Petrosix

Petrosix is currently the world’s largest surface oil shale pyrolysis retort with an convert|11|m|ft|0 diameter vertical shaft kiln, operational since 1992. It is located in São Mateus do Sul, Brazil, and it is owned and operated by the Brazil energy company Petrobras. Petrosix means also the Petrosix process, an externally generated hot gas technology of extracting oil from oil shale. The technology is tailored to Irati oil shale formation.

History

Petrobras started oil shale processing activities in 1953 by developing Petrosix technology for of extracting oil from oil shale of Irati formation. A convert|5.5|m|ft|0 inside diameter semi-works retort (the Irati Profile Plant) with capacity of 2,400 tons per day, was brought on line in 1972, and began limited commercial operation in 1980. The first retort, which used current Petrosix technology, was convert|0.2|m|ft|1 internal diameter retort pilot plant, started in 1982. It followed by a convert|2|m|ft|0 retort demonstration plant in 1984. A convert|11|m|ft|0 retort was brought into service in December 1991, and the commercial production started in 1992. At present, the company operates 2 retorts, which processing 8,500 tons of oil shale daily.

Retort

The Petrosix convert|11|m|ft|0 vertical shaft Gas Combustion Retort (GCR) is the world’s largest operational surface oil shale pyrolysis reactor.Cite paper | 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; U.S. Department of Energy | date =2004 | url=http://www.fossil.energy.gov/programs/reserves/npr/publications/npr_strategic_significancev2.pdf | format = PDF | accessdate =2007-06-23] Cite paper
last =Laherrère | first =Jean
author-link =Jean Laherrère
title =Review on oil shale data
publisher = Hubbert Peak
date = 2005
url=http://www.hubbertpeak.com/laherrere/OilShaleReview200509.pdf
format = PDF
accessdate =2007-06-17] It was designed by Cameron Engineers. The retort has the upper pyrolysis section and lower shale coke cooling section. The retort capacity is 6,200 tons of oil shale per day, and it yields a nominal daily output of 3,870 barrels of shale oil, 132 tons of fuel gas, 50 tons of liquefied shale gas, and 82 tons of sulfur.

Process

Petrosix is one of fives technologies of oil shale extraction, which is currently in commercial use.Cite paper
last = Qian | first = Jialin
last2 = Wang | first2 = Jianqiu
title = World oil shale retorting technologies
date = 7-9 November 2006
place = Amman, Jordan
url = http://www.sdnp.jo/International_Oil_Conference/rtos-A118.pdf
format = PDF
accessdate = 2007-06-29] It is an above-ground retorting technology, which uses externally generated hot gas for the oil shale pyrolysis.Cite paper
last = Burnham | first = Alan K.
last2 = McConaghy | first2 = James R.
title = Comparison of the Acceptability of Various Oil Shale Processes
date = 16-18 October 2006
place =Golden | publisher = 26th Oil Shale Symposium
url =http://www.llnl.gov/tid/lof/documents/pdf/341283.pdf
format = PDF | id =UCRL-CONF-226717
accessdate =2007-06-23] After mining the shale is transported to a crusher, where it is reduced to particles (lump shale). These particles are measured between convert|12|mm|in|1 and convert|75|mm|in|1 and have an approximately parallelepipedic shape.Cite journal
last = Porto | first = P. S. S.
last2 = A. C. L. Lisbôa | first2 = A. C. L.
title = Modelling the drying of a parallelepipedic oil shale particle
year = 2006
volume = 22
issue = 2
pages = pp. 233—238
journal = Brazilian Journal of Chemical Engineering
url = http://www.scielo.br/pdf/bjce/v22n2/24917.pdf
format = PDF
id = ISSN 0104-6632
accessdate = 2008-04-21] These particles are transported on a belt to retort, where the shale to be heated for pyrolysis up to the temperature about convert|500|°C|°F|0. As of result, the kerogen will yield in the form of oil and gas. After pyrolysis the oil is cooled for the vapor to condensate, and shale gases undergo another cleaning process for light oil extraction. The rest is then sent to the gas treatment unit, where fuel and liquefied petroleum gas (LPG) are produced and sulfur recovered.Cite web
title =The Petrosix Process
publisher = Petrobras
url=https://www.petrobras.com.br/minisite/refinarias/petrosix/ingles/processo/index.asp
accessdate =2007-09-02] Part of the cooled retort gas is used as fuel in a tubular heater, part is heated in the heater’s pipes and recirculated back to the middle of the retort as hot gas carrier for heating and pyrolyzing the oil shale feed, and part is circulated and enters into the bottom of the retort, where it cools down the hot shale coke, heated up itself, and ascends into the pyrolysis section for heating the oil shale feed as supplementary heat source. The drawback of this process is that the potential heat of fixed carbon contained in the shale coke is not utilized.

ee also

* Oil shale
* Petrobras

References