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Tytuł:
Effect of spray distance on the microstructure and corrosion resistance of WC - based coatings sprayed by HVOF
Autorzy:
Jonda, Ewa
Łatka, Leszek
Maciej, Artur
Godzierz, Marcin
Gołombek, Klaudiusz
Radziszewski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2204526.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
WC-based powders
AZ31 magnesium alloy
high velocity oxy fuel
HVOF
microstructure
corrosion resistance
stop magnezu AZ31
mikrostruktura
odporność na korozję
natryskiwanie naddźwiękowe cieplne
proszek na bazie węglika wolframu
Opis:
Cermet coatings provide protection against aggressive operating environment of machine and device elements, such as corrosion, wear or high-temperature conditions. Currently WC-based cermet coatings are frequently used in the different industry branches. In this work, conventional WC-based powders (WC-Co and WC-Co-Cr) were sprayed with High Velocity Oxy Fuel (HVOF) onto AZ31 magnesium alloy with different spray distances (320 and 400 mm). The aim of the research was to investigate the effect of the spray distance on the microstructure of the coatings, phase composition and electrochemical corrosion resistance. Results revealed that higher spray distance results in greater porosity, 1.9% and 2.3% for 320 mm and 2.8% and 3.1% for 400 mm in case of WC-Co and WC-Co-Cr coatings, respectively. Also the influence has been observed for coatings microhardness, c.a. 1300 HV0.3 for shorter spray distance, whereas for longer one it was less than 1100 HV0.3. The corrosion resistance estimated in potentiodynamic polarization measurements was the best for WC-Co-Cr coating deposited from the shorter spray distance, corrosion current density was equal to 2.9 µA·cm-2 and polarization resistance was equal to 8424 Ω∙cm2.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 2; art. no. e144610
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations on the Microstructure and Corrosion Performance of Different WC-Based Cermet Coatings Deposited by High Velocity Oxy Fuel Process onto Magnesium Alloy Substrate
Autorzy:
Jonda, Ewa
Łatka, Leszek
Maciej, Artur
Khozhanov, Aleksandr
Powiązania:
https://bibliotekanauki.pl/articles/2201928.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
AZ91 magnesium alloy
HVOF
thermal spraying
metal matrix composite coatings
microstructure
electrochemical corrosion
Opis:
In the field of surface engineering, thermal spraying is very wide adopted in many branches of the industry. The main reasons of such situation are its flexibility as well as cost effectiveness. Among others, High Velocity Oxy Fuel (HVOF) technique is dedicated for spraying hardmetal and cermet coatings, especially for wear- and corrosion resistance. Such type of coating could be a promising candidate as protective layer for magnesium alloys elements. These materials need a strong improvement in the corrosion protection as well as on the field of wear resistance in order to be widely used in the industry. In this work, different WC-based coatings, namely: (i) WC-Co, (ii) WC-Co-Cr and (iii) WC-Cr3C2-Ni manufactured by HVOF spraying, were investigated. The form of all feedstock materials was agglomerated and sintered powder. All coatings were sprayed with the same technological parameters, especially spray distance which was equal to 400 mm on the AZ91 magnesium alloy substrate. The main aim of the studies was to investigate the influence of the powder material on the corrosion resistance of obtained coatings. The manufactured coatings were examined in terms of its microstructure, using scanning electron microscope (SEM) and corrosion performance, which was assessed in the electrochemical corrosion investigations in 3.5% NaCl solution by Tafel method. The study showed that the corrosion resistance increasing in such order: AZ91 < WC-Cr3C2-Ni < WC-Co < WC-Co-Cr. It should be stressed that WC-Cr3C2-Ni coating exhibits very low corrosion performance, which could be effected by relatively high porosity (c.a. 3 vol.%) and because of that the more complex composition promotes creation of many corrosion cells.
