Nowadays much importance is placed on the problems of energy saving and environmental safety. In particular, these issues are of great significance while servicing fuel equipment.

The water-fuel emulsions are proved to contribute to conservation of fuel and energy resources and improve environmental conditions.  The water-fuel emulsion may consist of different components such as:

(1) water – fuel oil;

(2) water – diesel oil;

(3) water – gasoline; and

(4) water- fuel oil – coal dust.

Water that has entered into fuel oil during transportation, storing or warming up increases its viscosity and it may have negative consequences.  But properly prepared water-fuel emulsions makes it possible to achieve good results.

Often, the content of  water in fuel oil exceeds the admissible limit value (12-16% instead of 1.5 %). It may be difficult to separate water from fuel by sedimentation as density of water and fuel oil are almost the same.  Water does not settle to the bottom of the container and distributes unevenly in the diesel fuel.  As a result, the flame is disturbed, the injectors go out slowly and sometimes it may be troublesome to fire the injectors.

Restarting of the boiler units can cause strong puffs and damages because of accumulated combustible gases.  The regulatory documents state that the water content of the fuel oil that is to be burnt must be 0.3 -1 %.

According to the traditional technologies, there are only two procedures of fuel oil preparation: dehydration and heating.  Water expulsion is an energy-consuming process that leads to the loss of fuel volatile components.

As previously mentioned, sedimentation is time-consuming and does not provide a desirable effect. It is not reasonable to apply chemical or biological methods since they require additional areas, operational and financial expenditures.

The fuel oil emulsion combustion provides for substantial economic effect, improves boiler’s efficiency (3-5 %) and reduces the amount of harmful discharges into the air.

The significant cost savings are possible when adding 10-15% of water into the fuel oil.  More than 20 % of water in the emulsion will lower the quality of the combustion process.  But it is desirable to increase the water content with a view to the waste water disposal. If to increase the water content in fuel oil emulsion up to 50 %, there may be observed some positive environmental impacts since waste water is the main component of the fuel oil emulsion.

The use of homogenized fuel oil emulsion allows for fuel saving, reduction of such discharges as NO x and CO x and improves the quality of the fuel combustion.

How are these effects achieved?

The atomizer disperses fuel oil that is supplied to the burner.  The size of the droplets should be 0.1 – 1 mm.  If there is water in the droplets, it will turn into vapor when heated.  The dispersion of the fuel, being supplied to the burner is increased due to the breakdown of the fuel oil droplets.

Additionally, the fuel and air contact area is extended that will lead to the improvement of the fuel-air mixture quality.  The homogenized fuel oil emulsion is less viscous than fuel oil, which makes the fuel transfer process much easier.

No less important factor that weighs in favour of fuel oil emulsions is that they benefit the durability of the fuel firing equipment.

How to achieve all these effects?

The answer is simple – just to make finely-dispersed and non-segregating fuel oil emulsion. GlobeCore has developed and is still producing  the USB units that contribute to the fuel oil emulsion production.  They are designed to blend liquid petroleum products such as fuel oil, diesel oil or stove fuel with additives and water.  The USB units are equipped with high-accurate electronic control system that ensures the precise metering of components.

The ready-made emulsions can be applied in any heating equipment and stored during a long period of time without settling.

The biggest problem of nowadays is that people have never thought that fuel and power resources are at risk of becoming depleted.  Future generations may pay a high price for such wastefulness of their ancestors.

Heavy fuel oil enjoys a wide application in housing maintenance and utility.

It is difficult to find a boiler house that does not use this dark brown substance to produce heat.

One of the major benefits of heavy fuel oil is its high energy value: 1 kilogram of such substance is able to produce 9150 kilocalories of heat while burning.  If to compare diesel fuel and heavy fuel oil, used for house heating, the latter is proved to be much cheaper.  Viscosity is considered to be one of the essential performance characteristics of heavy fuel oil and depends on the heating temperature.  The fuel oil consumption rate is measured at 80-100ºC/176- 212ºF.

