This study investigates the combustion of agricultural biomass rich in alkali elements in the fluidized bed. The experiments were performed with smashed corn cob in a 500 kW fluidized bed combustor which was designed for work under low bed temperatures (650–700 °C). During the experiments, the formed compounds from corn cob combustion were measured by sampling particulate matter, and mineral compositions were determined. Also, the temperature profile of the FBC was established. It was determined that the emissions of K and Na elements from the FBC increased from 4 to 7.3% and from 1.69 to 3%, respectively, changing the bed temperature from 650 to 700 °C. Though alkali emissions are reduced at a 650 °C bed temperature, CO emissions are higher by about 50% compared to the case of 700 °C. The addition of 3% of dolomite reduced the pollutant emissions and alkali emissions as well. Potassium content decreased by about 1% and 4%, respectively, at the bed temperatures of 650 °C and 700 °C. The NOx emissions were less than 300 mg/m³ and did not exceed the limit for medium plants regarding DIRECTIVE (EU) 2015/2193. During extended experiments lasting 8 h, no agglomeration of the fluidized bed was observed. Moreover, the proposed configuration of the FBC and its operational parameters prove suitable for facilitating the efficient combustion of agricultural biomass.

The European industries are transitioning from natural gas usage to renewable gases to enhance climate neutrality and energy security—therefore, hydrogen and ammonia gases could be great alternatives to natural gas. Hydrogen can be produced via electrolysis powered by renewable energy or from natural gas with carbon capture. Moreover, ammonia, composed of hydrogen and nitrogen, could also act as an energy carrier and storage medium. This study investigates the combustion process and efficiency of the hydrogen-enriched NH₃ and CH₄ blends using nonthermal plasma assistance. The experiments were performed with a gas burner with a thermal power of 1.30 kW using fully premixed gas blends. The nonthermal plasma was created with a high-voltage and high-frequency generator at 120 kHz and 8.33 kV. Time-resolved chemiluminescence data for OH* and NH₂* were captured using an ICCD camera, an MIR emission spectrometer and a thermal irradiance flux meter. The results indicated that nonthermal plasma enhances the flame stability and increases the infrared radiation intensity. The MIR spectroscopy showed an intensity increase of 13% for ammonia-hydrogen blends under plasma assistance and heat flux measurements showed a 15% increase for the 70% ammonia and 20% hydrogen mixture. These results demonstrate that plasma-assisted combustion can enhance the efficiency and stability of low-carbon fuel blends, facilitating their integration into current infrastructure while reducing greenhouse gas emissions.