A delayed coker is a type of coker whose process consists of heating a residual oil feed to its thermal cracking temperature in a furnace with multiple parallel passes. A coker or coker unit is an Oil refinery processing unit that converts the Residual oil from the vacuum distillation column or the atmospheric Fuel oil is a fraction obtained from Petroleum Distillation, either as a distillate or a residue In Petroleum geology and Chemistry, cracking is the process whereby complex organic Molecules such as Kerogens or heavy Hydrocarbons A furnace is a device used for Heating The name derives from Latin fornax, Oven. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Fuel oil is a fraction obtained from Petroleum Distillation, either as a distillate or a residue Petroleum coke (often abbreviated petcoke) is a Carbonaceous solid derived from Oil refinery Coker units or other cracking processes [1][2][3] Delayed coking is one of the unit processes used in many oil refineries. In manufacturing a unit process is single component part of the end-to-end manufacturing process that transforms Raw materials into finished goods An oil refinery is an industrial Process plant where Crude oil is processed and refined into more useful Petroleum products, such as Gasoline
Contents |
Description
Cracking begins in the furnace, continues in the transfer line, and finishes in the coke drum. In Petroleum geology and Chemistry, cracking is the process whereby complex organic Molecules such as Kerogens or heavy Hydrocarbons
As cracking continues in the drum, gas oil and lighter components are generated in vapor phase and separate from the liquid and solids. The drum effluent is vapor only except for any liquid or solids entrainment, and is directed to a fractionation column where it is separated into the desirable boiling point fractions. A fractionating column or fractionation column is an essential item used in the Distillation of liquid mixtures so as to separate the mixture into its component parts Solid coke is deposited in the drum in a porous structure that allows flow through the pores. All solids and uncracked residual liquid produced from the vapor and liquid feed are intended to remain in the drum.
After the drum is full of the solidified coke, the hot mixture from the furnace is switched to a second drum. While the second drum is filling, the full drum is steamed to further reduce hydrocarbon content of the petroleum coke, and then water quenched to cool it. The top and bottom heads of the full coke drum are removed, and the solid petroleum coke is then cut from the coke drum with a high pressure water nozzle, where it falls into a pit, pad, or sluiceway for reclamation to storage.
Larger cokers have several pairs of tandem drums.
Typical schematic flow diagram
Composition of coke
The table below illustrates the wide range of compositions for raw petroleum coke (referred to as green coke[4]) produced in a delayed coker and the corresponding compositions after the green coke has been calcined at 2375 °F (1302 °C):
| Component | Green coke as produced |
Coke calcined at 2375 °F |
|---|---|---|
| Fixed carbon, wt % | 80 − 95 | 98. 0 − 99. 5 |
| Hydrogen, wt % | 3. 0 − 4. 5 | 0. 1 |
| Nitrogen, wt % | 0. 1 − 0. 5 | |
| Sulfur, wt % | 0. 2 − 6. 0 | |
| Volatile matter, wt % | 5 − 15 | 0. 2 − 0. 8 |
| Moisture, wt % | 0. 5 − 10 | 0. 1 |
| Ash, wt % | 0. 1 − 1. 0 | 0. 02 − 0. 7 |
| Density, g/cc | 1. 2 − 1. 6 | 1. 9 − 2. 1 |
| Metals, ppm weight: | ||
| Aluminum | 15 − 100 | 15 − 100 |
| Boron | 0. 1 − 15 | 0. 1 − 15 |
| Calcium | 25 − 500 | 25 − 500 |
| Chromium | 5 − 50 | 5 − 50 |
| Cobalt | 10 − 60 | 10 − 60 |
| Iron | 50 − 5000 | 50 − 5000 |
| Manganese | 2 − 100 | 2 − 100 |
| Magnesium | 10 − 250 | 10 − 250 |
| Molybdenum | 10 − 20 | 10 − 20 |
| Nickel | 10 − 500 | 10 − 500 |
| Potassium | 20 − 50 | 20 − 50 |
| Silicon | 50 − 600 | 50 − 600 |
| Sodium | 40 − 70 | 40 − 70 |
| Titanium | 2 − 60 | 2 − 60 |
| Vanadium | 5 − 500 | 5 − 500 |
See also
References
- ^ Gary, J. In Petroleum geology and Chemistry, cracking is the process whereby complex organic Molecules such as Kerogens or heavy Hydrocarbons The Shukhov cracking process is a thermal cracking process invented by Vladimir Shukhov and Sergei Gavrilov The Burton process is a thermal cracking process invented by William Merriam Burton and Robert Humphrey Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal. A visbreaker is a processing unit in Oil refinery whose purpose is to reduce the quantity of residual oil produced in the Distillation of Crude oil and H. and Handwerk, G. E. (1984). Petroleum Refining Technology and Economics, 2nd Edition, Marcel Dekker, Inc. ISBN 0-8247-7150-8.
- ^ Leffler, W. L. (1985). Petroleum refining for the nontechnical person, 2nd Edition, PennWell Books. ISBN 0-87814-280-0.
- ^ Petroleum Coke Glossary
- ^ Petroleum coke on the website of the IUPAC Compendium of Chemical Terminology
External links
The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organizationDapyx Software network: MP3 Explorer | Ebook Manager | Zenithic