Petroleum Bitumen Asphalt 80/100
Petroleum Bitumen Asphalt
Bitumen is black material which is consumed from 4000 years B.C. its previous Latin name was PIXTU-MEN and today Bitumen and Asphalt are used as its name. its main usage is in roads and streets asphalt and insulation.The first street in the world was covered with asphalt in Washington in 1876 and in Iran Felestin Street was the first in 1933.One of the types of bitumen which is used more is refined bitumen produced in refineries. Also a kind of tar is produced from coal. There are natural bitumen mines in nature which need to be refined. Bitumen is divided into two main groups in usage: paving grade and roofing grade.Chemically bitumen components are divided into two groups of Hydrocarbure , Asphaltine , and Maltin. There is 5-30% Asphaltin in bitumen which causes the hardness of the bitumen. Maltin is made of grease and resin. The heaviest derivative which is separated from crude oil in the vacuum distillation unit is the residue of the vacuum distillation which is briefly referred to as "vacuum bottom" or VB. This residue is the main feed for bitumen producing unit. In this unit,v.b is oxidized using air. Oxidation continues as long as the feed reaches standard properties of bitumen such as the penetration number and softening point (melting temperature). Since the temperature of bitumen is increased in oxidation process, output of reactor is passed through a cooler and then is sent to storage tanks. By regulating operational variables such as the temperature of reactor, residence time in the reactor, and the ratio of air to feed it will be possible to produce different grades of bitumen for various consumptions such as road and industrial types. Moreover adding some proper additives allows us to produce modified bitumen like Polymer Modified Bitumen (PMB) which is highly resistant in heavy traffic and bad climatic conditions. Another bitumen product is bitumen emulsion which is gradually substituting cutbacks for its environmental privileges as well as energy consumption savings.