Cetane number - Revision history

104.128.161.37: sulfur was incorrectly spelled

2024-09-14T17:47:16Z

sulfur was incorrectly spelled

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	{{Short description\|Performance measurement of diesel fuel}}		{{Short description\|Performance measurement of diesel fuel}}
	'''Cetane number''' ('''cetane rating''') ('''CN''') is an indicator of the [[combustion]] speed of [[diesel fuel]] and compression needed for [[wikt:ignition\|ignition]]. It plays a similar role for [[diesel fuel\|diesel]] as [[octane rating]] does for [[gasoline]]. The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel fuel's quality include (but are not limited to) energy content, [[density]], lubricity, cold-flow properties and ~~sulphur~~ content.<ref name=Ullmann>Werner Dabelstein, Arno Reglitzky, Andrea Schütze and Klaus Reders "Automotive Fuels" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2007, Wiley-VCH, Weinheim.{{doi\|10.1002/14356007.a16_719.pub2}}</ref>		'''Cetane number''' ('''cetane rating''') ('''CN''') is an indicator of the [[combustion]] speed of [[diesel fuel]] and compression needed for [[wikt:ignition\|ignition]]. It plays a similar role for [[diesel fuel\|diesel]] as [[octane rating]] does for [[gasoline]]. The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel fuel's quality include (but are not limited to) energy content, [[density]], lubricity, cold-flow properties and sulfur content.<ref name=Ullmann>Werner Dabelstein, Arno Reglitzky, Andrea Schütze and Klaus Reders "Automotive Fuels" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2007, Wiley-VCH, Weinheim.{{doi\|10.1002/14356007.a16_719.pub2}}</ref>

	== Definition ==		== Definition ==

MimiKal797: Replaced chemical synonym with the term used previously to avoid confusion

2024-06-08T00:59:28Z

Replaced chemical synonym with the term used previously to avoid confusion

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	== Definition ==		== Definition ==
	The cetane number of a fuel is defined by finding a blend of [[cetane]] and [[heptamethylnonane\|isocetane]] with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel [[Alpha-methyl naphthalene\|alpha-methylnaphthalene]], which was assigned a cetane number of 0. Once the blend is known, the cetane number is calculated as a volume-weighted average, rounded to the nearest whole number, of cetane's 100 and isocetane's 15.<ref name=":0" />		The cetane number of a fuel is defined by finding a blend of [[cetane]] and [[heptamethylnonane\|isocetane]] with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel [[Alpha-methyl naphthalene\|alpha-methylnaphthalene]], which was assigned a cetane number of 0. Once the blend is known, the cetane number is calculated as a volume-weighted average, rounded to the nearest whole number, of cetane's 100 and isocetane's 15.<ref name=":0" />
	:cetane number = % ''n''-cetane + 0.15(% ~~heptamethylnonane~~)<ref name=":0" />		:cetane number = % ''n''-cetane + 0.15(% isocetane)<ref name=":0" />

	[[Cetane]] number is an inverse function of a fuel's ignition delay, the time period between the start of ignition and the first identifiable pressure increase during combustion of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane numbers are only used for the relatively light distillate diesel oils. For heavy (residual) fuel oil two other scales are used, [[Calculated Carbon Aromaticity Index\|CCAI]] and [[Calculated Ignition Index\|CII]].		[[Cetane]] number is an inverse function of a fuel's ignition delay, the time period between the start of ignition and the first identifiable pressure increase during combustion of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane numbers are only used for the relatively light distillate diesel oils. For heavy (residual) fuel oil two other scales are used, [[Calculated Carbon Aromaticity Index\|CCAI]] and [[Calculated Ignition Index\|CII]].

MimiKal797: Replaced chemical synonym with the term used previously to avoid confusion

