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 suspended in water. Such slurries are used to transport coal. Typically, the slurry is dried prior to combustion.{{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 }}
In principle but not in practice, coal slurries can be used to power boilers, gas turbines, diesel engines, and heating and power stations.
Characteristics
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 μm, % | ≤ 0.05 | 0.05–0.20 | 0.20–0.80# |
| Particles up to 75 μm, % | colspan="3" | ≥ 75.0 | ||
| Volatile content, % | > 30 | 20–30 | ≤ 20 |
Production
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.[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"]
Large particle coal-water slurry fuel can be used to produce steam in boilers. Smaller (under 80 micrometer) particle coal-water slurry fuel can be used in diesel engines 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 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 region, Russia.{{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}}]]
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[http://liquidcoal.ru/wpg2?g2_itemId=88 Production of CWS, video]{{dead link|date=March 2013}} |
| 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, Siberia. The coal-water slurry fuel was transported through a 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.[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. 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.[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. In 2004, a coal-water slurry fuel production plant was opened at Enskiy village, Murmansk.[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
=Austria=
File:CWS production equipment, Austria.jpg
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.,[http://cwstech.at/ "Coal water slurry production unit"] cwstech.at in English.[https://www.youtube.com/embed/EiYf5c8cCOI?rel=0"CWS production and combustion process"][https://www.youtube.com/watch?v=59iIDBKnpKU "CWS swirl combustion technique"] developed by group of companies EET.
=Ukraine=
Verkhovna Rada requested China Development Bank credit for the implementation of coal-water slurry fuel technology.{{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. Ukteplokom, a state owned entity, commenced operation.[https://web.archive.org/web/20120405062819/http://www.ukrproject.gov.ua/node/28 "Energy of Nature"] ukrproject.gov.ua. 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.]
See also
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]