Sulfur in Diesel Fuel: Problem and Solution. Diesel Fuel Expertise: Will Diesel Be Poisoned? Sulfur content standards for different types of fuel

Last but not least, the properties of the fuel affect. Today manufacturers in Russia also offer GOST 305-82 diesel fuel. The state standard, developed back in 1982, is already outdated, as well as the fuel itself, which until recently was produced using it.

GOST 305-82

Created in the Soviet Union, this standard, which regulates the manufacture of diesel fuel, is interstate. It defines both the technical conditions of production and the characteristics of the fuel that was intended for cars, industrial units and ships with high-speed diesel engines.

Modern fuel, manufactured in accordance with international European standards, practically ousted diesel fuel from the market, for the production of which the old GOST was used. Diesel fuel EURO, in addition to having significantly higher performance characteristics, also much more environmentally friendly.

However, even today it is believed (at least in the post-Soviet space) that a fuel in which various permitted additives can be used has some advantages due to its versatility and a wide range of operating temperatures.

Application area

Diesel fuel (GOST 305-82) was used until recently for military, agricultural equipment, diesel ships and old-style trucks.

This fuel was used to heat low-rise buildings located far from the central heating supply. The combination of low prices and sufficiently high energy efficiency made it possible to save the cost of maintaining houses.

Why in the past? The state standard of 1982 was replaced by GOST 305-2013, which came into force in January 2015. And it clearly states that GOST 305-2013 diesel fuel is not sold through public gas stations and is intended for high-speed and gas turbine engines both within the country and in (Kazakhstan and Belarus).

Main advantages

So, the main advantages are versatility and operating temperatures. In addition, the advantages of good old diesel fuel are considered its operational reliability, proven for decades; possibility of long-term storage without deterioration of technical characteristics; increase in engine power.

Diesel fuel GOST 305-82 is easily filtered, contains a small amount of sulfur compounds and does not destroy engine parts.

The indisputable advantage of diesel fuel is its low price compared to other types of liquid fuels.

The main disadvantage

The main disadvantage of the fuel, due to which, in fact, its use is limited, is its low environmental friendliness class. Diesel fuel GOST 305-82 (2013) belongs to the K2 class. And today on the territory of the Russian Federation even types of fuel with the environmental class K3 and K4 are prohibited for circulation.

Diesel fuel brands

The old GOST established three new ones - four. Also, the temperature ranges of their use and characteristics differ slightly.

Parameters (GOST) of summer diesel fuel (L): operating temperature - from minus 5 ° С, flash point for general purpose- 40 ° С, for gas turbine, ship and diesel locomotives - 62 ° С.

The same flash point for off-season fuel (E), the operating temperatures of which start from minus 15 ° C.

Winter fuel (Z) is used at temperatures up to minus 35 ° С and up to minus 25 ° С. And if in the technical conditions of 1982 the operating temperature range was determined by the pour point of the fuel, then in the new document we are talking about the filtration temperature - minus 35 ° C and minus 25 ° C, respectively.

Arctic (A) diesel fuel GOST 305-82 could be used starting from a temperature of minus 50 ° C. In the new document, this limit was raised by five degrees, the already recommended temperature is called from 45 ° C and above.

Diesel fuel types

Diesel fuel GOST 52368-2005 (EURO) is divided by mass sulfur content into three types:

• I - 350 mg;
• II - 50 mg;
• III - 10 mg per kg of fuel.

In GOST 305-82, diesel fuel, depending on the percentage of sulfur, is divided into types:

• I - fuel of all grades, in which the sulfur content is not more than 0.2%;
• II - diesel fuel with a sulfur content for grades L and Z - 0.5%, and for grade A - 0.4%.

The new GOST 305-2013, approaching international standards, divides the fuel into two types according to the mass content of sulfur, regardless of the brand. Type I refers to fuel with a sulfur content of 2.0 g, and type II - 500 mg per kilogram of fuel.

Even type II contains one and a half times more sulfur than type I fuel, which meets international standards.

A large amount of sulfur is harmful emissions into the atmosphere, but also good lubricating properties of the fuel.

Symbols

In GOST 305-82, the fuel was marked with a capital letter L, Z or A (summer, winter or arctic, respectively), the mass fraction of sulfur, the flash point of summer and the pour point of winter fuel. For example, З-0.5 minus 45. The highest grades, the first or without it, characterizing the quality of the fuel, are indicated in the passport for the batch.

Diesel fuel (GOST R 52368-2005) is marked with the letters DT, the grade or class is indicated depending on the filterability and cloudiness temperatures, as well as the type of fuel I, II or III.

The Customs Union has its own document regulating the requirements for fuel, including its symbol. It includes the letter designation DT, the brand (L, Z, E or A) and the environmental factor from K2 to K5, showing the sulfur content.

Since there are many documents, the concept of grade is different in them, and the characteristics are indicated in more detail in the quality passport, today it is not uncommon to announce the type "Sale of diesel fuel pipe grade 1 GOST 30582005". That is, all parameters and quality of fuel correspond to the specified standard, except for the sulfur content.

The main characteristics of diesel fuel

The most important performance indicators that characterize diesel fuel GOST 305-82 (2013) are: cetane number, fractional composition, density and viscosity, temperature characteristics, mass fractions of various impurities.

