Paliva (Fuels) is a scientific journal issued quarterly by the Faculty of Environmental Technology, ICT Prague. Fuels publishes papers on a broad range of topics covering exploitation, processing, upgrading, and utilization of various types of fuels, and power engineering.
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Current issue

2/2018

Determination of CO2 emitted by anthropogenic and biogenic processes to indoor areas

Barbora Miklová, František Skácel

Carbon dioxide is produced by natural process and also by a number of anthropogenic activities. Thanks to this processes CO2 is released into outdoor and indoor air, where it is an undesirable component in higher concentrations. The quality of indoor air has always been slightly neglected issue. However, in recent years, there has been a growing interest in this issue, because some symptoms such as headaches, eye or throat irritations etc. occur in humans more and more. These symptoms are caused by Sick Building Syndrome, which disappears after leaving a building. Indoor air contains various pollutants, which affect the symptoms mentioned above. Carbon dioxide was chosen as a representative compound for the quality of indoor air. The paper is focused on highlighting issues coming from poor air quality and brings recommendation how to avoid them. Furthermore, it states analytical methods, which can be used for the determination the concentration in the indoor and outdoor air and to draw consequences for human health.

2/2018 - pages 39 - 48download PDF file

Comparison of NOx emissions calculated using road traffic emission model (MEFA) with emissions deriv

Katerina Maneva Mitrovikj, František Skácel

Vehicles activity contribute significantly to NOx emission. Numerous mathematical models performing emission assessment of road-related pollutants were developed. These traffic emission models are characterized by emission factors (EF), which quantify the amount of the emitted pollutant. A comprehensive emission model for the calculation of the EF for Czech fleet composition is used. Emission factors were calculated with the emission model MEFA 13. Here, we present a comparison of NOx emission calculations in MEFA 13 model and NOx tunnel measurements. Simultaneous measurements of NOx concentration and traffic activity counting were performed in short tunnel (Zelený most), in the Czech Republic. Emission factors for road transport de-rived from the Czech emission model MEFA 13 were applied.

2/2018 - pages 49 - 54download PDF file

Study of possibility of reducing deposits formation during crude oil storage using polymeric additiv

Violetta Pospelová, Daniel Maxa, Petr Straka
This study focuses on problems associated with the long-term storage of crude oil. The long-term storage is accompanied by a change in quality of petroleum, mainly due to the sedimentation of water and solids, especially paraffinic hydrocarbons. Currently used methods to re-move deposits are chemical and mechanical cleaning of tanks. Each of these methods has different disadvantages, for instance, complicated ecological disposal of deposits. The aim of this work is a verification of a new way for prevention or slowing of sediments deposition. The met-hod is based on an addition of polymeric compounds ori-ginally intended to reduce the aerodynamic resistance in pipelines affecting the rheological properties of crude oil. The assumption of the efficiency of these additives under static storage conditions is the change of the apparent dynamic viscosity, which causes slowing down the sedimentation of solid paraffin particles. The experiments were carried out in a laboratory model of the storage tank. Two types of polymeric compounds in a mixture with crude oil at two different concentrations were compared. The sample mixtures were stored for three periods of time equivalent to 6, 12, 18 months in a real tank.
After storage, five consecutive layers were taken from the bottom of each sedimentation cylinder. Separation of saturated hydrocarbons was performed by high-temperature adsorption liquid chromatography with special sorbents. Subsequently, the samples were analyzed by gas chromatography. The deposition was evaluated by the content and distribution of n-alkanes in the lower layers of the model. One of the additives showed a significant reduction in the rate of deposition. Since no similar laboratory studies on the influence of drag-reducing polymer additives on long-term storage of oil are available, it is recommended to continue the research in the selected direction.
2/2018 - pages 55 - 63download PDF file

Analysis of a Volatile Fraction of Bio-oils from Pyrol-ysis of Cellulose, Hemicellulose and Lignins

Martin Staš, Aneta Závodníková, Siarhei Skoblia, Miloš Auersvald, Dan Vrtiška, Pavel Šimáček, David Kubička

Pyrolysis bio-oil is a liquid product of biomass pyrolysis, which is considered to be a potential biofuel or source of valuable oxygen-containing chemicals. To further develop the use of pyrolysis bio-oils, a sufficient knowledge of their chemical composition is required. In this work, we studied he chemical composition of bio-oils from slow and fast pyrolysis of the basic building components of biomass, i.e., cellulose, hemicellulose and lignin. The study is presented in two articles. Here, in the first part, we present (i) the results of the analyses of pyrolysis feedstock, (ii) the preparation of bio-oils and (iii) the structural analysis of their volatile fractions. The volatile fractions were analysed using GC-MS. In the second part, analyses of non-volatile fractions of the cellulose, hemicellulose and lignin bio-oils will be presented. The obtained results can help us to understand the chemical composition of entire bio-oils from biomass and achieve their more widespread use.

2/2018 - pages 64 - 74download PDF file

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