Źródło:
Advances in Science and Technology. Research Journal; 2023, 17, 2; 25--35
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance of cryogenic oxygen production unit with exhaust gas bleed for sewage sludge gasification and different oxygen purities
Autorzy:
Kaszuba, Maja
Ziółkowski, Paweł
Mikielewicz, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/27312208.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
thermodynamic analysis
oxy-combustion of syngas
BECCS
cryogenic air separation
penalty production
oxygen production
Opis:
The paper presents a thermodynamic analysis of the integration of a cryogenic air separation unit into a negative CO2 emission gas power plant. The power cycle utilizes sewage sludge as fuel so this system fits into the innovative idea of bioenergy with carbon capture and storage. A cryogenic air separation unit integrated with the power plant was simulated in professional plant engineering and thermodynamic process analysis software. Two cases of the thermodynamic cycle have been studied, namely with the exhaust bleed for fuel treatment and without it. The results of calculations indicate that the net efficiencies of the negative CO2 emission gas power plant reach 27.05% (combustion in 95.0% pure oxygen) and 24.57% (combustion in 99.5% pure oxygen) with the bleed. The efficiencies of the cycle without the bleed are 29.26% and 27.0% for combustion in 95.0% pure oxygen and 99.5% pure oxygen, respectively. For the mentioned cycle, the calculated energy penalty of oxygen production was 0.235 MWh/kgO2 for the lower purity value. However, for higher purity namely 99.5%, the energy penalty of oxygen production for the thermodynamic cycle including the bleed and excluding the bleed was indicated 0.346 and 0.347 MWh/kgO2, respectively. Additionally, the analysis of the oxygen purity impact on the carbon dioxide purity at the end of the carbon capture and storage installation shows that for the case with the bleed, CO2 purities are 93.8% and 97.6%, and excluding the bleed they are 93.8% and 97.8%, for the mentioned oxygen purities respectively. Insertion of the cryogenic oxygen production installation is required as the considered gas power plant uses oxy-combustion to facilitate carbon capture and storage method.
Źródło:
Archives of Thermodynamics; 2023, 44, 3; 63--81
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors Influencing Cavitation Erosion of NiCrSiB Hardfacings Deposited by Oxy-Acetylene Powder Welding on Grey Cast Iron
Autorzy:
Szala, Mirosław
Walczak, Mariusz
Hejwowski, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/2023792.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
hardness
stainless steel
cavitation erosion
cast iron
surface engineering
powder welding
surface roughness
hardfacing
twardość
stal nierdzewna
erozja kawitacyjna
żeliwo
inżynieria powierzchni
spawanie proszkowe
chropowatość powierzchni
utwardzanie
Opis:
The work presents the results of a study on cavitation erosion (CE) resistance of two NiCrSiB self-fluxing powders deposited by oxy-acetylene powder welding on cast iron substrate grade EN-GJL-200. The mean hardness of deposits A-NiCrSiB, C-NiCrSiB is equal to 908 HV, 399 HV and exceeds those of EN-GJL-200 and X5CrNi18-10 reference specimens 197 HV and 209 HV, respectively. To study CE, the vibratory apparatus has been used and tests were conducted according to the ASTM G32 standard. Cavitation eroded surfaces were examined using a profilometer, optical and scanning electron microscopy. The research indicated that the CE resistance, expressed by the cumulative mass loss decreased in the following order C-NiCrSiB > A-NiCrSiB > X5CrNi18-10 > EN-GJL-200. Therefore, hardfacings were characterised by lower cumulative mass loss, in turn, higher CE resistance than the reference sample and therefore they may be applied as layers to increase resistance to cavitation of cast iron machine components. Results indicate that in the case of multiphase materials, hardness cannot be the main indicator for CE damage prediction while it strongly depends on the initial material microstructure. To qualitatively estimate the cavitation erosion damage (CEd) of NiCrSiB self-fluxing alloys at a specific test time, the following factors should be considered: material microstructure, physical and mechanical properties as well as surface morphology and material loss both estimated at specific exposure time. A general formula for the CEd prediction of NiCrSiB deposits was proposed.
