Pub Date : 2021-09-30DOI: 10.35933/paliva.2021.03.03
M. Vojtíṥková, P. Jeníček
Anaerobic sludge digestion is an important tool for converting sludge into a renewable fuel - biogas. However, digested sludge can also be used as a fuel, and a fundamental parameter determining the energy value of digested sludge is as effective as possible dewatering. The main aim of the presented study was to evaluate how the anaerobic digestion (AD) technology and post-treatment technology can affect sludge dewaterability. Two technological alternatives of AD were evaluated: mesophilic (MAD) and thermophilic (TAD). In addition, also the effect of postaeration of digested was evaluated. The dewaterability was assessed using two methods based on centrifugation and filter pressing. Finally, the sludge cake concentration of total suspended solids (TSS) was compared. The results showed the difference in sludge dewaterability for the tested sludges: The sludge cake concentration was similar or slightly higher for MAD compared to TAD sludge. Post-aeration of digested sludge increased sludge cake concentration.
{"title":"Impact of the anaerobic digestion process configuration on the sludge dewaterability","authors":"M. Vojtíṥková, P. Jeníček","doi":"10.35933/paliva.2021.03.03","DOIUrl":"https://doi.org/10.35933/paliva.2021.03.03","url":null,"abstract":"Anaerobic sludge digestion is an important tool for converting sludge into a renewable fuel - biogas. However, digested sludge can also be used as a fuel, and a fundamental parameter determining the energy value of digested sludge is as effective as possible dewatering. The main aim of the presented study was to evaluate how the anaerobic digestion (AD) technology and post-treatment technology can affect sludge dewaterability. Two technological alternatives of AD were evaluated: mesophilic (MAD) and thermophilic (TAD). In addition, also the effect of postaeration of digested was evaluated. The dewaterability was assessed using two methods based on centrifugation and filter pressing. Finally, the sludge cake concentration of total suspended solids (TSS) was compared. The results showed the difference in sludge dewaterability for the tested sludges: The sludge cake concentration was similar or slightly higher for MAD compared to TAD sludge. Post-aeration of digested sludge increased sludge cake concentration.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44111165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.35933/paliva.2021.03.05
K. Ciahotný
The article describes one of the gas desulphurisation technologies which has been developed in the Czech Republic. The technology uses washing solution of organic complexes of various metals to remove H2S from gases. H2S removal is realized by its reaction with complexes of suitable metals with organic reagents. This leads to the H2S oxidation to elemental sulfur and the reduction of the metal protected by the organic complex to a lower oxidation state, which is also bound in the organic complex. Regeneration of the washing solution is performed by oxidation of the reduced form of the complex using oxygen from the air. Complexes of iron with ethylenediaminetetraacetic acid, nitrile triacetic acid or diethylenetriaminopentaacetic acid are used for the preparation of washing solutions. The reaction of the ferric complex of ethylenediaminetetraacetic acid with H2S is accompanied by a change in the color of the washing solution from a deep red color (like red wine) to a light brown color (like coffee with milk) of the ferrous complex of ethylenediaminetetraacetic acid. When this complex is completely depleted, it begins to decompose to black ferrous sulfide by further contact with H2S. This reaction is irreversible. The ferrous complex of ethylenediaminetetraacetic acid can be regenerated by reaction with oxygen, which also takes place at normal or elevated temperatures. The rate of this reaction is much slower compared to the reaction of H2S with the ferric complex. The process was discovered and intensively researched at the Institute for Fuel Research in Prague and later also at the University of Chemistry and Technology Prague. The first pilot plant tests took place with the desulfurization of coke oven gas at the Coking Plant Vítězný únor in Ostrava, where the first operating facility working with the given technology was later built. Another operating facility working with this technology was put into operation at the Antonín Zápotocký High pressure gasification plant in Ústí nad Labem and was used for desulphurization of expansion gases from pressure purification of waste gas of the Rectisol system. The technology was named Sulfint. Both facilities operated successfully until the end of operation of the town-gas supply system in the Czech Republic in the mid-1990s.