The cetane number characterizes the flammability of the fuel. The higher this indicator, the less time passes from fuel injection into the working cylinder to the beginning of its combustion, and, consequently, the shorter the engine warm-up time.

The fractional composition determines the completeness of fuel combustion, as well as the toxicity of exhaust gases. When distilling diesel fuel, the moment of complete boil-off of a certain amount of fuel (50% or 95%) is recorded. The heavier the friction composition, the narrower the temperature range and the higher the lower boiling point, which means that the fuel spontaneously ignites in the combustion chamber later.

Density and viscosity affect fuel delivery, injection, filtration and efficiency.

Impurities affect engine wear, corrosion resistance fuel system, the appearance of burning plaque in it.

Filterability limiting temperature is that low temperature at which the thickened fuel no longer passes through a filter with a certain mesh size. Another temperature indicator is the cloud point at which paraffin begins to crystallize, that is, diesel fuel becomes cloudy.

The characteristics of GOST 305-2013 establish the same for all brands: cetane number, mass fraction of sulfur, acidity, iodine number, ash content, carbon content, pollution, water content. The differences relate to temperature and fuel density. In GOST 305-82 there were also differences in coking capacity.

Technical requirements for diesel fuel

So, the cetane number for all grades of fuel is 45, the sulfur content is either 2.0 g or 500 mg per kg. These are the most important fuel indicators.

The density of diesel fuel in accordance with GOST varies from 863.4 kg / cu. m for fuel grades L and E up to 833.5 kg / cu. m for grade A, kinematic viscosity - from 3.0-6.0 sq. mm / s up to 1.5-4.0 sq. mm / s, respectively.

It is characterized by a temperature range from 280 ° С to 360 ° С for all grades of fuel, with the exception of the arctic, for which boiling temperatures are in the range from 255 ° С to 360 ° С.

The characteristics (new GOST) of summer diesel fuel are no different from the characteristics of off-season fuel, with the exception of the limiting filterability temperature.

The flash point of general-purpose winter fuel is 30 ° С, for gas turbine, marine and diesel locomotive - 40 ° С, arctic - 30 ° С and 35 ° С, respectively.

Differences between diesel fuel GOST 305-82 (2013) and EURO

Back in 1993, European quality standards set a cetane number of at least 49. Seven years later, the standard that determined specifications fuel EURO 3, set more stringent indicators. The cetane number should be more than 51, the mass fraction of sulfur should be less than 0.035%, and the density should be less than 845 kg / cu. m. The standards were tightened in 2005, and today the international ones established in 2009 are in effect.

Today in the Russian Federation, diesel fuel GOST R 52368-2005 is produced with a cetane number above 51, a sulfur content of less than 10 mg / kg, a flash point of 55 ° C, a density ranging from 820 to 845 kg / cubic meter. m and a filterability temperature from plus 5 to minus 20 ° C.

Even comparing the first two indicators, it can be concluded that the diesel fuel GOST 305-2013 does not correspond to modern environmental requirements.

Safety requirements

Since diesel fuel is a flammable liquid, the safety measures concern, first of all, protection against fire. Only 3% of its vapors in the total volume of air in the room are enough to provoke an explosion. Therefore, high requirements are imposed on the sealing of equipment and apparatus. Protected are electrical wiring and lighting, tools are used only those that do not even accidentally strike a spark.

Temperature indicators concerning the ability to burn are important for compliance with safety measures and storage conditions for diesel fuel GOST 305-82 (2013).

It is especially important to observe safety measures and temperature regimes in places of long-term storage of many thousands of tons of diesel fuel, for example, in power plants.

Characteristics of diesel fuel for power plants

Diesel power plants still use fuel in accordance with GOST 305-82. Both domestic and foreign equipment is installed on them.

For example, F.G. Wilson recommends for use the highest and first grade of all grades of fuel with a cetane number of 45, sulfur content no more than 0.2%, water and additives - 0.05%, density 0.835 - 0.855 kg / cu. dm. Fuel type I of GOST 305-82 (2013) corresponds to these characteristics.

The contract for the supply of diesel fuel to the power plant must indicate its physical and chemical properties: cetane number, density, viscosity, flash point, sulfur content, ash content. Mechanical impurities and water are not allowed at all.

To check the quality of the supplied fuel and the compliance of its characteristics with the limits established by the state standard, the content of undesirable impurities and the flash point are determined. If equipment malfunctions are observed and its parts wear out intensively, other indicators are also determined.

GOST 305-82 is outdated and replaced, but the new document, introduced in early 2015, has not significantly changed the requirements for diesel fuel for high-speed engines. Maybe someday such fuel will be banned from use at all, but today it is still used both in power plants and in diesel locomotives, heavy military equipment and trucks, the fleet of which has been preserved since the times of the Soviet Union.

Diesel fuel is a rather old, but still demanded type of fuel for piston engines. to improve performance and make diesel fuel environmentally friendly.

What is diesel fuel

Diesel fuel is a heavy oil fraction based on hydrocarbons with a high - 200-350 ° С - boiling point. It is used as a fuel in diesel engines and gas diesel engines.

