In a "scientific" sense, a chemical process is a method or means of somehow changing one or more chemicals or chemical compounds. Such a chemical process can occur by itself or be caused by somebody. Such a chemical process commonly involves a chemical reaction of some sort. In an "engineering" sense, a chemical process is a method intended to be used in manufacturing or on an industrial scale (see Industrial process) to change the composition of chemical(s) or material(s), usually using technology similar or related to that used in chemical plants or the chemical industry. In science, a process is any method (or event) that results in a transformation in a physical or biological object, a substance or an organism. ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... A chemical compound is a chemical substance of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... Vapours of hydrogen chloride in a beaker and ammonia in a test tube meet to form a cloud of a new substance, ammonium chloride A chemical reaction is a process that results in the interconversion of chemical substances. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... Manufacturing (from Latin manu factura, making by hand) is the use of tools and labor to make things for use or sale. ... Industrial processes are procedures involving chemical or mechanical steps to aid in the manufacture of an item or items, usually carried out on a very large scale. ... A Chemical plant is an industrial process plant that manufactures chemicals, usually on a large scale. ... Chemical tanks in Lillebonne, France Chemical industry includes those industries involved in the production of petrochemicals, agrochemicals, pharmaceuticals, polymers, paints, oleochemicals etc. ...

Neither of these definitions is exact in the sense that one can always tell definitively what is a chemical process and what is not; they are practical definitions. There is also significant overlap in these two definition variations. Because of the inexactness of the definition, chemists and other scientists use the term "chemical process" only in a general sense or in the engineering sense. However, in the "process (engineering)" sense, the term "chemical process" is used extensively. The rest of the article will cover the engineering type of chemical process.

Although this type of chemical process may sometimes involve only one step, often multiple steps, referred to as unit operations, are involved. In a plant, each of the unit operations commonly occur in individual vessels or sections of the plant called units. Often, one or more chemical reactions are involved, but other ways of changing chemical (or material) composition may be used, such as mixing or separation processes. The process steps may be sequential in time or sequential in space along a stream of flowing or moving material; see Chemical plant#Continuous and Batch operation. For a given amount of a feed (input) material or product (output) material, an expected amount of material can be determined at key steps in the process from empirical data and material balance calculations. These amounts can be scaled up or down to suit the desired capacity or operation of a particular chemical plant built for such a process. More than one chemical plant may use the same chemical process, each plant perhaps at differently scaled capacities. Ore Extraction unit operations at Quincy Mine, Hancock, MI ca. ... This article or section does not cite any references or sources. ... Vapours of hydrogen chloride in a beaker and ammonia in a test tube meet to form a cloud of a new substance, ammonium chloride A chemical reaction is a process that results in the interconversion of chemical substances. ... In chemistry and chemical engineering, a separation process is a process that transforms a mixture of substances into two or more compositionally-distinct products. ... A Chemical plant is an industrial process plant that manufactures chemicals, usually on a large scale. ... A feedstock is a petrochemical used as a raw material to be fed into a machine or processing plant. ...

Such chemical processes can be illustrated generally as block flow diagrams or in more detail as process flow diagrams. Block flow diagrams show the units as blocks and the streams flowing between them as connecting lines with arrowheads to show direction of flow. An example block diagram, showing the Microsoft Windows 2000 operating system architecture. ... We dont have an article called Process flow diagram Start this article Search for Process flow diagram in. ...

In addition to chemical plants for producing chemicals, chemical processes with similar technology and equipment are also used in oil refining and other refineries, natural gas processing, polymer and pharmaceutical manufacturing, and water and wastewater treatment. View of Shell Oil Refinery in Martinez, California. ... A refinery is composed of a group of chemical engineering unit processes and unit operations used for refining certain materials or converting raw material into products of value. ... A natural gas processing plant Natural gas processing plants are used to purify the raw natural gas extracted from underground gas fields and brought up to the surface by gas wells. ... A polymer (from Greek: πολυ, polu, many; and μέρος, meros, part) is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ... Pharmacology (in Greek: pharmacon is drug, and logos is science) is the study of how chemical substances interfere with living systems. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Wastewater is any water that has been adversely affected in quality by anthropogenic influence. ...

See also

• Chemical plant
• Industrial process
• Process (engineering)