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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Hydrotreating of gas oil containing used frying oil

Pavel Šimáček, David Kubička, Milan Pospíšil, Gustav Šebor

Hydrotreating of atmospheric gas oil (AGO) containing 10 wt. % of used frying oil (UFO) was carried out in a laboratory flow reactor under the pressure of 4 MPa and at temperature 330, 340 and 350 °C. Reference feed, pure AGO, was hydrotreated under the same reaction conditions. Obtained products were evaluated using gas chromatography and standard test methods designed for petroleum products. It was found that UFO present in the mixed feed was completely converted into hydrocarbons. Composition and physico-chemical properties of all prepared products are discussed.

2/2012 - pages 28 - 32DOI: 10.35933/paliva.2012.02.01

Laboratory evaluation of biomass gasification

Petr Buryan, Siarhei Skoblia, Bohumil Koutský, Jiří Malecha

The article reports findings relating to the gasification rate of pyrolysis chars from various wood materials like beech, oak, willow, poplar and roses. Carbon diox-ide and steam in nitrogen was used as gasification medium. Gasification rate was determined by thermogra-vimetric measurements.

2/2012 - pages 33 - 36DOI: 10.35933/paliva.2012.02.02

Pigging – modern tool for the pipeline maintenance and diagnostic

Tomáš Hlinčík, Ondřej Prokeš, Daniel Tenkrát

The article sumps up the basic facts and information about the process of pigging. Thereinafter the fundamental methods and processes of using the pigs in the praxis, firstly for the maintenance of pipeline, are presented in this paper. The originally using of pigs has been changed and nowadays pigs are used as a modern tool for the service of steel pipeline nets. Two fundamental and authentic functionality of pigging are still kept – cleaning the internal parts of pipeline from solid and fluid impurities and detection the decrease of pipe thickness according to the corrosion or attack the third parties.

2/2012 - pages 37 - 42DOI: 10.35933/paliva.2012.02.03

Application potentials and limits of Life Cycle Assess-ment of biofuels

Vladimír Kočí

The article briefly summarizes the current proble-matic dealing with Life Cycle Assessment of biofuels. Principal needs for application of LCA on this topic in Czech Republic are presented, mainly the questions associated with allocation rules, data collection and verification.

2/2012 - pages 43 - 47DOI: 10.35933/paliva.2012.02.04

Effect of lowering feedstock 95% boiling point on hydrodesulphurisation efficiency and properties of

Josef Blažek, Daniel Maxa, Josef Chudoba

The work deals with the comparison of hydrodesulphurization of common feedstock for the production of diesel fuel and the same feedstock whose heavy end (5 % vol.) was cut off by distillation. In this way most of benzothiophenes with eleven or more carbons in alkyl substituents, dibenzothiophenes with four or more carbons in alkyl substituents, almost all benzonaphthothiophenes were removed. Part of polyaromatic hydrocarbons and nitrogen-containing compounds was also removed. Both raw materials were subjected to deep catalytic hydrodesulfurization under the same reaction conditions. Lowering final boiling point of feedstock resulted in lower 95 % boiling point of hydrodesulphurization product, a slightly lower content of sulphur and nitrogen, and better filterability. Most of the sulfur, which was identified in both products of hydrodesulfurization, was bound in the form of dibenzothiophenes with two or more carbon atoms in alkyl substituents. The removal of heaviest components from middle distillates enables production of diesel fuel with lower sulfur content or achievement of required sulfur content under less severe reaction conditions.

2/2012 - pages 48 - 54DOI: 10.35933/paliva.2012.02.05

Organosilicon compounds and their negative impact to engines of cogeneration units

Alice Procházková, Veronika Vrbová, Karel Ciahotný, Tomáš Hlinčík

The presence of silicone in biogas seems to be in the last years very important topic, especially for many operators of cogeneration units using biogas as fuel. Silicones are substances often found in various products used on an industrial scale, but also in the households. These compounds are the cleaners, shampoos, deodorants and various kinds of cosmetic products. Most low-molecular siloxanes are losing quickly into the atmosphere, however, the rest is transferred into effluents or on the landfill of waste, when the consumer washes or disposes the used product or its packaging.

Siloxanes are not harmful or dangerous, many workers at sewage treatment plants or landfill of them never heard of. However, in the case of the use of biogas for energy purposes, siloxanes are one of the most monitored and inspected contaminants in biogas. By the combustion of biogas in engines of cogeneration units, the siloxanes are oxidized to a very fine powder that consists of mainly SiO2, which is precipitated on internal metal areas of combustion space in engines cogeneration unit. The release of SiO2 deposits may cause severe consequences for the operation of the engine and in many cases can lead to a crash of the engine or the destruction of the block of the engine.
2/2012 - pages 55 - 60DOI: 10.35933/paliva.2012.02.06

technical support editor-in-chief