|SYNONYMS||Asphalt,Paving Grade Bitumen|
Bitumen is black, dense, viscous, amorphous and cementitious material. It is a naturally occurring organic by-product of decomposed organic material. It is the thickest form of petroleum based hydrocarbon and is made up of 83% carbon, 10% hydrogen and lesser amount of oxygen, nitrogen and other elements. It is natural polymer with low molecular weight. Bitumen is very rigid and brittle at low temperature and is it semi liquid as it flows in higher temperature.
In U.S - Bitumen is refereed as Asphalt, it is often confused with Tar, which is obtained from destructive distillation of coal giving Coal gas and Tar residue (which was used for paving roads as bitumen substitute earlier).Bitumen is a most important material of today?s modern world. It connect cities and countries across vast distances.
Different Grades of Bitumen:
1. Oxidised Bitumen.
2. Cutback Bitumen
3. Polymer Modified Bitumen.
4. Hard Grade Bitumen
5. Paving Grade ? This grade of bitumen is only used for paving road. And it has several grades depending on the penetration rate (mm/10). Grades which are used generally 60/70, 80/100,100/120.
It is a naturally occurring product and is found in deposits of oil sands and Pitch Lake. The world's largest deposit of natural bitumen, known as the Athabasca oil sands is located in the McMurray Formation of Northern Alberta. These naturally bitumen is formed from the decomposition of remains of microscopic algae and other once-living things.
Production from Crude Oil /Petroleum Processing
Bitumen is produced from crude oils through Fractional Distillation. Crude oil is heated to a temperature of between 300 and 350 degrees Celsius where it partly vaporized into an atmospheric distillation column, where physical separation of components occurred. The lightest fractions of the crude rise to top and it separated while the heavier fractions, which remain liquid fall to bottom and enter a vacuum distillation column. This process produces a "short residue" that is used to manufacture several grades of bitumen. The pressure and temperature conditions within the vacuum process will determine the hardness of the short residue, and. The short residue may be further modified by 'air blowing' in which air is passed through the residue at temperatures of 250 - 300 degrees Celsius. This process is called straight run vacuum distillation.
Glacial Acetic Acid is used to enhance flavor and as a preservative in pickles and sauces. Its E number is E260. E-number is given to substances which can be used as food additives.
The main use of acetic acid is for the production of vinyl acetate which is polymerized to polyvinyl acetate. PVA is used in paint and adhesives.
It is used as a solvent in many chemicals production such as terephthalic acid. It is used as a solvent in the recrystallization for the purification of organic compounds.