Paliva最新文献

{"title":"Properties and Analysis of Liquid Alternative Fuels I: Fatty Acid Esters","authors":"Martin Staš, Z. Mužíková, P. Šimáček","doi":"10.35933/paliva.2022.03.04","DOIUrl":"https://doi.org/10.35933/paliva.2022.03.04","url":null,"abstract":"The importance of alternative fuels is constantly growing due to environmental reasons, saving fossil fuels and reducing the dependence of the world countries on the supply of fossil raw materials from politically unstable regions. This article is further in a series of review articles focused on an overview of technical requirements and testing methods for selected alternative fuels. It is also the first in a series of papers focused on liquid alternative fuels. The aim of this series of articles is to provide an overview of the required properties of individual alternative fuels, the possibilities of their analysis and the importance of the individual analyzes. This article focuses on fuels containing fatty acid esters.Biodiesel can be burned in diesel engines either in a mixture with conventional diesel or as an individual fuel. Unlike conventional diesel, which is composed of hydrocarbons of petroleum origin, biodiesel contains fatty acid methyl esters. In addition to this main component, glycerol (by-product of transesterification), methanol, free fatty acids, glycerides (mono-, di- and tri-), catalyst residues, water, and possibly other components can be present also. These contaminants can, in certain concentrations, cause some undesirable properties both in pure biodiesel and in biodiesel/diesel blends. Compared to conventional diesel, biodiesel has a higher density and viscosity, but a slightly lower higher heating value, and considerably worse oxidation stability. In terms of pollutant emissions, the combustion of biodiesel produces less hydrocarbons, carbon monoxide and solid particles, but slightly more nitrogen oxides than the combustion of mineral diesel. Gas chromatography, infrared spectroscopy, titration methods, and atomic spectroscopy methods have typically been used for the evaluation of these fuels. In addition to the properties monitored by these methods, conventional fuel parameters such as density, viscosity, low-temperature properties, oxidation stability, corrosion properties, flash point, cetane number, and others are monitored for biodiesel and biodiesel/diesel blends. In general, it can be stated that the analysis of fuels containing biodiesel is well managed. Instrumental equipment and (modified) analytical methods used for the analysis of conventional liquid fuels can be used to analyze these fuels.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47158910","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}

{"title":"Properties and Analysis of Gaseous Alternative Fuels II: Fuels Based on Natural Gas and Biogas","authors":"Martin Staš, J. Kroufek, T. Hlinčík, P. Šimáček","doi":"10.35933/paliva.2022.03.05","DOIUrl":"https://doi.org/10.35933/paliva.2022.03.05","url":null,"abstract":"The importance of alternative energy sources is constantly growing, especially due to the ever-increasing energy consumption of mankind and due to the effort to replace existing sources with more environmentally friendly ones. This article is another in a series of articles focused on an overview of technical requirements and testing methods for alternative gaseous, liquid, and solid fuels. This series of articles aims to provide an overview of the required properties of individual alternative fuels, the possibilities of their analysis, and the significance of individual analyzes.\u0000This article provides an overview of the technical requirements prescribed by legislation and relevant standards for automotive fuels based on natural gas (fossil methane) and biomethane. Furthermore, prescribed analytical tests are presented, which have been used to monitor the quality of these fuels. To a lesser extent, the importance of selected analytical tests is also discussed. Natural gas can be compressed or liquefied for use in automobile transport. In the first case, CNG fuel is obtained, and in the second, LNG. As a source of renewable methane or biomethane, biogas can be used, which is produced by anaerobic fermentation of agricultural waste or other raw materials in biogas plants. The obtained biogas can be used for the combined production of heat and energy. Alternatively, it can be purified into biomethane, which can be injected into the natural gas distribution network or used in automobile transport in the form of bio-CNG and bio-LNG. In general, it can be stated that the analysis of fuels based on natural gas and biomethane is well managed. Instrumental equipment and analytical methods used for natural gas analysis can be used to analyze these fuels.\u0000The properties of fuels based on natural gas and biomethane are closely related to their composition. In terms of proper operation and performance of the combustion engine, the lower heating value, Wobbe number, and methane number are critical parameters. An important parameter is also the sulfane content, increased content of which can lead to corrosion of engine components. In terms of emissions, the total sulfur content is an important parameter also. Sulfur compounds are undesirable in emissions for environmental reasons. At the same time, they are also catalytic poisons. Other critical parameters of fuels based on natural gas and bio-methane are the water content or dew point of water.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47870587","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}