Why diesel? Because unlike gasoline engines, in which a mixture of gasoline and air is ignited by a spark, in a diesel piston engine fuel ignites spontaneously under strong compression.

Outwardly, diesel fuel is a transparent liquid with a higher viscosity than gasoline, the color of which can be yellow or brown in different shades. The color is influenced by the resins in the fuel.

When burned, any fuel produces energy. Diesel fuel, in addition to this main task, performs several more important functions in the operation of the engine. It lubricates friction surfaces in fuel injectors and pumps, cools the walls of the combustion chamber and regulates exhaust parameters on engines.

Sea and river vessels, diesel locomotives, military and trucks- almost all heavy vehicles are powered by diesel engines.

In recent decades, it has become popular in the developed countries of Europe a car that runs on diesel fuel... Fuel consumption is 40% lower in a diesel engine, while tractive effort, power, cross-country ability and safety exhaust gases more than in gasoline.

It is economical to operate and cost-effective fuel. It is used in stationary diesel power generators and in boilers of autonomous heating systems.

Diesel oil, which is popularly called simply diesel fuel, is a residual diesel fuel with a high viscosity and a boiling point of up to 400 ° C. This type of fuel is used for low-speed engines on water and railway transport, tractors. In addition, leather is impregnated with solarium in the leather industry. Diesel oil is part of the cutting fluid for metal cutting and quenching fluid for heat treatment.

Main characteristics

The cetane number (the main parameter of diesel fuel) characterizes the flammability of the fuel. It determines the period of the combustion delay of the working mixture, that is, the time that elapses between the injection of fuel into the cylinder and the beginning of its combustion. The shorter this period of time, the higher the cetane number and the shorter the engine warm-up time. True, this increases the smoke of the exhaust, which becomes critical at a cetane number above 55.

For the processes of pumping and injection of fuel, its viscosity is important, on which the lubricating characteristics also depend.

Its efficiency and economy depend on it, because the higher the density, the more energy is generated during combustion.

An important characteristic is the amount of sulfur that diesel fuel contains. These are sulfur compounds that reduce the corrosion resistance of the fuel system.

The quality of diesel fuel is also indicated by the limiting filterability temperature, that is, the temperature at which the diesel fuel thickens so much that it no longer passes at all or passes very slowly through a filter with certain dimensions.

It is below the cloud point, that is, the temperature at which the wax contained in the fuel begins to crystallize.

Until 2015, diesel fuel in Russian standards was divided by type. In the state standard, which came into force in January 2015, the division coincides with the division into environmental classes in accordance with the European standard and takes place depending on the sulfur content of the fuel. Sulfur content no more than 350, 50 and 10 mg / kg corresponds to type I, type II and type III according to the outdated and ecological classes K3, K4 and K5 according to the new state standard, respectively.

It is not recommended to use fuels with high sulfur content, as this increases harmful emissions into the atmosphere, accelerates corrosion and wear of the fuel system elements, respectively, increases the cost of frequent replacement filters and oils.

As a rule, an improvement in some properties leads to a deterioration in others. A decrease in sulfur content is a decrease in the lubricating properties of diesel fuel. Therefore, to maintain one of the main functions, various additives are added to the fuel.

Diesel fuel grades

Diesel fuels differ in temperature below which the fuel cannot be used. The limiting filterability temperature is used as a criterion. Moreover, summer and off-season diesel fuel with this indicator not lower than -20 ° C is broken down by grade.

Grade A is characterized by a temperature of at least 5 ° C above zero. For each next grade B, C, D, E and F, the indicator decreases by 5 ° C.

An example is diesel fuel EURO, grade C, type II and III or B new version ecological classes K4 and K5 with a filterability temperature of up to five degrees below zero and a sulfur content of no more than 50 and 10 milligrams per kilogram of fuel.

Diesel fuel classes

The division into classes of diesel fuel for winter or cold climates is not only based on the filterability temperature, the second characteristic is the cloud point.

In winter and arctic diesel fuel, at low temperatures, paraffin crystallization begins, which degrades performance.

If the diesel fuel designation after the diesel fuel designation is not a letter, but a number, it means that this fuel is winter or arctic.

Diesel fuel brands

According to the physicochemical and application conditions, diesel fuel is divided into four types, which are marked with capital letters of the alphabet:

Summer (L), which includes fuel grades A, B, C, D with a limiting filterability temperature from +5 to -10 ° C. This diesel fuel can be used at temperatures not lower than 0 ° C.

Interseasonal (E), grades E and F, with temperatures up to -15 and -20 ° C, respectively, is used in autumn, when the air temperature ranges from +5 to -5 ° C.

Winter (З), which is divided into classes from 0 to 3 and a filterability temperature in the range from -20 to -38 ° C and is used at an air temperature of at least minus 20 ° C.

Arctic (A) fuel of class 4 with a maximum filterability temperature of minus 44 ° C and an ambient temperature of up to minus 50 ° C (in documents, a negative value is often accompanied by the word “minus”, and not an icon to avoid inaccuracies).

Fuel marking

Diesel fuel grades include the name (DT), grade or class, depending on the conditions of use, and environmental class. That is, only two parameters are indicated in the brand: the sulfur content and the limiting temperature of filterability.

