Heavy Oil Science Centre - Overburden

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Upgrader Plant Labels

Plant # 10 - Crude Unit

The Crude Unit has three major purposes:

  • removes any remaining contaminants such as: water, salts or solids

  • applies very high heat to separate crude into different components (fractions) according to boiling range and weight

  • sends the various fractions to other plants for further processing. Examples: diluent is stripped off and returned to the field, jet kerosene is sent to the Naphtha/Jet Hydrotreater, gas oil is sent to the Gas Oil Hydrotreater, and residuum is sent to the Hydrocracker Reaction Unit


Plant # 21 - Hydrocracker Reaction Unit

The main purpose of this unit is to crack residuum

  • residuum (the heaviest fraction) from the crude unit is heated and mixed with a hydrogen rich gas stream

  • the heated mixture passes through an expanded catalyst bed where cracking of the residuum occurs

  • the hydrogen reacts with the cracked compounds forming a de-sulphurized, de-metalized, de-nitrified, and hydrogen saturated product

  • the hydrocracking process converts about 60% of the residuum into lighter fractions which are sent to the Hydrocracker Fractionation Unit for further processing


Plant # 22 - Delayed Coking Unit

The main purpose of this unit is to process heavy hydrocarbon feedstock into lighter, more valuable fractions or into coke

  • the feedstock undergoes partial vapourization and mild cracking as it passes through a coking furnace

  • the lighter fractions removed are sent to other plants for processing

  • the petroleum coke remains in a coke drum from which it is cut into fragments, crushed, and sent to coke loading facilities


Plant # 23 - Gas Recovery Unit

This plant compresses, cools, and cleans gases produced by fractionation in other plants

  • some heavier hydrocarbons are recovered and blended into the synthetic crude oil product

  • lighter gases such as naphtha or butane are sweetened (hydrogen sulphide gas removed or reduced) and sent to other plants for processing or recycled as fuel for other units


Plant # 24 - Hydrocracker Fractionation Unit

This unit applies two stages of processing to the residuum from the Hyrdocracker Reaction Unit

  • First, an atmospheric fractionator applies heat and produces gases or liquids

  • The gases, such as hydrogen sulphide and naphtha are sent to the Gas Recovery Unit

  • Liquids such as gas oil and jet kerosene are removed as side cuts and are sent to the Gas Oil Hydrotreater and the Naphtha/Jet Hydrotreater respectively

  • Heavier fractions are heated again in a vacuum tower, under sub-atmospheric conditions, producing light and heavy vacuum gas oils and vacuum residuum

  • The remaining residuum is sent to the Delayed Coking Unit


Plant # 30 - Hydrogen Plant

The purpose of this plant is to provide an abundant supply of high quality hydrogen to the other plants requiring it

  • The hydrogen is produced through steam reforming of natural gas (methane) in the presence of a catalyst

  • The steps in the process are: desulphurization, reforming, carbon monoxide shift, and purification

  • The purified hydrogen is filtered and compressed before being sent to the other units


Plant # 41 - Naphtha/Jet Hydrotreater

This unit processes straight run jet kerosene produced during fractionation in other plants

  • The processing reduces the sulphur and nitrogen content of the feedstock to improve its combustion characteristics

  • Secondly, hydrotreating reduces the amount of aromatic hydrocarbons which can give jet kerosene a poor smoke point or diesel fuel a poor cetane number

  • The processed fuels are sent to the storage area where they are blended into the synthetic crude oil product that leaves the Upgrader by pipeline

  • When they reach a refinery, they can be easily extracted and subjected to further processing


Plant # 42 - Gas Oil Hydrotreater

The purpose of this unit is to reduce sulphur, nitrogen, and aromatic hydrocarbons to allow processing of the gas oils in a conventional refinery

  • The unit processes straight-run atmospheric and vacuum gas oils from the Crude Unit, and cracked atmospheric and vacuum gas oils from the Hydrocracker Fractionation Unit and the Delayed Coking Unit

  • As a result of hydrotreating, the sulphur compounds are converted to hydrogen sulphide, nitrogen compounds changed to ammonia, and the aromatics are saturated


Plant # 50 - Sulphur Recovery Unit

This plant, actually three units in one, produces liquid elemental sulphur

  • Other plants use amine absorbers to remove hydrogen sulphide

  • In the Amine Unit, super heated steam is applied to break the chemical bonds between the amine molecules and the hydrogen sulphide molecules

  • The Claus Unit produces elemental sulphur as a result of the following chemical conversion: 2H2S + SO2 » 3S + 2H2O

  • The Tail Gas Clean-Up Unit reduces any unreacted sulphur compounds to a level consistent with emission regulations

  • The condensed liquid sulphur is collected, degassed to remove dissolved hydrogen sulphide, and exported from the site on railcars or trucks.

Used with permission (© SAIT Polytechnic, MacPhail School of Energy, 2009)