The production of bitumen in the refinery has a general method at the beginning; The bitumen produced by different processing methods is then converted into various types of petroleum bitumen. Crude oil is heated in a pressurized furnace at a temperature of 300 to 350 ° C. Heated crude oil then enters the distillation tower, in which case the distillation tower inlet contains liquid and steam.
Naturally, the part of crude oil whose boiling point is higher than the defined boiling point remains as a liquid, and the part that has a boiling point lower than the furnace temperature enters the distillation tower as steam.
Under these conditions, light components such as kerosene, gasoline and gas oil are separated from crude oil, and heavier components leave the distillation tower. In general, the extracted heavy material consists of two main components: bitumen and lubricating oil. Therefore, in the second stage, the two must be separated from each other.
At this stage, to separate the bitumen and oil, the furnace temperature rises to 400 ° C. They also reduce the pressure inside the tower to prevent molecules from breaking down and being heat-damaged. This helps to reduce the temperature required for separation.
In fact, this material is used as feed in making different types of bitumen with different grades. Bitumen or natural bitumen obtained from a vacuum tower can be used in some cases; But most of the time, the properties of this bitumen must be improved through processes, so that they can be used in various industries. In the continuation of this article, we will introduce the types of petroleum bitumen made from this bitumen.
Blown bitumen is the most famous and widely used type of gilsonite. This type of bitumen is used in various cases. For example, blown bitumen is used as waterproofing, insulation blocks, asphalt, roof sealing and the like. Of course, this bitumen has various types that are designed according to ASTM standards, and each has its own characteristics and properties. The method of making blown gilsonite is relatively simple. This bitumen was first made in 1890 due to the reaction of heated bitumen with oxygen. This led to a lot of research in this field and the scientific method of manufacturing it and its devices were produced.
Simply put, soluble bitumen is obtained by dissolving pure bitumen in petroleum solvents or oils. This bitumen is mostly used in industries and road construction operations for technical and economic reasons. In fact, pure Gilsonites are all solid and cannot be used in road construction operations.
Soluble bitumen as one of the types of petroleum bitumen includes different grades and qualities. From the quality of pure bitumen used to the type and amount of solvent, all affect the final quality of soluble bitumen. Naturally, the purer the amount of petroleum solvents in it; The resulting liquid will be thinner and smoother. This percentage typically varies from 10 to 50 percent.
Pure bitumen Another type of petroleum bitumen for various reasons does not have very good physical and mechanical properties. These bitumen have weaknesses in their various functions due to their inherent properties. For example, high sensitivity, low stress resistance, low elasticity and low temperature tolerance range are all items that are reflected in pure bitumen.
