Where Does Bitumen Come From ?
The sources of bitumen are both natural and processed. In this article we state two sources of bitumen:
- Refinery bitumen
- Natural bitumen
Refinery bitumen can be obtained by air blowing through vacuum bottoms in petroleum refineries. But, the natural bitumen can be extracted from the mines or derived from the natural lakes.
Read more details about these bitumen sources in the below.
Refinery Bitumen
How is Bitumen Produced in the Petroleum Refinery?
The process of producing bitumen from crude oil begins in the atmospheric distillation tower in the petroleum refinery.
The crude oil enters the distillation tower from the pipelines. In the distillation tower there are different trays.
In each of these trays, the crude oil is distilled and results in different materials which each of them has a specific molecular weight.
The heaviest components that have the highest molecular weight remain at the bottom of the distillation tower. It is called Vacuum Bottom which is the raw material for producing refinery bitumen.
To produce bitumen, the vacuum bottom should be transferred to the vacuum distillation tower.
In this tower, the air at high temperature is blown through the vacuum bottom. The physical and chemical properties of the vacuum bottom starts to change.
In this stage, the bitumen which has more asphaltene and molecular weight, with higher penetration degree compared to the vacuum bottom is produced.
If you would like to see the infographic of the refinery bitumen production process, you can check the bitumen production process.
Generally, the properties and quality of bitumen depend mainly on the crude oil used in its manufacturing process.
Natural Bitumen
How Bitumen is Formed in Nature?
Generally natural bitumen is classified into 2 types:
- Gilsonite
- Lake Bitumen
Gilsonite and Lake bitumen are both hydrocarbon materials. But they are different in their physical and chemical properties.
Gilsonite
Gilsonite is a type of natural bitumen which is formed in the mines. It is solid and has different ash contents.
This type of bitumen compared to refinery bitumen has high asphaltene and nitrogen contents and it is more soluble in organic solvents like methanol and acetone.
Complete details are stated in the page Gilsonite or Natural Bitumen.
Lake Bitumen
There is a type of bitumen that is obtained from the natural lake which is located in the southern part of Trinidad and Tobago.
This type of bitumen is a thick, black, liquid and tar-like material.
Generally, When crude oil naturally rises through the fractured layers of the earth, natural bitumen forms as lakes on the ground.