2024-06-08T00:58:41Z

Replaced chemical synonym with the term used previously to avoid confusion

← Previous revision		Revision as of 00:58, 8 June 2024
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	== Definition ==		== Definition ==
	The cetane number of a fuel is defined by finding a blend of [[cetane]] and [[heptamethylnonane\|isocetane]] with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel [[Alpha-methyl naphthalene\|alpha-methylnaphthalene]], which was assigned a cetane number of 0. Once the blend is known, the cetane number is calculated as a volume-weighted average, rounded to the nearest whole number, of cetane's 100 and ~~heptamethylnonane~~'s 15.<ref name=":0" />		The cetane number of a fuel is defined by finding a blend of [[cetane]] and [[heptamethylnonane\|isocetane]] with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel [[Alpha-methyl naphthalene\|alpha-methylnaphthalene]], which was assigned a cetane number of 0. Once the blend is known, the cetane number is calculated as a volume-weighted average, rounded to the nearest whole number, of cetane's 100 and isocetane's 15.<ref name=":0" />
	:cetane number = % ''n''-cetane + 0.15(% heptamethylnonane)<ref name=":0" />		:cetane number = % ''n''-cetane + 0.15(% heptamethylnonane)<ref name=":0" />

Comfr: remove duplicate

2024-03-14T23:55:41Z

remove duplicate

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	== Definition ==		== Definition ==
	The cetane number ~~(or CN)~~ of a fuel is defined by finding a blend of [[cetane]] and [[heptamethylnonane\|isocetane]] with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel [[Alpha-methyl naphthalene\|alpha-methylnaphthalene]], which was assigned a cetane number of 0. Once the blend is known, the cetane number is calculated as a volume-weighted average, rounded to the nearest whole number, of cetane's 100 and heptamethylnonane's 15.<ref name=":0" />		The cetane number of a fuel is defined by finding a blend of [[cetane]] and [[heptamethylnonane\|isocetane]] with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel [[Alpha-methyl naphthalene\|alpha-methylnaphthalene]], which was assigned a cetane number of 0. Once the blend is known, the cetane number is calculated as a volume-weighted average, rounded to the nearest whole number, of cetane's 100 and heptamethylnonane's 15.<ref name=":0" />
	:cetane number = % ''n''-cetane + 0.15(% heptamethylnonane)<ref name=":0" />		:cetane number = % ''n''-cetane + 0.15(% heptamethylnonane)<ref name=":0" />

Comfr: show acronym

2024-03-14T23:54:47Z

show acronym

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	{{Short description\|Performance measurement of diesel fuel}}		{{Short description\|Performance measurement of diesel fuel}}
	'''Cetane number''' ('''cetane rating''') is an indicator of the [[combustion]] speed of [[diesel fuel]] and compression needed for [[wikt:ignition\|ignition]]. It plays a similar role for [[diesel fuel\|diesel]] as [[octane rating]] does for [[gasoline]]. The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel fuel's quality include (but are not limited to) energy content, [[density]], lubricity, cold-flow properties and sulphur content.<ref name=Ullmann>Werner Dabelstein, Arno Reglitzky, Andrea Schütze and Klaus Reders "Automotive Fuels" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2007, Wiley-VCH, Weinheim.{{doi\|10.1002/14356007.a16_719.pub2}}</ref>		'''Cetane number''' ('''cetane rating''') ('''CN''') is an indicator of the [[combustion]] speed of [[diesel fuel]] and compression needed for [[wikt:ignition\|ignition]]. It plays a similar role for [[diesel fuel\|diesel]] as [[octane rating]] does for [[gasoline]]. The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel fuel's quality include (but are not limited to) energy content, [[density]], lubricity, cold-flow properties and sulphur content.<ref name=Ullmann>Werner Dabelstein, Arno Reglitzky, Andrea Schütze and Klaus Reders "Automotive Fuels" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2007, Wiley-VCH, Weinheim.{{doi\|10.1002/14356007.a16_719.pub2}}</ref>

	== Definition ==		== Definition ==

AnomieBOT: Dating maintenance tags: {{Clarify}}

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Dating maintenance tags: {{Clarify}}