{"title":"Energy saving technology in power plants industry by HFRW","authors":"M. Sadeghi, H. Sabet","doi":"10.35933/paliva.2022.03.02","DOIUrl":"https://doi.org/10.35933/paliva.2022.03.02","url":null,"abstract":"This paper aims at investigating the use of high frequency resistance welding (HFRW) to deploy energy saving technology in power plants industry. The new approach of dissimilar welds A240TP409 finned and 2¼ Cr-1 Mo seamless tube under various conditions of high frequency resistance welding (HFRW) are found in power plant boilers and reducing energy costs is possible through the use of finned tubes. HFRW have accom-plished on samples by changing multiple parameters including current of welding, electric potential, travel speed and fin pitch. Microstructural evolution in weld bond, hardness and tensile strength tests revealed that metallurgical bonding more than 90 % was measured at the weld interface and the average of tensile strengths were more than 275MPa, with setting on appropriate welding parameters and optimum pressure. Since the pitch and fin thickness can be severely reduced, the output transfer surface treatment in final process can be dramatically diminished. Lastly, a well-engineered approach to the design of the best conditions of finned tube welding bond is discussed in modern combined cycle power plant (CCPP).","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48177627","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}

{"title":"Investigation of the combustion process of the developed composite granules","authors":"Yu.P. Novikova, Z. Petrova, L. Vorobiov, V. Chmel, Yevhen Skliarenko, Inessa Novikova","doi":"10.35933/paliva.2022.03.03","DOIUrl":"https://doi.org/10.35933/paliva.2022.03.03","url":null,"abstract":"The urgent task of each country is to achieve energy independence through the transition from traditional energy sources to alternative ones. Sewage treatment plants can be considered a potential source of additional raw materials. In Ukraine, one of the problems is the disposal of sludge that are more than 30 years old and to which activated sludge has not been added. This sludge has a low content of organic components, which are not suitable for combustion in pure form and fertilizers. Since the old sludge have a small content of organic components, for their better utilization it is proposed to create composite granules, their subsequent drying and combustion, during which the resulting ash will be used for the production of building materials. The aim of the work is to study the combustion of composite granules based on sludge, peat and biomass. The determined specific heat of combustion of composite granules exceeds this index of peat by 1.2 times. The study of the combustion process of composite granules showed that the obtained results can be used in fuel combustion in different ways. The combustion rate of granules is much lower than the combustion rate of the original biomass, but the combustion rate of a separate part of sludge prevails. The combustion rate of granules is much lower than the combustion rate of the original biomass, but the combustion rate of a separate part of sludge prevails. The conducted experiments showed the possibility of decontamination of sludge and its disposal as an alternative fuel.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45888701","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}

