View source for Coal-water slurry fuel

{{Short description|Combustible mixture of coal particles in water}}
{{refimprove|date=October 2015}}
'''Coal-water slurry fuel''' is a mixture of fine [[coal]] particles [[suspension (chemistry)|suspended in water]].  Such slurries are used to transport coal.  Typically, the slurry is dried prior to combustion.<ref>{{cite book |doi=10.1002/0471238961.0315011222151818.a01.pub3 |chapter=Coal |title=Kirk-Othmer Encyclopedia of Chemical Technology |date=2016 |last1=Hower |first1=James |pages=1–63 |isbn=978-0-471-48494-3 }}</ref>
In principle but not in practice, coal slurries can be used to power boilers, [[gas turbine]]s, [[diesel engine]]s, and heating and [[power station]]s.
==Characteristics==
[[File:Водовугілля.png|thumb|right|220px|Coal-water slurry fuel, Grade III]]
A coal-water slurry fuel is defined by a number of factors including its [[viscosity]], particle size, rate of [[sedimentation]], [[ignition temperature]] ({{convert|800|–|850|Celsius|disp=sqbr}}), combustion temperature ({{convert|950|–|1150|Celsius|disp=sqbr}}), ash content and [[calorific value]] ({{convert|3700|–|4700|kcal/kg|MJ/kg|1|disp=sqbr}}).
When coal-water slurry fuel combusts, over ninety-nine percent of its [[carbon]] content is consumed.{{Citation needed|date=October 2016}} Coal-water slurry fuel is fire-proof and explosion-proof.{{Citation needed|date=October 2016}} Ash content of less than ten percent is desirable for boilers. For diesel engines, there is no limit.
{| class="wikitable" style="text-align:center"
|-
! Parameters !! І GRADE !! ІІ GRADE !! ІІІ GRADE
|-
| Coal content, % || ≥ 65 || 63–65 || 60–63
|-
| Viscosity{{clarify|date=September 2015|reason=units?}} || colspan="3" | ≤ 1200
|-
| Minimum energy yield (kcal/kg) || ≥ 4700 || 4420–4660 || 4000–4420
|-
| Ash content, % || ≤ 6 || 6–8 || 8–10
|-
| Sulfur content, % || ≤ 0.35 || 0.35–0.65 || 0.65–0.80
|-
| Ash softening temperature{{clarify|date=September 2015|reason=units?}} || colspan="3" | ≤ 1250
|-
| Particles of more than 300&nbsp;μm, % || ≤ 0.05 || 0.05–0.20 || 0.20–0.80#
|-
| Particles up to 75&nbsp;μm, % || colspan="3" | ≥ 75.0
|-
| Volatile content, % || > 30 || 20–30 || ≤ 20
|}
==Production==
[[File:Cws ball mills.jpg|thumb|right|220px|Ball mills for production of coal-water slurry in Russia]]
The production of coal-water slurry fuel involves the crushing of coal or coal sludge to particles between 10 and 65 micrometers diameter (standard crushers can be used); wet milling and homogenisation (with additives as required). The resulting product ([[coal slurry]]) is then prepared for intermediate storage or transport.<ref>[https://avs.globecore.com/water-coal-slurry-alternative-natural-gas-heavy-fuel-oil.html "Water-coal slurry as an alternative to natural gas and heavy fuel oil"]</ref>
Large particle coal-water slurry fuel can be used to produce steam in [[boiler]]s. Smaller (under  80 micrometer) particle coal-water slurry fuel can be used in [[diesel engine]]s with or without co-fuels. For example, low speed marine or modular power plant diesels can operate on pure coal-water slurry fuel whereas medium speed diesels such as [[Diesel locomotive|locomotive engines]] may need diesel as a co-fuel which will act as an ignition source. Very small (5 to 10 micrometer) particle coal-water slurry fuel has been trialled in [[combined cycle]] gas turbine power plants. Smaller sized particles are more versatile in use but are more difficult to produce.{{Cn|date=November 2024}}
==Prototypes==
[[File:Bscap048.jpg|thumb|Combustion of coal water slurry fuel in a steam boiler, [[Murmanskaya]] region, Russia.<ref>{{cite video | url=https://www.youtube.com/watch?v=6vy1Ssy5rWA  |archive-url=https://ghostarchive.org/varchive/youtube/20211215/6vy1Ssy5rWA |archive-date=2021-12-15 |url-status=live| title=Горение ВУТ в котле ДКВР-6,5-13. Видео 1}}{{cbignore}}</ref>]]
Converting coal into a liquid form may simplify the delivery and dispensing of the fuel. It may be a cost-efficient alternative to oil and natural gas. Separating non-carbonaceous material before making the slurry may reduce the production of ash to two percent.{{Cn|date=November 2024}}
===Development===
{| class="wikitable"
|-
!Type of coal
!Possibility
|-
| [[Brown coal]] (lignite)
| possible, tested and confirmed
|-
| Flame coal (V=40–45%)
