Welcome to the website of the journal Paliva ("Fuels"). The journal is Open Access, with articles published under CC BY 4.0 license. The journal is issued online only.
Paliva journal is open not only to researchers but also for technicians and other professionals working in plants, refineries, power stations, gasworks and companies processing, handling or trading both fossil and alternative fuels. The aim of the journal is to share information between professional research organizations and users of research results.
Since 2010 the journal Paliva (Fuels) is included in the list of recognized peer-reviewed journals, issued by the Research, Development and Innovation Council of the government of the Czech Republic. Amongst other requirements that must be met to be a member of the group of journals, all papers published in the journal undergo a review process by two independent reviewers. We sincerely hope you become regular readers of the journal and perhaps contributors in its future issues.
Paliva (Fuels) included in Scopus database
In 2019, when Paliva celebrated its 10th anniversary, the journal was succesfully evaluated and included in Scopus. Paliva is the only periodical in its research field published in the Czech Republic indexed by Scopus database. Since then, we expect further increase of the quality of published papers and greater proportion of papers written in English. It is also an oncoming opportunity for new authors from both industry and academic sphere.
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|
2-year |
3-year |
4-year |
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2023 Impact Factor |
0.316 |
0.233 |
0.200 |
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2022 Impact Factor |
0.317 |
0.213 |
0.213 |
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2021 Impact Factor |
0.31 |
0.31 |
0.31 |
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2020 Impact Factor |
0.05 |
0.05 |
0.05 |
Scopus Impact Factor and other scientometric data
Paliva (Fuels) Journal included in CAS databases
We are proud to annouce that Paliva (Fuels) Journal was successfully evaluated by Chemical Abstracts Service (CAS) and included to the CAS databases among more than 10 thousand scientific journals worldwide. Starting with the 2015 issues, CAS collects bibliographic information and abstracts of articles issued by Fuels, which makes the access to the findings published in the journal substantially easier for scientists and field specialists from over the world.
Current issue:
Ondřej Hlaváček, Alice Vagenknechtová, Lukáš Kejla
Due to decreasing BAT emission limits of NOx the owners of heating plant are looking for DeNOx solution, especially by solid fuel firing boilers. Fluidized bed boilers combustion temperature is generally lower, and some primary precautions were sufficient. Nowadays lots of plants install secondary precautions (especially SNCR) into their boilers due to increasing periods of exceeding emission NOx limits.
The article is about comparison of water solution of urea (41 % wt.), ammonium sulfate (33 % wt.) and ammonia (22 % wt.) and their utilization in SNCR technology. Laboratory determination specified exact content of functional substance and content of redox nitrogen. Also, significant content of heavy metals was not detected.
Operational tests were realized in CFB coal-biomass boiler (steam parameters: 140 t·h-1, 525 °C, 12.5 MPa). Dosing of DeNOx additives were only during boiler performance higher than 92 %, for lower performance primary precautions were sufficient. There was higher temperature through the combustion chamber during active SNCR dosing (877 °C, standard temperature 850 °C), although the amount of combustion air was increased. Complication connected with high emission of NH3 was not detected. Lower emission of CO was also detected.
All three additives are suitable for application in SNCR technology. To reach emission limits were needed 3.7 l·h-1 of ammonia solution, 5.04 l·h-1 of urea solution and 5.74 l·h-1 of ammonium sulfate solution. After recalculation it means 0.65 kg·h-1 (ammonia), 1.1 kg·h-1 (urea) and 0,38 kg·h-1 (ammonium sulfate) of redox nitrogen content.
Keywords: selective non-catalytic reduction, urea, ammonium sulphate, ammonia
Marek Staf, Veronika Kyselová, Adam Loos
The study presented here focused on the research of adsorbents for the separation of carbon dioxide from flue gas or other waste gases. Specifically, it focused on the possibility of eliminating the permanent problem with the insufficient resistance of inorganic adsorbents to unwanted – parasitic – adsorption of moisture from the processed gas. Based on the promising data published in recent papers regarding the wet impregnation of adsorbents with branched polyethyleneimine (PEI), four methods for the preparation of PEI-impregnated zeolite were tested. Penetration of the agent into the porous structure of the zeolite was achieved by: applying ultrasound, applying vacuum, combining vacuum and overpressure and boiling off the solvent without further operation.
