Superior multimineral process
Encyclopedia
The Superior multimineral process (also known as the McDowell–Wellman process or circular grate process) is an above ground shale oil extraction technology designed for production of shale oil
, a type of synthetic crude
oil. The process heats oil shale
in a sealed horizontal segmented vessel (retort
) causing its decomposition into shale oil, oil shale gas
and spent residue. The particularities of this process is a recovery of saline mineral
s from the oil shale, and a doughnut-shape of the retort. The process is suitable for processing of mineral-rich oil shales, such as in the Piceance Basin
. It has a relatively high reliability and high oil yield. The technology was developed by the American oil company Superior Oil.
, now part of ExxonMobil
, for processing of the Piceance Basin
's oil shale. The technology tests were carried out in pilot plants in Cleveland, Ohio
. In 1970s, Superior Oil planned a commercial-size demonstration plant in the northern Piceance Basin area with a capacity of 11500 to 13000 bbl (1,828,353.9 to 2,066,834.8 ) of shale oil per day; however, because of low crude oil price these plans were never implemented.
, sodium carbonate
, and aluminum from nahcolite
and dawsonite
, occurring in oil shales of the Piceance Basin. In this process, the nahcolite is recovered from the raw oil shale by crushing it to lumps smaller than 8 inches (203.2 mm). As a result, most of the nahcolite in the oil shale becomes a fine powder what could screened out. Screened oil shale lumps are further crushed to particles smaller than 3 inches (76.2 mm). Oil shale particles are further processed in a horizontal segmented doughnut-shaped traveling-grate retort in the direct or indirect heating mode. The retort was originally designed by Davy McKee Corporation for iron ore pelletizing
and it also known as the Dravo
retort. In the direct retort, oil shale moves past ducts
through which are provided hot inert gas for heating the raw oil shale, air for combustion of carbon residue (char or semi-coke) in the spent oil shale, and cold inert gas for cooling the spent oil shale. The oil pyrolysis takes place in the heating section. To minimize solubility of aluminium compounds in the oil shale, the heat control is a crucial factor. Necessary heat for pyrolysis is generated in the carbon recovery section by combustion of carbon residue (char or semi-coke) remained in the spent oil shale. While blowing inert gases through the spent oil shale, the spent oil shale is cooled and gases are heated to cause pyrolysis. The indirect mode is similar; the difference is that combustion of carbonaceous residue takes place in separate vessel. The last section is for discharging of oil shale ash. Aluminium oxide
and sodium carbonate
are recovered from calcined dawsonite and calcined nahcolite in the oil shale ash.
. The technology has also a relatively high reliability. The sealed system of this process has environmental advantage as it prevents gas and mist leakage.
Shale oil
Shale oil, known also as kerogen oil or oil-shale oil, is an unconventional oil produced from oil shale by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock into synthetic oil and gas...
, a type of synthetic crude
Synthetic crude
Synthetic crude is the output from a bitumen/extra heavy oil upgrader facility used in connection with oil sand production. It may also refer to shale oil, an output from an oil shale pyrolysis. The properties of the synthetic crude depend on the processes used in the upgrading. Typically, it is...
oil. The process heats oil shale
Oil shale
Oil shale, an organic-rich fine-grained sedimentary rock, contains significant amounts of kerogen from which liquid hydrocarbons called shale oil can be produced...
in a sealed horizontal segmented vessel (retort
Retort
In a chemistry laboratory, a retort is a glassware device used for distillation or dry distillation of substances. It consists of a spherical vessel with a long downward-pointing neck. The liquid to be distilled is placed in the vessel and heated...
) causing its decomposition into shale oil, oil shale gas
Oil shale gas
Oil shale gas is a synthetic gas mixture produced by oil shale pyrolysis. Although often referred to as shale gas, it differs from the natural gas produced from shale, which is also known as shale gas.-Process:...
and spent residue. The particularities of this process is a recovery of saline mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s from the oil shale, and a doughnut-shape of the retort. The process is suitable for processing of mineral-rich oil shales, such as in the Piceance Basin
Piceance Basin
The Piceance Basin is a geologic structural basin in northwestern Colorado, in the United States. It includes geologic formations from Cambrian to Holocene in age, but the thickest section is made up of rocks from the Cretaceous Period...
. It has a relatively high reliability and high oil yield. The technology was developed by the American oil company Superior Oil.
History
The multimineral process was developed by Superior Oil CompanySuperior Oil Company
Superior Oil Company was an independent American oil company that is now part of ExxonMobil. Superior Oil was founded in 1921 in Coalinga, California by William Myron Keck, also founder of the W. M. Keck Foundation....
, now part of ExxonMobil
ExxonMobil
Exxon Mobil Corporation or ExxonMobil, is an American multinational oil and gas corporation. It is a direct descendant of John D. Rockefeller's Standard Oil company, and was formed on November 30, 1999, by the merger of Exxon and Mobil. Its headquarters are in Irving, Texas...
, for processing of the Piceance Basin
Piceance Basin
The Piceance Basin is a geologic structural basin in northwestern Colorado, in the United States. It includes geologic formations from Cambrian to Holocene in age, but the thickest section is made up of rocks from the Cretaceous Period...