Źródło:
Advances in Science and Technology. Research Journal; 2021, 15, 4; 376-386
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of process stability and weld quality of underwater wet flux-cored arc welding of low-alloy high-strength steel with oxy-rutile wire
Autorzy:
Li, Hongliang
Liu, Shixiong
Ma, Qiang
Wang, Pengfei
Liu, Duo
Zhu, Qiang
Powiązania:
https://bibliotekanauki.pl/articles/1955594.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
arc stability
weld quality
low alloy high-strength steel
underwater wet welding
Opis:
The paper described the experimental findings of underwater wet welding of E40 steel using self-shielded flux-cored wire with a TiO2 -FeO-MnO slag system. The arc stability, weld quality and corrosion resistance with different heat inputs were studied. The results showed that the wet welding process of the designed wire displayed good operability in the range of investigated parameters. The microstructure and mechanical properties of the weld metal depended on the heat input. Due to the high fraction of acicular ferrite in the weld metal, the mechanical properties of the weld metal under low heat input had better tensile strength and impact toughness. Fracture morphologies at low heat input had uniform and small dimples, which exhibited a ductile characteristic. The diffusible hydrogen content in the deposited metal obtained at a heat input of 26 kJ/cm significantly reduced to 14.6 ml/100g due to the combined effects of Fe2 O3 addition and the slow solidification rate of molten metal. The microstructure also had a significant effect on the corrosion resistance of the weld metal. The weld metal with high proportions of acicular ferrite at low heat input exhibited the lowest corrosion rate, while the base metal possessed a reduced corrosion resistance. These results were helpful to promote the application of low alloy high strength steel in the marine fields.
Źródło:
Polish Maritime Research; 2021, 3; 100-109
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research and development of a high-performance oxy-fuel combustion power cycle with coal gasification
Autorzy:
Kindra, Vladimir
Rogalev, Andrey
Zlyvko, Olga
Sokolov, Vladimir
Milukov, Igor
Powiązania:
https://bibliotekanauki.pl/articles/1955073.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carbon dioxide
Oxy-fuel combustion
Gasification
energy efficiency
thermodynamic analysis
Opis:
Recent climate changes stimulate the search and introduction of solutions for the reduction of the anthropogenic effect upon the environment. Transition to the oxy-fuel combustion power cycles is an advanced method of CO2 emission reduction. In these energy units, the main fuel is natural gas but the cycles may also work on syngas produced by the solid fuel gasification process. This paper discloses a new highly efficient oxy-fuel combustion power cycle with coal gasification, which utilizes the syngas heat in two additional nitrogen gas turbine units. The cycle mathematics simulation and optimization result with the energy unit net efficiency of 40.43%. Parametric studies of the cycle show influence of the parameters upon the energy unit net efficiency. Change of the cycle fuel from natural gas to coal is followed by a nearly twice increase of the carbon dioxide emission from 4.63 to 9.92 gmCO2/kWh.
Źródło:
Archives of Thermodynamics; 2021, 42, 4; 155-168
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of an innovative steam turbine power plant with oxy-methane combustors
Autorzy:
Kindra, Vladimir Olegovich
Osipov, Sergey Konstantinovich
Zlyvko, Olga Vladimirovna
Shcherbatov, Igor Alexandrovich
Sokolov, Vladimir Petrovich
Powiązania:
https://bibliotekanauki.pl/articles/1955067.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Combined cycle power plant
carbon capture
storage system
precombustion capture
post-combustion capture
oxy-fuel combustion
Opis:
The Rankine cycle steam turbine power plants make a base for world electricity production. The efficiency of modern steam turbine units is not higher than 43–45%, which is remarkably lower compared to the combined cycle power plants. However, an increase in steam turbine power plant efficiency could be achieved by the rise of initial cycle parameters up to ultra-supercritical values: 700–780◦C, 30–35 MPa. A prospective steam superheating technology is the oxy-fuel combustion heating in a sidemounted combustor located in the steam pipelines. This paper reviews thermal schemes of steam turbine power plants with one or two side-mounted steam superheaters. An influence of the initial steam parameters on the facility thermal efficiency was identified and primary and secondary superheater parameters were optimized. It was found that the working fluid superheating in the side-mounted oxy-methane combustors leads to an increase of thermal efficiency higher than that with the traditional boiler superheating in the initial temperature ranges of 700–780◦C and 660–780◦C by 0.6% and 1.4%, respectively.
