Kiviter process
{{Short description|Shale oil extraction technology}}
{{Redirect|Kiviter|the former oil shale company|Viru Keemia Grupp}}
{{Infobox industrial process
| name = Kiviter process
| image =
| caption =
| type = Chemical
| sector = Chemical industry
oil industry
| technologies =
| feedstock = oil shale
| product = shale oil
| companies = VKG Oil
Kiviõli Keemiatööstus
| facility =
| inventor =
| year =
| developer = VKG Oil
}}
The Kiviter process is an above ground retorting technology for shale oil extraction.
History
The Kiviter process is based on the earlier vertical retort technology (Pintsch's generator). This technology underwent a long process of development. The early concept of central inlet of the heat carrier was later replaced by a concept of heat carrier gas cross flow in the retort.
The Kiviter technology has been used in Estonia since 1921, when first experimental Kiviter retorts were built.
{{Cite journal
| last1 =Väli | first1 = E.
| last2 =Valgma | first2 = I.
| last3 =Reinsalu | first3 = E.
| title = Usage of Estonian oil shale
| journal =Oil Shale. A Scientific-Technical Journal
| publisher = Estonian Academy Publishers
| volume = 25
| issue = 2
| pages =101–114
| year =2008
| url= http://www.kirj.ee/public/oilshale_pdf/2008/issue_2S/oil-2008-2S-2.pdf
| issn = 0208-189X
| accessdate =2008-11-23
| doi =10.3176/oil.2008.2S.02}}
The first commercial scale oil plant based on the Kiviter technology was built in 1924.{{Cite web
|last = Kattai
|first = V.
|author2 = Lokk, U.
|title = Historical review of the kukersite
|publisher = Geological Survey of Estonia
|date = 1998-02-17
|url = http://deepthought.ttu.ee/maeinst/os/2_katlok.html
|accessdate = 2008-11-23
|archive-url = https://web.archive.org/web/20170324045321/http://deepthought.ttu.ee/maeinst/os/2_katlok.html
|archive-date = 2017-03-24
|url-status = dead
}}
From 1955 to 2003, Kiviter technology was used for oil shale processing also in Slantsy, Russia.
{{Cite book
| last = Uustalu | first = Jaan
| editor1-last=Rofer | editor1-first= Cheryl K.
| editor2-last=Kaasik | editor2-first= Tõnis
| title = Turning a Problem Into a Resource: Remediation and Waste Management at the Sillamae Site, Estonia
| chapter = Utilization of semi-coke for energy production
| publisher = Axel Springer AG
| page = 223
| year =2000
| chapter-url= https://books.google.com/books?id=hkTGV56jbI0C&pg=PA223
| isbn = 978-0-7923-6186-2
| accessdate =2008-11-23}}
{{cite book
|title = Survey of energy resources
|publisher = World Energy Council (WEC)
|year = 2007
|edition = edition 21
|pages = 93–115
|url = http://www.worldenergy.org/documents/ser2007_final_online_version_1.pdf
|isbn = 978-0-946121-26-7
|accessdate = 2008-11-23
|url-status = dead
|archive-url = https://web.archive.org/web/20110409010229/http://www.worldenergy.org/documents/ser2007_final_online_version_1.pdf
|archive-date = 2011-04-09
}}
{{Cite conference
|last1=Leveinen |first1=Jussi
|last2=Aneshkin |first2=Boris
|last3=Blanchard |first3=Francois
|last4=Staudt |first4=Michael
|last5=Van den Dool |first5=Gijs
|last6=Sapon |first6=Svetlana
|last7=Kruglova |first7=Olga
|title=Modelling impacts of oil-shale mining on groundwater resources in the Slantsy region, Russia
|conference=15th Meeting of the Association of European Geological Societies
|date=16–20 September 2007
|url= http://www.gi.ee/maegs15/presentations/3_3_Leveinen.ppt
|archive-url=https://web.archive.org/web/20160304042641/http://www.gi.ee/maegs15/presentations/3_3_Leveinen.ppt
|format=PPT
|accessdate=2017-05-07
|archive-date=2016-03-04
}}
Technology
The Kiviter process is classified as an internal combustion technology.{{Cite web
| last1 = Burnham
| first1 = Alan K.
| last2 = McConaghy
| first2 = James R.
| title = Comparison of the acceptability of various oil shale processes
| date = 2006-10-16
| place = Golden
| publisher = 26th Oil shale symposium
| url = https://e-reports-ext.llnl.gov/pdf/341283.pdf
| id = UCRL-CONF-226717
| accessdate = 2008-11-23
| archive-url = https://web.archive.org/web/20160213164539/https://e-reports-ext.llnl.gov/pdf/341283.pdf
| archive-date = 2016-02-13
| url-status = dead
}} The Kiviter retort is a vertical cylindrical vessel that heats coarse oil shale with recycled gases, steam, and air.
