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Semibatch Reactor
For both chemical and biological engineering, Semibatch (semiflow) reactors operate much like batch reactors in that they take place in a single stirred tank with similar equipment. However, they are modified to allow reactant addition and/or product removal in time. A normal batch reactor is filled with reactants in a single stirred tank at time t=0 and the reaction proceeds. A semi batch reactor, however, allows partial filling of reactants with the flexibility of adding more as time progresses. Stirring in both types is very efficient, which allows batch and semi batch reactors to assume a uniform composition and temperature throughout. Advantages The flexibility of adding more reactants over time through semi batch operation has several advantages over a batch reactor. These include: Improved selectivity of a reaction Sometimes a particular reactant can go through parallel paths that yield two different products, only one of which is desired. Consider the simple example bel ... [...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] |
Biological Engineering
Biological engineering or bioengineering is the application of principles of biology and the tools of engineering to create usable, tangible, economically-viable products. Biological engineering employs knowledge and expertise from a number of pure and applied sciences, such as mass and heat transfer, kinetics, biocatalysts, biomechanics, bioinformatics, separation and purification processes, bioreactor design, surface science, fluid mechanics, thermodynamics, and polymer science. It is used in the design of medical devices, diagnostic equipment, biocompatible materials, renewable energy, ecological engineering, agricultural engineering, process engineering and catalysis, and other areas that improve the living standards of societies. Examples of bioengineering research include bacteria engineered to produce chemicals, new medical imaging technology, portable and rapid disease diagnostic devices, prosthetics, biopharmaceuticals, and tissue-engineered organs. Bioengineering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batch Reactor
The batch reactor is the generic term for a type of vessel widely used in the process industries. Its name is something of a misnomer since vessels of this type are used for a variety of process operations such as solids dissolution, product mixing, chemical reactions, batch distillation, crystallization, liquid/liquid extraction and polymerization. In some cases, they are not referred to as reactors but have a name which reflects the role they perform (such as crystallizer, or bioreactor). A typical batch reactor consists of a storage tank with an agitator and integral heating/cooling system. These vessels may vary in size from less than 1 litre to more than 15,000 litres. They are usually fabricated in steel, stainless steel, glass-lined steel, glass or exotic alloy. Liquids and solids are usually charged via connections in the top cover of the reactor. Vapors and gases also discharge through connections in the top. Liquids are usually discharged out of the bottom. The advan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactant
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a substance ''consumed'' in the course of a chemical reaction. ''Solvents'', though involved in the reaction mechanism, are usually not called reactants. Similarly, ''catalysts'' are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates. Definitions Organic chemistry In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents. Analytical chemistry In analytical chemistry, a reagent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Mass
In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance which is the number of moles in that sample, measured in moles. The molar mass is a bulk, not molecular, property of a substance. The molar mass is an ''average'' of many instances of the compound, which often vary in mass due to the presence of isotopes. Most commonly, the molar mass is computed from the standard atomic weights and is thus a terrestrial average and a function of the relative abundance of the isotopes of the constituent atoms on Earth. The molar mass is appropriate for converting between the mass of a substance and the amount of a substance for bulk quantities. The molecular mass and formula mass are commonly used as a synonym of molar mass, particularly for molecular compounds; however, the most authoritative sources define it differently. The difference is that molecular mass is the mass of one specific particle or molecul ... [...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 concen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exothermic Reactions
In thermodynamics, an exothermic process () is a thermodynamic process or Chemical reaction, reaction that releases energy from the system to its Environment (systems), surroundings, usually in the form of heat, but also in a form of light (e.g. a spark, flame, or flash), electricity (e.g. a battery), or sound (e.g. explosion heard when burning hydrogen). The term ''exothermic'' was first coined by 19th-century French chemist Marcellin Berthelot. The opposite of an exothermic process is an endothermic process, one that absorbs energy usually in the form of heat. The concept is frequently applied in the Outline of physical science, physical sciences to chemical reactions where chemical bond energy is converted to thermal energy (heat). Two types of chemical reactions Exothermic and endothermic describe two types of chemical reactions or systems found in nature, as follows: Exothermic After an exothermic reaction, more energy has been released to the surroundings than was absor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concentration
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', ''number concentration'', and ''volume concentration''. The concentration can refer to any kind of chemical mixture, but most frequently refers to solutes and solvents in solutions. The molar (amount) concentration has variants, such as normal concentration and osmotic concentration. Etymology The term concentration comes from the word concentrate, from the French , from con– + center, meaning “to put at the center”. Qualitative description Often in informal, non-technical language, concentration is described in a qualitative way, through the use of adjectives such as "dilute" for solutions of relatively low concentration and "concentrated" for solutions of relatively high concentration. To concentrate a solution, one must add more solute (for example, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Phase
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena. Water is by far the most common liquid on Earth. The density of a liquid is usually close to that of a solid, and much higher than that of a gas. Therefore, liquid and solid are both termed condensed matter. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capital Cost
Capital costs are fixed, one-time expenses incurred on the purchase of land, buildings, construction, and equipment used in the production of goods or in the rendering of services. In other words, it is the total cost needed to bring a project to a commercially operable status. Whether a particular cost is capital or not depend on many factors such as accounting, tax laws, and materiality. Categories Capital costs include expenses for tangible goods such as the purchase of plants and machinery, as well as expenses for intangibles assets such as trademarks and software development. Capital costs are not limited to the initial construction of a factory or other business. Namely, the purchase of a new machine to increase production and last for years is a capital cost. Capital costs do not include labor costs (they do include construction labor). Unlike operating costs, capital costs are one-time expenses but payment may be spread out over many years in financial reports and tax r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating Cost
Operating costs or operational costs, are the expenses which are related to the operation of a business, or to the operation of a device, component, piece of equipment or facility. They are the cost of resources used by an organization just to maintain its existence. http://www.operatingcosts.com Business operating costs For a commercial enterprise, operating costs fall into three broad categories: * fixed costs, which are the same whether the operation is closed or running at 100% capacity. Fixed Costs include items such as the rent of the building. These generally have to be paid regardless of what state the business is in. It never changes * variable costs, which may increase depending on whether more production is done, and how it is done (producing 100 items of product might require 10 days of normal time or take 7 days if overtime is used. It may be more or less expensive to use overtime production depending on whether faster production means the product can be more profit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
