The TOSCO II process is an above ground retorting technology for
shale oil extraction
Shale oil extraction is an industrial process for unconventional oil production. This process converts kerogen in oil shale into shale oil by pyrolysis, hydrogenation, or thermal dissolution. The resultant shale oil is used as fuel oil or ...
, which uses fine particles of
oil shale
Oil shale is an organic-rich Granularity, fine-grained sedimentary rock containing kerogen (a solid mixture of Organic compound, organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general compos ...
that are heated in a
rotating kiln. The particularity of this process is that it use hot ceramic balls for the heat transfer between the retort and a heater. The process was tested in a 40 tonnes per hour test facility near
Parachute, Colorado
Parachute is a home rule municipality in Garfield County, Colorado, United States. The population was 1,390 at the 2020 census.
The town is the birthplace of Willard Libby, recipient of the 1960 Nobel Prize in Chemistry.
History
The town's ...
.
History
TOSCO II process is a refinement of the Swedish Aspeco process.
[
] The
Tosco Corporation
Tosco (from "The Oil Shale Corporation") was an independent US-based petroleum refining and marketing corporation based in Stamford, Connecticut. It was founded in 1955 in Santa Monica, California by A&P heir Huntington Hartford, and originally ...
purchased its patent rights in 1952.
[ In 1956, the Denver Research Institute performed research and development of this technology, including testing of a 24 ]ton
Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses.
As a unit of mass, ''ton'' can mean:
* the '' long ton'', which is
* the ''tonne'', also called the ''metric ...
per day pilot plant, which operated until 1966. Later the technology development was continued under Tosco's own directions.[
] In 1964 Tosco, Standard Oil of Ohio
The Standard Oil Company (Ohio) was an American petroleum industry, petroleum company that existed from 1870 to 1987. The company, known commonly as Sohio, was founded by John D. Rockefeller. It was established as one of the separate entities cre ...
, and Cleveland Cliffs Iron Company formed Colony Development, a joint venture company to develop the Colony Shale Oil Project and to commercialize the TOSCO II technology. The project was ended in April 1972.[
]
Technology
The TOSCO II process is classified as a hot recycled solids technology.[
] It employs a horizontal rotating kiln-type retort. In this process, oil shale is crushed smaller than and enters the system through pneumatic lift pipes in which oil shale is elevated by hot gas streams and preheated to about .[
] After entering into retort, oil shale is mixed with hot ceramic balls with temperature from to . This increases the oil shale temperature to between and , in which pyrolysis occurs. In the pyrolysis process, kerogen
Kerogen is solid, insoluble organic matter in sedimentary rocks. It consists of a variety of organic materials, including dead plants, algae, and other microorganisms, that have been compressed and heated by geological processes. All the kero ...
decomposes to oil shale gas
Oil shale gas (also: retort gas or retorting gas) is a synthetic non-condensable gas mixture (syngas) produced by oil shale thermal processing (pyrolysis). Although often referred to as shale gas, it differs from the natural gas produced from shal ...
and oil vapors, while the remainder of the oil shale forms spent shale
Spent shale or spent oil shale (also known as retorted shale) is a solid residue from the shale oil extraction process of producing synthetic shale oil from oil shale. It consists of inorganic compounds (minerals) and remaining organic matter kno ...
. Vapors are transferred to a condensor (fractionator
Fractionation is a separation process in which a certain quantity of a mixture (of gasses, solids, liquids, enzymes, or isotopes, or a suspension) is divided during a phase transition, into a number of smaller quantities (fractions) in which t ...
) for separation into various fractions
A fraction (from , "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, thre ...
.[ At the kiln passage, the spent shale and the ceramic balls are separated in a perforated rotating separation drum (]trommel
A trommel screen, also known as a rotary screen, is a mechanical screening machine used to separate materials, mainly in the Mining, mineral and Waste management, solid-waste processing industries.Stessel et al. 1996, pp. 558-568. It consists of a ...
).[ The crushed spent shale falls through holes in the trommel, while ceramic balls are transferred to the ball heater.][
] Combustible shale gas is burned in the ball heater to reheat the ceramic balls.[
The overall thermal efficiency of TOSCO II process is low because the energy of spent shale is not recovered and much of the produced shale gas is consumed by the process itself. The efficiency could be increased by burning char (carbonaceous residue in the spent shale) instead of shale gas as a fuel of the ball heater. The process' other disadvantages are mechanical complexity and large number of moving parts. Also the lifetime of ceramic balls is limited. Disposal of spent shale includes environmental problems because it is very finely crushed and contains carbon residue.][
]
See also
* Alberta Taciuk Process
The Alberta Taciuk process (ATP; known also as the AOSTRA Taciuk process) is an above-ground dry thermal retorting technology for extracting oil from oil sands, oil shale and other organics-bearing materials, including oil contaminated soils, slud ...
* Kiviter process
* Petrosix process
* Galoter process
* Fushun process
* Paraho process
* Lurgi-Ruhrgas process
References
{{Reflist
Oil shale technology