vhvi technology. VHVI Technology (Very High Viscosity Index)

Hydrocracking is a technology of advantages.

Hydrocracked base oils are becoming increasingly common in the lubricants industry. Today, the largest manufacturer of this base is SK Corporation, which supplies this raw material to the markets of various countries and to leading oil producers. The features of hydrocrack oils produced by SK, the advantages of products manufactured on their basis were discussed at the seminar “ZIC Motor Oil - VHVI technology” held within the framework of the 15th international motor show SIA "2007"

It is known that the main component of lubricants is the base oil. The better it is, the better the characteristics of the final product will be. Additives, of course, also have an effect, however, they are mainly aimed at giving the oil some additional properties and are a kind of "auxiliary" elements. Therefore, the base oil is the key component that largely determines the performance of the oil and maintaining the stability of its properties.

To separate base oils according to their technical characteristics, API (American Petroleum Institute) introduced an appropriate classification, dividing them into five groups. Gradation is carried out according to the viscosity index, saturation and sulfur content. Saturation indicates the content of isoparaffins and cycloparaffins in the composition of the oil. Highly saturated base oil has high thermal and antioxidant stability; additives work more effectively in it. For long-term and high-quality operation of the lubricant, the purity of the base oil is of no small importance. After all, if it contains contaminants, a certain amount of additives will gradually react with their particles. In this case, the effectiveness of the additives and the properties of the oil will deteriorate more rapidly during operation. When using highly refined base oils for the production of lubricants, more additives are kept in an active state. Consequently, the efficiency of the oil increases.

Of course, many have heard of hydrocracked oils. These products are classified in the third group of base oils according to the API classification and are often equated with polyalphaolefins (group IV). Today, one of the largest producers of Group III base oils is SK Corporation, which provides about 60% of the world market with this type of base. The hydrocracking oils produced by the company are called Yubase and are obtained using advanced oil base technology - VHVI technology (Very High Viscosity Index - a very high viscosity index). Yubase oils, although they belong to the third group, have a slightly different hydrocarbon composition and characteristics than their counterparts. In appearance, they are almost transparent, which indicates a high degree of purification from harmful impurities, such as aromatic compounds, sulfur, nitrogen, etc. ). However, not all Yubase oils can be used to make engine oil. To do this, only their special categories are selected, which, together with carefully selected additives that are combined with the Yubase base, make it possible to obtain high-class oils. This is the technology of SK Corporation - VHVI - a technology for producing excellent base oils and ZIC lubricants with good low-temperature fluidity, excellent overall engine protection, low consumption and extended oil change intervals. To date, the majority of ZIC motor oils are produced on the basis of Yubase base oils. Their combination with high-performance additives makes it possible to obtain products that meet the requirements of well-known world classifications (API, ACEA, ILSAC), as well as many car manufacturers. ZIC oils are also used for factory filling (for example, on Hyundai and KIA conveyors). It should be noted that many lubricant manufacturers position oils based on hydrocracked base oils in the synthetic sector. Others still classify them as semi-synthetic, preferring to call only oils made from a traditional synthetic base synthetic. Each company uses its marketing moves to draw attention to its products and has the right to attribute a particular product to a particular sector. Hydrocracking oils differ significantly from mineral oils, of course, in a positive direction, while approaching synthetic ones as much as possible. However, everywhere there are "buts". Approaching - not yet identical. And how then to call classic products based on synthetic base oils? "Full" synthetics? There are quite heated discussions about this, and everyone defends his point of view.

Base oils are divided into five groups, which differ in chemical composition, and hence properties. From this (and their mixing) depends on what will be the final motor oil sold on store shelves. And the most interesting thing is the fact that only 15 world oil companies are engaged in their production, as well as the additives themselves, while there are much more grades of the final oil. And here, for sure, many had a logical question: what then is the difference between oils and which one is the best? But first, it makes sense to deal with the classification of these compounds.

Base oil groups

The classification of base oils involves dividing them into five groups. This is spelled out in API 1509 Appendix E.

API base oil classification table

Oils of the 1st group

These compositions are obtained by refining petroleum products remaining after the production of gasoline or other fuels and lubricants using chemical reagents (solvents). They are also called coarse oils. A significant disadvantage of such oils is the presence of a large amount of sulfur in them, more than 0.03%. In terms of performance, such formulations have poor viscosity index values ​​(i.e., viscosity is highly dependent on temperature and can only work normally in a narrow temperature range). Currently, group 1 of base oils is considered obsolete and only one is produced from them. The viscosity index of such base oils is 80…120. And the temperature range is 0°С…+65°С. Their only advantage is their low price.