{"title":"Activation of solid residues from batch pyrolysis of waste tires","authors":"M. Staf, Běla Ondrová, V. Šrámek","doi":"10.35933/paliva.2022.03.01","DOIUrl":"https://doi.org/10.35933/paliva.2022.03.01","url":null,"abstract":"The paper deals with a two-stage process of thermal treatment of waste tires in order to obtain a carbonaceous adsorbent. A fraction of 0.4 ‒ 0.8 mm of the ground material was involved in the experiments. In the first stage, pyrolysis took place in a retort apparatus, which provided about 43 % of solid residues, 41 % of condensates and 16 % of gas at temperatures of 600 and 800 ° C.\u0000The mass balance was confirmed by the TGA method independently of the retort apparatus. N-alkanes, mono- to trialkylated benzenes, cycloalkenes, higher alcohols, ethers, acetates and aliphatic and aromatic thiols were identified in the liquid product by GC-MS. The main components of the condensates were: 50% n-al-kanes and more than 25 % alkylated benzenes. According to GC-TCD-FID, the separated pyrolysis gases contained nine main components with a volume fraction >1 %. Of these majority compounds, methane with volume fractions approaching 30 % was the most represented. Other important compounds were in descending order: hydrogen (20.2 and 20.8 %), carbon dioxide (8.9 %), ethane (8.5 %) and ethene (7.0 %). Due to the upper calorific value of 44 ‒ 45 MJ m‒3, the gas can be advantageously used energetically, but the high sulfur content must be considered anyway.\u0000The solid residues were subjected to steam activation in a separate apparatus. The activation apparatus operated with a batch reactor of similar design as the pyrolysis retort. By activation, the specific surface area of the pyrolysis residues was increased from a very small initial value <59 m2 g‒1 to a maximum of 337 m2 g‒1. However, this result, in contrast to the reference sample prepared from hardwood, required aggressive conditions, namely 900 °C combined with a steam exposure time of 60 min. The combination of the lower of the selected pyrolysis temperatures and the higher activation temperature led to better results than the opposite setting.\u0000Both the crude pyrolysis residues and the obtained activated products were significantly mesoporous and pores with a diameter of 20 ‒ 80 nm predominated in their structure. Prior to activation, the pyrolysis residues always had a pore content of at least 60 %, while the activation further increased their proportion to 81 %. Such a significant proportion of mesopores 20 - 80 nm suggests that the material could be suitable for the next modification/improving step in the form of wet impregnation.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42536234","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}

{"title":"Properties and Analysis of Gaseous Alternative Fuels I: Hydrogen and liquefied petroleum gases","authors":"Martin Staš, J. Kroufek, T. Hlinčík, P. Šimáček","doi":"10.35933/paliva.2022.02.03","DOIUrl":"https://doi.org/10.35933/paliva.2022.02.03","url":null,"abstract":"The importance of alternative fuels has increased significantly and continues to grow due to gradually lowering fossil fuel sources as well as environmental reasons. This article is the first in a series of articles focused on gaseous, liquid, and solid alternative fuels. The aim of the articles is to provide an overview of the required properties and testing methods for individual alternative fuels prescribed by the relevant standards. This first article in the forthcoming series focuses on gaseous alternative fuels based on hydrogen and liquefied petroleum gases.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46035935","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}

{"title":"Comparison of Properties of Different Materials by Adsorptions N2 and Ar at Temperature –196 °C","authors":"Veronika Kyselová, K. Ciahotný","doi":"10.35933/paliva.2022.02.04","DOIUrl":"https://doi.org/10.35933/paliva.2022.02.04","url":null,"abstract":"The article is focused on comparing of the structural properties of different adsorption materials. The measurement of adsorption isotherms was carried out in nitrogen and argon at a temperature of –196 °C. The individual isotherms using selected samples were measured on an Autosorb ASiQ instrument. BET surfaces and total pore volumes of individual samples were calculated and compared from the resulting isotherms. The results show relatively high differences between the adsorption isotherm measured by using nitrogen and argon. For the Envisorb sample, which consists of up to 85% silicagel, the BET surface area calculated from the nitrogen adsorption isotherm was 45 % higher than when measuring the adsorption isotherm using argon as the adsorptive. For silicagel SGR 50 was the difference between BET surface area measurements with nitrogen and argon only 4 %. The opposite phenomenon was calculated for the material activated carbon SC 40, where the BET surface measured by argon was higher than BET surface measured by nitrogen.\u0000Of the adsorbents used, nitrogen appears to be more suitable; only for carbonbased microporous materials is it better to use argon as an adsorptive.\u0000The evaluation of the measured adsorption isotherms by the t-plot method showed a good usability of this method when it is applied similarly to the BET method for adsorption isotherms in the range of adsorptive rel. pressure ranged from 0.05 to 0.35. This method is a reliable tool for determining the proportion of the smallest pores (micropores) in the total surface area of a given adsorbent. However, in the case of adsorbents with a very low proportion of micropores, its accuracy is lower.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42388788","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}

