Diesel fuel sulfur content mg ​​kg. The real situation with diesel fuel. Carcinogens and aromatics

Once the representatives of the foreign automotive industry expressed their assessment of the Russian diesel fuel. They considered that hardly any car engine running on it is capable of overstepping 600,000 kilometers. Practice has shown the opposite, it happens, and they can withstand more mileage. After contacting such specialists from VNII NP for clarification as V. D. Reznikov and A. M. Bakaleinik, the general picture became clear.

Where does the sulfur in the fuel come from?

The presence of sulfur and its compounds in crude oil does not surprise anyone, it is simply contained there in its elemental state. And elemental sulfur, hydrogen sulfide and mercaptans quite aggressively cause corrosion of the metal, if it is allowed to be present in diesel fuel or gasoline. At refineries they are removed from the final product, while mercaptans are strictly limited. For other sulfur compounds, a limit is set, above which it is impossible to go, and it is called the "mass fraction of sulfur".

As this regulation becomes more and more stringent, oil refiners are spending more and more money on the refining and production of diesel fuel, and it also grows in price. Sulfur is not removed completely, a small amount (within the normal range) still occurs in any “commercial” fuel.

A bit of history and chemistry

According to this standard, fuels can be “low sulfur” and “sulphurous”. These words were previously understood ambiguously. When there were no or almost no restrictions on the amount of harmful emissions, the sulfur content standard was needed only so that it would not harm the engine. This approach to fuel production was not as costly as it is now, and falls on the period from 1950 to 1970.

At that time, the "sulfurous" fuel was considered to have 1% sulfur in the composition, "low-sulfur" was limited to 0.2%. In addition to the wear of the components and components of the diesel engine, we did not see any problems. Deposits on the metal formed during the combustion of sulfur compounds SO3 and SO2 were also of concern.

Basically, these compounds are discharged from the engine along with the exhaust gases. The other part of these sulfur products interacts with water vapor and forms sulfuric and sulfurous acids.

The result of their impact on the engine is as follows:

• increased corrosion on the parts of the piston group;
• formation reduces heat transfer from the piston;
• Carbon deposits limit the mobility of the rings and the compression is reduced.

The influence of the base number of oil on the wear of the piston rings of a diesel engine

They began to solve this problem with the help of the chemical composition of the oil. The additives in it were supposed to neutralize acids due to their alkaline and detergent properties. If the oil is changed in a timely manner, then corrosion and the formation of carbon deposits are completely prevented.

Fuels with a high percentage of sulfur require more frequent oil changes, and the mileage of these engines is lower.

Now the situation is somewhat different. The limits have changed at times:

• sulphurous fuel contains 0.2% sulfur;
• low-sulfur - 0.035%.

The whole reason is that they began to fight for the state of the environment. The fleet of cars has grown many times over and in order to save nature, they tightened the emission standards for everything that a car pollutes it with. Accordingly, the manufacturers of equipment have strained, supplying engines with afterburners, catalysts and filters. Changes have been made to the process of preparing the combustion of fuel.

Sulfur compounds in the composition of fuel during combustion increase the level of toxicity of exhaust gases. Therefore, not only equipment is being modernized to meet new standards, but also requirements are being implemented to reduce the percentage of sulfur in motor fuel.

GOSTs and TUs for diesel fuel produced in Russia regulate its quality not only for road vehicles, but also for ships, diesel locomotives, agricultural vehicles, road repair and construction parks. GOST 305-82 covers 85% of the diesel fuel produced. Sulfur percentage 0.2% is taken as a basis. Fuel of the second type allows an increase in the percentage of sulfur up to 0.5%. But now the standards provide for a sulfur content of up to 0.05%.

Stages of tightening the standard for the sulfur content in car fuel

Special technical conditions have been developed for the quality of diesel fuel, which will be used in difficult ecological regions and large cities of the country. The sulfur content of the fuel must be maximum 0.05%.

From 01.11.2011, TU 38.401-58-296-2001 was introduced, limiting the percentage of sulfur in fuel to 0.035%.

A little later, the industry focuses on the production of gasoline and diesel fuel, taking into account the EURO-3 requirements and a sulfur content of no more than 0.015% in gasoline. This process is not one day and lasted for 5 years. This means that the previous technical conditions were still in effect.

When the sulfur percentage became less than 0.035%, the lubricating properties of the diesel fuel deteriorated. This accelerates the wear of the fuel pumps and other elements of the fuel system. There is a need for additives in order to improve the lubricating properties. And they are mainly of imported origin.

