Editing Diesel fuel (section)

=== Biodiesel ===
{{Main|Biodiesel}}
[[File:Bequer-B100-SOJA-SOYBEAM.jpg|thumb|right|upright|[[Biodiesel]] made from [[soybean oil]]]]

[[Biodiesel]] is obtained from [[vegetable oil]] or animal fats (bio[[lipid]]s) which are mainly [[fatty acid methyl ester]]s (FAME), and [[transesterification|transesterified]] with [[methanol]]. It can be produced from many types of oils, the most common being [[rapeseed]] oil (rapeseed methyl ester, RME) in Europe and [[soybean oil]] (soy methyl ester, SME) in the US. Methanol can also be replaced with ethanol for the transesterification process, which results in the production of ethyl esters. The transesterification processes use catalysts, such as sodium or potassium hydroxide, to convert vegetable oil and methanol into biodiesel and the undesirable byproducts glycerine and water, which will need to be removed from the fuel along with methanol traces. Biodiesel can be used pure (B100) in engines where the manufacturer approves such use, but it is more often used as a mix with diesel, BXX where XX is the biodiesel content in percent.<ref name="Bosch">Bosch Automotive Handbook, 6th edition, pp. 327–328</ref><ref name="acea.be">{{cite web |url=http://www.acea.be/images/uploads/070208_ACEA_FAME_BTL_final.pdf |title=ACEA Position on the use of bio-diesel (FAME) and synthetic bio-fuel in compression-ignition engines |publisher=acea.be |access-date=2010-08-21 |url-status=dead |archive-url=https://web.archive.org/web/20110611201410/http://www.acea.be/images/uploads/070208_ACEA_FAME_BTL_final.pdf |archive-date=2011-06-11 }}</ref>

FAME used as fuel is specified in [[EN 14214|DIN EN 14214]]<ref>{{cite web |url=http://www.worldenergy.net/products/biodiesel/eu_specs.php |title=Biodiesel: EU Specifications |publisher=World Energy |access-date=2010-08-21 |archive-date=2011-07-24 |archive-url=https://web.archive.org/web/20110724132859/http://www.worldenergy.net/products/biodiesel/eu_specs.php |url-status=dead }}</ref> and ASTM D6751 standards.<ref>{{cite web |title=Biodiesel: ASTM International Specifications (B100) |url=http://www.worldenergy.net/products/biodiesel/us_specs.php |publisher=World Energy |url-status=live |archive-url=https://web.archive.org/web/20070917072738/http://www.worldenergy.net/products/biodiesel/us_specs.php|archive-date=17 September 2007 }}</ref>
<!-- off topic or tangential.  This section is about the sources of diesel, period.
Fuel Injection Equipment (FIE) manufacturers have raised several concerns regarding biodiesel, identifying FAME as being the cause of the following problems: corrosion of fuel injection components, low-pressure fuel system blockage, increased dilution and [[polymerization]] of engine sump oil, pump seizures due to high fuel viscosity at low temperature, increased injection pressure, elastomeric seal failures and fuel injector spray blockage.<ref>{{cite web |url=http://journeytoforever.org/biofuel_library/FIEM.pdf |title=Fatty Acid Methyl Ester Fuels as a Replacement or Extender for Diesel Fuels |publisher=FAME Fuel - Joint FIE Manufacturers Statement |date=June 2000 |access-date=14 March 2022}}</ref> Pure biodiesel has an energy content about 5–10% lower than petroleum diesel.<ref>{{Cite news |url=http://www.biodiesel.com/biodiesel/benefits/ |title=Biodiesel Benefits - Why Use Biodiesel? - Pacific Biodiesel |newspaper=Pacific Biodiesel |access-date=2017-02-14 |language=en-US |archive-url=https://web.archive.org/web/20170625021106/http://www.biodiesel.com/biodiesel/benefits/ |archive-date=2017-06-25 |url-status=dead}}</ref> The loss in power when using pure biodiesel is 5–7%.<ref name="acea.be" />

[[Unsaturated fatty acid]]s are the source for the lower oxidation stability. They react with oxygen and form peroxides and result in degradation byproducts, which can cause sludge and lacquer in the fuel system.<ref>{{cite web |url=http://altfuelsgroup.org/site/images/M_images/projects/b100overview.pdf |title=Lubrizol B100 Overview |date=September 2007 |publisher=Lubrizol Corporation |access-date=14 March 2022}}</ref>

As biodiesel contains low levels of sulfur, the emissions of [[sulfur oxide]]s and [[sulfate]]s, major components of [[acid rain]], are low. Use of biodiesel also results in reductions of unburned hydrocarbons, [[carbon monoxide]] (CO), and particulate matter. CO emissions using biodiesel are substantially reduced, on the order of 50% compared to most petrodiesel fuels. The exhaust emissions of particulate matter from biodiesel have been found to be 30% lower than overall particulate matter emissions from petrodiesel. The exhaust emissions of total hydrocarbons (a contributing factor in the localized formation of smog and ozone) are up to 93% lower for biodiesel than diesel fuel.{{Citation needed|date=April 2023}}-->