Źródło:
Archives of Thermodynamics; 2021, 42, 4; 123-140
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of cycle arrangements of the coal-fired thermal power plants with carbon capture
Autorzy:
Kindra, Vladimir Olegovich
Milukov, Igor Alexandrovich
Shevchenko, Igor Vladimirovich
Shabalova, Sofia Igorevna
Kovalev, Dmitriy Sergeevich
Powiązania:
https://bibliotekanauki.pl/articles/1955057.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
combined cycle power plant
carbon capture
storage system
precombustion capture
post-combustion capture
oxy-fuel combustion
Opis:
The electricity production by combustion of organic fuels, especially coal, increases the atmospheric CO2 content, which contributes to global warming. The greenhouse gas emissions by the power production industry may be reduced by the application of CO2 capture and storage systems, but it remarkably decreases the thermal power plant (TPP) efficiency because of the considerable increase of the auxiliary electricity requirements. This paper describes the thermodynamic analysis of a combined cycle TPP with coal gasification and preliminary carbon dioxide capture from the syngas. Utilization of the heat produced in the fuel preparation increases the TPP net efficiency from 42.3% to 47.2%. Moreover, the analysis included the combined cycle power plant with coal gasification and the CO2 capture from the heat recovery steam generator exhaust gas, and the oxy-fuel combustion power cycle with coal gasification. The coal-fired combined cycle power plant efficiency with the preliminary CO2 capture from syngas is 0.6% higher than that of the CO2 capture after combustion and 9.9% higher than that with the oxy-fuel combustion and further CO2 capture. The specific CO2 emissions are equal to 103 g/kWh for the case of CO2 capture from syngas, 90 g/kWh for the case of CO2 capture from the exhaust gas and 9 g/kWh for the case of oxy-fuel combustion.
Źródło:
Archives of Thermodynamics; 2021, 42, 4; 103-121
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cagnazzo Daniela Immacolata, Alcune note su Eschilo (?), P.OXY. XX 2247
Some notes on Aeschylus (?), P.Oxy. XX 2247
Autorzy:
Cagnazzo, Daniela Immacolata
Powiązania:
https://bibliotekanauki.pl/articles/1045678.pdf
Data publikacji:
2020-12-15
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Aeschylus
fragmenta dubia
Greek tragedy
Greek papyrology
Opis:
This paper analyzes P.Oxy. XX 2247, which is attributed to Aeschylus on the paleographic basis. After a general presentation of the papyrus, a linguistic commentary is proposed, suggesting, where it is possible, some remarks and overall reconstruction of the context; moreover, we discuss elements that confirm the attribution of this work to Aeschylus.
Źródło:
Symbolae Philologorum Posnaniensium Graecae et Latinae; 2020, 30; 47-52
0302-7384
Pojawia się w:
Symbolae Philologorum Posnaniensium Graecae et Latinae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Some Inorganic Anions and Organic Compounds as Corrosion Inhibitors of Cu-Zn Alloys in H2SO4 and HNO3 Solutions
Autorzy:
Ahmed, Amal S. I.
Ghanem, Wafaa A.
Hussein, Walaa A.
Gaber, Ghalia A.
Powiązania:
https://bibliotekanauki.pl/articles/351226.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cu-Zn alloys
oxy-acid solution
inhibition efficiency
inorganic anions
organic compounds
Opis:
Evaluation of inorganic and organic compounds as corrosion inhibitors of Cu-Zn alloys in H2 SO4 and HNO3 solutions was studied using potentiodynamic and impedance spectroscopy along with scanning electron microscope (SEM) and energy dispersive X-Ray analyzer (EDX) investigations. The corrosion inhibition of Cu-Zn alloys was investigated in oxy acid solutions using inorganic potassium permanganate and di-hydrogen phosphate, amino acids as environmentally safe materials, commercial cooling water, and green tea extracts. Both potassium permanganate and di-hydrogen phosphate improve the corrosion resistance of Cu-Zn alloys. Phosphate appears more effective as corrosion inhibitor for Cu-Zn alloys than permanganate. The inhibition efficiency (IE%) of the different amino acids such as valine, leucine and lysine was also calculated. The experimental results have shown