{"title":"Combustion effectivity of high ash coal in adiabatic calorimeter","authors":"B. Taraba, P. Gřunděl","doi":"10.35933/paliva.2022.02.05","DOIUrl":"https://doi.org/10.35933/paliva.2022.02.05","url":null,"abstract":"A series of coal-mineral matter mixtures was investigated by bomb combustion calorimetry (IKA C4000, Germany) to elucidate boundary for ash content in coal at which combustion proceeds with lowered efficiency.\u0000For the experiments, a high rank bituminous coal was mixed with particles of mine stone, both being milled to size below 0.2 mm. Before the usage, the sample of stone was heated at 900°C for 2 hours in air to stabilize mineral matter composition. Mixtures 5, 10, 15, 20, 25, 30, 40, and 50% of coal were used, with sample weights both of 1 g and/or 2 grams being applied. The efficiency of the combustion process at the bomb test was assessed of the measured calorific value and that of “theoretically” calculated. The “theoretical” calorific value of the mixture was determined from the actual content of the coal proving known specific calorific value (36.6 MJ/kg).\u0000Based on the measurements, mineral matter content of about 50% was found as limiting for fully efficient combustion of coal in the bomb calorimeter. At content of 90% of mineral matter, the efficiency of combustion is about 70 % (sample weight 1 g) and/or 50 % (sample weight 2 g). Afterwards, the combustion efficiency steeply decreases to zero.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70082724","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}

{"title":"Co-combustion of Sewage Sludge in the Coal-Fired Heating Plant","authors":"Ondřej Hlaváček","doi":"10.35933/paliva.2022.02.02","DOIUrl":"https://doi.org/10.35933/paliva.2022.02.02","url":null,"abstract":"Due to greening of production of electricity and heat some owners of heating plant are changing their fuel mix from fossil fuels to biomass one. The stabilized sewage sludge is in this biomass category as well. New Czech national legislation limits are stricter in parameters of biological activity, so the owners of water treatment plant are looking for new utilization of their stabilized sludge. There are some possibilities in combustion or co-combustion of this sludge in currently heating plant.\u0000The article describes the trial test of stabilized sludge combustion on heating plant technology. The heating plant is originally designed for combustion of brown coal. The stabilized sludge was produced at the municipal wastewater treatment plant, from where it was transported to low-temperature (78 °C) drying technology, from where it was transported in granular form to the heating plant in Mladá Boleslav. The fuel mixture of trial test was in energetic ratio of 23% dried sludge and 77% brown coal. The sludge was transported into the boilers by pneumatic conveying, which is used in normal operation for conveying pelletized phytomass. The result shows an increase in SO2 emissions from the original 189.91 mg∙m-3 to 407.98 mg∙m-3 and an increase in NOx emissions from 148.45 mg∙m-3 to 181.46 mg∙m-3. There were also detected increasing NH3 emissions due to reac-tion of control system in SNCR technology od decreasing of NOx emissions. The trial test was done during full op-eration of the heating plant. During the test there was also a lower steam production, from originally 38.17 kg∙s-1 to 34.44 kg∙s-1, which is related to the lower LHV compared to the reference fuel. There were no major operation problems, except higher dustiness during unloading of sludge.\u0000Finally, the Czech legislative problems associated with the combustion of stabilized sewage sludge are mentioned. In the current system, the sludge is established as waste, which forbids the combustion of it in conventional heating plants, even though all emission legislative limits are complied with. Nowadays the Ministry of the Environment of the Czech Republic is working on new regulation, which will determine new category of solid alternative fuels and it will be solution of this situation.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45076309","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}

{"title":"Synergy of blending hydrotreated and hydrocracked kerosene in the production of jet fuel","authors":"H. Kittel, D. Kadleček","doi":"10.35933/paliva.2022.02.01","DOIUrl":"https://doi.org/10.35933/paliva.2022.02.01","url":null,"abstract":"Aviation kerosene is the fastest growing transportation fuel. Regardless of the ambition to replace it by SAF, consumption of the mineral component in JET fuel will grow. In oil refineries, kerosene fractions are used to produce JET fuel and as a component of diesel fuel. These fractions can differ in origin and composition. In this article the possibility of blending hydrocracked kerosene used for JET production and hydrotreated kerosene used for diesel fuel production was investigated. It was concluded that significant synergies can be achieved by blending of these fractions in terms of increasing JET fuel production by up to 2.5 times, controlling the aromatics content of hydrocracked kerosene and obtaining a fraction for blending of diesel fuel with improved low temperature properties.","PeriodicalId":36809,"journal":{"name":"Paliva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41800736","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}