Today you can find designations both new and outdated, for example, diesel fuel winter EURO 5 grade F, which stands for winter diesel fuel with a sulfur content of no more than 50 mg / kg and a maximum filterability temperature of up to minus 20 ° C, that is, the most used in conditions Russian winter with high requirements for environmental friendliness fuel.

Until now, there is such a marking L-0.2-62, that is, summer fuel of the highest grade with an indication of the amount of sulfur (200 mg / kg) and a flash point of 62 ° C. Flash point is not the main indicator, but with other characteristics being equal, fuel with a higher temperature is considered the best for fire safety purposes.

How to store diesel fuel

For an ordinary consumer who has a personal car with a diesel engine, the issue of storing diesel fuel is not an issue.

But for where fuel is bought in bulk and stored for a long time, the storage problem is very urgent.

Storage of diesel fuel is possible at a temperature of 20 ° C throughout the year and at temperatures above 30 ° C for six months to a year in sealed containers protected from direct sunlight.

During storage, the fuel should not come into contact with copper, brass or zinc, so that the fuel does not become clogged with the products of chemical reactions with these metals. In addition, it must be protected from moisture and dust and must be free from additives that can degrade during storage. For example, lubricating additives are added to diesel fuels with a high environmental class, which degrade very quickly.

The efficiency of this fuel is high, the scope of its application is growing steadily. New brands of diesel fuel and new sources of its production appear. There are already new developments, and diesel fuel is produced not only from oil. Maybe the future belongs to diesel fuel made from vegetable oils.

(No. 8 for 2010)
Vladimir SHLYAKHOVOY

Sulfur

Diesel fuel is characterized by a number of rather important parameters, and one of the main among them is the sulfur content. In theory, the presence of sulfur improves the lubricating properties of the fuel, but this is simply nothing compared to the problems that arise when it burns while the engine is running. The resulting sulfur oxides react with water vapor to form sulfuric and sulphurous acids, which, in one amount or another, necessarily enter the engine lubrication system. But, besides, what kind of "Euro" can we talk about, if from exhaust pipe fumes of sulfuric acid? Yes, both exhaust gas neutralization systems and particulate filters quickly fail when using sulphurous fuel. Therefore, simultaneously with the growth of requirements for the purity of exhaust gases, the requirements for the quality of fuel naturally grow. Including the sulfur content in it.

For example, in accordance with current standards, the type of fuel must be indicated, depending on the sulfur content in it. In Russia, since 2005, the standard GOST R 52368-2005 (EN 590: 2004) has been in effect. Diesel fuel EURO. Technical conditions ", and in Ukraine on January 1, 2008, a similar standard DSTU 4840: 2007" Diesel fuel of improved quality. Technical conditions ", corresponding to the same standard EN 590: 2004. However, DSTU 3858-99 “Diesel fuel. Technical conditions ", which replaced GOST 305-82 in Ukraine since 1.09.1999, has not been canceled yet, it will operate along with DSTU 4840: 2007 until the end of 2010.

Table 1. Cetane number and limit sulfur content in different types of diesel fuels, mg / kg, depending on the standard

* Fuel with a sulfur content of not more than 10 mg / kg in accompanying documents may be designated as “sulfur-free”.

Table. 2 Cetane number and sulfur limit in diesel fuels of various environmental norms and standards

* Standard valid in Russia.

** Standards in force in Ukraine.

Thus, in Ukraine it is now possible with equal success to refuel both with diesel fuel of Euro-5 level, containing sulfur in the amount of 10 mg / kg, and “Soviet” diesel fuel, in which the sulfur concentration is 500 (!) Times higher.

Frost resistance

Perhaps the second most important parameter of diesel fuel is its frost resistance, which is inversely proportional to the amount of paraffins in it. When the temperature drops, paraffins tend to crystallize, as a result of which diesel fuel first becomes cloudy, then turns into "jelly", and then completely freezes. Therefore, the inherent characteristics of diesel fuel are its parameters such as cloud point and limiting filterability temperature, which are specific for each type of diesel fuel and are separated from one another by about 10 ºС.

At the same time, both of the above parameters are rather arbitrary, and therefore one should not think that it is possible to painlessly use clouded fuel. Especially if fuel filters do not have heating. Indeed, in this case, their filter elements will very quickly become tightly clogged with paraffin, which can no longer be removed. We will keep silent about the fact that in such a case the further operation of the engine is, in principle, impossible. And to solve the problem, you will have to change very expensive filter elements.

The reason for the turbidity of diesel fuel is the appearance of groups of oriented paraffin molecules, which become centers of crystal formation. At the same time, the minimum allowable temperature for using diesel fuel, at which its normal pumpability through the fuel system through the filter elements is ensured, is at least 2 ºС higher than its cloud point.

As for such a concept as "the limiting temperature of the filterability of diesel fuel", it means the limit at which the cooled diesel fuel is able to pass through a standard filter element at a certain speed. This indicator is used only to determine the ability to start the engine. But if, in this case, use non-heated fuel filters, they will immediately be blocked with paraffin.

