: Super User; petrochemical; 23 April 2024; Hits: 2634

Base Oil

We have all heard the name base oil many times. Do you know what base oil is? How many categories is it divided into?

Base oil is a type of oil that is used as a base to produce different oils.
In most cases, the base material is a crude base oil that has been used and then mixed with other materials to produce oils with specific characteristics, depending on the type of oil considered.
All lubricants are composed of a base oil. Typically, lubricants are composed of 90% base oil and 10% additives.
But how do we know which is the best base oil?
Trying to choose between natural and synthetic mineral oils can be overwhelming, we share our experience with you on our website.

What is base oil?

Different oils, including engine oil, hydraulic oil, etc., are all used to lubricate car parts and industrial machines. Base oil as a raw material is present in all these lubricants.
All lubricants follow a simple formula (base oil + additives). The only difference between oil and grease is that grease has an additional thickener, up to 30% of grease consists of thickener in a simple or complex soap.

Base Oil is the name given to lubricating grade oils that are originally produced from the refining of crude oil (mineral base oil) or through chemical synthesis (synthetic base oil). The American Petroleum Institute (API) has classified base oils into five groups. Group I, II and III are from crude oil (mineral oil), Group IV is a fully synthetic oil and Group V is for all base oils.
They are characterized by saturation level, sulfur level and viscosity index.

The meaning of these terms is that:

saturation level

Saturates are a type of molecule commonly found in base oil. They are naturally present in the base oil, but higher levels of saturation are achieved during the refining process.
If the level of saturation is higher, the molecular bond of the oil is stronger, this increases the resistance to breakdown and oxidation or loss of viscosity.

Sulfur level

Sulfur is a natural mineral element that is present in crude oil. It reacts with oxygen and can be harmful to the performance of oil. Also, sulfur improves oxidative stability due to being an effective antioxidant. When the amount of sulfur is less, its purity is better. It means that it reduces the possibility of corrosion and oxidation.

Viscosity index

Viscosity index refers to changes in viscosity compared to oil temperature. Viscosity is measured at 40°C and 100°C.
When the viscosity index is high, the changes with the temperature difference are less. All oils have an increase in viscosity as the temperature decreases and a decrease in viscosity as the temperature increases.

Features of base oil

All base oils have characteristics that determine how well they withstand lubrication challenges.
Industrial oil, whether mineral-based or synthetic-based, is designed in such a way that it has a specific application.

1. Thermal and chemical stability: The base oil must have good thermal and chemical stability so that it can be used in heat and high pressure conditions.

2. Neutralizing properties: The base oil must have good neutralizing properties to be able to use it in the production of chemicals and automotive accessories.

3. The ability to absorb and spread additives: the base oil must have the ability to absorb and spread additives so that it can be used in the production of different oils.

4. Insolubility with water: The base oil must not dissolve with water so that it can be used in humid conditions.

5. Ability to resist oxidation: The base oil must have good resistance to oxidation and polymerization in order to be able to be placed in long-term conditions.

6. Chemical and physical stability: The base oil must have good chemical and physical stability to be able to be placed in long-term conditions.

7. Preservation of properties at low temperature: base oil must maintain its properties at low temperature in order to be usable in cold conditions.

How many categories are base oils classified into?

Base oils are actually classified as one or more of these five API groups before any additives are added to the blend:

Group I
They are classified as saturated oils with less than 90% sulfur, more than 0.03% and with a viscosity index range of 80 to 120. This oil is produced from crude oil, as a result, they make the cheapest base oils available. This results in an oil with irregular molecules which increases the friction within the oil.

Group II
They are defined as more than 90 percent saturated, less than 0.03 percent sulfur, and with a viscosity index of 80 to 120. They are often made by hydrocracking, which is a more complex process than Group I base. Hydrocracking is a process that breaks down large hydrocarbon molecules into smaller molecules. The result gives them better antioxidant properties. The price of group II oils is close to that of group I oils.

Group III
More than 90% saturation is less than 0.03% sulfur and has a viscosity index above 120. This longer process is designed to achieve a purer base oil. More pressure and heat are applied during the refinery process, which means it is more resistant to oxidation than Group I oils. They are more resistant, and like the base oils of the second group, these oils are also increasing.

Group IV
Group IV base oils are polyalphaolefins (PAOs), i.e. they are the main synthetic (synthetic) industrial base oils used in industrial and automotive oils. These synthetic base oils are man-made through a process called synthesis. They have a much wider temperature range. They are excellent for use in cold and high heat conditions and are also significantly more expensive than Group III base oils.

Group V
Group V base oils are classified as all other base oils including silicone, phosphate ester, polyalkylene glycol (PAG), polyester, biolubes, etc... oils in this group can be used at higher temperatures even compared to PAO synthetic base oil (Synthetic) provides an excellent detergent, which in turn increases the hours of use. It should be said that group V oils are usually not used as base oil, but as an additive to other base oils.

