Editing Naphthalene (section)

== Production ==
[[File:Naphthalene.jpg|thumb|left|Naphthalene]]
From the 1960s until the 1990s, significant amounts of naphthalene were produced from heavy [[petroleum]] fractions during [[Oil refinery|refining]], but present-day production is mainly from [[coal tar]].<ref>{{Cite web |last=Government of Canada |first=Public Services and Procurement Canada |date=2017-03-29 |title=Fact sheet: Naphthalene — Compare environmental contaminants — Guidance and Orientation for the Selection of Technologies — Contaminated sites — Pollution and waste management — Environment and natural resources — Canada.ca |url=https://gost.tpsgc-pwgsc.gc.ca/Contfs.aspx?ID=42&lang=eng |access-date=2025-05-14 |website=gost.tpsgc-pwgsc.gc.ca}}</ref> {{As of|2023}}, the global napthalene market was 2.25 million tons.<ref>{{Cite web |title=Naphthalene Market Size, Share, Trends, Growth & Forecast |url=https://www.chemanalyst.com/industry-report/naphthalene-market-565 |access-date=2025-05-14 |website=www.chemanalyst.com}}</ref>

Naphthalene is the most abundant single component of coal tar.<ref name=":0">{{Cite journal |last=Ordabayeva |first=A T |last2=Meiramov |first2=M G |last3=Gazaliev |first3=A M |date=2020-08-01 |title=Physicochemical characteristics of the wide fraction of the coal tar from ArselorMittal Temirtau, JSC |url=https://iopscience.iop.org/article/10.1088/1742-6596/1611/1/012024 |journal=Journal of Physics: Conference Series |volume=1611 |issue=1 |pages=012024 |doi=10.1088/1742-6596/1611/1/012024 |issn=1742-6588|doi-access=free }}</ref> The composition of coal tar varies with coal type and processing, but typical coal tar is about 10% naphthalene by weight.<ref>{{Cite web |date=July 2024 |title=Table 4-6, Some Constituents and Weight Percentage of Eight Coal Tar Creosote Mixtures |url=https://www.ncbi.nlm.nih.gov/books/NBK606208/table/ch4.tab6/?report=objectonly |access-date=2025-05-14 |website=www.ncbi.nlm.nih.gov |language=en}}</ref> In industrial practice, [[distillation]] of coal tar yields an oil containing about 50% naphthalene, along with twelve other [[aromatic compound]]s.<ref name=":0" /> This oil, after being washed with aqueous [[sodium hydroxide]] to remove [[acid]]ic components (chiefly various [[phenol]]s), and with sulfuric acid to remove [[base (chemistry)|basic]] components, undergoes [[fractional distillation]] to isolate naphthalene. The crude naphthalene resulting from this process is about 95% naphthalene by weight. The chief impurities are the sulfur-containing aromatic compound [[benzothiophene]] (<&nbsp;2%), [[indane]] (0.2%), [[indene]] (<&nbsp;2%), and [[methylnaphthalene]] (<&nbsp;2%). Petroleum-derived naphthalene is usually purer than that derived from coal tar. Where required, crude naphthalene can be further purified by [[Recrystallization (chemistry)|recrystallization]] from any of a variety of solvents, resulting in 99% naphthalene by weight, referred to as 80&nbsp;°C (melting point).<ref name=Ullmann>{{Ullmann|author=Gerd Collin |author2=Hartmut Höke |author3=Helmut Greim |title=Naphthalene and Hydronaphthalenes|year=2003|doi10.1002/14356007.a17_001.pub2}}.</ref>

In [[North America]], the coal tar producers are [[Koppers]] Inc., Ruetgers Canada Inc. and Recochem Inc., and the primary petroleum producer is Monument Chemical Inc. In Western Europe the well-known producers are Koppers, Ruetgers, and Deza. In [[Eastern Europe]], naphthalene is produced by a variety of integrated [[metallurgy]] complexes (Severstal, Evraz, Mechel, MMK) in [[Russia]], dedicated naphthalene and phenol makers INKOR, Yenakievsky Metallurgy plant in [[Ukraine]] and ArcelorMittal Temirtau in [[Kazakhstan]].

=== Other sources and occurrences ===
Naphthalene and its alkyl [[Homologous series|homologs]] are the major constituents of [[creosote]].

Trace amounts of naphthalene are produced by [[magnolia]]s and some species of [[deer]], as well as the [[Formosan subterranean termite]], possibly produced by the termite as a repellant against "ants, [[Poisonous fungus|poisonous fungi]] and [[nematode]] worms".<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/sci/tech/76115.stm |title=Termite 'mothball' keep insects at bay |publisher=BBC News |work=Sci/Tech |date=April 8, 1998}}</ref> Some strains of the [[endophytic]] fungus ''[[Muscodor albus]]'' produce naphthalene among a range of volatile organic compounds, while ''[[Muscodor vitigenus]]'' produces naphthalene almost exclusively.<ref>{{cite journal |vauthors=Daisy BH, Strobel GA, Castillo U, etal |title=Naphthalene, an insect repellent, is produced by ''Muscodor vitigenus'', a novel endophytic fungus |journal=Microbiology |volume=148 |issue=Pt 11 |pages=3737–41 |date=November 2002 |pmid=12427963 |url=http://mic.sgmjournals.org/cgi/content/abstract/148/11/3737 | doi = 10.1099/00221287-148-11-3737 |doi-access=free }}</ref>