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Supercritical Hydrolysis
Supercritical hydrolysis is a chemical engineering process in which water in the supercritical state can be employed to achieve a variety of reactions within seconds. To cope with the extremely short times of reaction on an industrial scale, the process should be continuous. This continuity enables the ratio of the amount of water to the other reactants to be less than unity which minimizes the energy needed to heat the water above , the critical temperature. Application of the process to biomass provides simple sugars in near quantitative yield by supercritical hydrolysis of the constituent polysaccharides. The phenolic polymer components of the biomass, usually exemplified by lignins, are converted into a water-insoluble liquid mixture of low molecular phenols (monomerization). A private company, Renmatix, based in King of Prussia, PA, has developed a supercritical hydrolysis technology to convert a range of non-food biomass feedstocks into cellulosic sugars for application in b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Engineering
Chemical engineering is an engineering field which deals with the study of operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials into useful products. Chemical engineering uses principles of chemistry, physics, mathematics, biology, and economics to efficiently use, produce, design, transport and transform energy and materials. The work of chemical engineers can range from the utilization of nanotechnology and nanomaterials in the laboratory to large-scale industrial processes that convert chemicals, raw materials, living cells, microorganisms, and energy into useful forms and products. Chemical engineers are involved in many aspects of plant design and operation, including safety and hazard assessments, process design and analysis, modeling, control engineering, chemical reaction engineering, nuclear engineering, biological engineering, construction specification, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Process
Continuous production is a flow production method used to manufacture, produce, or process materials without interruption. Continuous production is called a continuous process or a continuous flow process because the materials, either dry bulk or fluids that are being processed are continuously in motion, undergoing chemical reactions or subject to mechanical or heat treatment. Continuous processing is contrasted with batch production. Continuous usually means operating 24 hours per day, seven days per week with infrequent maintenance shutdowns, such as semi-annual or annual. Some chemical plants can operate for more than one to two years without a shutdown. Blast furnaces can run from four to ten years without stopping. Common processes Some common continuous processes are the following: * Oil refining *Chemicals * Synthetic fibers *Fertilizers *Pulp and paper * Blast furnace (iron) *Metal smelting *Power stations * Natural gas processing *Sanitary waste water treatment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Point (thermodynamics)
In thermodynamics, a critical point (or critical state) is the end point of a phase equilibrium curve. The most prominent example is the liquid–vapor critical point, the end point of the pressure–temperature curve that designates conditions under which a liquid and its vapor can coexist. At higher temperatures, the gas cannot be liquefied by pressure alone. At the critical point, defined by a ''critical temperature'' ''T''c and a ''critical pressure'' ''p''c, phase boundaries vanish. Other examples include the liquid–liquid critical points in mixtures, and the ferromagnet–paramagnet transition (Curie temperature) in the absence of an external magnetic field. Liquid–vapor critical point Overview For simplicity and clarity, the generic notion of ''critical point'' is best introduced by discussing a specific example, the vapor–liquid critical point. This was the first critical point to be discovered, and it is still the best known and most studied one. The figu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance “lignine”, which is derived from the Latin word '' lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose. Lignin constitutes 30% of non-fossil organic carbon on Earth, and 20 to 35% of the dry mass of wood. Lignin is present in red algae, which suggest that the common ancestor of plants and red algae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenols
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule. Phenols are both synthesized industrially and produced by plants and microorganisms. Properties Acidity Phenols are more acidic than typical alcohols. The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12). Deprotonation of a phenol forms a corresponding negative phenolate ion or phenoxide ion, and the corresponding salts are called phenolates or phenoxides (aryloxides according to the IUPAC Gold Book). Condensation with aldehydes and ketones Phenols are susceptible to Electrophilic aromatic substitutions. Condensation with formald ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Monomers can be classified in many ways. They can be subdivided into two broad classes, depending on the kind of the polymer that they form. Monomers that participate in condensation polymerization have a different stoichiometry than monomers that participate in addition polymerization: : Other classifications include: *natural vs synthetic monomers, e.g. glycine vs caprolactam, respectively *polar vs nonpolar monomers, e.g. vinyl acetate vs ethylene, respectively *cyclic vs linear, e.g. ethylene oxide vs ethylene glycol, respectively The polymerization of one kind of monomer gives a homopolymer. Many polymers are copolymers, meaning that they are derived from two different monomers. In the case of condensation polymerizations, the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
King Of Prussia, Pennsylvania
King of Prussia (also referred to as KOP) is a census-designated place in Upper Merion Township in Montgomery County, Pennsylvania, United States. As of the 2020 census, its population was 22,028. The community took its unusual name in the 18th century from a local tavern named the King of Prussia Inn, which was named after King Frederick the Great of Prussia. Like the rest of Montgomery County, King of Prussia continues to experience rapid development. One of the largest shopping malls in the United States, King of Prussia, is located here. Also located here is the headquarters of the Nuclear Regulatory Commission Region I. King of Prussia is considered to be an edge city of Philadelphia, consisting of large amounts of retail and office space situated at the convergence of four highways. King of Prussia is located southeast of Allentown and northwest of Philadelphia. History The eponymous King of Prussia Inn was originally constructed as a cottage in 1719 by the Welsh Quake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulosic Sugars
Cellulosic sugars are derived from non-food biomass (e.g. wood, agricultural residues, municipal solid waste). The biomass is primarily composed of carbohydrate polymers cellulose, hemicellulose, and an aromatic polymer (lignin). The hemicellulose is a polymer of mainly five-carbon sugars C5H10O5 (xylose). and the cellulose is a polymer of six-carbon sugar C6H12O6 (glucose). Cellulose fibers are considered to be a plant’s structural building blocks and are tightly bound to lignin, but the biomass can be deconstructed using Acid hydrolysis, enzymatic hydrolysis, organosolv dissolution, autohydrolysis or supercritical hydrolysis. A more recent mechanical method offers hope that at last, a more economic and waste free method has been found although it is still to scale and is not yet commercial. Biomass (cellulose, hemicellulose and lignocellulose) contain vast amounts of fermentable sugars. These sugars may be produced from a wide variety of feedstocks and can be converted into a mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Chemistry
Green chemistry, also called sustainable 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 polluting chemicals on nature, green chemistry focuses on the 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 depletion. The development of green chemistry in Europe a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental Chemistry
Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ..., and water body, water environments; and the effect of human activity and biological activity on these. Environmental chemistry is an Interdisciplinarity, interdisciplinary science that includes Atmospheric chemistry, atmospheric, Aquatic chemistry, aquatic and soil chemistry, as well as heavily relying on analytical chemistry and being related to Environmental science, environmental and ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
