|
Supercritical Water
Supercritical water oxidation (SCWO) is a process that occurs in water at temperatures and pressures above a mixture's thermodynamic critical point (thermodynamics), critical point. Under these conditions water becomes a fluid with unique properties that can be used to advantage in the destruction of recalcitrant and hazardous wastes such as polychlorinated biphenyls (PCB) or per- and polyfluoroalkyl substances (PFAS). Supercritical water has a density between that of water vapor and liquid at standard conditions, and exhibits high gas-like diffusion rates along with high liquid-like collision rates. In addition, the behavior of water as a solvent is altered (in comparison to that of subcritical liquid water) - it behaves much less like a polar solvent. As a result, the solubility behavior is "reversed" so that oxygen, and organics such as chlorinated hydrocarbons become soluble in the water, allowing Homogeneous and heterogeneous reactions, single-phase reaction of aqueous waste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercritical H2Olr
Supercritical may refer to: Physics and technology Condensed matter physics * Critical temperature, TC, a temperature above which distinct liquid and gas phases do not exist for a given material ** Supercritical drying, a process used to remove liquid in a precisely controlled way, similar to freeze drying ** Supercritical fluid, a substance at a temperature and pressure above its thermodynamic critical point: *** Supercritical carbon dioxide: **** Supercritical fluid chromatography, a form of liquid chromatography using supercritical carbon dioxide as the mobile phase ***Supercritical water: **** Supercritical steam generator, a steam generator operating above the critical point of water, hence having no water–steam separation **** Supercritical water oxidation or SCWO, a process that occurs in water at temperatures and pressures above a mixture's thermodynamic critical point **** Supercritical water reactor (SCWR), a Generation IV nuclear reactor concept that uses supercritical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Chemistry
Green chemistry, similar to sustainable chemistry or circular chemistry, is an area of chemistry and chemical engineering focused on the design of products and processes that minimize or eliminate the use and generation of hazardous substances. While environmental chemistry focuses on the effects of pollutant, polluting chemicals on nature, green chemistry focuses on the environmentalism, environmental impact of chemistry, including lowering consumption of nonrenewable resources and technological approaches for preventing pollution. The overarching goals of green chemistry—namely, more resource-efficient and inherently safer design of molecules, materials, products, and processes—can be pursued in a wide range of contexts. History Green chemistry emerged from a variety of existing ideas and research efforts (such as atom economy and catalysis) in the period leading up to the 1990s, in the context of increasing attention to problems of chemical pollution and resource depletio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet Oxidation
Wet oxidation is a form of hydrothermal treatment. It is the oxidation of dissolved or suspended components in water using oxygen as the oxidizer. It is referred to as wet air oxidation (WAO) when air is used. The oxidation reactions occur in superheated water at a temperature above the normal boiling point of water (100 °C), but below the critical point (374 °C). The system must be maintained under pressure to avoid excessive evaporation of water. This is done to control energy consumption due to the latent heat of vaporization. It is also done because liquid water is necessary for most of the oxidation reactions to occur. Compounds oxidize under wet oxidation conditions that would not oxidize under dry conditions at the same temperature and pressure. Wet oxidation has been used commercially for around 60 years. It is used predominantly for treating wastewater. It is often referred to as Zimpro (from ZIMmerman PROcess), after Fred J. Zimmermann who commercial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercritical Fluid
A supercritical fluid (SCF) is a substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist, but below the pressure required to compress it into a solid. It can effuse through porous solids like a gas, overcoming the mass transfer limitations that slow liquid transport through such materials. SCFs are superior to gases in their ability to dissolve materials like liquids or solids. Near the critical point, small changes in pressure or temperature result in large changes in density, allowing many properties of a supercritical fluid to be "fine-tuned". Supercritical fluids occur in the atmospheres of the gas giants Jupiter and Saturn, the terrestrial planet Venus, and probably in those of the ice giants Uranus and Neptune. Supercritical water is found on Earth, such as the water issuing from black smokers, a type of hydrothermal vent. SCFs are used as a substitute for organic solvents in a range of industrial and laborato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per- And Polyfluoroalkyl Substances
Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain; there are 7 million known such chemicals according to PubChem. PFAS came into use with the invention of Teflon in 1938 to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. They are now used in products including waterproof fabric such as Nylon, yoga pants, carpets, shampoo, feminine hygiene products, mobile phone screens, wall paint, furniture, adhesives, food packaging, firefighting foam, and the insulation of electrical wire. PFAS are also used by the cosmetic industry in most cosmetics and personal care products, including lipstick, eye liner, mascara, foundation, concealer, lip balm, blush, and nail polish. Many PFAS such as PFOS and PFOA pose health and environmental concerns because they are persi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
County Cork