The raw zeolite was characterized by X-ray fluorescence spectrometry and X-ray diffractometry and also subjected to textural analysis. The characterization of the impregnated products mainly included thermogravimetric analysis, textural analysis and organic elemental analysis. In addition to gravimetric screening, the adsorption capacities of raw zeolite and impregnated products were primarily determined using a pressure flow-through apparatus with a fixed bed adsorber. The experimental conditions were determined to be close to real industrial installations: temperature during adsorption 20 and 40 °C, pressure during adsorption 600 kPa and 15% volume fraction of CO2 in the gas. Desorption was carried out by a combination of thermal desorption at 80 °C and vacuum.
By reproducing the impregnation procedures from the literature, a PEI loading in the range of 4.1–23.7% was achieved, which is significantly lower than the literature sources state for the same preparation procedures. The measurement of textural properties verified that, depending on the value of PEI loading, there is a gradual reduction of the specific surface area, the total pore volume and the virtual disappearance of micropores and small mesopores. Specifically, at a PEI loading of 4%, the BET surface area decreased compared to the pristine zeolite from 29.4 to 2.9 m2 g–1 and at the same time the total pore volume decreased from 0.13 to 0.02 cm3 g–1, etc.
The measurement of capacities did not confirm almost any of the results published in the literature. Without exception, the adsorption capacity decreased with the amount of PEI introduced into the zeolite particles. E.g. if a gas with 80% relative humidity and a content of 15% CO2 was used at a pressure of 600 kPa and a temperature of 40 °C, the capacity (by mass) decreased due to impregnation from 2.4% (for raw zeolite) to 0.8% for the sample with PEI mass fraction of 19%. Tests using dry gas resulted in even more marked deterioration. Thus, one can only partially agree with the literature data in the sense that humidity slightly compensates the negative effect of PEI on capacity.
The effect, where the capacity increases with increasing temperature due to the replacement of physical CO2 adsorption by its chemisorption in the PEI layer, was also not confirmed. For example, for the above sample, humidity and pressure, the capacity was 0.9% at 20 °C.
The impregnation procedure based on boiling off the solvent turned out to be completely unusable and, despite repeated rigorous attempts to reproduce it, did not lead to a product with a measurable capacity. The results of the study can be summarized in the following sentence. The problem is not that the experiments did not lead to a positive result, but above all the fundamental discrepancy between the published data and the attempts to reproduce them.
Keywords: zeolite, polyethyleneimine, impregnation, adsorption capacity, carbon dioxide
Matěj Mašín, Daniel Maxa, Jan Karl, Martin Stukbauer
The increasing pressure to decarbonise energy production leads to the need to use low or zero carbon fuels or energy carriers. One of the promising fuels of the future is hydrogen, which is carbon-free if renewable energy sources are used for its production. However, the capacity for hydrogen production is currently insufficient to make it applicable on a large scale. Adding hydrogen to natural gas allows for a reduced carbon footprint without costly modifications to pipeline distribution network. However, changing the composition of gas in transport and distribution facilities requires a thorough assessment of the impact on operational safety. Fire safety of flammable mixtures is commonly assessed on the basis of explosive limits and other parameters. Although methods are available to calculate these parameters based on the composition of the mixtures being evaluated, the final safety assessment should rely on actual measured values. The scope of this work is to determine the explosion limits of natural gas from the transit system and changes in the limits caused by the addition of hydrogen at the concentration levels of 10% and 20% (v/v). Obtained experimental results were further compared with theoretically calculated values. Attention was also paid to the change in maximum explosion pressure, maximum pressure rise rate and oxygen concentration limits (LOC). As a result, valuable data on the expansion of the explosion limits of natural gas after the addition of hydrogen are presented.
Keywords: fire safety, natural gas, hydrogen, explosion limit, limiting oxygen concentration
