{"term":{"id":"01578","title":"delayed coking process","longtitle":"IUPAC Gold Book - delayed coking process","doi":"10.1351\/goldbook.D01578","code":"D01578","status":"current","definitions":[{"id":1,"text":"A thermal process which increases the molecular aggregation or association in petroleum-based residues or coal tar pitches leading to extended mesophase domains. This is achieved by holding them at an elevated temperature (usually \\(750{-}765\\ \\rm{K}\\)) over a period of time (\\(12\\ \\rm{to}\\ 36\\ \\rm{h}\\)). It is performed in a coking drum and is designed to ultimately produce delayed coke. The feed is rapidly pre-heated in a tubular furnace to about \\(760\\ \\rm{K}\\).","notes":{"1":"Needle coke is the premium product of the delayed coking process. It is generally produced from highly aromatic residues from, for instance, the steam cracking of gas oil. Its appearance and preferred orientation of the graphene layers is a consequence of the evolved gaseous products percolating through the mesophase which must not have too high a viscosity. A close control of temperature, time and feedstock is essential. Lower grades, for instance isotropic cokes, are used for carbon electrodes applied, for example, in the production of aluminium."},"links":[{"term":"Needle coke","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/N04095"},{"term":"association","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/A00472"},{"term":"carbon electrodes","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/C00829"},{"term":"coal tar pitches","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/C01121"},{"term":"coking","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/C01144"},{"term":"cracking","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/C01387"},{"term":"delayed coke","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/D01577"},{"term":"graphene layers","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/G02683"},{"term":"isotropic","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/I03353"},{"term":"mesophase","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/M03849"},{"term":"viscosity","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/V06627"}],"sources":["PAC, 1995, 67, 473. 'Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)' on page 486 (https:\/\/doi.org\/10.1351\/pac199567030473)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/D01578\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/D01578\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/D01578\/plain"},"citation":"Citation: 'delayed coking process' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.D01578","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-04-19T04:21:35+00:00"}}