To this we can add that a parameter such as the "pour point of diesel fuel" is also normalized, the cause of which is the coalescence of hydrocarbon crystals among themselves into a rigid crystal lattice. The pour point determines the possibility of transportation, refueling, discharge and filling of diesel fuel into tanks and has no practical value for determining the possibility of starting the engine or its operation.

And so that you can easily determine in which temperature ranges you can use one or another diesel fuel, according to the requirements of the standards in its symbol the grade must be specified (depending on the filterability limit temperature, or class), determined by both the filterability temperature and the cloud point.

In this case, the grade is set for fuel intended for use in zones with a temperate climate, and the grade - for the Arctic zones.

Table 3. Requirements for low-temperature properties of diesel fuel (GOST R 52368-2005)

* N / N - not standardized.

At the same time, the Ukrainian DSTU 4840: 2007 provides for the same six grades (AF), but only two classes (0-1) of diesel fuel, as GOST R 52368-2005, regulates a lower sulfur content and a higher cetane number (at least 51 ). Whereas DSTU 3868-99, which will operate in Ukraine until 01.01.2011, provides only two brands of diesel fuel: L - summer and Z - winter.

Table 4. DSTU 3868-99 requirements for low-temperature properties of diesel fuel

In this regard, diesel fuel can be labeled as follows:

- "Diesel fuel EURO in accordance with GOST R 52368-2005 (EN 590: 2004), grade A, type I";

- "Diesel fuel of high quality (Euro) class 1, type II in accordance with DSTU 4840: 2007".

In a word, it is quite difficult to understand all this variety of grades, classes and types of diesel fuel. Theoretically, kerosene can be used as a substitute for winter and arctic diesel fuel for diesel engines. But in practice, this cannot be done, since kerosene has two significant drawbacks. Firstly, its cetane number is about 40, which is too low for normal engine operation. And secondly, kerosene, unlike diesel fuel, does not have lubricating properties, therefore, all rubbing parts in the fuel system (high-pressure fuel pump, plunger pairs, etc.) will quickly become unusable.

This is allowed only in exceptional cases and only as a temporary remedy, especially on old engines with a mechanical injection pump. But even in this case, it is necessary to introduce antiwear and cetane-enhancing additives. It is believed that without damage to the engine, it is possible to add up to 20% kerosene to summer diesel fuel to lower its pour point. But this, too, should be considered only as a last resort, unacceptable for modern engines with high pressure injection.

Cetane number

An important indicator for diesel fuel is the cetane number (CN), which characterizes the flammability rate of the fuel - from the moment of its injection into the cylinder to the start of combustion (autoignition delay period). And the higher the CN, the faster the diesel fuel ignites.

The numerical value of CN is equal to the percentage of cetane (C16H34, the CN of which is taken as 100) in its mixture with α-methylnaphthalene (its cetane number is 0), the flammability of which is equivalent to the test diesel fuel. In this case, the CC is determined by a test on a motor installation.

With a cetane number of less than 40, due to the long period of autoignition delay, the fuel in the cylinder has time to warm up well, therefore the ignition is explosive, the pressure in the cylinder rises sharply, which leads to knocking in the engine. Such work of a diesel engine is called hard, since it causes shock loads on the piston and crankshaft bearings, which leads to their accelerated wear.

The higher the cetane number, the shorter the ignition delay, the smoother the fuel mixture burns, the smoother the engine and the more environmentally friendly the exhaust. But this is good up to certain limits. Diesel fuel with a CCH higher than 55, having a short autoignition delay period, having entered the cylinder, does not have time to warm up well, therefore the pressure in the cylinder increases evenly and the engine runs smoothly. However, this worsens the mixture formation process, since the fuel does not have time to mix well with air, which leads to incomplete combustion of the fuel, a drop in engine power and economy, and an increase in exhaust gas smoke. In addition, diesel fuel with a high CN is significantly more expensive. Therefore, unlike the octane number, which the higher the better, the cetane number has its own operating range of 40 - 55 units, the optimum of which is 51 - 53 units.

At the same time, standard diesel fuel is characterized by a cetane number of 40 - 45, and the highest quality fuel has a cetane number of 51 - 55. According to modern standards, the CC number of summer and winter diesel fuel should be at least 49 units. (According to the EN 590: 2004 standard, the CN must be at least 51, and the cetane index (the same, but determined by calculation) - at least 46.)

To this we can add that the cetane number indirectly testifies to the low-temperature characteristics of the fuel - the lower it is, the lower the pour point. Therefore, summer and winter diesel fuels usually have different CCs, while for Arctic diesel fuel it is on the verge of hard engine operation. But here the soft operation of a diesel engine is often deliberately sacrificed for the sake of ensuring its normal start-up and pumping the fuel through filters in severe frosts. At the same time, diesel fuel High Quality lighter, contains more flammable light fractions and therefore more suitable for starting the engine in cold weather. In addition, the ratio of hydrogen to carbon in the light ends is higher, so less smoke is generated when such diesel fuel is burned.

Coking, ash content and others ...

Other standardized parameters of diesel fuel include its coking capacity, which contributes to the formation of deposits in the combustion chamber and on piston rings, and ash content, which determines the incombustible fuel residue. So, the coking capacity of the ten percent residue remaining after the distillation of the volatile fractions of diesel fuel should be within 0.3%, and the ash content should not exceed 0.01%, whereas according to previous standards, this value was ten times higher.

