michal safar - Academia.edu (original) (raw)
Papers by michal safar
Journal of Ecological Engineering
Zbadano spalanie materialow biomasowych na bazie drewna w polączeniu z syntetycznymi polimerami. ... more Zbadano spalanie materialow biomasowych na bazie drewna w polączeniu z syntetycznymi polimerami. Materialz zawieraly sklejke i drewniane plyty wiorowe. Do porownania uzyto zrebkow z drewna liściastego - drewna bukowego i miekkiego - świerka. Proces spalania scharakteryzowano prowadyc analizą termiczną - termograwimetrią i roznicową kalorymetri€ skaningową. Do oznaczenia zawartosci związkow organicznych i ich pochodnych powstalych w trakcie procesu uzyto pirolitycznej chromatografii gazowej z detekcją spektrometryczną. Zwrocono uwage na związki organiczne zawarte w kompozytach drewno-polimer.
Bioresource Technology, 2021
Energies, 2019
Soot and ash as residues from the combustion of peat briquettes were analysed by chemical and min... more Soot and ash as residues from the combustion of peat briquettes were analysed by chemical and mineralogical methods. The study aimed to characterize combustion in domestic boilers of two different emission classes. Ten samples of soot deposited in exhausting ways of boilers were obtained (five of each emission class). The analyses of organic substances in soot were performed using a combination of the methods for the determination of elemental and organic forms of carbon with analytical pyrolysis. Pyrolysis gas chromatography with mass spectrometric detection (Py-GC/MS) allowed the identification of organic compounds belonging to twenty different groups. The major and minor elements in peat briquettes, char and soot, were determined by X-ray fluorescence spectroscopy. The identification of grains and the chemical character of soot was performed using a scanning electron microscope with energy dispersive X-ray spectrometry. The mineral phases in ash were determined by X-ray diffracti...
Inżynieria Mineralna, 2018
2019 IEEE International Conference on Environment and Electrical Engineering and 2019 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe)
Peat briquettes were burned in boilers of emission class 2 and 3 with manual loading. Analytical ... more Peat briquettes were burned in boilers of emission class 2 and 3 with manual loading. Analytical pyrolysis was used for identification and quantification of organic compounds contained in deposits in exhausting ways. Organic compounds of 19 groups were identified in deposits in exhaust ways. Amounts of soot produced by combustion of 1 kg of fuel are comparable for boilers of emission classes 2 and 3 (0.58 ± 0.20 g/1 kg of fuel). It was proved statistically that a higher amount of soot trapped at a boiler decreases the content of bound organic compounds. The deposits from the boilers of emission class 3 contain more organic compounds which indicate the highly carbonized cellulose (benzofurans and dibenzofurans). An increased combustion temperature in boilers of emission class 3 is indicated by increased concentrations of heterocyclic and aliphatic nitrogen compounds.
2017 18th International Scientific Conference on Electric Power Engineering (EPE), 2017
Waste engineering wood in the form of chipboard and plywood is a potential source of renewable en... more Waste engineering wood in the form of chipboard and plywood is a potential source of renewable energy in boilers for biomass combustion. The conditions causing the silicate melt slagging during combustion were studied by proximate analysis, mineralogical analysis using X-ray diffraction, scanning electron microscope with energy dispersive analyser and thermogravimetry. Slags are formed by refractory mineralogical phases of Ca, Si, Ti and Al.
Energy Procedia, 2019
District heating networks are commonly addressed in the literature as one of the most effective s... more District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand-outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
Applied Energy, 2019
Catalytic effects of potassium on biomass thermochemical reactions are studied. • Crystallinity o... more Catalytic effects of potassium on biomass thermochemical reactions are studied. • Crystallinity of cellulose decreases with increasing potassium concentration. • Reactivity of biomass impregnate by potassium in pyrolysis is intensified. • Ignition temperature of treated biomass is lowered slightly, whereas its burnout temperature is reduced profoundly. • Substantial time saving can be achieved for potassium-impregnated biomass in torrefaction.
