2/2012
Hydrotreating of gas oil containing used frying oil
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.
Laboratory evaluation of biomass gasification
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.
Pigging – modern tool for the pipeline maintenance and diagnostic
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.
Application potentials and limits of Life Cycle Assess-ment of biofuels
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.
Effect of lowering feedstock 95% boiling point on hydrodesulphurisation efficiency and properties of
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.
Organosilicon compounds and their negative impact to engines of cogeneration units
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.