Effects of Natural Gas Application in Combustion of Pulverized Solid Fuels – Reburning Technology

The energy transition basically implies a phased and significant reduction in the use of fossil fuels, until the final cessation of use in the near future. Renewable energy sources and alternative fuels are an increasingly important part of the energy transition. At the same time, it is necessary that energy systems increase energy efficiency and environmental acceptability. In this regard, great efforts are being made to expand the portfolio of primary fuels in existing large energy systems, e.g. thermal power plants. Therefore, today in large boilers, in order to reduce NOx emission, staged air supply for combustion is inevitably used as the primary measure in the furnace (air staging). In addition to the previous measure, there are many examples of staged fuel supply to the combustion zone (fuel staging), and still a small number of examples of the use of third or additional fuel, e.g. application of biogas or natural gas in combustion of pulverized solid fuels (reburning technology). General, these measures simultaneously increase the efficiency of primary energy conversion from fuel and reduce the emission of undesirable components into the environment. The results of this paper show the extent to which the effects of the use of natural gas in the co-firing of Bosnian coal and waste wood biomass are expressed. In this process there is an additional reduction of NOx in proportion to the share of gas - at a process temperature of 1350 °C and at 10% of the energy content of gas in combustion with coal, compared to emissions without additional fuel, recorded reduction of NOx emissions by more than 250 mg/mn 3.