Fuel oil plays an important role in the energy balance of our country. The quality of fuel oil significantly affects the conditions of its transport, storage, and combustion; release of contaminants to atmosphere; and the operation of main and auxiliary facilities of HPPs. According to the Energy Strategy of Russia for the Period until 2030, the oil-refining ratio gradually increases; as a result, the fraction of straight-run fuel oil in heavy fuel oils consistently decreases, which leads to the worsening of performance characteristics of fuel oil. Consequently, the problem of the increase in the quality of residual fuel oil is quite topical. In this paper, it is suggested to treat fuel oil by additives during its combustion, which would provide the improvement of ecological and economic indicators of oil-fired HPPs. Advantages of this method include simplicity of implementation, low energy and capital expenses, and the possibility to use production waste as additives. In the paper, the results are presented of industrial tests of the combustion of fuel oil with the additive of dewatered carbonate sludge, which is formed during coagulation and lime treatment of environmental waters on HPPs. The design of a volume delivery device is developed for the steady additive input to the boiler air duct. The values are given for the main parameters of the condition of a TGM-84B boiler plant. The mechanism of action of dewatered carbonate sludge on sulfur oxides, which are formed during fuel oil combustion, is considered. Results of industrial tests indicate the decrease in the mass fraction of discharged sulfur oxides by 36.5%. Evaluation of the prevented damage from sulfur oxide discharged into atmospheric air shows that the combustion of the fuel oil of 100 brand using carbonate sludge as an additive (0.1 wt %) saves nearly 6 million rubles a year during environmental actions at the consumption of fuel oil of 138240 t/year.

The possibilities of reducing the viscosity of heavy fuel oil with an increased proportion of residual fractions through the use of nanomaterials, such as carbon nanotubes (CNTs) and...

The experimental investigations of the dynamic viscosity of the M100 brand heavy fuel oil with addition of nanostructured additives at temperatures of 65 °C and 75 °C have been presented. The study of the dynamic viscosity conducted for M100 fuel oil sample with the addition of a suspension of carbon nanotubes dispersed in diproksamin (concentration of 0.0125 wt.% CNT + 0.5 wt.% diproksamin) showed its decrease in almost the entire range of shear rates. The reduction in viscosity was observed even at low shear rates, which indicates the absence of extensive spatial structure in the oil heterogeneous system. Thus, the additive based on carbon nanotubes dispersed in diproksamin, improves the rheological properties of oil, reducing its viscosity to 12-15%. Therefore the energy consumption for fuel oil heating and pumping through pipelines can be reduced.

The results of experimental studies into the viscosity of heavy fuel oils mixed with a liquid additive Diproksamin-157 and a solid additive based on dehydrated carbonate water treatment sludge with a concentration of 0.5 wt. % are presented. Experimentally it has been found out that the viscosity characteristics of fuel oil at the addition of Diproksamin-157 showed nearly 20 % improvement, and at addition the carbonate slurry –7 – 10% improvement. In the case of water-fuel emulsion comprising carbon nanotubes the improvement of the rheology oil characteristics to 10 – 25% by introduction of carbon nanotubes water suspension containing 0.82 wt. % into fuel has been observed. However this result at the moment has only basic value as it is not economically reasonable to use carbon nanotubes in such concentration.

It was shown that nanotechnology methods and materials can be used to create a composite fuel with improved performance characteristics. To reduce the viscosity of various types of hydrocarbon fuel, small amounts of nanoparticles can be added, leading to an additional structure formation, which may result in a change in the rheological properties due to the transition to layerwise shear flow. The possibilities of using carbon nanotubes and dehydrated carbonate sludge of water treatment were analyzed. The presence of a synergistic effect in the joint application of carbon nanotubes with carbonate sludge has been established. It has been shown that the choice of corresponding nanoparticles and their dispersion medium for a particular type of hydrocarbon fuel can significantly improve its performance characteristics.