Bitumen Manufacturing Process: How Is Bitumen Made?

Bitumen is a form of petroleum with high viscosity and a sticky texture. This material is widely used for applications such as road paving, construction, or industrial purposes. Bitumen offers several beneficial features, such as durability, flexibility, waterproofing, and viscosity, which make it the required material in many projects. Bitumen is manufactured in different forms. The common methods are straight run, air blowing, solvent deasphalting, and blending. Also, in addition to different production methods, there are different types and grades of bitumen. Penetration grade bitumen, performance grade (PG) bitumen, and viscosity grade (VG) bitumen are three grades of bitumen, each of which serves properly in specific conditions and applications. Polymer-modified bitumen is also an enhanced form of bitumen. It is used for specific uses due to its improved flexibility, resistance to water damage and skid, and increased cohesion and adhesion.

What is Bitumen?

1. Bitumen is a form of petroleum. This material has a sticky and viscous form that makes it a suitable choice for wide applications in the construction industry. Bitumen manufacturing process includes separating different components of petroleum. This separation is based on the boiling point of each component. This process is called bitumen distillation. The outcome is a material called bitumen that gets widely used for road paving, waterproofing, and roofing applications.
2. According to Infinity Galaxy, bitumen is mainly a composition of hydrocarbons. However, in the bitumen manufacturing process, other materials are used, such as small amounts of nitrogen, sulfur, and maltenes. It is also used in the asphalt refining process to provide the required durability for road construction. Bitumen production and the exact composition varies based on the crude oil source.

 

Bitumen has some key features that make it a popular choice for many industrial applications:

• Durability: Bitumen is considered one of the materials that is highly resistant to aging, temperatures, and weathering, which ensures a long service life.
• Viscosity: This material is perfectly suitable for adhesive and binding applications due to its high viscosity.
• Waterproofing: Bitumen waterproofing is a critical feature. This material has a hydrophobic nature, which makes it a suitable material for applications that need waterproofing.
• Flexibility: Bitumen is fairly flexible. This feature helps in preventing cracking or other kinds of damage, especially under heavy loads.

What Are Common Bitumen Production Methods?

The bitumen manufacturing process is done differently. There are several different bitumen production methods. However, there are a few common methods that are suitable for various applications.

Straight Run

Vacuum bottom or short residue has the properties of bitumen, such as proper viscosity and penetration. In paving projects, it can be used as bitumen with no barrier. The only issue is that most vacuum bottoms need enhanced processing to improve their properties.

Air Blowing

A vital bitumen manufacturing process is air blowing. In this method, air with a desired constant temperature blows through the vacuum bottom, which produces asphaltene molecules. The production of these molecules results in the increase of bitumen’s viscosity. All these procedures lead to the production of heavier molecules and asphaltene. The air-blowing method decreases the penetration of the vacuum bottom and increases its softening point.

Semi-Blowing or Air Rectification

This process includes two different methods: batch blowing and continuous blowing.

• Batch blowing: A certain volume of feedstock gets heated to enter the reactor. The blowing can last for 3 to 24 hours, depending on the viscosity of the product and the degree of penetration. Oxidation reactions occur in this process, which increases the temperature. Thus, to keep the temperature constant, a cooling system is provided in the tower.
• Continuous blowing: In this method, the critical point is that the vacuum bottom must have a constant flow rate before entering the reactor. This method offers several advantages, such as the increased production of bitumen per unit of time, ease of control and processing, and reduction of preheating costs of the vacuum bottom.

Fully Air Blowing

In the fully air-blowing method, the blown air through the feedstock is more than the semi-blown method. It is applied to a blend of a vacuum bottom that has a low viscosity, which leads to having oxidized bitumen. The temperature in the column and the air-to-feed ratio determine the amount of required blowing.