County Cork () is the largest and the southernmost Counties of Ireland, county of Republic of Ireland, Ireland, named after the city of Cork (city), Cork, the state's second-largest city. It is in the Provinces of Ireland, province of Munster and the Southern Region, Ireland, Southern Region. Its largest market towns are Mallow, County Cork, Mallow, Macroom, Midleton, and Skibbereen. , the county had a population of 584,156, making it the third-List of Irish counties by population, most populous county in Ireland. Cork County Council is the Local government in the Republic of Ireland, local authority for the county, while Cork City Council governs the city of Cork and its environs. Notable Corkonians include Michael Collins (Irish leader), Michael Collins, Jack Lynch, Mother Jones, Roy Keane, Sonia O'Sullivan, Cillian Murphy and Graham Norton. Cork borders four other counties: County Kerry, Kerry to the west, County Limerick, Limerick to the north, County Tipperary, Tipperary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johnson Matthey
Johnson Matthey plc is a British multinational speciality chemicals and sustainable technologies company headquartered in London, England. It is listed on the London Stock Exchange and is a constituent of the FTSE 250 Index. History Early years Johnson Matthey traces its origins to 1817, when Percival Norton Johnson set up business as a gold assayer in London. In 1851 George Matthey joined the business and its name was changed to Johnson & Matthey. The following year the firm was appointed official assayer and refiner to the Bank of England. The company had branches in the cities of Birmingham and Sheffield to supply the jewellery and silverware and cutlery trade with raw materials and ancillary supplies, such as silver solder and flux, which it manufactured. In 1874, the company was commissioned to manufacture the kilogram reference standard, made from 90% platinum and 10% iridium, and held in the ''Bureau International des Poids et Mesures'' (International Bureau of Weig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hanwha
Hanwha Group () is a large business conglomerate (chaebol) in South Korea. Founded in 1952 as Korea Explosives Co. (), the group has grown into a large multi-profile business conglomerate, with diversified holdings stretching from explosivestheir original businessto energy, materials, aerospace, mechatronics, finance, retail, and lifestyle services. In 1992, the company adopted its abbreviation as its new name: "Hanwha". History 1952–1999 Kim Chong-hee founded Korea Explosives Co. in October 1952. Prior to founding the company, Kim worked as a Explosives engineering, gunpowder engineer for the "Chosun Explosives Factory", a Japanese company. Later, he won the bid for the company and its Incheon factory and started the company there. From 1952 to 1963, the Korea Explosives Co. produced industrial explosives domestically, which was needed for construction and engineering of infrastructure. In the same time period, the Korea Explosives Co. started producing nitroglycerin, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fouling
Fouling is the accumulation of unwanted material on solid surfaces. The fouling materials can consist of either living organisms (biofouling, organic) or a non-living substance (inorganic). Fouling is usually distinguished from other surface-growth phenomena in that it occurs on a surface of a component, system, or plant performing a defined and useful function and that the fouling process impedes or interferes with this function. Other terms used in the literature to describe fouling include deposit formation, encrustation, crudding, deposition, scaling, scale formation, slagging, and sludge formation. The last six terms have a more narrow meaning than fouling within the scope of the fouling science and technology, and they also have meanings outside of this scope; therefore, they should be used with caution. Fouling phenomena are common and diverse, ranging from fouling of ship hulls, natural surfaces in the marine environment (fouling community, marine fouling), fouling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inconel 625
Inconel Alloy 625 (UNS designation N06625) is a nickel-based superalloy that possesses high strength properties and resistance to elevated temperatures. It also demonstrates remarkable protection against corrosion and oxidation. Its ability to withstand high stress and a wide range of temperatures, both in and out of water, as well as being able to resist corrosion while being exposed to highly acidic environments makes it a fitting choice for nuclear and marine applications. Inconel 625 was developed in the 1960s with the purpose of creating a material that could be used for steam-line piping. Some modifications were made to its original composition that have enabled it to be even more creep-resistant and weldable. Because of this, the uses of Inconel 625 have expanded into a wide range of industries such as the chemical processing industry, and for marine and nuclear applications to make pumps and valves and other high pressure equipment. Because of the metal's high Niobium ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyoto Protocol
The was an international treaty which extended the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is occurring and that human-made CO2 emissions are driving it. The Kyoto Protocol was adopted in Kyoto, Japan, on 11 December 1997 and entered into force on 16 February 2005. There were 192 parties (Canada withdrew from the protocol, effective December 2012) to the Protocol in 2020. The Kyoto Protocol implemented the objective of the UNFCCC to reduce the onset of global warming by reducing greenhouse gas concentrations in the atmosphere to "a level that would prevent dangerous anthropogenic interference with the climate system" (Article 2). The Kyoto Protocol applied to the seven greenhouse gases listed in Annex A: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexaflu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