As for various additives, they are usually industrially added only to special grades of diesel fuel, primarily in the Arctic. Although sometimes manufacturers also throw out special grades of fuel on the market.

These include, for example, Shell V-Power Diesel.

For the first time this fuel was presented in Italy in 2002. And now it has appeared in Ukraine. At the same time, neither Russian nor Belarusian drivers can yet refuel with such fuel, despite the fact that Shell came to Russia much earlier than to Ukraine. In Belarus, there are no Shell filling stations at all.

The new fuel is produced on the basis of Euro-4 diesel (type II), with the addition of a special detergent additive NEMO 2010. At the same time, as the manufacturer declares, the Shell V-Power Diesel composition helps to remove existing carbon deposits and prevents the formation of new deposits in the combustion chamber of the engine, which contributes to the extension of its resource, stable power and improvement of environmental parameters. This fuel contains no more than 0.05% (50 mg / kg) sulfur, but it also costs like AI-95.

According to the assurances of representatives of the Shell company, a mileage of 2,400 km on Shell V-Power Diesel fuel is sufficient for almost complete cleaning of the combustion chamber and injector. Naturally, the advantages of this fuel can be most pronounced when used on used cars, while on new cars the difference will not be noticeable.

Diesel fuel is obtained by refining petroleum, therefore sulfur compounds remain one of its components. Although there is no pure sulfur in the fuel, its derivatives are still present in a fairly large amount (up to 7%). To remove some of the sulfurous substances and improve the environmental friendliness of diesel fuel, they use different kinds purification - hydrocracking and caustic soda alkaline treatment.

The reasons for limiting the sulfur content in fuel are:

1. corrosive effect on piston elements;
2. the appearance of carbon deposits and deposits;
3. premature wear of fuel and exhaust system;
4. exhaust smoke;
5. emission of sulfur compounds and other harmful substances into the atmosphere;
6. non-compliance with standards, which limits the use of cars.

To extend the life of diesel engines and avoid environmental pollution, limits have been adopted on the sulfur content of diesel fuel.

Effect of Sulfur in Diesel Fuel on Engine

The current standards strictly regulate the fractional composition of fuel, including sulfur compounds. However, a certain percentage of such substances still remain, despite the purification and processing of the feedstock. It is very expensive and unprofitable to completely remove sulfides and other sulfurous elements.

The presence of such sulfurous substances when interacting with water vapor leads to the formation of sulfurous and sulfuric acid. As a result, corrosion of metal parts occurs piston group, fuel and exhaust system. The formation of deposits impairs heat dissipation, reduces compression, and limits the mobility of the rings.

The effect of sulfur on fuel properties is also limited by the technical characteristics of the diesel engines themselves, namely:

• power decreases;
• fuel consumption increases;
• power and acceleration characteristics deteriorate.

Due to the high sulfur content in marine fuel or fuel for other diesel engines, the combustion process of the mixture itself changes. As a result, a loss of power, a decrease in efficiency and a deterioration in the dynamics of the diesel engine is possible.

It should be borne in mind that low sulfur content is also not very good for a diesel engine. With a decrease in sulfur compounds below 0.035%, the lubricating properties of the fuel deteriorate. As a result, premature wear appears and the life of the fuel system is reduced. To eliminate this problem, special additives are used.

Diesel fuel environmental standards

A certain balance between the sulfur content and the environmental friendliness of the fuel was achieved with the advent of the corresponding standards (Euro 0-6). These standards regulate the emission of harmful elements and the technical characteristics of diesel fuel. The last adopted options are Euro 5 and 6 (2009 and 2015, respectively), according to which harmful emissions should not exceed the following values:

1. carbon monoxide - 0.5;
2. nitric oxide - 0.18 - 0.08;
3. suspended particles - 0.005.

Hydrocarbons and VOCs are not allowed at all.

Diesel fuel specifications

Cars, trucks, buses and special equipment are refueled in accordance with climatic conditions. There are summer, winter and arctic fuels. According to the temperature of use, the fuel is divided into grades (A-F) and classes (0-4). Such fuel is distinguished by the following indicators:

• cetane number 45-51;
• sulfur content in diesel fuel Euro 5 and 6 - no more than 10 mg;
• filtration temperature - up to -55 ° С;
• density within 0.830-0.860 g / cm 3.

According to Russian GOST, the sulfur content in diesel fuel should also not exceed 10 mg.

If you liked our article and we somehow were able to answer your questions, then we will be very grateful for good review about our site!

All jokes, and when our material was almost ready for publication, the news slipped in the American journal Microbiology: a mushroom was found that produces ... diesel fuel! The miracle tree, in whose wood such an advanced mold lives, grows somewhere in northern Patagonia. I wonder if these mushrooms are familiar with Euro IV?

Of course, such messages are at the level of a journalistic duck. Real diesel fuel consists of about 900 hydrocarbon compounds, and no mushroom can do anything like that. Therefore, we will not chase after "mushroom" fuel, we will limit ourselves to analyzing what is sold at Russian gas stations.