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	===Cetane index===		===Cetane index===
	{{Main\|Cetane index}}		{{Main\|Cetane index}}
	Another statistic used by fuel-users to control quality is the cetane index (CI), which is a calculated number based on the [[density]] and a distillation range of the fuel. There are various versions of this, depending on whether metric or Imperial units are used, and the number of distillation points that are used. These days most [[petroleum industry\|oil companies]] use the '4-point method', ASTM D4737, based on density and 10% 50% and 90% recovery temperatures. The '2-point method' is defined in [[ASTM]] D976 and uses just density and the 50% recovery temperature. This 2-point method tends to overestimate the cetane index and is not recommended. Cetane index calculations cannot account for cetane improver additives and therefore do not measure the total cetane number for additized diesel fuels. Diesel engine operation is primarily related to the actual cetane number, and the cetane index is merely an estimation of the base (unadditized){{clarify}} cetane number.		Another statistic used by fuel-users to control quality is the cetane index (CI), which is a calculated number based on the [[density]] and a distillation range of the fuel. There are various versions of this, depending on whether metric or Imperial units are used, and the number of distillation points that are used. These days most [[petroleum industry\|oil companies]] use the '4-point method', ASTM D4737, based on density and 10% 50% and 90% recovery temperatures. The '2-point method' is defined in [[ASTM]] D976 and uses just density and the 50% recovery temperature. This 2-point method tends to overestimate the cetane index and is not recommended. Cetane index calculations cannot account for cetane improver additives and therefore do not measure the total cetane number for additized diesel fuels. Diesel engine operation is primarily related to the actual cetane number, and the cetane index is merely an estimation of the base (unadditized){{clarify\|date=October 2023}} cetane number.

	===Industry standards===		===Industry standards===

Ehrenkater: /* Cetane index */

2023-10-16T21:39:42Z

Cetane index

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	===Cetane index===		===Cetane index===
	{{Main\|Cetane index}}		{{Main\|Cetane index}}
	Another ~~method~~ ~~that~~ fuel-users control quality is ~~by using~~ the cetane index (CI), which is a calculated number based on the [[density]] and a distillation range of the fuel. There are various versions of this, depending on whether metric or Imperial units are used, and the number of distillation points are used. These days most [[petroleum industry\|oil companies]] use the '4-point method', ASTM D4737, based on density, 10% 50% and 90% recovery temperatures. The '2-point method' is defined in [[ASTM]] D976 and uses just density and the 50% recovery temperature. This 2-point method tends to overestimate the cetane index and is not recommended. Cetane index calculations ~~can not~~ account for cetane improver additives and therefore do not measure the total cetane number for additized diesel fuels. Diesel engine operation is primarily related to the actual cetane number and the cetane index is ~~simply~~ an estimation of the base (unadditized) cetane number.		Another statistic used by fuel-users to control quality is the cetane index (CI), which is a calculated number based on the [[density]] and a distillation range of the fuel. There are various versions of this, depending on whether metric or Imperial units are used, and the number of distillation points that are used. These days most [[petroleum industry\|oil companies]] use the '4-point method', ASTM D4737, based on density and 10% 50% and 90% recovery temperatures. The '2-point method' is defined in [[ASTM]] D976 and uses just density and the 50% recovery temperature. This 2-point method tends to overestimate the cetane index and is not recommended. Cetane index calculations cannot account for cetane improver additives and therefore do not measure the total cetane number for additized diesel fuels. Diesel engine operation is primarily related to the actual cetane number, and the cetane index is merely an estimation of the base (unadditized){{clarify}} cetane number.

