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Reflux
Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations. It is also used in chemistry to supply energy to reactions over a long period of time. Reflux in industrial distillation The term ''reflux'' is very widely used in industries that utilize large-scale distillation columns and fractionators such as petroleum refineries, petrochemical and chemical plants, and natural gas processing plants. In that context, reflux refers to the portion of the overhead liquid product from a distillation column or fractionator that is returned to the upper part of the column as shown in the schematic diagram of a typical industrial distillation column. Inside the column, the downflowing reflux liquid provides cooling and condensation of the upflowing vapors thereby increasing the efficiency of the distillation column. The more reflux provided for a given numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflux Labled
Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations. It is also used in chemistry to supply energy to reactions over a long period of time. Reflux in industrial distillation The term ''reflux'' is very widely used in industries that utilize large-scale distillation columns and fractionators such as petroleum refineries, petrochemical and chemical plants, and natural gas processing plants. In that context, reflux refers to the portion of the overhead liquid product from a distillation column or fractionator that is returned to the upper part of the column as shown in the schematic diagram of a typical industrial distillation column. Inside the column, the downflowing reflux liquid provides cooling and condensation of the upflowing vapors thereby increasing the efficiency of the distillation column. The more reflux provided for a given ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distillation
Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids); this may involve chemical changes such as destructive distillation or cracking. Distillation may result in essentially complete separation (resulting in nearly pure components), or it may be a partial separation that increases the concentration of selected components; in either case, the process exploits differences in the relative volatility of the mixture's components. In industrial applications, distillation is a unit operation of practically universal importance, but is a physical separation process, not a chemical reaction. An installation used for distillation, especially of distilled beverages, is a distillery. Distillation includes th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fractional Distillation
Fractional distillation is the separation of a mixture into its component parts, or fractions. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize. It uses distillation to fractionate. Generally the component parts have boiling points that differ by less than 25 °C (45 °F) from each other under a pressure of one atmosphere. If the difference in boiling points is greater than 25 °C, a simple distillation is typically used. It is used to refine crude oil. Laboratory setup Fractional distillation in a laboratory makes use of common laboratory glassware and apparatuses, typically including a Bunsen burner, a round-bottomed flask and a condenser, as well as the single-purpose fractionating column. As an example, consider the distillation of a mixture of water and ethanol. Ethanol boils at while water boils at . So, by heating the mixture, the most volatile component (ethanol) will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Distillation
Continuous distillation, a form of distillation, is an ongoing separation in which a mixture is continuously (without interruption) fed into the process and separated fractions are removed continuously as output streams. Distillation is the separation or partial separation of a liquid feed mixture into components or fractions by selective boiling (or evaporation) and condensation. The process produces at least two output fractions. These fractions include at least one '' volatile'' distillate fraction, which has boiled and been separately captured as a vapor condensed to a liquid, and practically always a ''bottoms'' (or ''residuum'') fraction, which is the least volatile residue that has not been separately captured as a condensed vapor. An alternative to continuous distillation is batch distillation, where the mixture is added to the unit at the start of the distillation, distillate fractions are taken out sequentially in time (one after another) during the distillation, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condenser (laboratory)
In chemistry, a condenser is laboratory apparatus used to condense vaporsthat is, turn them into liquidsby cooling them down. Condensers are routinely used in laboratory operations such as distillation, reflux, and extraction. In distillation, a mixture is heated until the more volatile components boil off, the vapors are condensed, and collected in a separate container. In reflux, a reaction involving volatile liquids is carried out at their boiling point, to speed it up; and the vapors that inevitably come off are condensed and returned to the reaction vessel. In Soxhlet extraction, a hot solvent is infused onto some powdered material, such as ground seeds, to leach out some poorly soluble component; the solvent is then automatically distilled out of the resulting solution, condensed, and infused again. Many different types of condensers have been developed for different applications and processing volumes. The simplest and oldest condenser is just a long tube through w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Plate