Yes, and at domestic gas stations there are still no separate dispensers for various brands of diesel fuel. By mixing different varieties in one container, the seller (the owner of the gas station) degrades the ecological properties of the fuel. And here it is already necessary to resolve the issue of infrastructure so that diesel fuel comes from the manufacturer to the consumer without loss of quality. And this is not a matter of one day.

(No. 8 for 2010)
Vladimir SHLYAKHOVOY

Sulfur

Diesel fuel is characterized by a number of rather important parameters, and one of the main ones 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 sulfuric acid vapors are being felled from the exhaust pipe? 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 the 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 limiting sulfur content in different types of diesel fuels, mg / kg, depending on the standard

Characteristic	DSTU 3868-99	GOST R 52368-2005	DSTU 4840: 2007
Cetane number

* 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

	Cetane number	Sulfur, mg / kg
DSTU 3868-99 **
GOST R 52368-2005 *
EN 590 (up to 1.01.2005)
DSTU 4840: 2007 **
EN 590 (from 1.01.2005)

* 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. With a decrease in temperature, 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 the fuel filters are not heated. 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 ºC 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 a particular diesel fuel can be used, according to the requirements of the standards, its symbol must indicate the grade (depending on the values ​​of the limiting filterability temperature, or class), determined by both the filterability temperature and the temperature clouding.

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)

Indicator name
Limiting temperature of filterability, ºС, not higher
Cloud point temperature, ºС, not higher
Cetane number, not less

* 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, primarily 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 reduce its pour point. But this, too, should be considered only as a last resort, unacceptable on modern engines with high injection pressure.

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 beginning of combustion (autoignition delay period). And the higher the CC, 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 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 the smoke of the exhaust gases. 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 of summer and winter diesel fuel should be at least 49 units. (According to EN 590: 2004, the CN must be at least 51, and the cetane index (the same, but determined by calculation) must be 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, high quality diesel fuel is lighter, contains more flammable light fractions and therefore is 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 the piston rings, and ash content, which determines the non-combustible 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 the 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 still refuel with such fuel, despite the fact that Shell came to Russia much earlier than to Ukraine. In Belarus, there are no Shell gas 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 run of 2,400 km on Shell V-Power Diesel fuel is quite enough 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, so 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, various types of cleaning are used - hydrocracking and alkaline treatment with caustic soda.

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 the 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 the 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 of the piston group, fuel and exhaust systems appears. 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 a 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 a good review of our site!

In 2005, in connection with the government's obligations to reduce the environmental load from exhaust gases, as well as the need to comply with the requirements of European customers for export shipments, it was forced to develop a new standard for diesel fuel in Russia.

GOST R 52368-2005 duplicates all the requirements of the European standard EN 590: 2004 (that is why in the designations of diesel fuel manufactured in accordance with GOST R 52368-2005 the word "EURO" and a reference to "EN 590: 2004" must be present).

In autumn 2009, a new version of BS EN 590: 2009 came into force in Europe. The main differenceits from the previous standard is the exclusion of types of diesel fuel with a sulfur content of 50 mg / kg. Thus, in the European Union standard there is only one norm for the sulfur content - no more than 10 mg / kg.

In the Russian GOST R 52368-2005, the sulfur content rate of up to 350 mg / kg existed until December 31, 2011, and 50 mg / kg will last until December 31, 2014. Diesel fuel with a sulfur content of 10 mg / kg does not have a release date. limited. So, since 2012, the oil refining industry has been producing diesel fuel with a sulfur content of 10 and 50 mg / kg.

According to GOST R 52368-2005, diesel fuel is classified according to two parameters:

1. Limit sulfur content, reflected in the indicator "TYPE" of the fuel, namely:

type I - sulfur content not more than 350 ppm (mg / kg);

type II - sulfur content is not more than 50 ppm (mg / kg);

type III with a sulfur content of less than 10 ppm (mg / kg).

2. Application temperature (climatic zone in which diesel fuel can be used). For a temperate climatic zone, diesel fuel is divided into six grades: A, B, C, D, E, F.

Fuel requirements for temperate climates

For areas with a cold climate, diesel fuel is conventionally divided into five classes: 0, 1, 2, 3, 4.

The term “filterability temperature” was also introduced for the first time by the new GOST R 52368-2005 and denotes the temperature below which diesel fuel does not pass at the required rate (flow rate) through a standard reference filter.