that amino acid-like lysine can be used as an efficient corrosion inhibitor for the Cu-Zn alloys in oxy acid solutions. This may be due to the presence of two amino groups adsorbed together. For lysine, inhibition efficiency, IE%, of ~87 and ~59 is for H2SO4 and ~96.3 and 54.9 for HNO3 for alloy I and II respectively are observed. Due to the composition of green water have a great effect on the inhibition action on Cu-Zn alloys which reaching 91.8 and 96.5% for Alloy I and 95.4 and 87.1% for Alloy II in 0.5 M H2 SO4 and HNO3 respectively. Although benzotriazole, in cooling water, is an excellent inhibitor suitable for use in a wide variety of environments, it has toxic properties. So, much of the recent researches have focused on formulating new and more environmentally acceptable preservation solutions. The green tea, as plant extract, will be very environmentally friendly. The EDX confirm the formation of a protective layer on the Cu-Zn alloys containing aluminum in Alloy II. This sequence reflects the beneficial effects of Al in Alloy II. The presence of 2.43% Al in Alloy II improves the corrosion resistance due to the formation of thin, transparent, stable and self-healing Al2 O3 layer. This confirmed the results obtained from the potentiodynamic polarization measurements and EIS methods.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 2; 639-651
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
P. Oxy. LX X VII 5123 and the economic relations between the Apion estate and its coloni adscripticii
Autorzy:
Benaissa, Amin
Powiązania:
https://bibliotekanauki.pl/articles/2083697.pdf
Data publikacji:
2020
Wydawca:
Fundacja im. Rafała Taubenschlaga
Tematy:
coloni adscripticii
enapographoi georgoi
Apion estate (Oxyrhynchus) tenancy
viticulture in late-antique Egypt
Opis:
Starting from a detailed interpretation of P. Oxy. LXXVII 5123 (ad 555), I argue that the Apion estate favoured a tenancy arrangement with its enapographoi georgoi, the farmers registered on its tax-rolls. Such leases left them with a marketable surplus of the produce in remuneration, which they could sell either to their own estate or to outside parties. Contrary to the now current view of Apionic enapographoi georgoi as directly managed permanent employees or wage labourers, the evidence reviewed suggests that they were not an economically distinct and homogenous labour group.
Źródło:
The Journal of Juristic Papyrology; 2020, 50; 49-66
0075-4277
Pojawia się w:
The Journal of Juristic Papyrology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of addition oxy-hydrogen gas (HHO) on vehicle engines performance and emissions
Autorzy:
Nabil, Tamer
Khairat Dawood, Mohamed M.
Powiązania:
https://bibliotekanauki.pl/articles/95358.pdf
Data publikacji:
2019
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
HHO gas
engine performance
gas emissions
gaz HHO
wydajność silnika
emisja gazów
Opis:
The electrolysis process of water produces oxy-hydrogen (HHO) gas that can be used as an energy source to solve the shortage problem of fossil fuel and reduces the exhaust emissions of greenhouse gases from vehicles engines. In this study, HHO dry cell generator was designed, fabricated and tested experimentally to investigate its performance. The hybrid internal combustion engines using HHO gas is considered one of the most important studied applications. The vehicle engines performance and gas emissions are investigated for two different engines; 150CC with carburetor and 1300CC with Electronic Control Unit (ECU). The results recorded the consumption of the fuel is reduced by 14.8% for 150CC engine and 16.3% for 1300CC engine. HHO gas reduced the emission gases by 33% and 24.5% reduction in CO and 27.4% and 21% reduction in HC for 150CC and 1300CC engines respectively. HHO gas can be efficient used as a secondary fuel for vehicle engines.
Źródło:
Journal of Mechanical and Energy Engineering; 2019, 3, 2; 177-190
2544-0780
2544-1671
Pojawia się w:
Journal of Mechanical and Energy Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on co-combustion of sewage sludge and coal in oxy-fuel conditions
Badania współspalania mieszanek osadowo-węglowych w warunkach oxy-spalania
Autorzy:
Bień, Jurand D.