A common horror story: our diesel fuel is complete rubbish, you cannot refuel with it. So let's see how justified these fears are. Looking far ahead, let's say the main thing: although the results obtained reveal a lot of problems, they say unequivocally: the devil is not so terrible as he is portrayed. At least none of the fuel samples that we put up for testing will lead to a sudden death of the engine. But first things first.

To carry out this work, we have attracted six (!) Laboratories in two capitals. We will modestly keep silent about the cost of the work, but it is because of it that we decided to limit ourselves to six samples of diesel fuel from various gas stations - from the capital to those lost in the provinces.

We started, as always, with trips to the gas station. We described the selection method as early as ZR, 2008, No. 1, however ...

SELECTION TECHNIQUE AND GOOD PEOPLE

There is an opinion that every buyer can find out for himself whether high-quality fuel is sold at gas stations. To do this, you just need to ask for a copy of the quality passport. And we tried it.

Hey, my dear, I'm not catching up with something ... I allowed you to shoot? Car to the side, myself - follow me. Understood?

A kind man with a filthy gas station was very unhappy. He jabbed his finger at an ancient piece of paper hanging on his "hut": read and remember if you are so curious, but we do not hold copies. But when we used a camera instead of a copier, he left the shelter and resolutely demanded satisfaction.

This is our job. We will not whip up passions, we will note the main thing: the car did not suffer, the kind person was re-educated, and the certificate is in the photo.

So, six samples have been taken, all 40 liters each. About what parameters we checked and what is called diesel fuel in the country, read below. Let us also remind that the country of Russia is far from southern, and the sampling took place at the end of October. For owners of modern diesel engines who are reluctant to ponder over the contents of the tables, we suggest just taking a look at the photos from the gas station. The further from the start, the less this fuel is suitable for you.

CETANE AND SULFUR, WINTER AND SUMMER

If you don't write “Euro IV” on the dispenser today, you don't respect yourself. Let it be on a clumsy stencil and on a rusty surface, but how it sounds! And it doesn't matter that there is no such brand of diesel fuel neither in the current nor in the future regulatory documents! The mention of "Euro" for now should be considered not as a sign of high quality, but rather as a marketing ploy! Which, by the way, was confirmed by checks and quality passports - nowhere is the coveted word with a Roman numeral in sight.

As for the data obtained, we did not expect such inconsistency. See for yourself - everything is summarized in tables. The spread in the value of the central part was as much as six units. The lowest - 49 units - for samples from container refueling stations of the era of the Cherepanov steam locomotive. And the leader in this nomination is Kirishiavtoservice fuel, which was loaded with 55 cetane units. The promising Euro V is attracted by this parameter! But why? However, more on that below.

From cetane to sulfur. If, according to the old GOST, it was allowed to produce two types of fuel - with a sulfur content of 0.2 and 0.5%, then Euro IV allows only 50 ppm (that is, 50 parts per million), and Euro V generally brings it to the limit of determinability - 10 ppm. This is, respectively, 100 and 500 times less! And we have? The difference in sulfur content is 70 times! Leader - LUKOIL: only 60 ppm. The leader on the other hand is Kirishiavtoservice fuel: 0.41%. And what do quality passports say? And the fact that the purchased Kirish diesel fuel is made according to the ancient GOST 305–82 and really corresponds to it! As for Euro IV, in terms of sulfur content, all samples, except for Lukoil's, are far from these requirements.

Modern diesel is very sensitive to fuel quality.

In modern regulatory documents for diesel fuel, its lubricity is strictly standardized. Sulfur and sulfur compounds act as a kind of lubricant, but they were removed, replacing them with special lubricating additives, which, by the way, are very expensive. In this respect, LUKOIL is again the leader! Although there is very little sulfur in his sample, the contact spot is also the smallest - 268 microns. Great! Diesel oil from BP is also good in this parameter. But a rustic sample, bought at a funny container filling station with the inscription "Euro IV" against the background of a dead tractor, failed in this parameter with a bang!

What kind of fuel did we fill? For summer or winter operation? Maybe for the spring-autumn season, as allowed in GOST R 52368-2005? Two samples from one capital are transitional, from the other are summer, and rural ones are mixed: one is winter, the other is summer. Only 900 km from the Tula region to the Leningrad region, and what seasonal fluctuations: in the north it is still summer, and in the south, in Moscow, it is already autumn. On the highway, in general, the tropical climate alternates with fierce winters.

CARCINOGENS AND AROMATICS

How does the group composition of diesel fuel and its carcinogenic hazard relate? The protocol from the Russian Cancer Center clearly states: the more polycyclic aromatic hydrocarbons (PAHs), the more benz (a) pyrene should be. What do our results give?

In the sample with the minimum content of polycyclic aromatics, benzo (a) pyrene is indeed the least of all. But then there are continuous miracles. Four samples have approximately the same PAH content - about 6%, and the content of the evil carcinogen benzo (a) -pyrene in them differs by 2.5 times. And the funny thing is that in one of the samples from this four, where PAHs are at least slightly, but less, benzo (a) pyrene turned out to be the most! But in the sample with the maximum PAH content, a relatively moderate amount of the aforementioned carcinogen was found. The fact is that aromatic compounds are divided into light and heavy - the latter and include carcinogenic substances in their composition. It is about their presence that benzo (a) pyrene testifies, which is officially recognized as their indicator.

