Bitumen, also known as asphalt or petroleum asphalt, is a sticky, black, and highly viscous liquid that is present in most crude petroleums and in some natural deposits. It differs from crude oil in that it is composed mostly of substances that are soluble in carbon disulfide. It is a semisolid hydrocarbon substance. Bitumen comprises a large spectrum of aromatic and aliphatic hydrocarbons and other organic compounds.
Bitumen is produced by refining petroleum, or through the use of heavy crude oils. In many cases, bitumen has been used to improve the performance of pavements and reduce road maintenance costs. Its a versatile material that can be used for a variety of applications, such as waterproofing, surfacing roads, and undercoating insulation.
The major components of petroleum bitumen are asphalt and asphaltenes. Asphalt, which is mainly composed of compounds such as naphthenes, aliphatics, and small amounts of sulfur and nitrogen, is the fluid portion of bitumen and is generally referred to as the “binder”. Asphaltenes, which are large molecules composed of aromatic and heterocyclic rings, form solid particles at room temperature. Asphaltenes are insoluble in common hydrocarbons such as gasoline, and in many cases, require surfactants for solubility.
The characteristics of petroleum bitumen, such as viscosity, softening point, and penetration, are determined by the physical properties of the components and their relative proportions. In general, the asphaltic components of bitumen have greater solubility in carbon disulfide and lower viscosities than the asphaltenic components. This makes bitumen sticky and more difficult to handle.
Bitumen is used in numerous applications in transportation, construction, industrial and energy sectors. In the transportation sector, bitumen is used for paving roads and highways, constructing runways and taxiways, and waterproofing in airports, tunnels, bridges, and other structures. Bitumen is also used to seal and insulate buildings, surfaces and other structures.
In the industrial sector, bitumen is used to manufacture waterproofing membranes, pipe coatings, and joint sealants. Bitumen emulsions are also used in a variety of applications such as oil sands processing, cold asphalt paving, roof coatings, paving sealants, specialty lubricants, etc.
Another application of bitumen is in energy sector, where it is used for waterproofing and corrosion protection in pipe and tank linings, and oil and gas deposit coatings. Bitumen is also used in energy storage, in the form of asphalt concrete, which is a combination of aggregate, bitumen binder, and other additives for use in road bases, fill and pavements.
Finally, bitumen is used as a raw material for numerous products found in many industries such as rubber and plastic modifications, ink, paint and coatings, and adhesives.
In conclusion, bitumen is a naturally-occurring, complex material that has a wide variety of uses in many industries. Its applications are varied and extremely valuable, both economically and environmentally. As such, it is a major component of the oil industry and contributes significantly to the global economy.