Bień, Beata
Czakiert, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/389373.pdf
Data publikacji:
2019
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
sewage sludge
co-combustion
oxy-fuel
sulfur and nitrogen conversion
osady ściekowe
współspalanie z węglem
spalanie tlenowe
współczynnik konwersji siarki i azotu
Opis:
Oxy-fuel co-combustion of municipal dried sewage sludge and coal was conducted to observe the combustion characteristics as well as pollutant emissions generated under different oxygen injection rate in oxy-fuel atmosphere in 0.1 MWt CFB reactor. As a feed gas a mixture of oxygen and carbon dioxide was used. Oxygen concentration in a feed gas varied from 21% to 30% per volume. The following blending ratios of sewage sludge to coal were chosen: 50%, 30% and 10%. Flue gas components were on-line measured by a gas analyzer, determining CO2, CO, SO2, SO3, NO2, NO, N2O, NH3, HCN concentrations by non-dispersive infrared absorption. During the study the influence of oxygen concentration in the gas atmosphere and the mass fraction of sewage sludge in the fuel blend on the emission of sulfur and nitrogen compounds in the O2/CO2 atmosphere with varied proportions of components in the blend were determined. It was found that oxygen concentration in the gas mixture has a significant influence on the process conditions. When the oxygen concentration in the gas mixture increased, the temperature of thermal processing of fuel blends was higher. The proportion of sewage sludge also affected the obtained profiles, which was particularly visible at 21% oxygen content in the gas mixture. Then the conversion ratios of nitrogen and sulfur contained in blending fuel to NO, NO2, N2O, NH3, HCN, SO2, SO3 and H2S were determined. This paper reports some of the major findings obtained from these research activities.
W ramach prac badawczych przeprowadzono proces współspalania komunalnych osadów ściekowych oraz węgla na wielkolaboratoryjnym stanowisku z cyrkulacyjną warstwą fluidalną CWF o mocy 0,1 MWt. Ich celem było rozpoznanie procesu ze szczególnym zwróceniem uwagi na emisję zanieczyszczeń generowanych w trakcie procesu. Badanie przeprowadzono w zmodyfikowanej atmosferze O2/CO2, gdzie stężenie tlenu zmieniano w zakresie od 21% do 35% objętościowo. Termicznemu przekształceniu poddawano mieszankę osadowo-węglowo, gdzie masowy udział osadów ściekowych wynosił odpowiednio 50%, 30% i 10%. Składniki spalin mierzono on-line za pomocą analizatora gazów, określając stężenia związków takich jak CO2, CO, SO2, SO3, NO2, NO, N2O, NH3, HCN, H2O, HCl, HF za pomocą niedyspersyjnej absorpcji w podczerwieni. Analizowano wpływ stężenia tlenu w atmosferze gazowej i frakcji masowej osadów ściekowych w mieszance paliwowej na emisję związków siarki i azotu w atmosferze O2/CO2 przy różnych proporcjach składników w mieszance. Stwierdzono, że stężenie tlenu w mieszaninie gazowej ma znaczący wpływ na warunki realizowanego procesu, a udział masowy osadów ściekowych wpływa na rodzaj substancji emitowanych do atmosfery. Stąd dla poszczególnych warunków procesu wyznaczono współczynniki konwersji azotu i siarki zawartych w mieszance paliwa na składniki gazowe NO, NO2, N2O, NH3, HCN, SO2, SO3 i H2S.
Źródło:
Ecological Chemistry and Engineering. A; 2019, 26, 1-2; 7-18
1898-6188
2084-4530
Pojawia się w:
Ecological Chemistry and Engineering. A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Doświadczenia z tlenowego współspalania osadów ściekowych z węglem w cyrkulacyjnej warstwie fluidalnej
Experiences from oxy co-combustion of sewage sludge and coal in circulating fluidized bed
Autorzy:
Bień, J. D.
Bień, B.
Czakiert, T.