Fuel requirements for cold and arctic climates

Indicator name	Class
Limiting temperature of filterability,° С, not higher
Cloud point,° С, not higher
Density at 15 ° С, kg / cu. m	800-845	800-845	800-840	800-840	800-840
Kinematic viscosity at 40° С, sq. mm / s	1,50-4,00	1,50-4,00	1,50-4,00	1,40-4,00	1,20-4,00
Cetane number, not less	49,0	49,0	48,0	47,0	47,0
Cetane index, not less	46,0	46,0	46,0	43,0	43,0
Fractional composition:
Up to temperature 180° С,% (by volume), no more
Up to a temperature of 340° С,% (by volume), no more
Flash point in a closed cup,° С, not lower

It is important to remember: "SORT" or "CLASS" is the parameter of the temperature characteristic, and "VIEW" is the parameter of the sulfur content in diesel fuel.
Here are some examples of fuel symbol and its decoding.

Example 1. "DT Euro grade F, TYPE II". From this designation, we learn that diesel fuel is intended for a temperate climatic zone (grade F) - a winter grade, and the sulfur content in this fuel is not more than 50 ppm (mg / kg).

Example 2. "DT Euro class 2, type I". The word "CLASS" means that this fuel is intended for the cold and arctic climatic zone. Class "2" indicates that the limiting filterability temperature is minus -32 ° C. Type I indicates that the sulfur content is not more than 350 ppm (mg / kg).

Seasonal use of diesel fuels in the regions of the Russian Federation in accordance with the requirements for the limiting temperature of filterability

Central Federal District	The use of diesel fuel according to the limiting temperature of filterability
	summer period			transitional spring / autumn periods			winter period
	grade A	grade B	grade C	grade D	grade E	grade F and grade 0	class 1	class 2	class 3	class 4
	not higher than +5 ° С	not higher than 0 ° С	not higher	not higher than -10 ° С	not higher than -15 ° С	not higher -20 ° C	not higher -26 ° C	not higher than -32 ° С	not higher than -38 ° С	not higher than -44 ° С
Belgorod region
Bryansk region
Voronezh region
Kursk region
Lipetsk region
Oryol region

In accordance with climatic conditions, it is allowed to change the number of days of the spring and autumn transition periods towards winter or summer by agreement of the local administration with the regional services of the Hydrometeorological Center.

The requirements for diesel fuel in accordance with GOST R 52368-2005 (EN 590: 2009) are as follows:

Indicator name	Meaning
1. Cetane number, not less	51,0
2. Cetane index, not less	46,0
3. Density at 15 ° С, kg / cubic meter	820 - 845
4. Polycyclic aromatic hydrocarbons,% (by weight), no more
View I	350,0
View II	50,0
View III	10,0
6. Flash point in a closed crucible, ° С, above
7. Coking capacity of 10% distillation residue,% (by weight), no more	0,30
8. Ash content,% (by weight), no more	0,01
10. Total pollution, mg / kg, no more
11. Corrosion of a copper plate (3 h at 50 ° C) 6), units on a scale	Class 1
12. Oxidative stability: the total amount of sediment, g / cc. m, no more
13. Lubricity: the corrected diameter of the wear scar at 60 ° C, μm, no more
14. Kinematic viscosity at 40 ° C, sq. mm / s	2,00 - 4,50
15. Fractional composition:
At a temperature of 250 ° C,% (by volume), less
At a temperature of 350 ° C,% (by volume), not less
95% (by volume) is distilled at a temperature, ° С, not higher

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 the wood of which 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 painted. At least none of the fuel samples 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 each 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, and 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 received, 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 drawn 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 ppm), 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 use? 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 the village 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%, while 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 according to 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, having poured 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: it is not necessary 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 cars, we simulated this situation: in addition to 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 adjustments, the best results in terms of economy were shown by one of the fuels with the lowest cetane number - 49. This is especially noticeable at low load conditions, where the difference between 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, the process deteriorates. So, physics cannot be fooled by any pieces of paper!

SMOKE TRACE

In the exhaust gases of a 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 is also much less unburned hydrocarbons here than in a 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 selected 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 the optimal value significantly affects the smoke of the exhaust gases - 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 adjustment 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 the new Technical Regulations being introduced in its current form 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, neither the taste nor the color of the quality of the fuel can be determined. 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 will not hurt him too much, only the fuel consumption due to the non-optimal cetane number will slightly increase and the smoke will increase 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 funding 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!