Rafał Urbaniak

This paper presents the results of an experimental investigation of woody biomass combustion under real operating conditions of a heating boiler equipped with an integrated platinum-promoted oxidation catalyst (Pt-OX) and vanadium-based catalytic reactor (V-CAT) system for pollutant emission reduction, particularly nitrogen oxides (NO_x). Various configurations of the catalytic flue gas treatment system were investigated, including single-stage, dual-stage, and multi-stage vanadium- and platinum-based catalytic reactor arrangements. The investigated system incorporated platinum-promoted oxidation catalysts and a vanadium-based monolithic catalytic reactor. No external ammonia or urea injection was applied during the experimental campaign. Therefore, the catalytic system was evaluated under realistic biomass combustion conditions involving nitrogen-containing species naturally generated during fuel conversion processes. The obtained thermal and emission parameters were compared with those recorded during boiler operation without catalytic treatment. The investigated catalytic configurations significantly reduced pollutant emissions, with the highest-performing arrangement decreasing NO emissions from 112 ppm to 11 ppm, corresponding to a reduction efficiency exceeding 90%. The results demonstrate the potential of integrated catalytic reactor systems for improving the environmental performance of small-scale biomass-fired heating units operating under real conditions.

Air pollution with particulate matter (PM), recognized by the EU and WHO as a significant factor affecting human health, is subject to standards. Exceeding these standards on a daily or annual basis poses an increased health risk. This article presents an analysis of data from 2022 to 2024 from the administrative area of Pleszew (Poland), which, in 2023, ranked second in the country in terms of annual PM₁₀ concentration [µg/m³]. The main cause of the poor air quality is identified as so-called “low emissions” resulting from residential heating using high-emission coal-fired boilers. The methods used in this analysis not only identified the main causes of pollutant emissions but also demonstrated the seasonal impact of these sources on air quality, both on an annual and daily basis. The analysis utilized statistical tools such as a mixed linear regression model and Tukey’s post hoc tests performed after analysis of variance (ANOVA). The obtained regression model of PM₁₀ concentration on the outside air temperature (defining the intensity of operation of heating devices) clearly indicates the predicted air pollution. Dividing the day into three time intervals proved to be an effective analytical tool enabling the identification of periods with the highest risk of high PM₁₀ concentrations. The highest average PM₁₀ concentration values were recorded in the autumn and winter months between 3:00 PM and 9:00 PM. The developed methods can serve as fundamental tools for local government authorities, guiding further energy policy directions for the study area to improve the identified situation. At the same time, daily and hourly air pollution analysis clearly confirmed the characteristics of inefficient heat sources, which will allow residents to protect their health by avoiding spending time outdoors during peak particulate matter concentration hours. Until the energy situation in the region changes, this will continue.

This study presents an experimental analysis of two vacuum solar air collectors designed for residential heating applications. The research was conducted from November 2022 to April 2024 in real operating conditions. This study focused on assessing the thermal performance, energy efficiency, and feasibility of integrating these systems into hybrid heating solutions. The first collector (Solar Dragon 2022) utilized five vacuum tubes and achieved a total thermal energy output of 397.67 kWh over five months, with a peak thermal power of 0.55 kW. The second system (Solar Dragon 2023), equipped with 24 vacuum tubes, demonstrated a significantly higher performance, generating 911.69 kWh over the same period, with a peak thermal power of 1.8 kW. The study also identified challenges related to airflow distribution and excessive outlet air temperatures, reaching up to 84 °C in the modified system, which could negatively impact indoor comfort. The findings highlight the potential of vacuum solar collectors as an auxiliary heating source, particularly in transitional seasons, while emphasizing the need for optimized airflow control and thermal regulation strategies to enhance their practical application.

The aim of the research was to develop mathematical models describing the emission of selected pollutants correlated with the residual oxygen content in the flue gas. The correlation was made for low-temperature combustion of wood pellets in biomass boilers and furnaces. The developed models can...

The paper discusses the results of investigations of the change in thermal and emission-related parameters of a heating boiler fueled with biomass after a modification with a proprietary flue gas recirculation system made for this type of equipment. The results provide insight into the combustion process with a multistage flue gas recirculation that materially affected the boiler operation: a reduction in the mass concentration of nitrogen oxides (NO_x) by reducing the combustion temperature. The authors also observed a reduction in the emission of particulate matters (PM) and carbon monoxide (CO). For the investigations, the authors used a heating boiler fitted with an automatic fuel feed (timber pellets) and a proprietary patented flue gas recirculation system (Polish patent Pat. 243395) for low power solid fuel heating boilers. Aside from the measurement of the mass concentration of the emitted pollutants, the research focused on the measurements of the temperature inside the combustion chamber, the temperature of the flue gas and the level of oxygen in the flue gas. The aim of the research was to confirm the validity of using the flue gas recirculation technique to reduce emissions of harmful substances from biomass heating boilers, as a technique not previously used for this group of devices. Moreover, the aim of the research was to test an original engineering solution, in the form of a flue gas distribution valve, and investigate its effect on reducing NO_x emissions and improving other thermal and emission parameters of the boiler. The obtained research results confirm the validity of the chosen actions and provide a positive premise for the practical use of this technology in solid fuel heating boilers.

The paper presents the methods of determination of the actual operation of solid fuel heating boilers in Poland. The analysis was based on an average annual distribution of the actual power outputs of the solid fuel heating boilers operated in four selected locations in Poland. Based on said data, three characteristic percent shares have been estimated of the nominal power outputs, at which the heating boilers in Poland operate throughout the year (divided into four characteristic portions—the seasons of the year). Additionally, for the analysis, the authors took into account the average annual temperature amplitude and the annual air quality information for the discussed locations and analyzed 30 solid fuel heating boilers in terms of their performance in the laboratory certification tests. In the final stage of the investigations, the authors initiated laboratory tests on the application of the combustion quality analyzers and their potential benefits.

This article presents a thorough analysis of the main reasons behind the generation of nitrogen oxides (NO_x) during combustion of coal-derived fuels in low- and medium-power boilers. Tests were made based on data from real-exiting heating systems operating in Poland over the last three years. Results of analytical research were used to conduct original experimental tests indicating the main problems of scattered municipal power engineering in Poland.