	===Industry standards===		===Industry standards===

Ehrenkater: /* Chemical relevance */

2023-10-16T21:37:11Z

Chemical relevance

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	== Chemical relevance ==		== Chemical relevance ==
	[[Cetane]] is the hydrocarbon with chemical formulas C<sub>16</sub>H<sub>34</sub> and CH<sub>3</sub>(CH<sub>2</sub>)<sub>14</sub>CH<sub>3</sub>. ~~Named~~ n-hexadecane, it is an unbranched [[Saturated and unsaturated compounds\|saturated]] [[alkane]]. Cetane ignites with a short delay under compression, and is assigned a cetane number of 100. [[alpha-methyl naphthalene\|Alpha-methylnaphthalene]], which has a long delay period, was assigned a cetane number of 0, but has been replaced as a reference fuel by [[Isocetane\|2,3,4,5,6,7,8-heptamethylnonane]], ~~whose~~ cetane number is 15.<ref name=":0">{{Cite book\|last=Speight\|first=James G.\|url=http://doi.wiley.com/10.1002/9781118986370\|title=Handbook of Petroleum Product Analysis: Speight/Handbook of Petroleum Product Analysis\|date=2014-12-12\|publisher=John Wiley & Sons, Inc\|isbn=978-1-118-98637-0\|location=Hoboken, NJ\|language=en\|doi=10.1002/9781118986370}}</ref> All other [[hydrocarbon]]s in diesel fuel are indexed to cetane as to how rapidly they ignite under compression, i.e., [[diesel engine]] conditions. Since hundreds of components comprise diesel fuel, the overall cetane number of that fuel is the average cetane quality of all the components. High-cetane components have a disproportionate influence, hence the use of high-cetane additives.		[[Cetane]] is the hydrocarbon with chemical formulas C<sub>16</sub>H<sub>34</sub> and specifically the structural formula CH<sub>3</sub>(CH<sub>2</sub>)<sub>14</sub>CH<sub>3</sub>. Also named n-hexadecane, it is an unbranched [[Saturated and unsaturated compounds\|saturated]] [[alkane]]. Cetane ignites with a short delay under compression, and is assigned a cetane number of 100. [[alpha-methyl naphthalene\|Alpha-methylnaphthalene]], which has a long delay period, was assigned a cetane number of 0, but has been replaced as a reference fuel by [[Isocetane\|2,3,4,5,6,7,8-heptamethylnonane]], which is assigned a cetane number of 15.<ref name=":0">{{Cite book\|last=Speight\|first=James G.\|url=http://doi.wiley.com/10.1002/9781118986370\|title=Handbook of Petroleum Product Analysis: Speight/Handbook of Petroleum Product Analysis\|date=2014-12-12\|publisher=John Wiley & Sons, Inc\|isbn=978-1-118-98637-0\|location=Hoboken, NJ\|language=en\|doi=10.1002/9781118986370}}</ref> All other [[hydrocarbon]]s in diesel fuel are indexed to cetane as to how rapidly they ignite under compression, i.e. [[diesel engine]] conditions. Since hundreds of components comprise diesel fuel, the overall cetane number of that fuel is the average cetane quality of all the components. High-cetane components have a disproportionate influence, hence the use of high-cetane additives.

	== Measuring cetane number ==		== Measuring cetane number ==

Adrianarroyos: Updated citation URL to avoid 301 redirect, now direct to destination page

2023-10-16T21:30:27Z

Updated citation URL to avoid 301 redirect, now direct to destination page

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	In North America, most states adopt ASTM D975 as their diesel fuel standard and the minimum cetane number is set at 40, with typical values in the 42-45 range. Premium diesel fuel may or may not have higher cetane number depending on the supplier. Premium diesel often use [[fuel additive\|additives]] to improve CN and [[lubricity]], [[detergent]]s to clean the [[fuel injector]]s and minimize [[carbon]] deposits, water dispersants, and other additives depending on geographical and seasonal needs.{{citation needed\|date=January 2013}}. California diesel fuel has a minimum cetane of 53.<ref>{{cite web\|url=http://www.arb.ca.gov/enf/fuels/dieselspecs.pdf\|title=Specs table\|website=www.arb.ca.gov\|access-date=2013-06-08\|archive-url=https://web.archive.org/web/20170221021415/https://www.arb.ca.gov/enf/fuels/dieselspecs.pdf\|archive-date=2017-02-21\|url-status=dead}}</ref> Under the Texas Low Emission Diesel (TxLED) program there are 110 counties where diesel fuel must have a cetane number of 48 or greater, or else must use an approved alternative formulation or comply with the designated alternative limits.<ref>{{cite web\|url=https://www.tceq.texas.gov/airquality/mobilesource/txled/cleandiesel.html\|title=Texas Low Emission Diesel (TxLED) Program\|website=TCEQ}}</ref>		In North America, most states adopt ASTM D975 as their diesel fuel standard and the minimum cetane number is set at 40, with typical values in the 42-45 range. Premium diesel fuel may or may not have higher cetane number depending on the supplier. Premium diesel often use [[fuel additive\|additives]] to improve CN and [[lubricity]], [[detergent]]s to clean the [[fuel injector]]s and minimize [[carbon]] deposits, water dispersants, and other additives depending on geographical and seasonal needs.{{citation needed\|date=January 2013}}. California diesel fuel has a minimum cetane of 53.<ref>{{cite web\|url=http://www.arb.ca.gov/enf/fuels/dieselspecs.pdf\|title=Specs table\|website=www.arb.ca.gov\|access-date=2013-06-08\|archive-url=https://web.archive.org/web/20170221021415/https://www.arb.ca.gov/enf/fuels/dieselspecs.pdf\|archive-date=2017-02-21\|url-status=dead}}</ref> Under the Texas Low Emission Diesel (TxLED) program there are 110 counties where diesel fuel must have a cetane number of 48 or greater, or else must use an approved alternative formulation or comply with the designated alternative limits.<ref>{{cite web\|url=https://www.tceq.texas.gov/airquality/mobilesource/txled/cleandiesel.html\|title=Texas Low Emission Diesel (TxLED) Program\|website=TCEQ}}</ref>

