This paper presents the research results of the effect of using calcium oxide and potassium permanganate on the combustion of pellets from wheat bran and beet pulp. The measurements were performed in the technical laboratory of the Centre of Energy Utilization of Non-Traditional Energy Sources in Ostrava. The research examined the effect of the use of chemical substances on the amount of air pollutants from biomass thermal conversion in a low-power boiler and the process temperature. First, we performed technical and elementary analyses of agricultural waste. The raw material was then comminuted, mixed with a selected additive, pelletized, and finally burned in a low-power boiler. The additive was added in three proportions: 1:20, 1:10, and 1:6.67 (i.e., 15%) relative to the fuel weight. The combustion process efficiency was measured using a flue gas analyzer and three thermocouples attached to the data recorder. From the measurement results, we were able to determine the percentage reduction of pollutant emissions into the atmosphere (CO, NO_x, and SO₂) due to the use of additives. Because emission standards are becoming increasingly stringent and fuel and energy prices are rising, the results presented in this article may be useful to agri-food processing plants that want to manage these materials thermally.

A comparative study was carried out of emissions from the catalytic combustion of pellets made from furniture board waste and pellets made from wood mixed with Fe₂O₃. The mass content of the Fe₂O₃ catalyst in the fuel was varied from 0% to 5%, 10%, and 15% in relation to the total dry mass weight of the pellets. The average flame temperature in the boiler was between 730 and 800 °C. The effect of the catalyst concentration in the fuel was analysed with respect to the contents of O₂, CO₂, CO, H_2, and NO_x in the flue gas and the combustion quality of the pellets in the heating boiler. Changes in the CO₂ content and the proportion of unburned combustible components in the combustion residue were assessed. It was established that an increase in the Fe₂O₃ content of the prepared fuels had a positive effect on reducing NO_x, CO, and H₂ emissions. However, the proportion of iron oxide in the tested fuel pellets did not significantly influence changes in their combustion quality. A strong effect of the addition of Fe₂O₃ on the reduction of the average NOx content in the flue gas occurred with the combustion of furniture board fuel, from 51.4 ppm at 0% Fe₂O₃ to 7.7 ppm for an additive content of 15%. Based on the analysis of the residue in the boiler ash pan, the amount of unburned combustibles relative to their input amounts was found to be 0.09–0.22% for wood pellets and 0.50–0.31% for furniture board waste pellets.

This paper presents the results of research on exhaust gases from landfill gas combustion. The measurements were carried out in a reclaimed landfill in Kiełcz (a passive degassing system based on gas flare). The research concerned the effects of selected exhaust gas purification technologies (platinum catalyzer on a ceramic carrier, molecular sieve, copper(II) oxide) for the quality of exhaust gases, and their particulate matter content. This paper aims to indicate which catalytic systems are most suitable for this gas type and their most efficient positioning in the flue gas duct. Due to increasingly stringent emission standards, the outcomes presented in this article could be helpful for landfill owners who wish to avoid paying fines for not complying with applicable limits. The measurements were carried out using a flue gas analyser, a particulate matter analyser fitted with a probe, and four thermocouples connected with the data recorder. The research outcomes determined the percentage reduction of pollutant emissions into the atmosphere (CO, NO_x, and particulate matter) using catalysts. The potential benefits of using catalysts in landfill gas combustion systems due to their operating temperature ranges are discussed.

Using agricultural waste biomass pyrolysis to produce energy sources and biochar may support local economies in rural areas and enhance sustainability in the agricultural sector, reducing dependence on traditional energy sources and fertilisers. To obtain liquid and gaseous forms of biomass fuel, wheat straw pellets were pyrolysed in a screw reactor at temperatures of 300, 400, 500, 600, and 700 °C. An analysis was conducted to assess the influence of process temperature on the physicochemical composition of the raw material and the resulting biochar, pyrolysis liquid, and synthesis gas. The presence of potentially harmful substances in the biochar, whose addition to soil can improve soil properties, was assessed by quantitatively determining polycyclic aromatic hydrocarbons (PAHs). Similar tests were carried out for pyrolysis fluid. The assessments were based on the standards for the most dangerous PAHs: fluorene, anthracene, fluoranthene, benzo[b]fluorine, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene. The results indicated that the total content of polycyclic aromatic hydrocarbons in the biochar ranged from 346.81 µg·kg⁻¹ at 300 °C to 1660.87 µg·kg⁻¹ (700 °C). In the pyrolytic fluid, the PAH content ranged from 58,240.7 µg·kg⁻¹ (300 °C) to 101,889.0 µg·kg⁻¹ (600 °C). It was found that the increase in PAH content in both the biochar and the liquid progressed with increasing pyrolysis temperature. After finding a correlation between the increase in the PAH content in biochar and the increase in the content of high-energy gases in the synthesis gas, it was concluded that it is difficult to reconcile the production of PAH-free biochar in the pyrolysis of biomass with obtaining high-energy gas and pyrolysis oil.

The paper presents the research results on the use of permanent catalytic systems applied to the surface of a low-power boiler deflector. The tests were carried out on a standard 15 kW retort boiler. The boiler was powered by three types of biomass pellets (wood pellets, wheat straw pellets, and hemp expeller). In the research cycle, the influence of the catalysts on the emission of individual compounds, CO, NO_X, particulate matter (PM), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC) and the influence on the temperature in the combustion chamber were examined. The tests used an exhaust gas analyzer, a dust meter, a two-channel aspirator, and a laboratory gas chromatograph stand with a flame ionization detector. Four catalysts (copper, manganese, titanium, and platinum) were prepared for the analysis. Each catalyst had three variants of the active substance concentration on the ceramic support surface: 17.5 g, 35 g, 52.5 g for CuO, TiO₂, MnO₂, and, respectively, 0.05 g, 0.1 g, and 0.15 g for platinum. Concerning the deflector surface, this concentration corresponded to 140, 280, and 420 g·m⁻² for CuO, TiO₂, and MnO₂, and 0.4, 0.8, and 1.2 g·m⁻² for platinum catalysts. All the catalysts used contributed to an increase in the combustion temperature and a reduction in pollutant emissions. The results presented in the paper will allow the implementation of the developed solutions in the industry producing low-power boilers and in already-existing heating installations. The factor that motivates the introduction of changes may be continuously tightening European emission regulations.

This paper presents the results of a multifaceted analysis of the application of catalytic additives to hemp pellets’ combustion in a low-power boiler. The research concerns the effects of five catalytic additives applied inside the boiler’s combustion chamber—based on TiO₂, MnO₂, Cu(NO₃)₂ × 3H₂O, H₂PtCl₆ solution, and 99.5% pure urea solution—on the quality of hemp pellets’ combustion process. For this purpose, technical and elemental analyses of the used fuel were performed. The chemical composition of exhaust gases (NO_x, CO, SO₂, and PM content) was also examined using an exhaust gas analyzer and a dust meter. The highest reductions in emissions of individual pollutants were for CO (−113%; combustion with Ad3), NO_x (−66%; combustion with Ad 4), SO₂ (−48%; combustion with Ad3), and PM (−78%; combustion with Ad1). The study also determined the amount of avoided costs due to the use of catalytic additives, as well as the annual prevented CO₂ emissions to the atmosphere. Due to rising fuel and energy prices, this study could be helpful for biomass boiler owners who would like to burn locally available raw materials and increase the combustion process’ efficiency.