Oils 2 groups

Group 2 base oils are obtained by performing a chemical process called hydrocracking. Their other name is highly refined oils. This is also the purification of petroleum products, however, using hydrogen and under high pressure (in fact, the process is multi-stage and complex). The result is an almost clear liquid, which is the base oil. Its sulfur content is less than 0.03%, and they have antioxidant properties. Due to its purity, the service life of the engine oil obtained from it is significantly increased, and deposits and deposits in the engine are reduced. On the basis of hydrocracking base oil, the so-called "HC-synthetics" are made, which some experts refer to as semi-synthetics. The viscosity index in this case is also in the range from 80 to 120. This group is called the English abbreviation HVI (High Viscosity Index), which literally translates as high viscosity index.

Oils 3 groups

These oils are obtained in the same way as the previous ones from petroleum products. However, the features of group 3 is increased, its value exceeds 120. The higher this indicator, the wider the temperature range the resulting motor oil can operate, in particular, in severe frost. Often, 3 groups are made on the basis of base oils. The sulfur content here is less than 0.03%, and the composition itself consists of 90% chemically stable, hydrogen-saturated molecules. Its other name is synthetics, but in fact it is not. The name of the group sometimes sounds like VHVI (Very High Viscosity Index), which translates as a very high viscosity index.

Sometimes a 3+ group is separately distinguished, the base for which is obtained not from oil, but from natural gas. The technology for its creation is called GTL (gas-to-liquids), that is, the conversion of gas into liquid hydrocarbons. The result is a very pure water-like base oil. Its molecules have strong bonds that are resistant to aggressive conditions. Oils created on such a base are considered fully synthetic, despite the fact that hydrocracking is used in the process of their creation.

Group 3 feedstocks are excellent for formulating fuel-saving, synthetic, multi-purpose motor oils in the 5W-20 to 10W-40 range.

Oils 4 groups

These oils are based on polyalphaolefins, and are the basis for the so-called "true synthetics", which are distinguished by their high quality. This is the so-called base polyalphaolefin oil. It is produced by chemical synthesis. However, a feature of motor oils obtained on such a base is their high cost, so they are often used only in sports cars and premium cars.

Oils of the 5th group

There are separate types of base oils, which include all other compounds that are not included in the four groups listed above (roughly speaking, this includes all lubricating compounds, even non-automotive, that are not included in the first four). In particular, silicone, phosphate ester, polyalkylene glycol (PAG), polyesters, bio-lubricants, vaseline and white oils, and so on. They are, in fact, additives to other formulations. For example, esters serve as additives to the base oil to improve its performance properties. Thus, a mixture of essential oil and polyalphaolefins normally works at high temperatures, thereby providing an increased detergency of the oil and increasing its service life. Another name for such compounds is essential oils. They are currently the highest quality and highest performance. These include ester oils, which, however, are produced in very small quantities due to their high cost (about 3% of world production).

Thus, the characteristics of base oils depend on the way they are obtained. And this, in turn, affects the quality and characteristics of ready-made motor oils used in automobile engines. Oils derived from petroleum are also affected by its chemical composition. After all, it depends on where (in which region on the planet) and how oil was produced.

Which base oils are best

Volatility of base oils according to Noack

Oxidation resistance

The question of which base oils are the best is not entirely correct, since it all depends on what kind of oil you need to get and use in the end. For most budget cars, “semi-synthetics” is quite suitable, created on the basis of mixing oils of groups 2, 3 and 4. If we are talking about good “synthetics” for expensive premium foreign cars, then it is better to buy oil based on a group 4 base.

Until 2006, motor oil manufacturers could call "synthetic" oils obtained on the basis of the fourth and fifth groups. Which are considered the best base oils. However, it is currently allowed to do this even if a base oil of the second or third group was used. That is, only compositions based on the first basic group remained “mineral”.

What happens when you mix species?

It is allowed to mix individual base oils belonging to different groups. So you can adjust the characteristics of the final compositions. For example, if you mix group 3 or 4 base oils with similar compositions from group 2, you get a "semi-synthetic" with improved performance. If the mentioned oils are mixed with group 1, then you will also get "", but with already lower characteristics, in particular, a high sulfur content or other impurities (depending on the specific composition). Interestingly, oils of the fifth group in their pure form are not used as a base. To them are added compositions from the third and/or fourth groups. This is due to their high volatility and high cost.

