The easiest way to get a basic understanding of how the Upgrader works is to divide up the oil coming to the plant and to divide up the plant.
Each barrel of heavy oil coming to the plant from the field goes to the Crude Plant. At this stage it goes to the desalters for removal of contaminants such as water, salt, clay and sand. After pre-heating, the crude is directed to the crude column for fractionation. The lightest of the components is the diluent. The diluent was added to the heavy crude to make it easier to pump through the pipeline. After it is taken out of the oil, the diluent is shipped back out to the battery to be added to more shipments.
After going through the Crude Plant, the oil is ready for further separation. The lighter oil, which makes up approximately one-third of the field crude, will go through the Hydrotreaters, and the heavy oil (two-thirds) will go to the H-Oil Coker or Hydrocracker.
When the light fractions are sent through the Hydrotreaters, hydrogen (from the Hydrogen Plant) is added at high temperatures to extract the nitrogen and sulphur. The hydrogen sulphide is absorbed in water and sent to the sulphur plant where it is converted to elemental sulphur.
The majority of the crude, heavy oil, is sent to the Primary Upgrading Plant where hydrogen is added at high temperatures and at high pressure. The lighter of the oil extracted at this point is sent to the Hydrotreaters to be further cleaned.
There is still some of the heavy crude which could not be converted at the Hydrocracker and is sent to the Coker. At the coker unit even more separation is done with the extracted oil again being sent to the Hydrotreater unit. Like the sulphur unit, the coker unit extracts the coke, which is sold as an end product.
After all the oil has gone through the Hydrotreater, we have the final and most important product - synthetic crude.
The hydrogen needed by the plant is made by combining natural gas and steam at the Hydrogen Plant. It takes approximately 1000 cubic feet of natural gas to make one barrel of synthetic crude.
|Block Flow Diagram|
For Simplified Descriptions of the Major Upgrader Components - click here