Fuel oil М-40, М-100, F-5

Fuel oil C-40

Fuel oil is translated from Arabic as scraps, and fuel oil is actually obtained in the result of petroleum refining after separating of gasoline, gas-oil and kerosene components that have lower evaporation temperature. Fuel oil is the scraps of petroleum refining industry, but these scraps are necessary and important for fuel production. Physical and chemical characteristics of fuel oil primarily depend on distillation degree and petroleum composition.   

Fuel oil is a dark-brown compound of  hydrocarbons, petroleum resins, carbenes, asphaltenes, carboides and other metal-containing organic materials. Depending on the degree of distillation of distillate fractions, fuel oils are divided into motor bunker fuel and boiler fuel. Boiler fuels, fuel oil brands M40 and M100, found their application in steam land-type boilers, low-powered heating installations, in private premises, heat generators with not very large power and also in industrial furnaces.   

We will not compare the qualitative characteristics of fuel oil M40 and marine fuel, because entirely different requirements are specified for marine fuel oils of the most widespread brands F-5 and F-12.

Fuel oil C40 with qualitative characteristics excels its direct competitor fuel oil M100. Let’s consider these differences in details. The quality of boiler fuels is determined by viscosity, content of water and sulfur, mechanical impurities, content of ash, heat of combustion, average flash point and setting point. All these factors can visually demonstrate in what conditions one can use the fuel oil.   

Fuel oil M40 is less viscous in comparison with the brand 100, 10-15% diesel fractions are added into it, thus achieving more fluidness and reduction of setting point to 10°C. C100 sets at 25°C already and it is necessary to heat it continually during use and transportation. While M40 in favorable meteorological conditions can be safely transported and transshipped without additional heating. Optimal working temperature for M100 is approximately 60-70°C, that is up by 20 degrees than for M40.

If refer to flash  point, M40 has better result - 90°C, whereas M100 has flash point - 110°, and C200 – 140. Combustion heat of different types of fuel oil differs not greatly and is approximately 39-40,5 thous. kJ/kg. Sulfur content in fuel oil has little influence on its performance characteristics. Mechanical impurities are admitted in the range of 1%, if the quantity is greater, flammable characteristics will suffer.      

Separately we will speak about humidity content. According to standard GOST water content in the fuel oil must not exceed 1%. Reduced fuel oil M40 has no high requirements to the storage conditions, but still in the result of long-term storing it can become over-saturated with moisture, soaking up condensate and humidity, and it cannot but influence its characteristics, flash point is increased and warmth released in the result of combustion is reduced, and, consequently, excess fuel flow takes place. That’s why any fuel oil after long-term storing is sold at the reduced price.    

Reduced fuel oil M40 is referred to not very dangerous and hazardous chemical substances, it is assigned just 4 hazard class, but it does not mean one can neglect safety precautions during work and transportation of fuel oil.

Fuel oil C-100

Any fuel oil is a residual product that is formed when lighter fractions are extracted from the petroleum (kerosene, gasoline and others). From chemical point of view fuel oil is a compound of  hydrocarbons with impurities of petroleum resins, carbenes, asphaltenes, carboides and metal-containing organic materials. Chemical composition of feed stock for obtaining fuel oil and thorough separation of lighter fractions in the process of refining determine chemical and physical characteristics of fuel oil.

Different types of fuel oil differ in viscosity and peculiarities of chemical composition (particularly, sulfur content). Fuel oil brand M100 belong to reduced fuel oils that are used primarily in heating systems, boiler rooms, heat generators and so on. The main its difference from other basic brand of reduced fuel oil M-40 is the absence of diesel fractions (or middle-distillate fractions) in fuel oil M-100.     

Such parameters as heat of combustion, relative viscosity, flash point, setting point, content of ash, percentage of impurities (by mass) and others are used for the estimation of fuel oil quality (and generally for the estimation of conformity with the standards).

During estimation of fuel oil brand M-100 one should pay attention on the basic characteristics:

- the content of different impurities (in mass fractions); percentage of mechanical impurities (by mass) must be in the range from 0,1% to 1% (this parameter for the fuel oil M100 is often close to the extreme range); sulfur content (by mass)
– from 0,5% to 3,5% (relatively high content of sulfur is normal for 100M); water content (by mass) – 0,3% to 1% (M100 in this parameter is still not a leader among different brands of fuel oils);
- relative viscosity of fuel oil M100 is defined at a temperature 80ºC and 100ºC and is checked for the conformity with the standard;
- heat of combustion (fuel oil M100 especially with high percentage of sulfur content has lower heat of combustion in comparison for example with marine fuel oils);
- flash point (is in the range from 80ºC to 110ºC; average value for C100 is close to 100ºC);
- ash content of fuel oils must be in the range from 0,05% to 0,14% (C100 mainly does not differ by low ash content);
- setting point of fuel oil brand C100 is the highest in comparison with other types of fuel oils; it is explained by the absence of middle-distillate fractions in its composition, that are added to the fuel oils to reduce setting point (general range for all fuel oils: from -5ºC to 25ºC).

And one more essential remark concerning purchase of fuel oil. As mentioned above, reduced fuel oil brand M100 is most often used in heating systems, boiler rooms. That’s why price for this fuel oil is slightly reduced during summer season (the problem of heating in summer in most regions is absent). On the other part, during long-term storing M100 (as well as other fuel oils) considerably deteriorate its characteristics (primarily it concerns increase of mass fractions of water and mechanical impurities or pollution), it means that anticipating purchase of great amount of fuel oil is hardly has sense. Obviously, taking these considerations into account, it is necessary to come to  reasonable compromise of described discrepant factors when purchasing fuel oils.     

Fuel oil F-5

With mass fraction of sulfur to 2%
It is intended for use in ship power plants.
It is characterized by relatively low viscosity – not above 5.0 degrees RV at 50 C, low setting point – not above minus 5⁰C and high flash point – not below 80⁰C  
Delivery is carried out mainly in cistern wagons and by water transport in the period of navigation.