A distinctive feature of oils based on PAO is that it is impossible to make a 100% PAO composition. The reason is their very poor solubility. And it is needed to dissolve the additives that are added during the manufacturing process. Therefore, a certain amount of funds from lower groups (third and / or fourth) is always added to PAO oils.

The structure of molecular bonds in oils belonging to different groups is different. So, in low groups (first, second, that is, mineral oils), molecular chains look like a branched crown of a tree with a bunch of “crooked” branches. It is easier for this form to curl up into a ball, which happens when it freezes. Accordingly, such oils will freeze at a higher temperature. Conversely, in oils of high groups, hydrocarbon chains have a long straight structure, and it is more difficult for them to “curl up”. Therefore, they freeze at lower temperatures.

Production and production of base oils

In the production of modern base oils, viscosity index, pour point temperature, volatility and oxidation stability can be independently controlled. As mentioned above, base oils are produced from petroleum or petroleum products (for example, fuel oil), and there is also production from natural gas by conversion to liquid hydrocarbons.

How base engine oil is made

Oil itself is a complex chemical compound, which includes saturated paraffins and naphthenes, unsaturated aromatic olefins, and so on. Each such compound has positive and negative properties.

In particular, paraffins have good oxidation stability, but at low temperatures it is reduced to nothing. Naphthenic acids form a precipitate in the oil at high temperatures. Aromatic hydrocarbons adversely affect oxidative stability as well as lubricity. In addition, they form varnish deposits.

Unsaturated hydrocarbons are unstable, that is, they change their properties over time and at different temperatures. Therefore, all of these substances in base oils must be disposed of. And this is done in different ways.

Methane is a natural gas that has neither color nor smell, it is the simplest hydrocarbon consisting of alkanes and paraffins. Alkanes, which are the basis of this gas, unlike petroleums, have strong molecular bonds, and as a result, they are resistant to reactions with sulfur and alkali, do not form precipitates and varnish deposits, but can be oxidized at 200 ° C.

The main difficulty lies precisely in the synthesis of liquid hydrocarbons, but the final process is hydrocracking itself, where long chains of hydrocarbons are separated into different fractions, one of which is an absolutely transparent base oil without sulfate ash. The purity of the oil is 99.5%.

Viscosity coefficients are much higher than those produced from PAO, they are used to make fuel-saving automotive oils with a long service life. This oil has very low volatility and excellent stability both at very high and at extremely low temperatures.

Let us consider in more detail the oils of each of the above groups, how they differ in the technology of their production.

Group 1. They are obtained from pure oil or other oil-containing materials (often waste products in the manufacture of gasoline and other fuels and lubricants) by selective purification. For this, one of three elements is used - clay, sulfuric acid and solvents.

So, with the help of clay they get rid of nitrogen and sulfur compounds. Sulfuric acid in combination with impurities provides sludge sediment. And solvents remove paraffin and aromatic compounds. Most often, solvents are used, since this is the most effective.

Group 2. Here the technology is similar, but it is complemented by highly refined cleaning elements with a low content of aromatic compounds and paraffins. This improves oxidative stability.

Group 3. The base oils of the third group at the initial stage are obtained like the oils of the second. However, their feature is the hydrocracking process. In this case, petroleum hydrocarbons undergo hydrogenation and cracking.

In the process of hydrogenation, aromatic hydrocarbons are removed from the oil composition (they subsequently form a coating of varnish and soot in the engine). Sulfur, nitrogen and their chemical compounds are also removed. Next, the stage of catalytic cracking takes place, during which paraffin hydrocarbons are split and “fluffed up”, that is, the process of isomerization occurs. This results in linear molecular bonds. The harmful compounds of sulfur, nitrogen and other elements remaining in the oil are neutralized by adding additives.

Group 3+. Such base oils are produced by the hydrocracking process itself, only the raw material that can be separated is not crude oil, but liquid hydrocarbons synthesized from natural gas. Gas can be synthesized to produce liquid hydrocarbons using the Fischer-Tropsch technology developed back in the 1920s, but using a special catalyst. The production of the required product began only at the end of 2011 at the Pearl GTL Shell plant together with Qatar Petroleum.

The production of such a base oil begins with the supply of gas and oxygen to the plant. Then the gasification stage begins with the production of synthesis gas, which is a mixture of carbon monoxide and hydrogen. Then there is the synthesis of liquid hydrocarbons. And the next process in the GTL chain is the hydrocracking of the resulting transparent waxy mass.