{"title":"Sulfint – the Czech gas desulfurization technology","authors":"K. Ciahotný","doi":"10.35933/paliva.2021.03.05","DOIUrl":"https://doi.org/10.35933/paliva.2021.03.05","url":null,"abstract":"The article describes one of the gas desulphurisation technologies which has been developed in the Czech Republic. The technology uses washing solution of organic complexes of various metals to remove H2S from gases. H2S removal is realized by its reaction with complexes of suitable metals with organic reagents. This leads to the H2S oxidation to elemental sulfur and the reduction of the metal protected by the organic complex to a lower oxidation state, which is also bound in the organic complex. Regeneration of the washing solution is performed by oxidation of the reduced form of the complex using oxygen from the air. Complexes of iron with ethylenediaminetetraacetic acid, nitrile triacetic acid or diethylenetriaminopentaacetic acid are used for the preparation of washing solutions. The reaction of the ferric complex of ethylenediaminetetraacetic acid with H2S is accompanied by a change in the color of the washing solution from a deep red color (like red wine) to a light brown color (like coffee with milk) of the ferrous complex of ethylenediaminetetraacetic acid. When this complex is completely depleted, it begins to decompose to black ferrous sulfide by further contact with H2S. This reaction is irreversible. The ferrous complex of ethylenediaminetetraacetic acid can be regenerated by reaction with oxygen, which also takes place at normal or elevated temperatures. The rate of this reaction is much slower compared to the reaction of H2S with the ferric complex.\u0000The process was discovered and intensively researched at the Institute for Fuel Research in Prague and later also at the University of Chemistry and Technology Prague. The first pilot plant tests took place with the desulfurization of coke oven gas at the Coking Plant Vítězný únor in Ostrava, where the first operating facility working with the given technology was later built. Another operating facility working with this technology was put into operation at the Antonín Zápotocký High pressure gasification plant in Ústí nad Labem and was used for desulphurization of expansion gases from pressure purification of waste gas of the Rectisol system. The technology was named Sulfint. Both facilities operated successfully until the end of operation of the town-gas supply system in the Czech Republic in the mid-1990s.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45920923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.35933/paliva.2021.03.01
D. Alekseev, A. Smirnov, Konstantin Chalyy
The aim of this work is both the mathematical relation and the value variation analysis between CRI and CSR indexes. For this aim the physical mathematical model is proposed on the basis of the ISO-test. The physical basis of the model is a material balance of a one piece of coke from the ISO sample. Results of calculating by the model are curves of CSR=f(CRI) which reproduces the regressions in analogy with CSR=a+b.CRI for most coke-producing countries. The model showed that a larger part of CSR=f(CRI) curve is linear and that a universal regression in analogy with CSR=a+b.CRI does not exist. As follows from the model, every piece of coke from the ISO sample has its own CSR=f(CRI) curve with a CRI and CSR point. Between pieces of coke, variations of CRI and CSR values can be explained by the open pore amount, the coke pores’ surface area, the statistical distribution of molecular oriented domains on the basis of Lc and the coke piece mass. In our results, pores with a geometrical orientation from the outside to the center of a coke piece and having a minimum length significantly influence on the coke quality according to CRI and CSR indexes.
{"title":"A mathematical model of relation and origin of variation between CRI and CSR indexes","authors":"D. Alekseev, A. Smirnov, Konstantin Chalyy","doi":"10.35933/paliva.2021.03.01","DOIUrl":"https://doi.org/10.35933/paliva.2021.03.01","url":null,"abstract":"The aim of this work is both the mathematical relation and the value variation analysis between CRI and CSR indexes. For this aim the physical mathematical model is proposed on the basis of the ISO-test. The physical basis of the model is a material balance of a one piece of coke from the ISO sample. Results of calculating by the model are curves of CSR=f(CRI) which reproduces the regressions in analogy with CSR=a+b.CRI for most coke-producing countries. The model showed that a larger part of CSR=f(CRI) curve is linear and that a universal regression in analogy with CSR=a+b.CRI does not exist. As follows from the model, every piece of coke from the ISO sample has its own CSR=f(CRI) curve with a CRI and CSR point. Between pieces of coke, variations of CRI and CSR values can be explained by the open pore amount, the coke pores’ surface area, the statistical distribution of molecular oriented domains on the basis of Lc and the coke piece mass. In our results, pores with a geometrical orientation from the outside to the center of a coke piece and having a minimum length significantly influence on the coke quality according to CRI and CSR indexes.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42805995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.35933/paliva.2021.03.04
Ondřej Hlaváček, T. Hlinčík
Currently in the EU there are bigger tendencies to reduce emissions of carbon dioxide and phasing out of coal mining and combustion. There are some possibilities to transform current coal-fired power plant to steam-gas one. The advantages of steam-gas power plant are lower amount of emissions and higher efficiency unlike coal-fired one and stability of energy production unlike wind and solar one. The article focuses on principle, description and ad-vantages of steam-gas power plant. It also mentions and compares methods of transformation current coal-fired power plant to steam-gas one. Finally, the possible expansion of these power plant in the Czech Republic is discussed, with regard to economic aspects and EU cli-mate change policy.