Journal of Ecological Engineering
Zbadano spalanie materialow biomasowych na bazie drewna w polączeniu z syntetycznymi polimerami. ... more Zbadano spalanie materialow biomasowych na bazie drewna w polączeniu z syntetycznymi polimerami. Materialz zawieraly sklejke i drewniane plyty wiorowe. Do porownania uzyto zrebkow z drewna liściastego - drewna bukowego i miekkiego - świerka. Proces spalania scharakteryzowano prowadyc analizą termiczną - termograwimetrią i roznicową kalorymetri€ skaningową. Do oznaczenia zawartosci związkow organicznych i ich pochodnych powstalych w trakcie procesu uzyto pirolitycznej chromatografii gazowej z detekcją spektrometryczną. Zwrocono uwage na związki organiczne zawarte w kompozytach drewno-polimer.
Bioresource Technology, 2021
Energies, 2019
Soot and ash as residues from the combustion of peat briquettes were analysed by chemical and min... more Soot and ash as residues from the combustion of peat briquettes were analysed by chemical and mineralogical methods. The study aimed to characterize combustion in domestic boilers of two different emission classes. Ten samples of soot deposited in exhausting ways of boilers were obtained (five of each emission class). The analyses of organic substances in soot were performed using a combination of the methods for the determination of elemental and organic forms of carbon with analytical pyrolysis. Pyrolysis gas chromatography with mass spectrometric detection (Py-GC/MS) allowed the identification of organic compounds belonging to twenty different groups. The major and minor elements in peat briquettes, char and soot, were determined by X-ray fluorescence spectroscopy. The identification of grains and the chemical character of soot was performed using a scanning electron microscope with energy dispersive X-ray spectrometry. The mineral phases in ash were determined by X-ray diffracti...
Inżynieria Mineralna, 2018
2019 IEEE International Conference on Environment and Electrical Engineering and 2019 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe)
Peat briquettes were burned in boilers of emission class 2 and 3 with manual loading. Analytical ... more Peat briquettes were burned in boilers of emission class 2 and 3 with manual loading. Analytical pyrolysis was used for identification and quantification of organic compounds contained in deposits in exhausting ways. Organic compounds of 19 groups were identified in deposits in exhaust ways. Amounts of soot produced by combustion of 1 kg of fuel are comparable for boilers of emission classes 2 and 3 (0.58 ± 0.20 g/1 kg of fuel). It was proved statistically that a higher amount of soot trapped at a boiler decreases the content of bound organic compounds. The deposits from the boilers of emission class 3 contain more organic compounds which indicate the highly carbonized cellulose (benzofurans and dibenzofurans). An increased combustion temperature in boilers of emission class 3 is indicated by increased concentrations of heterocyclic and aliphatic nitrogen compounds.
2017 18th International Scientific Conference on Electric Power Engineering (EPE), 2017
Waste engineering wood in the form of chipboard and plywood is a potential source of renewable en... more Waste engineering wood in the form of chipboard and plywood is a potential source of renewable energy in boilers for biomass combustion. The conditions causing the silicate melt slagging during combustion were studied by proximate analysis, mineralogical analysis using X-ray diffraction, scanning electron microscope with energy dispersive analyser and thermogravimetry. Slags are formed by refractory mineralogical phases of Ca, Si, Ti and Al.
Energy Procedia, 2019
District heating networks are commonly addressed in the literature as one of the most effective s... more District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand-outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
Applied Energy, 2019
Catalytic effects of potassium on biomass thermochemical reactions are studied. • Crystallinity o... more Catalytic effects of potassium on biomass thermochemical reactions are studied. • Crystallinity of cellulose decreases with increasing potassium concentration. • Reactivity of biomass impregnate by potassium in pyrolysis is intensified. • Ignition temperature of treated biomass is lowered slightly, whereas its burnout temperature is reduced profoundly. • Substantial time saving can be achieved for potassium-impregnated biomass in torrefaction.