The gas-to-liquid conversion process results in a crystal clear base oil that is virtually free of the impurities found in crude oil. The most important representative of such oils made using PurePlus technology is Ultra, Pennzoil Ultra and Platinum Full Synthetic.

Group 4. The role of the synthetic base for such compositions is played by the already mentioned polyalphaolefins (PAO). They are hydrocarbons with a chain length of about 10...12 atoms. They are obtained by polymerization (combination) of the so-called monomers (short hydrocarbons 5 ... 6 atoms long. And the raw materials for this are butylene and ethylene petroleum gases (another name for long molecules is decenes). This process resembles “crosslinking” on special chemical machines It consists of several stages.

The first of these is the oligomerization of decene in order to obtain a linear alpha olefin. The oligomerization process takes place in the presence of catalysts, high temperature and high pressure. The second stage is the polymerization of linear alpha-olefins, resulting in the desired PAOs. This polymerization process takes place at low pressure and in the presence of organometallic catalysts. At the final stage, fractional distillation is performed at PAO-2, PAO-4, PAO-6, and so on. Appropriate fractions and polyalphaolefins are selected to provide the necessary characteristics of the base engine oil.

Group 5. As for the fifth group, such oils are based on esters - esters or fatty acids, that is, compounds of organic acids. These compounds are formed as a result of chemical reactions between acids (usually carboxylic) and alcohols. The raw materials for their production are organic materials - vegetable oils (coconut, rapeseed). Also, sometimes oils of the fifth group are made from alkylated naphthalenes. They are obtained by alkylation of naphthalenes with olefins.

As you can see, the manufacturing technology from group to group becomes more complicated, which means it becomes more expensive. That is why mineral oils have a low price, and PAO-synthetic oils are expensive. However, when you need to consider many different characteristics, and not just the price and type of oil.

Interestingly, oils belonging to the fifth group contain polarized particles that are magnetic to the metal parts of the engine. This way they provide the best protection compared to other oils. In addition, they have very good detergent properties, so that the amount of detergent additives is minimized (or simply eliminated).

Oils based on esters (fifth basic group) are used in aviation, because aircraft fly at an altitude where the temperature is much lower than that which is recorded even in the far north.

Modern technologies make it possible to create completely biodegradable ester oils, since the mentioned esters are environmentally friendly products and easily decompose. Therefore, these oils are environmentally friendly. However, due to their high cost, motorists will not soon be able to use them everywhere.

Base oil manufacturers

Ready engine oil is a mixture of base oil and an additive package. Moreover, it is interesting that there are only 5 companies in the world that produce these same additives - these are Lubrizol, Ethyl, Infineum, Afton and Chevron. All well-known and not so well-known companies that produce their own lubricating fluids buy additives from them. Over time, their composition changes, is modified, companies conduct research in chemical areas, and try not only to improve the performance of oils, but also to make them more environmentally friendly.

As for the producers of base oils, there are actually not so many of them, and mainly these are large, world-famous companies, such as ExonMobil, which ranks first in the world in this indicator (about 50% of the world volume of base oils of the fourth group , as well as a large share in groups 2,3 and 5). In addition to it, there are still such large ones in the world with their own research center. Moreover, their production is divided into the above mentioned five groups. For example, such "whales" as ExxonMobil, Castrol and Shell do not produce base oils of the first group, since it is "out of order" for them.

The listed base oils are initially divided by viscosity. And each of the groups has its own designations:

• First group: SN-80, SN-150, SN-400, SN-500, SN-600, SN-650, SN-1200 and so on.
• The second group: 70N, 100N, 150N, 500N (although the viscosity may vary from manufacturer to manufacturer).
• Third group: 60R, 100R, 150R, 220R, 600R (here also the figures may differ depending on the manufacturer).

The composition of motor oils

Depending on what characteristics the finished automotive engine oil should have, each manufacturer chooses its composition and the ratio of its constituent substances. For example, a semi-synthetic oil typically consists of about 70% mineral base oil (Group 1 or 2), or 30% hydrocracked synthetic (sometimes 80% and 20%). Next comes the "game" with additives (they are antioxidant, anti-foam, thickening, dispersion, detergent, dispersant, friction modifiers), which are added to the resulting mixture. Additives are usually of low quality, so the resulting finished product does not have good characteristics, and can be used in budget and / or old cars.

