Marcin Odziomek

The use of conventional biomass in pulverized fuel boilers is constrained by its poor and highly variable grinding characteristics. This study investigates spray-dried biomass as a controlled model additive for coal–biomass co-firing. Maltodextrin, a water-soluble carbohydrate, was selected to produce biomass particles with well-defined morphology and composition by spray drying under conditions corresponding to primary air temperatures in pulverized-fuel systems. Three fuel types were examined: pulverized coal, spray-dried biomass, and their blends. The resulting biomass particles were characterized in terms of size distribution, morphology, density, and thermal and combustion properties. Spray drying enabled the formation of spherical, homogeneous particles with sizes significantly smaller than those of pulverized coal. Thermogravimetric analysis, Pyro-MS, and combustion tests in a Godbert–Greenwald furnace and a Down-Fire reactor revealed that the addition of spray-dried biomass reduces ignition temperature by approximately 50 K and enhances devolatilization and flame propagation. The observed positive effects were proportional to the biomass content. The results demonstrate that spray-dried biomass provides a reproducible and scalable model fuel with controlled physicochemical properties, offering a novel approach for systematic investigation and optimization of coal–biomass co-firing processes.

The article presents an extensive review of modern technological solutions for pulverized coal combustion, with emphasis on combustion modifiers and biomass co-firing. It highlights the role of coal in the national energy system and the need for its sustainable use in the context of energy transition. The pulverized coal combustion process is described, along with factors influencing its efficiency, and a classification of modifiers that improve combustion parameters. Both natural and synthetic modifiers are analyzed, including their mechanisms of action, application examples, and catalytic effects. Special attention is given to the synergy between transition metal compounds (Fe, Cu, Mn, Ce) and alkaline earth oxides (Ca, Mg), which enhances energy efficiency, flame stability, and reduces emissions of CO, SO₂, and NO_x. The article also examines biomass-coal co-firing as a technology supporting energy sector decarbonization. Co-firing reduces greenhouse gas emissions and increases the reactivity of fuel blends. The influence of biomass type, its share in the mixture, and processing methods on combustion parameters is discussed. Finally, the paper identifies directions for further technological development, including nanocomposite combustion modifiers and intelligent catalysts integrating sorption and redox functions. These innovations offer promising potential for improving energy efficiency and reducing the environmental impact of coal-fired power generation.

Ti₃C₂T_x MXene-modified hydrogels offer a unique platform for exploring the interplay between nanomaterials, hydrogel structures, and biological interactions.

A dispersion of oxygen nanobubbles (O₂-NBs) is an extraordinary gas–liquid colloidal system where spherical gas elements can be considered oxygen transport agents. Its conversion into inhalation aerosol by atomization with the use of nebulizers, while maintaining the properties of the dispersion, gives new opportunities for its applications and may be attractive as a new concept in treating lung diseases. The screening of O₂-NBs interactions with lung fluids is particularly needed in view of an O₂-NBs application as a promising aerosol drug carrier with the additional function of oxygen supplementation. The aim of the presented studies was to investigate the influence of O₂-NBs dispersion combined with the selected inhalation drugs on the surface properties of two types of pulmonary surfactant models (lipid and lipid–protein model). The characteristics of the air–liquid interface were carried out under breathing-like conditions using two selected tensiometer systems: Langmuir–Wilhelmy trough and the oscillating droplet tensiometer. The results indicate that the presence of NBs has a minor effect on the dynamic characteristics of the air–liquid interface, which is the desired effect in the context of a potential use in inhalation therapies.

Inhalation is a non-invasive method of local drug delivery to the respiratory system. This study analyzed the potential use of aqueous dispersion of oxygen nanobubbles (ADON) as a drug carrier with the additional function of oxygen supplementation to diseased lungs. The suitability of the membrane-based method of ADON preparation and, next, the stability of ADON properties during storage and after aerosolization in nebulizers of various designs (jet, ultrasonic, and two vibrating mesh devices) was investigated. The increased oxygen content in the aerosol generated in two mesh nebulizers suggests that the proposed concept may be helpful in the oxygen supplementation during drug delivery by aerosol inhalation without using an additional oxygen source. This application can increase the overall effectiveness of lung disease treatment and pulmonary rehabilitation.

The article presents a method of controlling the size of droplets generated by a system that sprays a high-viscosity liquid containing particles of a solid body, i.e., a catalyst. The work is a continuation of previous research concerning the spraying of liquids with a catalyst, which improves the efficiency of the process. As a result of the conducted CFD calculations, it was found that to bring the catalyst to the system, a droplet with a diameter of at least 30 µm should be generated. The tests were carried out on a laboratory scale on a model isopropanol-water system. A polymer containing Raney nickel particles was added to the suspension. The analysis of the obtained data confirmed the possibility of generating droplets with the desired diameters in order for the liquid carrying the catalyst to not evaporate before it is delivered to the combustion chamber. The designed and constructed test system allows the diameters of the generated droplets to be controlled by changing the settings of the spraying nozzle. Moreover, it enables the parameters of the process, and the spraying itself, to be controlled. In further work, tests on a real 0.5 MW facility are planned. Due to the use of a catalyst, a greater degree of fuel burnout can be obtained, and the dynamics of the combustion process can be improved. Additionally, the parameters of the emitted exhaust gases and ash composition can also be enhanced.

This article presents the concept of a method of improving the dynamics of combustion in boilers operating in power plants, cogeneration plants, and heating plants by introducing a catalyst that is fed with a carrier in the form of droplets. Thanks to the proposed method, a greater degree of fuel burnout can be obtained, which, in turn, results in lower energy consumption in the case of producing the same amount of power. The parameters of the emitted exhaust gases and ash are also improved. The method described in the article involves the adding of a catalyst to the dust pipe of the boiler, which improves the combustion parameters. The catalyst was implemented using a sprayer/nebulizer. In order to obtain the correct flow parameters, the sprayer was modeled using CFD calculations. The calculations include trajectories, velocities and concentrations with regards to various flow parameters. Particular attention should be paid to the model of the evaporation of moving droplets. The results of these calculations enable the parameters that guarantee that the catalyst reaches the dust channel outlet in the desired form to be assessed. The analysis is an introduction to experimental research that is carried out on a medium and large scale.

Independent lung ventilation (ILV) is a life-saving procedure in unilateral pulmonary pathologies. ILV is underused in clinical practice, mostly due to the technically demanding placement of a double lumen endotracheal tube (ETT). Moreover, the determination of ventilation parameters for each lung in vivo is limited. In recent years, the development of 3D printing techniques enabled the production of highly accurate physical models of anatomical structures used for in vitro research, considering the high risk of in vivo studies. The purpose of this study was to assess the influence of double-lumen ETT on the gas transport and mixing in the anatomically accurate 3D-printed model of the bronchial tree, with lung lobes of different compliances, using various ventilation modes. The bronchial tree was obtained from Respiratory Drug Delivery (RDD Online, Richmond, VA, USA), processed and printed by a dual extruder FFF 3D printer. The test system was also composed of left side double-lumen endotracheal tube, Siemens Test Lung 190 and anesthetic breathing bag (as lobes). Pressure and flow measurements were taken at the outlets of the secondary bronchus. The measured resistance increased six times in the presence of double-lumen ETT. Differences between the flow distribution to the less and more compliant lobe were more significant for the airways with double-lumen ETT. The ability to predict the actual flow distribution in model airways is necessary to conduct effective ILV in clinical conditions.