{"title":"Transformation of coal-fired power plants on steam-gas power plants","authors":"Ondřej Hlaváček, T. Hlinčík","doi":"10.35933/paliva.2021.03.04","DOIUrl":"https://doi.org/10.35933/paliva.2021.03.04","url":null,"abstract":"Currently in the EU there are bigger tendencies to reduce emissions of carbon dioxide and phasing out of coal mining and combustion. There are some possibilities to transform current coal-fired power plant to steam-gas one. The advantages of steam-gas power plant are lower amount of emissions and higher efficiency unlike coal-fired one and stability of energy production unlike wind and solar one.\u0000The article focuses on principle, description and ad-vantages of steam-gas power plant. It also mentions and compares methods of transformation current coal-fired power plant to steam-gas one. Finally, the possible expansion of these power plant in the Czech Republic is discussed, with regard to economic aspects and EU cli-mate change policy.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46462253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.35933/paliva.2021.03.02
M. Staf, B. Votavová
The article deals with the issue of carbon dioxide adsorption on mineral samples, two of which are rich in montmorillonite and one in kaolinite. The last comparative sample is clinoptilolite, which is widely used as a sorbent in agriculture, water treatment, etc. The theoretical part summarizes several current researches on the use of bentonites as adsorbents, both in their raw form and after various chemical treatments. The study presented here does not suggest any modification procedure, but tests untreated samples and samples subjected to calcinations at temperatures of 250-750 ° C. The calcination of units of grams was carried out by means of a carousel TGA, which made it possible to record curves of mass changes and to obtain a sufficient amount of calcinates for further analyses at the same time. From the point of view of achieving the highest specific surface area and the total pore volume, the optimal calcination temperature for the phyllosilicate samples ranged from 250 to 450 °C. Natural zeolite, on the other hand, showed a deterioration of both of these parameters at any temperature exceeding 150 °C. The same temperature dependence was found in the case of adsorption capacities determined by an automatic analyser Autosorb IQ using pure CO2. Measurements on this instrument also confirmed that selected inexpensive natural materials provide comparable adsorption capacities as the commercially available 13X molecular sieve used as a reference sample. Based on the performed analyses, the initial conditions of sample preparation for the upcoming measurement of adsorption properties on a larger apparatus operating in the PSA/TSA mode were determined. The primary aim of the tests using the selfdesigned high-pressure adsorption unit will be to determine the adsorption capacities that will take into account the temperature and pressure conditions in a real postcombustion carbon dioxide capture system. Unlike the automatic analyser described above, it will be possible to quantify the influence of important factors such as: flue gas humidity, the presence of other permanent gases (especially SO2) and last but not least various CO2 partial pressures and absolute pressure during adsorption and desorption. The experiments will verify the extent to which the presence of noncondensing moisture in the gaseous mixture is problematic. In the case of phyllosilicates, it is not just the parallel adsorption of H2O that affects the adsorption capacity available for CO2 capture. It will be empirically determined to what extent the swelling of the sorbent occurs in the wet gas, changing the gas flow through the layer and especially the pressure loss. The results of measurements on high-pressure apparatus will be the basis for the design and construction of a larger pilot scale unit.