{{Cite journal
| last1 = Jaber | first1 = Jamel O.
| last2 = Sladek | first2 = Thomas A.
| last3 = Mernitz | first3 = Scott
| last4 = Tarawneh | first4 = T. M.
| title = Future Policies and Strategies for Oil Shale Development in Jordan
| year = 2008
| volume = 2
| issue = 1
| pages = 31–44
| journal = Jordan Journal of Mechanical and Industrial Engineering
| url = http://jjmie.hu.edu.jo/files/V2/004-v2-1.pdf
| issn = 1995-6665
| accessdate = 2008-11-22}}
To supply heat, gases (including produced oil shale gas) and carbonaceous spent residue are burnt within the retort. Raw oil shale is fed into the top of the retort, and is heated by the rising gases, which pass laterally through the descending oil shale causing decomposition of the rock. Pyrolysis is completed in the lower section of the retort, where the spent shale contacted with more hot gas, steam and air is heated to about {{convert|900|°C|°F}} to gasify and burn the residual carbon (char). Shale oil vapors and evolving gases are delivered to a condensing system, where condensed shale oil is collected, while non-condensable gases are fed back to the retort. Recycled gas enters the bottom of the retort and cools the spent shale, which then leaves the retort through a water-sealed discharge system.
{{Cite journal
|last=Koel|first=Mihkel
| title=Estonian oil shale
| journal=Oil Shale. A Scientific-Technical Journal
| publisher=Estonian Academy Publishers
| issue=Extra
| year=1999
| url=http://www.kirj.ee/public/oilshale/Est-OS.htm
| issn=0208-189X
| accessdate=2008-11-23}}
The Kiviter process uses large amounts of water, which is polluted during processing, and the solid waste residue contains water-soluble toxic substances that leach into the surrounding area.
{{Cite journal
|last=Mölder
|first=Leevi
|title=Estonian Oil Shale Retorting Industry at a Crossroads
|journal= Oil Shale. A Scientific-Technical Journal
|publisher=Estonian Academy Publishers
|volume=21
|issue=2
|pages =97–98
|year=2004
|doi=10.3176/oil.2004.2.01
|s2cid=252707682
|url=http://www.kirj.ee/public/oilshale/1_ed_page_2004_2.pdf
|issn=0208-189X
| accessdate =2008-11-23}}
|last1 = Soone
|first1 = Jüri
|last2 = Riisalu
|first2 = Hella
|last3 = Kekisheva
|first3 = Ljudmilla
|last4 = Doilov
|first4 = Svjatoslav
|title = Environmentally sustainable use of energy and chemical potential of oil shale
|pages = 2–3
|publisher = Jordanian Natural Resources Authority
|conference = International Oil Shale Conference
|date = 2006-11-07
|url = http://www.sdnp.jo/International_Oil_Conference/rtos-A104.pdf
|accessdate = 2007-06-29
|archive-url = https://web.archive.org/web/20070928110803/http://www.sdnp.jo/International_Oil_Conference/rtos-A104.pdf
|archive-date = 2007-09-28
|url-status = dead
}}
Commercial use
The Kiviter process is used by the Estonian Viru Keemia Grupp's subsidiary VKG Oil.
{{Cite web
| title =Strategic significance of America's oil shale resource. Volume II: Oil shale resources, technology and economics
| publisher= Office of Deputy Assistant Secretary for Petroleum Reserves; Office of Naval Petroleum and Oil Shale Reserves; United States Department of Energy
| year=2004
| url=http://www.fossil.energy.gov/programs/reserves/npr/publications/npr_strategic_significancev2.pdf
| accessdate =2008-11-23
}} The company operates several Kiviter retorts, the largest of them having a processing capacity of 40 tonnes per hour of oil shale feedstock.
{{Cite web
|title=An Assessment of Oil Shale Technologies
|date=June 1980
|url=http://www.princeton.edu/~ota/disk3/1980/8004/8004.PDF
|id=NTIS order #PB80-210115
|accessdate=2008-11-23}}