Now for the funnest! According to this analysis, the most humane diesel fuel was the one that was bought ... in a village on the highway. Benz (a) pyrene in it is almost four times less than in Lukoil fuel! Where does such a miracle come from for winter fuel, which barely crawls even in accordance with GOST 305–82 in terms of the flash point parameter and with very weak lubricating properties?

The oil workers laugh: they say, a similar picture is usually observed when winter fuel is made from summer fuel by pouring kerosene into diesel fuel.

There is no need to refuel an old diesel engine with modern diesel fuel, and a new one - with an old one!

THE NOISEST THING

For a whole week, the laboratory building was shaken by the roar of the YaMZ-238 diesel engine - now indignant, now pacified. And the neighbors in the building grumbled: "When will all this end?"

Finished! And they reaffirmed the previous conclusions: there is no need to offer the old diesel engine a new solarium, as well as the new one - the old one. This is the exact opposite of the situation with gasoline. This is because for the working process of any diesel engine, whether old or new, it is not the content of sulfur, carcinogens or the lubricity of the fuel that is important, but its composition, cetane number, viscosity, density, surface tension coefficient, and the presence of combustion catalysts. And most of these parameters are not defined in any way in the Euro fuel standards!

For testing, we took a large diesel engine, because 90% of diesel fuel in the country is consumed by trucks and agricultural machinery, and more than 70% of them are domestic. It is they that largely determine the level of environmental pollution. But since Euro fuels are intended for more modern machines, we have simulated this situation: in addition to the basic adjustments designed for diesel fuel with a low cetane number, we repeated the test cycle with a new adjustment specially selected for "Euro".

Lovers of numbers are again referred to the tables. With basic settings best results in terms of efficiency, one of the fuels with the lowest cetane number showed - 49. This is especially noticeable at low load conditions, where the difference between the samples in some places exceeds 15%. As the load on the engine increases, the difference begins to decrease to 3-4%. The worst result is the diesel fuel with the highest cetane number and that strange - winter one, bought in the village. The motor confirms: it does not tolerate experiments on fuel! But on the adjustments for "Euro" the picture has changed. The optimum of the cetane number immediately shifted to the zone of 52–53 units, but all the same - at a high CN, a deterioration of the process is observed. So, physics cannot be fooled by any pieces of paper!

SMOKE TRACE

In exhaust gases diesel engine there is practically no carbon monoxide CO, since a diesel engine plows on a very poor air-fuel mixture compared to a gasoline engine. There are also significantly less unburned hydrocarbons here than in gasoline engine... But they are the main carriers of carcinogens. And if we recalculate the carcinogenic hazard of exhaust gases, taking into account the CH output, then the laurels of the winner, which we almost awarded the strange fuel from the village with a dead tractor, quickly switched to the sample taken at the BP gas station. But for LUKOIL in this nomination, the trouble came from the high content of benz (a) -pyrene in the initial fuel.

But the main thing in assessing the toxicity of diesel exhaust gases is the content of particulate matter (smoke, that is) and nitrogen oxides. According to the theory, the deviation of the cetane number from optimal value- this was confirmed by tests. True, fuel was released from the village again - everything is not like everyone else's! As for nitrogen oxides, which are trying to pressurize with both urea and recirculation, the easiest way to overcome them is by shifting the injection advance angle back. Look at the table: in this way, having implemented the engine control for Euro fuel, we have reduced the NOx content by more than two times! And in order not to ruin the efficiency and power of the engine, just fuel with improved flammability properties, that is, with a higher cetane number, is required. What is done in Eurosolar.

There is no need to follow the West in the pursuit of the complete elimination of sulfur in fuel!

IS IT POSSIBLE TO BUY DIESEL?

You can buy! But refuel - take a closer look: the range of fuel parameters is crazy. The root cause of the confusion, in our opinion, was the lack of professionalism of the officials who created the paper confusion. As long as several regulatory documents are in force in the country at once, according to which it is possible to produce both Euro minus one and Euro V fuel, there will be no order. And introduced new Technical regulations in its current form, it will not correct the situation, but will only aggravate it.

It is difficult to give specific recommendations on where to go for diesel fuel. After all, the quality of fuel cannot be determined either by taste or color. It remains to trust the passports, which must be at every gas station. You should pay attention to what GOST fuel is made according to. If you are going to feed KamAZ, beaten with life, then it does not need Euro-type fuel at all (we omit the numbers for the above reasons). But it won't hurt him too much, only the fuel consumption due to the non-optimal cetane number will slightly increase and there will be more smoke at high loads. But there will be a gain in terms of the resource of both the engine itself and its fuel equipment.

On the other hand, new foreign-made cars with diesel engines are not allowed to use the fuel used in accordance with the old GOST 305–82. Better to look for another gas station.

And further. What quality of diesel fuel can we talk about if there are only a couple of laboratories in the country that can check this quality? I would invest money in them! But the fashionable prefix "nano" cannot be attached to these laboratories, and without it financing is going on, oh, how tight it is today.

The inscription "EURO IV" on the column is most often a marketing ploy. There is no such thing in our GOSTs!