{"title":"Low-cost natural carbon dioxide sorbents available in the Czech Republic","authors":"M. Staf, B. Votavová","doi":"10.35933/paliva.2021.03.02","DOIUrl":"https://doi.org/10.35933/paliva.2021.03.02","url":null,"abstract":"The article deals with the issue of carbon dioxide adsorption on mineral samples, two of which are rich in montmorillonite and one in kaolinite. The last comparative sample is clinoptilolite, which is widely used as a sorbent in agriculture, water treatment, etc. The theoretical part summarizes several current researches on the use of bentonites as adsorbents, both in their raw form and after various chemical treatments. The study presented here does not suggest any modification procedure, but tests untreated samples and samples subjected to calcinations at temperatures of 250-750 ° C.\u0000The calcination of units of grams was carried out by means of a carousel TGA, which made it possible to record curves of mass changes and to obtain a sufficient amount of calcinates for further analyses at the same time. From the point of view of achieving the highest specific surface area and the total pore volume, the optimal calcination temperature for the phyllosilicate samples ranged from 250 to 450 °C. Natural zeolite, on the other hand, showed a deterioration of both of these parameters at any temperature exceeding 150 °C. The same temperature dependence was found in the case of adsorption capacities determined by an automatic analyser Autosorb IQ using pure CO2. Measurements on this instrument also confirmed that selected inexpensive natural materials provide comparable adsorption capacities as the commercially available 13X molecular sieve used as a reference sample. Based on the performed analyses, the initial conditions of sample preparation for the upcoming measurement of adsorption properties on a larger apparatus operating in the PSA/TSA mode were determined.\u0000The primary aim of the tests using the selfdesigned high-pressure adsorption unit will be to determine the adsorption capacities that will take into account the temperature and pressure conditions in a real postcombustion carbon dioxide capture system. Unlike the automatic analyser described above, it will be possible to quantify the influence of important factors such as: flue gas humidity, the presence of other permanent gases (especially SO2) and last but not least various CO2 partial pressures and absolute pressure during adsorption and desorption.\u0000The experiments will verify the extent to which the presence of noncondensing moisture in the gaseous mixture is problematic. In the case of phyllosilicates, it is not just the parallel adsorption of H2O that affects the adsorption capacity available for CO2 capture. It will be empirically determined to what extent the swelling of the sorbent occurs in the wet gas, changing the gas flow through the layer and especially the pressure loss.\u0000The results of measurements on high-pressure apparatus will be the basis for the design and construction of a larger pilot scale unit.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45207969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.35933/paliva.2021.02.04
Dominik Schlehöfer, A. Vráblík, R. Černý
On 1st January 2020, a drastic change came into force to reduce the maximum permitted sulphur content of marine fuels from 3.5 % wt. to 0.5% wt. for the deep sea and oceans. This change had an impact not only on the shipping industry, but also on the entire refining sector, be it oil marketers, refineries, traders and manufacturers of fuels and end-user additives. In 2017 and 2018, the situation regarding marine fuels and the impending IMO 2020 changes was mapped out in the articles "Marine Fuels Post-2020" and "Marine Fuels Post-2020 II" published in Paliva journal. These publications are directly followed by the present article, which summarises the current data (as of early 2021) and experience from the past year, the first year of implementation of IMO 2020. The article describes how vessel operators have coped with this drastic reduction of the maximum sulphur content of marine fuels, as well as the economic consequences of this change.
{"title":"Marine fuels after 2020 III","authors":"Dominik Schlehöfer, A. Vráblík, R. Černý","doi":"10.35933/paliva.2021.02.04","DOIUrl":"https://doi.org/10.35933/paliva.2021.02.04","url":null,"abstract":"On 1st January 2020, a drastic change came into force to reduce the maximum permitted sulphur content of marine fuels from 3.5 % wt. to 0.5% wt. for the deep sea and oceans. This change had an impact not only on the shipping industry, but also on the entire refining sector, be it oil marketers, refineries, traders and manufacturers of fuels and end-user additives. In 2017 and 2018, the situation regarding marine fuels and the impending IMO 2020 changes was mapped out in the articles \"Marine Fuels Post-2020\" and \"Marine Fuels Post-2020 II\" published in Paliva journal. These publications are directly followed by the present article, which summarises the current data (as of early 2021) and experience from the past year, the first year of implementation of IMO 2020. The article describes how vessel operators have coped with this drastic reduction of the maximum sulphur content of marine fuels, as well as the economic consequences of this change.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47827183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.35933/paliva.2021.02.03
K. Vondráková, T. Hlinčík
In recent years, efforts to use environmentally friendly resources and minimizing environmental impacts throughout the life cycle of products. The important point is that greening and reducing emissions from energy industry and transport. If we focus on emissions from transport, these are mainly CO2, NOx and particulate emissions. These emissions arise mainly from the use of fossil fuels. In the transport sector, local CO2, NOx and particulate emissions can be reduced by introducing hydrogen mobility that does not produce these emissions and can be based on renewable energy sources. The contribution shows that the overall efficiency of the conversion of chemical energy into mechanical energy of the vehicle wheel movement, the socalled Well to Wheel (WtW) is the highest in the case of petroleum fuels (84%). The lowest efficiency WtW is in the case of hydrogen produced from water electrolysis. When assessing the overall efficiency WtW (fuel and utilization) is the highest value (18–21 %) in the case of a combination of fossil fuel and the combustion engine. The lowest value of the total efficiency is for the combination of hydrogen produced by electrolysis of water and the combustion engine (3–5 %).