A theoretical plate in many separation processes is a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other. Such equilibrium stages may also be referred to as an equilibrium stage, ideal stage, or a theoretical tray. The performance of many separation processes depends on having series of equilibrium stages and is enhanced by providing more such stages. In other words, having more theoretical plates increases the efficiency of the separation process be it either a distillation, absorption, chromatographic, adsorption or similar process. Applications The concept of theoretical plates and trays or equilibrium stages is used in the design of many different types of separation. Distillation columns The concept of theoretical plates in designing distillation processes has been discussed in many reference texts. Any physical device that provides good contact between the vapor and liquid phases pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fractionating Column
A fractionating column or fractional column is an essential item used in the distillation of liquid mixtures to separate the mixture into its component parts, or fractions, based on the differences in volatilities. Fractionating columns are used in small scale laboratory distillations as well as large scale industrial distillations. Laboratory fractionating columns A laboratory fractionating column is a piece of glassware used to separate vaporized mixtures of liquid compounds with close volatility. Most commonly used is either a Vigreux column or a straight column packed with glass beads or metal pieces such as Raschig rings. Fractionating columns help to separate the mixture by allowing the mixed vapors to cool, condense, and vaporize again in accordance with Raoult's law. With each condensation-vaporization cycle, the vapors are enriched in a certain component. A larger surface area allows more cycles, improving separation. This is the rationale for a Vigreux column or a pac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distillation Design
''Distillation Design'' is a book which provides complete coverage of the design of industrial distillation columns for the petroleum refining, chemical and petrochemical plants, natural gas processing, pharmaceutical, food and alcohol distilling industries. It has been a classical chemical engineering textbook since it was first published in February 1992. The subjects covered in the book include: *''Vapor–liquid equilibrium(VLE)'': Vapor–liquid K values, relative volatilities, ideal and non-ideal systems, phase diagrams, calculating bubble points and dew points *''Key fractional distillation concepts'': theoretical stages, x-y diagrams, multicomponent distillation, column composition and temperature profiles *'' Process design and optimization'': minimum reflux and minimum stages, optimum reflux, short-cut methods, feed entry location *''Rigorous calculation methods'': Bubble point method, sum rates method, numerical methods (Newton–Raphson technique), inside out meth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round Bottom Flask
Round-bottom flasks (also called round-bottomed flasks or RB flasks) are types of Laboratory flask, flasks having spherical bottoms used as laboratory glassware, mostly for chemistry, chemical or biochemistry, biochemical work. They are typically made of glass for chemical Chemically inert, inertness; and in modern days, they are usually made of heat-resistant borosilicate glass. There is at least one tubular section known as the ''neck'' with an opening at the tip. Two- or three-necked flasks are common as well. Round bottom flasks come in many sizes, from 5 mL to 20 L, with the sizes usually inscribed on the glass. In pilot plants even larger flasks are encountered. The ends of the necks are usually conical ground glass joints. These are standardized, and can accept any similarly-sized tapered (male) fittings. Ground glass joint, 24/20 is common for 250 mL or larger flasks, while smaller sizes such as 14/20 or 19/22 are used for smaller flasks. Because of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners ( toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers ( hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Bath
A sand bath is a common piece of laboratory equipment made from a container filled with heated sand. It is used to evenly heat another container, most often during a chemical reaction. A sand bath is most commonly used in conjunction with a hot plate or heating mantle. A beaker is filled with sand or metal pellets (called shot) and is placed on the plate or mantle. The reaction vessel is then partially covered by sand or pellets. The sand or shot then conducts the heat from the plate to all sides of the reaction vessel. This technique allows a reaction vessel to be heated throughout with minimal stirring, as opposed to heating the bottom of the vessel and waiting for convection to heat the remainder, cutting down on both the duration of the reaction and the possibility of side reactions that may occur at higher temperatures. A variation on this theme is the water bath in which the sand is replaced with water. It can be used to keep a reaction vessel at the temperature of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Plate
A hot plate is a portable self-contained tabletop small appliance cooktop that features one or more electric heating elements or gas burners. A hot plate can be used as a stand-alone appliance, but is often used as a substitute for one of the burners from an oven range or a kitchen stove. Hot plates are often used for food preparation, generally in locations where a full kitchen stove would not be convenient or practical. They can also be used as a heat source in laboratories. A hot plate can have a flat surface or round surface. Hot plates can be used for traveling or in areas without electricity. Description This type of cooking equipment is typically powered by electricity; however, gas fired hot plates were not uncommon in the 19th and 20th century and are still available in various markets around the world. In scientific research In laboratory settings, hot plates are generally used to heat glassware or its contents. Some hot plates also contain an integrated magne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