| well developed<ref>[http://liquidcoal.ru/wpg2?g2_itemId=88 Production of CWS, video]{{dead link|date=March 2013}}</ref>
|-
| Gas flame coal, gas coal (V=28–40%)
| well developed
|-
| Fat coal – [[anthracite]] (V=7–28%)
| possible, tested and confirmed
|}
===Belovo Novosibirsk project ===
In the late 1950s, the [[Soviet Union]] looked for new methods of using coal sludge for power generation. Coal-water slurry fuel was made in a [[ball mill]] which pulverised the coal or coal sludge. This was done near a coal mine in [[Belovo, Kemerovo Oblast|Belovo]], [[Siberia]]. The coal-water slurry fuel was transported through a [[Pipeline transport|pipeline]] to Novosibirskaya TEC-5, [[Novosibirsk]], a distance of {{convert|262|km|mi|abbr=on}}. The pipeline had three intermediate pumping stations. The Belovo Novosibirsk project used coal-water slurry fuel in steam boilers at a rate of 1340 tonnes per hour.<ref>[http://vodougol.ru/en/technology/%d0%b8%d1%81%d1%82%d0%be%d1%80%d0%b8%d1%8f-%d0%b2%d1%83%d1%82-%d0%b2-%d1%80%d0%be%d1%81%d1%81%d0%b8%d0%b8/%d0%b1%d0%b5%d0%bb%d0%be%d0%b2%d0%be-%d0%bd%d0%be%d0%b2%d0%be%d1%81%d0%b8%d0%b1%d0%b8%d1%80%d1%81%d0%ba/ "Belovo-Novosibirsk project."] {{Webarchive|url=https://web.archive.org/web/20160305104604/http://vodougol.ru/en/technology/%d0%b8%d1%81%d1%82%d0%be%d1%80%d0%b8%d1%8f-%d0%b2%d1%83%d1%82-%d0%b2-%d1%80%d0%be%d1%81%d1%81%d0%b8%d0%b8/%d0%b1%d0%b5%d0%bb%d0%be%d0%b2%d0%be-%d0%bd%d0%be%d0%b2%d0%be%d1%81%d0%b8%d0%b1%d0%b8%d1%80%d1%81%d0%ba/ |date=2016-03-05 }} Vodougol.ru archived 5 February 2015.</ref> There was a further project at Belovo Novosibirsk between 1989 and 1993 and development of coal-water slurry fuel technology for [[district heating]] stations and power stations.<ref>[http://liquidcoal.ru "ЖИДКИЙ УГОЛЬ; Блог о Водоугольном Топливе."]  {{webarchive|url=https://web.archive.org/web/20090712033621/http://liquidcoal.ru/ |date=July 12, 2009 }} Liquidcoal.ru |Accessed 30 March 2013 in Russian. Dead link.</ref> In 2004, a coal-water slurry fuel production plant was opened at [[Enskiy village]], [[Murmansk]].<ref>[http://vodougol.ru/enskiy "Водоугольное топливо в пос. Ёнский"] {{webarchive |url=https://web.archive.org/web/20140519165225/http://vodougol.ru/enskiy |date=May 19, 2014 }} Vodougol.ru</ref>
===Austria===
[[File:CWS production equipment, Austria.jpg|thumbnail|right|220px|Coal water slurry fuel production machine in Austria]]
In 2012, the Austrian company, Effective Energy Technology GmbH (EET) built facilities for production and combustion of coal-water slurry fuel in Europe. Examples of the technology in practice are ''hydroshock'' type wet-milling devices and standard water boilers equipped with swirl pre-chamber and coal-water slurry nozzle.,<ref>[http://cwstech.at/ "Coal water slurry production unit"] cwstech.at in English.</ref><ref>[https://www.youtube.com/embed/EiYf5c8cCOI?rel=0"CWS production and combustion process"]</ref><ref>[https://www.youtube.com/watch?v=59iIDBKnpKU "CWS swirl combustion technique"]</ref> developed by group of companies EET.
===Ukraine===
[[Verkhovna Rada]] requested [[China Development Bank]] credit for the implementation of coal-water slurry fuel technology.<ref>{{cite web |url=http://forum.for-ua.com/read.php?1%2C2223733%2C2224096 |title=Китай даст Украине денег на замену российского газа углем |accessdate=2014-06-10 |url-status=dead |archiveurl=https://web.archive.org/web/20140714175116/http://forum.for-ua.com/read.php?1%2C2223733%2C2224096 |archivedate=2014-07-14 }} Forum.for-ua.com. Dead link.</ref> ''Ukteplokom'', a state owned entity, commenced operation.<ref>[https://web.archive.org/web/20120405062819/http://www.ukrproject.gov.ua/node/28 "Energy of Nature"] ukrproject.gov.ua. </ref><ref>Biletsky V. et al [https://archive.today/20150404221631/http://www.crcnetbase.com/doi/abs/10.1201/b16354-20 "Fundamentals of highly loaded coal water slurries." CRC Press, Taylor and Francis Group, London, UK. A Balkema Book 2013 pp. 105–14.]</ref>
==See also==
* [[Coal dust]]
* [[Pulverized coal-fired boiler]]
== References ==
{{reflist}}
==External links==
*[http://adsabs.harvard.edu/abs/1993STIN...9436348W NASA Coal fueled diesels for modular power generation]
*[http://www.osti.gov/bridge/servlets/purl/10137691-JXPjGX/ Coal fueled diesel emission control]
[[Category:Energy economics]]
[[Category:Energy development]]
[[Category:Coal]]
[[Category:Fuels]]