{"title":"Hydrogen for transport","authors":"K. Vondráková, T. Hlinčík","doi":"10.35933/paliva.2021.02.03","DOIUrl":"https://doi.org/10.35933/paliva.2021.02.03","url":null,"abstract":"In recent years, efforts to use environmentally friendly resources and minimizing environmental impacts throughout the life cycle of products. The important point is that greening and reducing emissions from energy industry and transport. If we focus on emissions from transport, these are mainly CO2, NOx and particulate emissions. These emissions arise mainly from the use of fossil fuels. In the transport sector, local CO2, NOx and particulate emissions can be reduced by introducing hydrogen mobility that does not produce these emissions and can be based on renewable energy sources. The contribution shows that the overall efficiency of the conversion of chemical energy into mechanical energy of the vehicle wheel movement, the socalled Well to Wheel (WtW) is the highest in the case of petroleum fuels (84%). The lowest efficiency WtW is in the case of hydrogen produced from water electrolysis. When assessing the overall efficiency WtW (fuel and utilization) is the highest value (18–21 %) in the case of a combination of fossil fuel and the combustion engine. The lowest value of the total efficiency is for the combination of hydrogen produced by electrolysis of water and the combustion engine (3–5 %).","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44317508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.35933/paliva.2021.02.01
D. Řimnáčová, Dominik Vöröš, L. Medvecká, E. Geršlová
Textural properties as micropore surfaces and sorption capacity, chemical and technological analyses of sediments collected in the Lazy coal mine landfill (Upper Silesian Coal basin) are presented. The adsorption capacities together with net calorific values (Qid) and total organic carbon (TOC) decreased in the direction of flow while the ash content (Ad) increased. The samples with the highest TOC content have a relatively beneficial Qid and for residual coal particles from coal mining, were comparable with the Qid values of brown coal. The sorption capacity increased with increasing micropore content and correlated with higher levels of TOC. The sorption capacity decreased with distance from the saline water input. These materials play a significant role in the self-cleaning of mine water in-situ.
{"title":"Textural properties and organic matter in sediments from a hard coal mine landfill","authors":"D. Řimnáčová, Dominik Vöröš, L. Medvecká, E. Geršlová","doi":"10.35933/paliva.2021.02.01","DOIUrl":"https://doi.org/10.35933/paliva.2021.02.01","url":null,"abstract":"Textural properties as micropore surfaces and sorption capacity, chemical and technological analyses of sediments collected in the Lazy coal mine landfill (Upper Silesian Coal basin) are presented. The adsorption capacities together with net calorific values (Qid) and total organic carbon (TOC) decreased in the direction of flow while the ash content (Ad) increased. The samples with the highest TOC content have a relatively beneficial Qid and for residual coal particles from coal mining, were comparable with the Qid values of brown coal. The sorption capacity increased with increasing micropore content and correlated with higher levels of TOC. The sorption capacity decreased with distance from the saline water input. These materials play a significant role in the self-cleaning of mine water in-situ.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44115528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.35933/paliva.2021.02.05
Anna Mágrová, P. Jeníček
Sewage sludge biomass is a renewable energy source commonly produced by anaerobic digestion (AD). However, the limited biodegradability of sewage sludge causes a poor energy conversion of organic material into biogas and requires further enhancement. One possible solution is sludge disintegration by a thermal hydrolysis process (THP) that has already proven to enhance biogas production and improve the quality of digested sludge. This article reviews possible THP configurations, such as THP-AD, ITHP, and PAD-THP, together with different input materials and their impact on the energy balance of the wastewater treatment plant (WWTP). Data from full-scale THP demonstrate differences between the configurations and input material. Moreover, the general advantages and disadvantages of THP integration are summarized and presented as a multicriteria analysis that simplifies the decision-making whether the THP should be integrated in the WWTP.
