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This article extends earlier research by the authors that was devoted to the experimental evaluation of ultra-fine particles produced by the laboratory combustion of beechwood samples. These particles can have severe influence on human health. The current paper presents a parametrical study carried out to assess the influence of the composition of the atmosphere and the temperature on the production of ultra-fine particles during the micro-scale combustion process. The paper presents a laboratory procedure that incorporate the thermogravimetric analysis (TGA) and detailed monitoring of the size distribution of the produced fine particles. The study utilises the laboratory scale identification of the formation and growth of the fine particles during the temperature increase of beech wood samples. It also compares the particle emissions produced by beech heartwood and beech bark. The size of the emitted particles is very strongly influenced by the concentration of light volatiles released from the heated wood sample. From the experimental study, decreasing oxygen content in the atmosphere generally results in higher particulate matter (PM) production.

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Abstract. Fine particles generated from laboratory biomass combustion are discussed in this study. The approach combines the thermogravimetric analysis during thermal decomposition of beech wood sample with detailed monitoring of the size distribution of fine particles produced. Thermogravimetric analysis (TGA) allows monitoring the exact temperature influence of a small fuel sample (wood) according to the desired schedule. The cool aerosol stream leaving TGA enters a Scanning Mobility Particle Sizer (SMPS) where the particle size fractions are separated. The monodisperse aerosol is counted by the condensation particle counter (CPC). The parametrical study was carried out to assess the influence of composition, size and surface of the wood sample on the production and size distribution of ultrafine particles

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Domestic boilers are generally characterized by higher emissions of airborne dust. A commonly used secondary method of reducing emissions in the energy sector is a cyclone. However, its wider expansion in households is limited by, among other things, the low efficiency of particle capture below 1 micrometre in diameter, and it is these sizes that dominate in the flue gas of domestic heating devices. By sharply lowering the temperature of the flue gas below the dew point of the vapour, it condenses on all available surfaces. This effect could increase the diameter of the particles, which could be separated with higher efficiency. A change in the numerical distribution of the fine particles with a temperature and thus the supersaturation of the flue gas was sought. The flue gas passed through an impinger filled with water and isopropyl alcohol at three different temperature regimes. The impinger also served to capture the condensate, which was then subjected to morphology analysis using an electron microscope and determination of particle distribution in the condensate.

Currently, more and more emphasis is placed on improving the air quality and promoting alternative methods of household heating, including the use of biomass. Although these combustion processes are considered to be environment-friendly, the fine and ultra-fine particles are also produced in these cases, which can have a negative impact on human health. The paper presents the results of experimental biomass combustion, where the concentrations and generated particle sizes were monitored during the process. In particular, selected combustion parameters were taken into account such as temperature, amount of oxygen, etc., which have a significant influence on particle formation. The particles were sampled during the measurements with the aim to determine their morphology and chemical compositions. The gathered results are intended to be used for the design of the technical measure based on the principle of temperature stabilization, leading to reducing the concentration of fine and ultra-fine particles produced by small combustion devices.

In this paper, aspects of pulsed direct current (PDC) water splitting are described. Electrolysis is a simple and wellknown method to produce hydrogen. The efficiency is relatively low in normal conditions using conventional DC. PDC in electrolysis brings about many advantages. It increases efficiency of hydrogen production, and performance of the electrolyser may be smoothly controlled without compromising efficiency of the process. In our approach, ultra-short pulses are applied. This method enhances efficiency of electrical energy in the process of decomposition of water into hydrogen and oxygen. Efficiency depends on frequency, shape and width of the electrical pulses. Experiments proved that efficiency was increased by 2 to 8 per cent. One of the prospects of PDC electrolysis producing hydrogen is in increase of efficiency of energy storage efficiency in the hydrogen. There are strong efforts to make the electrical grid more efficient and balanced in terms of production by installing electricity storage units. Using hydrogen as a fuel decreases air pollution and amount of carbon dioxide emissions in the air. In addition to energy storage, hydrogen is also important in transportation and chemical industry.