Integripedia Topic
Crude Distillation Unit (CDU)
In petroleum refining, the Crude Distillation Unit (CDU) (often referred to as the Atmospheric Distillation Unit) is usually the first processing equipment through which crude oil is fed. Crude oil is composed of a mixture of hydrocarbons, and the distillation process separates this crude oil into broad categories of its component hydrocarbons, or "fractions," which serve as feedstocks for all other processing units at the refinery.
As oil is being fed into the CDU, the first thing that happens is the crude is heated to a temperature between 215 and 280°F (100 -137°C). This allows salts, which can be harmful and corrosive to some equipment, to be removed at the desalter. The now desalted crude is further heated to temperatures above 650°F (350°C) as it is fed into the atmospheric distillation tower where the vapors and liquids separate based on the different temperatures at which they boil/condense. The lighter hydrocarbons will condense at higher points in the distillation tower, while heavier hydrocarbons will condense lower in the tower. These hydrocarbons (naphtha, kerosene, diesel and gas oil) are then moved out of the tower through different streams at various heights and sent to other units at the refinery for further processing or blending. The heaviest hydrocarbons that do not vaporize are drawn from the bottom of the atmospheric tower and sent to the vacuum distillation unit to be further refined.
References
- https://en.wikipedia.org/wiki/Petroleum_refining_processes#The_crude_oil_distillation_unit
- http://www.ou.edu/class/che-design/che5480-07/Petroleum%20Fractionation-Overview.pdf
- http://www.refiningnz.com/visitors--learning/classroom--learning-resources/learning-centre/how-it-works---the-refining-process/first-step-distillation.aspx
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Temporary Cooling Equipment Can Resolve Temporary Condensation Problems in Vacuum Distillation Units
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NewsReuters, June 8, 2021
Eneos Corporation, Japan's biggest refiner, is dealing with outages and maintenance events at several of its refineries.
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NewsReuters, March 10, 2021
Marathon Petroleum Corp is preparing to restart a crude distillation unit (CDU) by early next week at its 585,000 bpd Galveston Bay Refinery.
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NewsReuters, September 8, 2020
Motiva Enterprises restarted the crude distillation units (CDUs), coker, and hydrocracker on Saturday at its 607,000 barrel-per-day (bpd) Port Arthur, Texas, refinery.
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NewsReuters, September 8, 2020
Valero Energy Corp restarted the large crude distillation unit (CDU) at its 335,000 barrel-per-day (bpd) Port Arthur, Texas refinery on Sunday.
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NewsReuters, March 10, 2020
ExxonMobil has restarted the last crude distillation unit that had been shut by a Feb 12 fire at its 502,500 bpd Baton Rouge refinery.
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NewsReuters, December 10, 2019
On Monday, Exxon Mobil Corp began restarting the large crude distillation unit (CDU) at its 369,024 barrel-per-day (bpd) Beaumont, Texas, refinery.
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NewsReuters, July 31, 2019
A crude unit at the refinery has been affected by a line failure, and will be shut for a couple of weeks, said a source familiar with the plant operations.
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