{"title":"Thermal hydrolysis to enhance energetic potential of sewage sludge: A review","authors":"Anna Mágrová, P. Jeníček","doi":"10.35933/paliva.2021.02.05","DOIUrl":"https://doi.org/10.35933/paliva.2021.02.05","url":null,"abstract":"Sewage sludge biomass is a renewable energy source commonly produced by anaerobic digestion (AD). However, the limited biodegradability of sewage sludge causes a poor energy conversion of organic material into biogas and requires further enhancement. One possible solution is sludge disintegration by a thermal hydrolysis process (THP) that has already proven to enhance biogas production and improve the quality of digested sludge. This article reviews possible THP configurations, such as THP-AD, ITHP, and PAD-THP, together with different input materials and their impact on the energy balance of the wastewater treatment plant (WWTP). Data from full-scale THP demonstrate differences between the configurations and input material. Moreover, the general advantages and disadvantages of THP integration are summarized and presented as a multicriteria analysis that simplifies the decision-making whether the THP should be integrated in the WWTP.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42660306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.35933/paliva.2021.02.02
J. Berka, J. Petrů
The corrosion resistance of the alloys designed for precise casting Inconel 713LC and Inconel 738 in high temperature gas environment were tested. The environments during tests simulated helium coolant of advanced gas cooled reactors and high temperature carbon capture storage environment (CO2). The specimens were exposed in helium containing 500 vppm CO, 100 vppm CH4, 100 vppm H2 a 10 vppm H2O at 900 °C for 1000 hours and in CO2 at 900 °C during 200 hours. After exposure weight changes were investigated, the corrosion damage was observed by optical and electron microscope, the samples exposed in CO2 were investigated by XPS (X-ray Photoelectron Spectroscopy), GD-OES (Glow Discharge Optical Emission Spectrometry). After exposure in helium, 2 types of scales with different composition were observed on the sample surface. The depth corrosion damage was up to 20 μm, on the alloy Inconel 738 was deep corrosion damage only local, on the alloy Inconel 713LCcontinuous. After exposure in CO2 the surface corrosion layer was compact and almost uniform, corrosion interfered up to 30 μm under the surface layer. In high temperature helium, the alloy Inconel 738 could be said to bo more corrosion resistant than Inconel 713LC. In high temperature CO2 both tested alloys performed almost the same corrosion resistance.
{"title":"Degradation of nickel-based alloys for precise casting in high-temperature gas environment","authors":"J. Berka, J. Petrů","doi":"10.35933/paliva.2021.02.02","DOIUrl":"https://doi.org/10.35933/paliva.2021.02.02","url":null,"abstract":"The corrosion resistance of the alloys designed for precise casting Inconel 713LC and Inconel 738 in high temperature gas environment were tested. The environments during tests simulated helium coolant of advanced gas cooled reactors and high temperature carbon capture storage environment (CO2). The specimens were exposed in helium containing 500 vppm CO, 100 vppm CH4, 100 vppm H2 a 10 vppm H2O at 900 °C for 1000 hours and in CO2 at 900 °C during 200 hours. After exposure weight changes were investigated, the corrosion damage was observed by optical and electron microscope, the samples exposed in CO2 were investigated by XPS (X-ray Photoelectron Spectroscopy), GD-OES (Glow Discharge Optical Emission Spectrometry). After exposure in helium, 2 types of scales with different composition were observed on the sample surface. The depth corrosion damage was up to 20 μm, on the alloy Inconel 738 was deep corrosion damage only local, on the alloy Inconel 713LCcontinuous. After exposure in CO2 the surface corrosion layer was compact and almost uniform, corrosion interfered up to 30 μm under the surface layer. In high temperature helium, the alloy Inconel 738 could be said to bo more corrosion resistant than Inconel 713LC. In high temperature CO2 both tested alloys performed almost the same corrosion resistance.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49345662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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