Simple sketch of pyrolysis chemistry

Pyrolysis usually means the chemical decomposition of organic materials by heating in the absence of oxygen or any other reagents, except possibly steam. Image File history File links Pyrolysis. ... chemical decomposition is the gradual fragmentation of a chemical compound into smaller molecules. ... Benzene An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with the exception of carbides, carbonates, carbon oxides and elementary carbon. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... In physical chemistry, and in engineering, steam refers to vaporized water. ...

Extreme pyrolysis, that leaves only carbon as the residue, is called carbonization. Pyrolysis is a special case of thermolysis. General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Carbonization is the term for the conversion of an organic substance into carbon or a carbon-containing residue. ... Thermolysis (from thermo- meaning heat and -lysis meaning break down) is a chemical process by which a substance is decomposed into other substances by use of heat. ...

Pyrolysis is a means of reusing scrap tires. Pyrolysis in this context is the degradation of the rubber of the tire using heat in the absence of oxygen. It is used to recycle car tires rather than burn or bury them, which can have a detrimental effect on the environment.   The international symbol for recycling. ...

Anhydrous pyrolysis

Pyrolysis is usually understood to be anhydrous (without water).

This phenomenon commonly occurs whenever solid organic material is sufficiently heated, e.g. when frying, roasting, baking, toasting. (Even though such processes are carried out in a normal atmosphere, the outer layers of the material keep its interior oxygen-free.) Organic has several meanings and related topics. ... Frying is the cooking of food with cooking oil as the heat transfer medium. ... Roasting is cooking with dry heat, whether an open flame, oven, or other heat source. ... Wikibooks Cookbook has more about this subject: Baking Baking is the technique of cooking food in an oven by dry heat applied evenly throughout the oven or only from the bottom element. ... For other meanings see Toast (disambiguation) Toasting, chatting, or DJing is the act of talking or chanting over a rhythm or beat. ...

The process also occurs when burning compact solid fuel, like wood. In fact, the flames of a wood fire are due to combustion of gases released by pyrolysis, not combustion of the wood itself. Thus, the pyrolysis of common materials like wood, plastic and clothing is extremely important for fire safety and fire fighting. Combustion or burning is a chemical process, an exothermic reaction between a substance (the fuel) and a gas (the oxidizer), usually O2, to release heat. ... Fire safety is a component of Building Safety. ... Fire fighting is the knowledge and techniques required to extinguish a fire. ...

An ancient industrial use of anhydrous pyrolysis is the production of charcoal through the pyrolysis of wood. More recently, pyrolysis has been used on a massive scale to turn coal into coke for metallurgy, especially steelmaking. Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents of animal and vegetable substances. ... A tree trunk as found at the Veluwe, The Netherlands Wood derives from woody plants, notably trees but also shrubs. ... Coal (previously referred to as pitcoal or seacoal) is a fossil fuel extracted from the ground by underground mining or open-pit mining (surface mining). ... Coke is a solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal. ... Metallurgy is a domain of materials science and of materials engineering that studies the physical and chemical behavior of metallic elements, their intermetallic compounds and their mixtures, which are called alloys. ... Steel making technologies: Bessemer converter LD Process Basic oxygen furnace Electric arc furnace Related topics: Steel Blast furnace This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

Anhydrous pyrolysis has been assumed to take place during catagenesis, the conversion of kerogen to fossil fuels. Catagenesis is a term used in petroleum geology to describe the cracking process which results in the conversion of organic kerogens into hydrocarbons. ... Kerogens are chemical compounds that make up a portion of the organic matter in sedimentary rocks. ... Fossil fuels are hydrocarbon-containing natural resources such as coal, petroleum and natural gas. ...

In many industrial applications the process is done under pressure and at operating temperatures above 430°C (800°F). The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ...

Anhydrous pyrolysis can also be used to produce liquid fuel similar to diesel from solid biomass. The most common technique uses very low residence times (<2 seconds) and high heating rates using a temperature between 350-500 °C and is called either fast or flash pyrolysis. Diesel or Diesel fuel is a specific fractional distillate of fuel oil (mostly petroleum) that is used as fuel in a diesel engine invented by German engineer Rudolf Diesel. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Pyrolysis also can be used to degrade wastes, as a form of incineration. To meet Wikipedias quality standards, this article or section may require cleanup. ...

Hydrous pyrolysis

The term pyrolysis is sometimes used to encompass also thermolysis in the presence of water, such as steam cracking of oil, or more generally hydrous pyrolysis. An example of the latter is thermal depolymerization of organic waste into light crude oil. In petroleum geology and chemistry, cracking is the process whereby complex organic molecules (e. ... Hydrous pyrolysis refers to the chemical processes which take place when material is heated to high temperatures in the presence of water. ... Thermal depolymerization (TDP) is a process for the reduction of complex organic materials (usually waste products of various sorts, often known as biomass) into light crude oil. ... Nodding donkey pumping an oil well near Sarnia, Ontario Petroleum (from Greek petra – rock and oleum – oil), crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish liquid. ...

See also

• Gasification
• Karrick process