's oil shale. The technology tests were carried out in pilot plants in Cleveland, Ohio
Cleveland, Ohio
Cleveland is a city in the U.S. state of Ohio and is the county seat of Cuyahoga County, the most populous county in the state. The city is located in northeastern Ohio on the southern shore of Lake Erie, approximately west of the Pennsylvania border...
. In 1970s, Superior Oil planned a commercial-size demonstration plant in the northern Piceance Basin area with a capacity of 11500 to 13000 bbl (1,828,353.9 to 2,066,834.8 ) of shale oil per day; however, because of low crude oil price these plans were never implemented.
Process
The process was developed to combine the shale oil production with production of sodium bicarbonateSodium bicarbonate
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
, sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...
, and aluminum from nahcolite
Nahcolite
Nahcolite is a soft, colourless or white carbonate mineral with the composition of sodium bicarbonate also called thermokalite. It crystallizes in the monoclinic system....
and dawsonite
Dawsonite
Dawsonite is a mineral composed of sodium aluminium carbonate hydroxide, chemical formula NaAlCO32. It crystallizes in the orthorhombic crystal system. It is not mined for ore. It was discovered in 1874 during the construction of the Redpath Museum in a feldspathic dike on the campus of McGill...
, occurring in oil shales of the Piceance Basin. In this process, the nahcolite is recovered from the raw oil shale by crushing it to lumps smaller than 8 inches (203.2 mm). As a result, most of the nahcolite in the oil shale becomes a fine powder what could screened out. Screened oil shale lumps are further crushed to particles smaller than 3 inches (76.2 mm). Oil shale particles are further processed in a horizontal segmented doughnut-shaped traveling-grate retort in the direct or indirect heating mode. The retort was originally designed by Davy McKee Corporation for iron ore pelletizing
Pelletizing
Pelletizing is the process of compressing or molding a material into the shape of a pellet. A wide range of different materials are pelletized including chemicals, iron ore, animal compound feed, and more.- Pelletizing of iron ore :...
and it also known as the Dravo
Dravo Corporation
Dravo Corporation was a shipbuilding company with shipyards in Pittsburgh, Pennsylvania and Wilmington, Delaware. It was founded by Frank and Ralph Dravo in Pittsburgh during the 1890s.-Facilities:...
retort. In the direct retort, oil shale moves past ducts
Duct (HVAC)
Ducts are used in heating, ventilation, and air conditioning to deliver and remove air. These needed airflows include, for example, supply air, return air, and exhaust air. Ducts also deliver, most commonly as part of the supply air, ventilation air...
through which are provided hot inert gas for heating the raw oil shale, air for combustion of carbon residue (char or semi-coke) in the spent oil shale, and cold inert gas for cooling the spent oil shale. The oil pyrolysis takes place in the heating section. To minimize solubility of aluminium compounds in the oil shale, the heat control is a crucial factor. Necessary heat for pyrolysis is generated in the carbon recovery section by combustion of carbon residue (char or semi-coke) remained in the spent oil shale. While blowing inert gases through the spent oil shale, the spent oil shale is cooled and gases are heated to cause pyrolysis. The indirect mode is similar; the difference is that combustion of carbonaceous residue takes place in separate vessel. The last section is for discharging of oil shale ash. Aluminium oxide
Aluminium oxide
Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...
and sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...
are recovered from calcined dawsonite and calcined nahcolite in the oil shale ash.
Advantages
The traveling-grate retort allows close temperature control, and therefore better control of dawsonite's solubility during the burning stage. During retorting, there is no relative movement of oil shale, which avoids dust creation, and therefore increase the quality of generated products. The oil recovery yields greater than 98% Fischer AssayFischer Assay
The Fischer assay is a standardized laboratory test for determining the oil yield from oil shale to be expected from a conventional shale oil extraction. A 100 gram oil shale sample crushed to...
. The technology has also a relatively high reliability. The sealed system of this process has environmental advantage as it prevents gas and mist leakage.
See also
- Alberta Taciuk ProcessAlberta Taciuk ProcessThe Alberta 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, sludges and wastes...
- Galoter processGaloter processThe Galoter process is a shale oil extraction technology for a production of shale oil, a type of synthetic crude oil. In this process, the oil shale is decomposed into shale oil, oil shale gas, and spent residue...
- Fushun processFushun processThe Fushun process is an above-ground retorting technology for shale oil extraction. It is named after the main production site of Fushun, Liaoning province in northeastern China.-History:...
- Kiviter processKiviter process-History:The Kiviter process is based on the earlier vertical retort technology . This technology underwent a long process of development...
- Lurgi-Ruhrgas processLurgi-Ruhrgas processThe Lurgi–Ruhrgas process is an above-ground coal liquefaction and shale oil extraction technology. It is classified as a hot recycled solids technology.-History:...
- PetrosixPetrosixPetrosix is currently the world’s largest surface oil shale pyrolysis retort with an 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...
- TOSCO II processTOSCO II processThe TOSCO II process is an above ground retorting technology for shale oil extraction, which uses fine particles of oil shale 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...
- Union processUnion processThe Union process is an above ground shale oil extraction technology for production of shale oil, a type of synthetic crude oil. The process uses a vertical retort where heating causes decomposition of oil shale into shale oil, oil shale gas and spent residue...