Result:
Referring to the fact that base oil is produced by refining crude oil, how do we know whether crude oil is suitable for turning into base oil or not?
Crude oil refining means that oil is heated so that different derivatives can be separated from each other. During the heating process, light and heavy hydrocarbons are separated. The light type can be refined to make gasoline and other fuels, while the heavier ones are used for bitumen and oils. They are a suitable base.
There are many crude oils around the world that are used to produce base oil. In fact, the characteristics of the base oil determine the resistance of the respective lubricant, so the American Petroleum Institute (API) has classified base oils into five groups: Group I, II, III is from crude oil (petroleum), Group IV is a fully synthetic oil and Group V is for all base oils which generally contribute to a longer useful life. It is owned by RLG .
RLG operates in the field of selling industrial, diesel and motor lubricants

: Super User; petrochemical; 23 April 2024; Hits: 2640

bitumen

What is bitumen?

Bitumen is a black, paste-like substance that is used in moisture insulation and asphalt construction. Bitumen has various types, each of which has a specific application. Bitumen is a derivative of oil and is often produced in oil refineries.
Bitumen is a black to dark brown hydrocarbon substance that dissolves completely in carbon sulfide and carbon tetrachloride. Bitumen is solid at room temperature, but with increasing temperature, it turns into a paste and then becomes liquid.

The important use of bitumen is due to the presence of two important properties of this substance:

Impermeable to water
Stickiness

Bitumen is usually obtained from the distillation of crude oil. Such bitumen is called petroleum bitumen or distillation bitumen. Petroleum bitumen is the product of two stages of crude oil distillation in the distillation tower:
In the first stage of distillation, light materials such as gasoline and propane are separated from crude oil. This process is carried out at a pressure close to one atmosphere (unit).
In the second stage, heavy compounds such as diesel and kerosene are removed. This process takes place in a pressure close to vacuum. Finally, a mixture of very fine solid particles called asphaltene remains, which is immersed in a grease-like fluid called maltene.
But some types of bitumen are obtained in nature as a result of the gradual conversion of crude oil and the evaporation of its volatile substances over many years. Such a product is called natural bitumen and its durability is longer than petroleum bitumen. Such bitumen may exist in pure form in nature (lake bitumen) .

Types and sources of bitumen and applications
Bitumen is a hydrocarbon substance that has its own definition, characteristics, sources and special characteristics. Bitumen materials are more diverse than oil because bitumen has other sources besides oil.
Bitumens are divided into the following three categories depending on their origin:

Natural bitumen
Petroleum bitumen
Tar tars

Natural Bitumen
Natural bitumen is a naturally occurring hydrocarbon resin that has been rediscovered in recent history in the Bonita River in northeastern Utah.
This natural asphalt is similar to a hardened crude oil asphalt, usually the names of asphalt, utanite and asphaltum are also used for this material.
Natural bitumen, like natural asphalt, is soluble in aliphatic and aromatic solvents, due to the high compatibility of this product, it is usually used to harden diluted petroleum derivatives.
Natural bitumen in lump form is a shiny, black material, very similar to obscenity, and very brittle, and in micronized powder form, it has a dark brown color. Natural bitumen is found underground in vertical layers due to the mining front. Today, natural bitumen is extracted using excavators, loaders, hammers and other new mechanical tools.

Characteristics of natural bitumen:

High solubility in organic solutions
High purity and stable properties
High molecular weight
High nitrogen content

Natural bitumen includes a class of solid bitumen known as asphaltites and is distinguished from other asphaltites due to the following characteristics:
Natural bitumen, which is also known as bentonite, asphaltite, natural asphalt, decorative asphalt, asphaltum and mineral bitumen, is a natural hydrocarbon resin and is the best moisture insulator in nature. It is brittle and has a dark brown color in micronized powder. Natural bitumen is found underground in vertical layers.

Natural bitumen is an additional raw material for improving waterproofing insulation, which by increasing the waterproofing property, volume, it also plays the role of replacing other raw materials and additives. The products used in the civil engineering sector are also thermal modifiers due to the improvement of the softening point and the creation of greater resistance to heat.
Natural bitumen has characteristics such as high solubility in organic solutions, high purity and stable properties, high molecular weight and high nitrogen content.
Natural bitumen is an organic material, hydrocarbon and the best moisture insulator in nature. Also, it has a softening point of 130 to 250 degrees Celsius, depending on its type and quality, and it improves its importance in construction and thermal insulation purposes, and as a primary material and substitute additive and modifier in many uses, including Construction projects and especially road construction are used.

Petroleum bitumen:

Petroleum tars are solid and semi-solid tars that are obtained directly from the distillation of crude oil or by other additional operations such as air blowing. Petroleum tar is the heavy residue of crude oil distillation. The amount of tar in crude oil varies from zero to more than half of that. In addition, bitumen’s obtained from different sources can have many differences. Therefore, bitumen producing refineries must choose their crude oil carefully to ensure the quality of bitumen.

