle allows the separation of H2 and O2 in two steps, making high-temperature gas separation redundant. Process description The thermochemical two-step water splitting process (thermochemical cycle) uses redox systems: *Dissociation: 2 CeO2 → Ce2O3 + 0.5 O2 *Hydrolysis: Ce2O3 + H2O → 2 CeO2 + H2 For the first endothermic step, cerium(IV) oxide is thermally dissociated in an inert gas atmosphere at and 100-200 mbar into cerium(III) oxide and oxygen. In the second exothermic step cerium(III) oxide reacts at – in a fixed bed reactor with water and produces hydrogen and cerium(IV) oxide. See also * Copper–chlorine cycle * Heliostat * Hybrid sulfur cycle * HYDROSOL * Iron oxide cycle * Solar thermal energy * Sulfur–iodine cycle * Zinc–zinc oxide cycle For chemical react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractory Material
In materials science, a refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractories are polycrystalline, polyphase, inorganic, non-metallic, porous, and heterogeneous. They are typically composed of oxides or carbides, nitrides etc. of the following materials: silicon, aluminium, magnesium, calcium, boron, chromium and zirconium. ASTM C71 defines refractories as "...non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above ." Refractory materials are used in furnaces, kilns, incinerators, and reactors. Refractories are also used to make crucibles and moulds for casting glass and metals and for surfacing flame deflector systems for rocket launch structures. Today, the iron- and steel-industry and metal casting sectors use a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass-lined Steel
Industrial porcelain enamel (also known as glass lining, glass-lined steel, or glass fused to steel) is the use of porcelain enamel (also known as vitreous enamel) for industrial, rather than artistic, applications. Porcelain enamel, a thin layer of ceramic or glass applied to a substrate of metal, is used to protect surfaces from chemical attack and physical damage, modify the structural characteristics of the substrate, and improve the appearance of the product. Enamel has been used for art and decoration since the period of Ancient Egypt, and for industry since the Industrial Revolution. It is most commonly used in the production of cookware, home appliances, bathroom fixtures, water heaters, and scientific laboratory equipment. Characteristics The most important characteristic of porcelain enamel, from an industrial perspective, is its resistance to corrosion. Mild steel is used in almost every industry and a huge array of products; porcelain enamel is a very economic way of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
