Bitumen is a low-grade crude oil that consists of complex and heavy hydrocarbons. Bitumen is a thick and viscous fluid that is found in an oil reservoir and must be extracted from it for exploitation. When extracting it, a lot of heat and effort is needed to upgrade that product to better grades for use. Although it is difficult to extract bitumen from the ground and it has many problems, but it can bubble up and come out naturally in the seepage of oil. These spills occur where fossil fuels and petroleum products erupt from the ground instead of being trapped deep underground. Bitumen and asphalt are removed in these leaks and collected in a place called bitumen pool. In addition, bitumen is the main component of oil sands fossil fuel. When bitumen is combined with asphaltene, a solid substance is formed that is useful for asphalt road surfaces.
In addition to being found naturally in seeps and oil sands, bitumen can be produced by removing the lighter fractions from crude oil during the oil refining process in the distillation column. The parts that are removed from crude oil are: Liquid gas, gasoline and diesel.
Once the crude oil is extracted from the ground, it is possible to start producing bitumen from the extracted oil. Crude oil is pumped from storage tanks through a system that increases the temperature of crude oil to 200 degrees Celsius. Then this heated oil is transferred to a furnace, where it is heated even to a temperature of 300 degrees Celsius and higher, and enters a distillation column. Here the separation of different components of crude oil takes place. As the lighter components rise, the heavier components – including bitumen – fall to the bottom of the column. This process is known as fractional distillation (cuts of crude oil). Finally, the bitumen with more distillation is the residue at the end of the distillation column.
Most refined bitumen is used in the construction industry. It is mainly used in paving and roofing applications. 85% of the total bitumen is used as an adhesive in the asphalt of roads, runways, parking lots and sidewalks. To use bitumen on the road surface, sand and gravel are mixed with thick bitumen and used to cover the road surface. 10% of the bitumen used worldwide is used in the construction of roofs, because its waterproof qualities contribute to the good performance of roofs. 5% bitumen is used for sealing and insulating purposes in various building materials, including behind tiles and under paint.
In addition to these main uses, bitumen also has many minor uses. Other examples include sound insulation, use in explosives, protection against mold, glue in briquettes, shoe soles, fence covering and soil stabilization, etc.