Solvent Deasphalting

Modifying the vacuum bottom in propane deasphalting units is a common method of bitumen manufacturing. This process is normally used on crude oil containing low amounts of heavy molecules. The vacuum bottom gets mixed with propane or butane, resulting in the extraction of deasphalting oil. Bitumen is produced at the end of this process. Propane deasphalting further reduces residue. The solvent deasphalting method produces a bituminous product with lower viscosity, enhanced temperature resistance compared to other bitumen, and higher ductility.

Blending

Referring to Raha Bitumen, an indirect bitumen manufacturing process is blending. This method is usually implemented to get bitumen with desirable properties. The blending method includes mixing several different types of bitumen together. The result is achieving bitumen with the preferred and desired specifications and properties. In a specific case, penetration bitumen 40/50 is mixed together with penetration bitumen 200/300, which ends up obtaining the intended bitumen, bitumen 80/100.

What Are Different Types and Grades of Bitumen?

There are several different bitumen grades offered by bitumen suppliers in the UAE. Each of these types has its specifications and properties. There are three common bitumen grades, which have their unique characteristics. These grades and types are applied for construction, paving, and industrial purposes. The right choice of bitumen will ensure a reliable and optimal performance.

Penetration Grade Bitumen

The results of the penetration test determine this classification. It mainly measures the depth to which a standard needle penetrates the bitumen sample under specific conditions. The most common grades are 40/50, 60/70, and 80/100. The lower numbers show harder bitumen. These grades are perfectly suitable for waterproofing and road construction applications.

Performance Grade (PG) Bitumen

Performance grade, also known as PG, bitumen is classified by the performance it has in varying temperatures, including PG-22 and PG-28 grades. The first number shows its performance in high temperatures, and the second one represents bitumen’s properties in low temperatures. Performance grade bitumen is suitable for applications for roads in harsh climates since it provides better resistance to temperature extremes.

Viscosity Grade (VG) Bitumen

VG bitumen, standing for viscosity grade, categorizes the material based on different viscosities at a standard temperature. There are several grades, from VG10 to VG40. As the number lowers, the viscosity decreases as well. This type of bitumen is good for asphalt production as it shows proper workability and stability in various temperature ranges.

What Is Polymer-Modified Bitumen?

Polymer-modified bitumen (PMB) is a specific type of bitumen improved by adding polymers in the bitumen manufacturing process. The additional polymers result in enhanced properties of this type of bitumen. PMB provides various benefits and advantages, especially over traditional bitumen. That is why it is widely used in various industries, such as road construction, roofing solutions, and pavement. PMB has enhanced properties that help it offer enhanced performance and durability.

Improved Flexibility

PMB has additional polymers in its structure, which make it more flexible. The enhanced flexibility prevents cracking or damage, especially under heavy loads. It also makes PMB a suitable choice for applications where there is varying temperature.

Resistance to Water Damage

Polymer-modified bitumen has improved resistance to water ingress. Applying this type of bitumen leads to protecting the road base. All this ends up preventing issues like potholes or rutting, which has a crucial effect in such applications.

Enhanced Skid Resistance

PMB has improved texture with enhanced cohesion. These two improved features result in better skid resistance. Thus, roads get much safer for vehicles by using polymer-modified bitumen as the main material. This feature ensures a more reliable operation, especially in the long term.

Durability

It is proven that PMB shows more durability compared to traditional bitumen. This results in a longer service life when used for roads. It also helps with reducing maintenance costs. The increase in durability will also increase the level of reliability of its performance in several different applications.

Increased Cohesion and Adhesion

PMB offers much more enhanced cohesion or internal strength. It also demonstrates better adhesion (binding to aggregate), especially more than traditional bitumen. The improvement in these two features leads to improved resistance to stripping or separation of bitumen from aggregate. All together, PMB offers a more optimal performance in asphalt mixes.

Conclusion

Bitumen is widely used in various industries for several applications. However, for some applications, it isn’t a proper choice. Thus, an improved form of it, polymer-modified bitumen, is used widely due to the advantages it offers. The bitumen manufacturing process directly affects its workability and specifications. The right choice of the proper type and grade of bitumen highly depends on the project need and the specific conditions of the project.