Direct extraction of bitumen from crude oil:

Distillation is a basic process in refining crude oil. The first stage of distillation is done under atmospheric pressure and usually involves heating the crude oil to a temperature of about 650 to 800 degrees Fahrenheit and then injecting it into a separation column. And the bituminous residue is called atmospheric residue, this is the first step in the entire purification process.
Many crude oils contain high percentages of high-boiling fractions that cannot be distilled in an atmospheric still.
To separate these cuts and prepare bitumen with the desired characteristics, a secondary separation tower that works in vacuum conditions is used.
The remainder of this process is called direct extraction bitumen. The process of producing asphalt by vacuum distillation method has very little effect on other properties of bitumen except for permeability. The origin of crude oil used also has a significant effect on the physical properties of extracted bitumen.

tar pitch
Different types of bitumen chemically, there are different classifications for bitumen, two of the most common of which are the classification based on whether the bitumen is natural or petroleum, and the more common one is based on the type of bitumen source, i.e. oil, coal, or wood.

(Tar) Bitumen This type of bitumen is sometimes known by the same name due to its appearance and use similar to oil bitumen, because the source of this type of bitumen is different from oil bitumen, it has different chemical composition and physical properties, which is a general word for liquids. Tar has a different behavior during use and performance in service than burning natural organic materials such as wood or coal and their destructive distillation in the absence of air.
Two types of tar can be prepared from coal burning or carbonization according to the type of process:
1- A process that results in a bitumen with a high percentage of aromatics, a bitumen that is obtained at a temperature of 600 degrees Celsius and has a low percentage of triaromatics, which after cooling the vapors and separating the oily fractions of the remaining coal tar materials Is .
2- BS is obtained with oil cuttings and in the Pich standard it is produced by mixing (refined tar) refinery tar pitch, which has 8 different grades after tar and pitch. Coal has been almost abandoned and its consumption has been greatly reduced.
Today, 90% of these products are used in the four functional groups of road construction, mold coal slag, coal electrodes, and glazing and coating of pipes, but the use of bitumen obtained from refinery coal on roads is only limited to the mixture for surface coatings, and this The reason is that these bitumens are more soluble and perform better at low temperatures, and as a result, they create better adhesion, but the main weakness of these bitumens is their greater thermal sensitivity compared to petroleum bitumen.

Four applications of Tar :

Road Tar
Briquettin
Electrode Binder
Pipe Enamels

The use of bitumen obtained from refined tar on the road is limited only to bitumen-tar mixture for surface coatings.
The coal bitumen used in this mixture is more soluble at low temperature and has better performance. Generally, it is believed that because the acid property of Tar is high, good adhesion is created with the materials.

Therefore, the wetting of materials is better and adhesion is improved, but due to environmental problems and the development of chemical adhesion agents, the use of tar is limited.
Although the use of tar can be used due to the fact that tar is less affected by oil and diesel leaks in vehicle parking areas and similar cases, the main drawback of tar can be its greater thermal sensitivity than petroleum bitumen.

Bitumen specifications

1- Degree of influence:
The degree of penetration test is used to determine the hardness of bitumen. In this test, a standard needle under the effect of a load of 100 grams penetrates into the bitumen at a temperature of 25 degrees for 5 seconds. The amount of penetration in tenths of a millimeter is called the degree of penetration and whatever If it is less, the bitumen is harder.

2- Viscosity:
The higher the mental retardation of the bitumen, the more solid properties it shows. It is clear that the mental retardation is lower at higher temperatures. This characteristic of bitumen is measured with C-bolt Fiorel device or by kinematic method.

3- Degree of ignition:
The degree of ignition is the temperature at which if the bitumen reaches that temperature, the gases emitted from it will ignite as the flame approaches, and the flame will appear on that surface. The maximum temperature that can be heated in the workshop is limited to the ignition degree.

4- Weight loss:
The weight loss of bitumen at high temperature is due to the evaporation of part of its oils and petroleum compounds. This characteristic is also one of the important properties of bitumen.

5- Plasticity or stigma:
If we pull a sample of bitumen with a cross-sectional area of 1 cm2 at a speed of 5 cm/min, the amount of increase in the length of the sample before breaking is called the angmi property of bitumen.

6- Degree of purity:
We know that the solvent of bitumen is carbon tetrachloride and carbon sulfur, so if we dissolve a sample of bitumen in any of these substances, its impurities will remain and from there we can determine the degree of purity of bitumen.
The degree of purity is: (weight of bitumen sample) ÷ [(weight of impurity) – (weight of bitumen)

7- Degree of softness:
Softness degree is the temperature at which bitumen turns from solid to liquid when bitumen reaches that temperature. The higher the degree of bitumen softness, the less sensitive it is to temperature changes. The degree of softness of ordinary bitumen is about 60 to 70.

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