Bitumen

Bitumen is a category of organic liquids that are highly viscous, black, sticky and wholly soluble in carbon disulfide, mostly made up of highly condensed polycyclic aromatic hydrocarbons.

Bitumen is obtained by fractional distillation of crude oil. Bitumen being the heaviest and being the fraction with the highest boiling point, it appears as the bottommost fraction.

In British English, 'bitumen' refers to heavy, black viscous material obtained from the distillation of crude oil. The word 'asphalt' in British English refers to a mixture of mineral aggregate and bitumen (tarmac in common parlance). The word 'tar' refers to a black viscous material obtained from the destructive distillation of coal and is a chemically distinct material different to bitumen.(In American English, 'bitumen' is referred to as 'asphalt' or 'asphalt cement' in engineering jargon. In Australian English, 'bitumen' is sometimes used as the generic term for road surfaces).

Bitumen is primarily used for paving roads. Its other uses are for general waterproofing products, including the use of bitumen in the production of roofing felt and for sealing flat roofs. It is also the prime feed stock for petroleum production from tar sands currently under development in Alberta, Canada.

In the past, bitumen was used to waterproof boats, and even as a coating for buildings; it is possible, for example, that the city of Carthage was easily burnt down due to extensive use of bitumen in construction.

Vessels for the heating of bitumen or bituminous compounds are usually excluded by public liability insurance policies.

Most geologists believe that naturally occurring deposits of bitumen are formed from the remains of ancient, microscopic algae and other once-living things. These organisms died and their remains were deposited in the mud on the bottom of the ocean or lake where they lived. Under the heat and pressure of burial deep in the earth, the remains were transformed into materials such as bitumen, kerogen, or petroleum.

The world has become increasingly concerned over the global climate change problem in recent years due to the pollution that is released into the atmosphere. Most of the emisions are derived primarily from burning fossil fuels. This has led to the introduction of bitumen alternatives that are more environmentally friendly and non toxic. Bitumen can now be made from non-petroleum based renewable resources such as sugar, molasses and rice, corn and potato starches etc. To further help the environment bitumen can also be made from the waste material from fractional distillation produced in the process of cleaning used motor oils , this waste is normally disposed by burning or dumping into land fills.

These new non-petroleum based bitumen binders can be colored, which thereby help reduce the temperatures of road surfaces which contribute to the Urban heat island which in turn contributes to global climate change.

For millions of people living in and around cities, heat islands are of growing concern. This phenomenon describes urban and suburban temperatures that are 2 to 10°F (1 to 6°C) hotter than nearby rural areas. Elevated temperatures can impact communities by increasing peak energy demand, air conditioning costs, air pollution levels, and heat-related illness and mortality. Fortunately, there are common-sense measures that communities can take to reduce the negative effects of heat islands, such as replacing conventional black asphalt road surfaces with the new pigmentable bitumen that gives lighter colors [1]