	Neste MY Renewable Diesel sold in North America has a cetane number of ~~75-85~~.<ref>{{Cite web\|url=https://www.neste.us/neste-my/~~superior~~-~~performance~~\|title=~~Renewable~~ ~~Diesel~~ ~~Performance:~~ No ~~Odor~~ ~~and~~ ~~Lower~~ ~~Maintenance~~\|date=~~2019~~-02-13\|website=Neste in North America\|language=en\|access-date=~~2020~~-01-15}}</ref>		Neste MY Renewable Diesel sold in North America has a cetane number of 70+.<ref>{{Cite web\|url=https://www.neste.us/neste-my-renewable-diesel/product-information\|title=The Advantages of Neste MY Renewable Diesel (HVO or R99 Diesel)\|date=2022-07-22\|website=Neste in North America\|language=en\|access-date=2023-10-16}}</ref>

	==Additives==		==Additives==

67.209.10.178: /* Chemical relevance */Fixed typo

2023-03-08T19:10:57Z

Chemical relevance: Fixed typo

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	== Chemical relevance ==		== Chemical relevance ==
	[[Cetane]] is the hydrocarbon with chemical formulas C<sub>16</sub>H<sub>34</sub> and CH<sub>3</sub>(CH<sub>2</sub>)<sub>14</sub>CH<sub>3</sub>. Named n-hexadecane, it is an unbranched [[Saturated and unsaturated compounds\|saturated]] [[alkane]]. Cetane ignites with a short delay under compression, and is assigned a cetane number of 100. [[alpha-methyl naphthalene\|Alpha-methylnaphthalene]], which has a long delay period, was assigned a cetane number of 0, but has been replaced as a reference fuel by [[Isocetane\|2,3,4,5,6,7,8-heptamethylnonane]], whose cetane number is 15.<ref name=":0">{{Cite book\|last=Speight\|first=James G.\|url=http://doi.wiley.com/10.1002/9781118986370\|title=Handbook of Petroleum Product Analysis: Speight/Handbook of Petroleum Product Analysis\|date=2014-12-12\|publisher=John Wiley & Sons, Inc\|isbn=978-1-118-98637-0\|location=Hoboken, NJ\|language=en\|doi=10.1002/9781118986370}}</ref> All other [[hydrocarbon]]s in diesel fuel are indexed to cetane as to how rapidly they ignite under compression, i.e., [[diesel engine]] conditions. Since hundreds of components in comprise diesel fuel, the overall cetane number of that fuel is the average cetane quality of all the components. High-cetane components have a disproportionate influence, hence the use of high-cetane additives.		[[Cetane]] is the hydrocarbon with chemical formulas C<sub>16</sub>H<sub>34</sub> and CH<sub>3</sub>(CH<sub>2</sub>)<sub>14</sub>CH<sub>3</sub>. Named n-hexadecane, it is an unbranched [[Saturated and unsaturated compounds\|saturated]] [[alkane]]. Cetane ignites with a short delay under compression, and is assigned a cetane number of 100. [[alpha-methyl naphthalene\|Alpha-methylnaphthalene]], which has a long delay period, was assigned a cetane number of 0, but has been replaced as a reference fuel by [[Isocetane\|2,3,4,5,6,7,8-heptamethylnonane]], whose cetane number is 15.<ref name=":0">{{Cite book\|last=Speight\|first=James G.\|url=http://doi.wiley.com/10.1002/9781118986370\|title=Handbook of Petroleum Product Analysis: Speight/Handbook of Petroleum Product Analysis\|date=2014-12-12\|publisher=John Wiley & Sons, Inc\|isbn=978-1-118-98637-0\|location=Hoboken, NJ\|language=en\|doi=10.1002/9781118986370}}</ref> All other [[hydrocarbon]]s in diesel fuel are indexed to cetane as to how rapidly they ignite under compression, i.e., [[diesel engine]] conditions. Since hundreds of components comprise diesel fuel, the overall cetane number of that fuel is the average cetane quality of all the components. High-cetane components have a disproportionate influence, hence the use of high-cetane additives.

	== Measuring cetane number ==		== Measuring cetane number ==