Nevada–Texas–Utah retort
| Process type | chemical |
|---|---|
| Industrial sector(s) | oil industry |
| Feedstock | Oil shale |
| Product(s) | Shale oil |
| Inventor | Roy C. Dundas Raymond T. Howes |
| Year of invention | 1923 |
| Developer(s) | NTU Company |
The Nevada–Texas–Utah retort process (also known as NTU, Dundas–Howes or Rexco process) was an above-ground shale oil extraction technology to produce shale oil, a type of synthetic crude oil. It heated oil shale in a sealed vessel (retort) causing its decomposition into shale oil, oil shale gas and spent residue. The process was developed in the 1920s and used for shale oil production in the United States and in Australia. The process was simple to operate; however, it was ceased from the operation because of a small capacity and labor extensiveness.
History
The NTU retort was a successor of the 19th-century
In 1925–1929, the process was tested by the United States Bureau of Mines in the Oil Shale Experiment Station at Anvil Point in Rifle, Colorado.[1][3] Retorting was carried out from 17 January to 28 June 1927. The plant was dismantled when work was terminated in June 1929.[3] One of the leading technologist involved in this stage was Lewis Cass Karrick, an inventor of the Karrick process.[5] In 1946–1951, two pilot plants with nominal capacities of 40 tons of raw oil shale were located at the same location. More than 12,000 barrels of shale oil was produced during this period. During the World War II, three NTU retorts were operated at Marangaroo, New South Wales, Australia.[1][6][7] Almost 500,000 barrels of shale oil was produced by these retorts by retorting local torbanite.[1]
Retort
The NTU retort was a vertical downdraft retort, which used internal combustion to generate heat for an oil shale pyrolysis (chemical decomposition). The retort was designed as a steel cylinder, lined with fire bricks. At the top it was equipped with an air supply pipe and at the bottom it was equipped with an exhaust pipe. The batch of crushed oil shale was loaded from the top; after that the retort was sealed. To start the pyrolysis process the fuel gas was ignited at the top of retort, and air injection into the retort started. The supply of fuel gas stopped after the upper quarter of the oil shale batch started to burn. At the same time the air injection continued bringing temperature in the burning part to about 1,500 °F (820 °C).
The heated gas caused a pyrolysis on the lower part of oil shale and produced shale oil and oil-shale gas are escaped from the retort through exhaust pipe at the bottom of retort. The pyrolysis occurred at the temperature about 800 °F (430 °C). By time-being, the combustion zones moved downward, and the
Advantages and disadvantages
The advantage of the NTU retort process was simple design, simple operation, and limited need for external fuel. It was suitable for processing of wide variety of oil shales. The disadvantage of this process was a batch mode of operation not allowing continuous retorting, and therefore having small capacity being labor extensive at the same time. The process also had a relatively low oil yield and it required cooling water.[1][8]
See also
- Alberta Taciuk process
- Petrosix
- Kiviter process
- Galoter process
- TOSCO II process
- Fushun process
- Superior multimineral process
- Pumpherston retort
References
- ^ a b c d e f g
ISBN 978-1-4289-2463-5. NTIS order #PB80-210115. Retrieved 2009-07-06.
- ^ a b c
Baughman, Gary L.; Hendrickson, Thomas A. (1978). Synthetic fuels data handbook: U.S. oil shale, U.S. coal, oil sands. Cameron Engineers. p. 67.
- ^ a b c Carter, George William; Jacobsen, Samuel Clark; Mackintosh, Helen Winchester Youngberg (1939). Low-temperature carbonization of Utah coals: a report of the Utah conservation and research foundation to the governor and state Legislature. Quality press. p. 373.
- ^ "California, Oil Shale, Progress in 1925". Journal of the Institution of Petroleum Technologists. 12. Institution of Petroleum Technologists: 371. 1926. Retrieved 2009-07-08.
- ^ Harris, Alan (2008-08-29). "The impact of an emissions trading scheme on the fuel and energy industry. Submission to the Senate Enquiry on Fuel and Energy" (PDF). Senate. Parliament of Australia. pp. 2, 7, 10. Archived from the original (PDF) on 2009-10-02. Retrieved 2009-07-04.
- ^ Prien, Charles H. (1951). "Pyrolysis of Coal and Shale". Industrial and Engineering Chemistry. 43. 43 (9). .
- ^ Mapstone, George E. (1950). "Wartime shale-oil production at Marangaroo, New South Wales". Oil shale and cannel coal; proceedings. 2. Institute of Petroleum. p. 489.
- ^ "The NTU retorting process". Quarterly of the Colorado School of Mines. 69. Colorado School of Mines Press: 47. 1974.