Heavy fuel oil should be pre-warmed because its high viscosity doesn’t allow it to be applied immediately.  It is warmed up by hot steam, but there may be negative consequences as condensed steam may get into the heavy oil fuel and hamper the burning process. As a result, the amount of heat being generated is significantly reduced.

Therefore, much fuel is needed to compensate the losses which will result in significant financial expenditures.  As this method has no chance of success, there should be found another way out.  A method of sedimentation is often used to separate water from oil products.  Though this method is considered very effective, it doesn’t work in cases with heavy fuel oil.  The water is difficult to separate from the oil product since its density is the same as that of heavy fuel oil.  But even in summer, some water may get into the fuel when stored for a long time.

Fuel oil emulsion however, has become an optimal solution to many problems.

The main problem is that it is very difficult to make the obtained substance finely-divided and stable.  Therefore, GlоbeCоre has developed the USB unit that is designed to make finely-divided and high-stable emulsions, based on liquid oil products (heavy fuel oil, diesel oil) and water (pure or waste waters, sream).

Heavy fuel oil efficiency is achieved due to its emulsification in the USB unit.  As a result, the efficiency of the boiler unit is increased as well and provided by such factors as:

(1) water is evenly distributed through the whole substance;

(2) fragmentation and incineration of substance inside the furnace are provided by low fanning blast, eliminating the risk of underburnings;

(3) the emulsion droplets are grinded down in the furnace; and

(4) stack gasses heat recovery;

The fuel oil emulsion gives the possibility of reducing by two times the smoke emissions and three to four times the carbon black emissions.  The benefits of fuel oil emulsion application are given below.

The advantages of fuel oil emulsion

Table 1

Heavy fuel oil is a dark brown liquid that is obtained from petroleum distillation.  Though the composition of heavy fuel oil may vary, there are such basic components as:

(1) long residuum;

(2) tar;

(3) vacuum gas oils;

(4) kerosine-gas oil fractions;

(5) catalytic gas oil;

(6) coker gas oil;

(7) visbreaker tar; and

(8) heavy resins of pyrolysis.

Nowadays, heavy fuel oil enjoys wide application while producing motor fuel or bunker oil and when heating homes due to such performance characteristics as:

(1) high calorific value; and

(2) low ash content;

Additionally, heavy fuel oil provides a luminous flame that ensures good heat transfer in the combustion chamber.

As any other product, furnace fuel oil has some drawbacks such as:

(1) Increased safety requirements;

(2) high sulphur content (about 3.5 %); and

(3) high freezing point (25-30ºС/77-86ºF).

Despite all the drawbacks, heavy fuel oil is still in demand.  Far-sighted use of resources is provided by significant reduction in the fuel and energy resources.

Every year people are trying to find new ways how to save on residential heating costs.  Additionally, the major attempts should be directed to the reduction of harmful discharges into the air resulting from the combustion process.

In our opinion, the solution to many problems may be found in the processing of heavy fuel oil before it is burned in the combustion process.  This method consists in the preparation of fuel oil emulsion that has such advantages as:

(1) fuel combustion intensification ;

(2) waste water disposal; and

(3) reduction of CO2 or NOX emissions;

You may wonder: “Why is this method considered to be cost saving?”.  It’s quite simple: The emulsion consists of the components that are cheaper than heavy fuel oil itself.

To prepare fuel oil emulsion, there may be needed such additives as:

(1) clean water;

(2) water that has been used to blow down into boilers;

(3) water vapor; and

(4) Waste water, contaminated by oil products.

One should remember that a desirable effect from the combustion of fuel oil emulsion may be obtained only if it is prepared in a proper way.  First, a special homogeneous mixture type “water-oil” is prepared.  The diameter of the water droplets constituting a dispersed phase is a few microns.  The properly prepared fuel oil emulsion provides good ignition and stable combustion of fuel.

And now little remains to be done – to choose equipment which provides for the production of high-quality fuel oil emulsion.

Globe Core has developed and is still producing  the USB units that are designed for production of fine emulsion, consisting of liquid oil products (heavy fuel oil, diesel fuel, stove fuel, or oil-sludge) and different additives.

The final product can be transported and stored for a long period of time. Additionally, it benefits the reduction of harmful discharges into the air and allows for cost reduction.