Powiązania:
https://bibliotekanauki.pl/articles/127081.pdf
Data publikacji:
2018
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
osady ściekowe
oxy-spalanie
mieszanka paliwowa
emisje zanieczyszczeń
sewage sludge
oxy-fuel combustion
fuel blends
pollutant emissions
Opis:
Termiczne metody unieszkodliwiania komunalnych osadów ściekowych ze względu na uwarunkowania prawne i techniczne stały się jedną z popularnych form zagospodarowania osadów w Polsce. Proces ten realizowany jest albo poprzez termiczne suszenie osadów do postaci granulek o wysokiej zawartości suchej masy albo poprzez poddanie spalaniu w reaktorach, w tym głównie pracujących w technologii fluidalnej. Obecnie w Polsce funkcjonuje 11 monospalarni o całkowitej przepustowości 160 tys. Mg s.m./rok. Proces spalania w tych obiektach prowadzony jest w atmosferze powietrza, przyczyniając się do znaczących emisji między innymi gazów cieplarnianych. Stąd celem autorów było przeprowadzenie badań współspalania osadów ściekowych z węglem w technologii spalania tlenowego. Badania wykonano na stanowisku wielkolaboratoryjnym pracującym w układzie cyrkulacyjnej warstwy fluidalnej o mocy 0,1 MW mocy cieplnej. Badania procesu spalania mieszanek węglowych o 50, 30 i 10 % udziale masowym osadów przeprowadzono w mieszaninie modyfikowanej o zmiennym udziale tlenu o udziale objętościowym z zakresu od 21 do 30 %. Prowadzono badania emisji zanieczyszczeń, w tym CO2, CO, SO2, SO3, H2S, NO2, NO, N2O, NH3, HCN.
On the basis of formal and legal conditions sewage sludge utilization by thermal methods has become one of basic methods of sewage sludge management in Poland in recent years. It should be noted that currently in Poland there are 11 mono-incinerators with the total processing capability of 160,000 Mg d.m./year. The process of sludge incineration in these facilities occurs through conventional combustion under conditions of air atmosphere. However, the change in combustion atmosphere involving the replacement of air with the mixture of oxygen and carbon dioxide, where the concentration of oxygen is higher than in air is an interesting technology for reducing CO2 emissions. Other benefit is a reduction in NOx emissions resulting from a substitute of N2 by CO2. It is predicted that the implementation of oxy-fuel technique in connection with circulating fluidized bed technology is a good solution for treatment of wide range of fuels including sewage sludge due to both techniques’ advantages. Oxy-fuel co-combustion of municipal dried sewage sludge and coal was conducted to observe the combustion characteristics as well as pollutant emissions generated under different oxygen injection rate in oxyfuel atmosphere in 0.1 MWth CFB reactor. As a feed gas a mixture of oxygen and carbon dioxide was used. Oxygen concentration in a feed gas varied from 21 to 30 % per volume. The combustion temperature was not fixed since it was a resulting parameter mostly from calorific value of different fuel components and oxygen supplied to the riser. The following blending ratios of sewage sludge to coal were chosen: 50, 30 and 10 %. Flue gas components were on-line measured by a gas analyzer, determining CO2, CO, SO2, SO3, NO2, NO, N2O, NH3, HCN concentrations by non-dispersive infrared absorption. The experimental results showed a strong influence of oxygen concentration on temperature in the combustion chamber during sewage sludge utilization. To realize which component in a flue gas played a main role the conversion ratios of sulfur and nitrogen contained in blending fuel to NO, NO2, N2O, NH3, HCN, SO2, SO3 and H2S were obtained. The values of sulfur conversion ratio to sulfur dioxide were relatively high and exceeded the level of 80 % under oxy-fuel conditions. What’s interesting conversion to SO3 was negligible. In the case of nitrogen conversion ratio remained low in the whole range of investigated conditions.
Źródło:
Proceedings of ECOpole; 2018, 12, 2; 433-442
1898-617X
2084-4557
Pojawia się w:
Proceedings of ECOpole
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coal Char Kinetics of Oxidation and Gasification Reactions
Autorzy:
Lewtak, R.
Hercog, J.
Powiązania:
https://bibliotekanauki.pl/articles/185256.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kinetic parameters
char particle oxidation and gasification
oxy-fuel combustion
parametry kinetyczne
utlenianie cząstek stałych
spalanie tlenowo-paliwowe
Opis:
Experimental investigations and numerical simulations have been conducted in this study to derive and test the values of kinetic parameters describing oxidation and gasification reactions between char carbon and O2 and CO2 occurring at standard air and oxy-fuel combustion conditions. Experiments were carried out in an electrically heated drop-tube at heating rates comparable to fullscale pulverized fuel combustion chambers. Values of the kinetic parameters, obtained by minimization of the difference between the experimental and modeled values of char burnout, have been derived and CFD simulations reproducing the experimental conditions of the drop tube furnace confirmed proper agreement between numerical and experimental char burnout.
Źródło:
Chemical and Process Engineering; 2017, 38, 1; 135-145
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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