Synthetic and semi-synthetic formulations based on group 3 base oils are the most common in the world today. They have the English designation Semi Syntetic. The technology of their manufacture is similar. They consist of approximately 80% base oil (often different groups of base oils are mixed) and an additive. Sometimes viscosity regulators are added.

Synthetic oils based on group 4 bases are already real Full Syntetic “synthetics”, based on polyalphaolephons. They have very high performance and long service life, but they are very expensive. As for rare ester motor oils, they consist of a mixture of base oils from groups 3 and 4, and with the addition of an ester component in a volume amount of 5 to 30%.

Recently, there are "craftsmen" who add about 10% of a fine ester component to the filled engine oil of a car in order to allegedly improve its performance. Should not be doing that! This will change the viscosity and may lead to unpredictable results.

The technology for manufacturing finished engine oil is not just a mixture of individual components, in particular, bases and additives. In fact, this mixing occurs in stages, at different temperatures, at different intervals. Therefore, for its production, you need to have information about the technology and appropriate equipment.

Most of the current companies with such equipment produce motor oils using the developments of the main base oil manufacturers and additive manufacturers, so it is quite common to come across the statement that manufacturers are fooling us and in fact all oils are the same.

In the production of ZIC lubricants, SK's own development - "VHVI Technology" is used, this is how YUBASE is obtained - base oils with a Very High Viscosity Index (VHVI)

VHVI technology endows them with properties identical to those of 100% synthetic base oils: YUBASE surpasses the performance of analogues in terms of Viscosity Index, has a much lower volatility, practically does not contain harmful impurities, so the additives in it work with very high efficiency.

Excellent base oil characteristics, combined with perfectly and precisely balanced active additive packages from LUBRIZOL and INFINEUM (world leaders in this field), provide a very high level of quality in ZIC lubricants.

The unique properties of ZIC oils and lubricants are provided by catalytic hydrocracking, the latest and most advanced deep oil refining technology in existence. It is on the basis of this technology that the YUBASE VHVI base oil (oil with a Very High Viscosity Index) is produced, which belongs to the III group according to the API (American Petroleum Institute) classification. The process of hydrocracking, which oils undergo, leads to the conversion of components into hydrocarbons of the required structure, which affects the stability of the resulting oils and brings their properties closer to synthetic ones.

By supplying YUBASE base oil to the world's leading lubricant manufacturers, SK controls over 60% of the global Group III base oil market. YUBASE base oil production technology has received international recognition and is protected by patents in 23 countries.

ZIC engine oils are manufactured using the highest quality components. Firstly, it is a base oil with a very high viscosity index, manufactured using deep catalytic hydrocracking technology, and secondly, balanced additive packages from the world leaders in this field - Lubrizol and Infineum.

Hydrocracking technology in the production of base oils has become a truly revolutionary step in the development of new generation motor oils. This process was put into practice in the mid-1970s in the United States, and then spread to other regions of the world. The merit of the manufacturer of ZIC - SK Corporation (http://www.skzic.com/eng/main.asp) is the significant modernization of traditional hydrocracking and the development of its own technology for the production of top quality base oil - VHVI Technologyhttp: http://www.yubase. com/eng/main.asp

Manufacturers of hydrocracked base oils tend to patent and protect their own production technologies. These technologies are usually assigned abbreviated characters. Shell has XHVI (Extra High Viscosity Index); BP - HC (Hydrocracker Component); Exxon has ExSyn. SK Corporation's technology has received the abbreviation VHVI (Very High Viscosity Index - that is, a very high viscosity index).

VHVI technology gives ZIC oils properties identical to "synthetics". VHVI base oils, unique in their quality, surpass the standard indicators of the third group in terms of viscosity index, have much lower volatility, and contain several times less aromatic hydrocarbons and sulfur. Therefore, ZIC engine oils practically do not change their original properties throughout the entire service life. The oil has excellent fluidity at low temperatures (when starting a cold engine) and a higher viscosity at engine operating temperature, therefore it is ideally resistant to wear. Low volatility and high flash point contribute to the achievement of minimum oil waste in the engine.

To date, ZIC motor oils are one of the best offers on the Ukrainian market. In terms of quality, they are in no way inferior to more eminent counterparts and at the same time are quite affordable. And the original tin packaging with several levels of protection virtually eliminates the possibility of counterfeiting SK products.

It is safe to say that VHVI technology products - ZIC lubricants, offered today on the Ukrainian market, demonstrate the advanced level of quality in the world petrochemistry, meet the latest domestic and international requirements for lubricants.

Pavel Lebedev
Photo ZIC

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