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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Preparation of impregnated material for separation of CO2

Veronika Kyselová, Jan Vysloužil, Karel Ciahotný

he aim of the work was to prepare a suitable sorption material, which can be used for low-temperature carbon dioxide sorption from flue gases and waste gases. First, several possible types of sorption materials were selected that could be used for sorption of carbon dioxide and at the same time increase the sorption capacity by subsequent impregnation with a suitable impregnating agent. Additionally, a suitable impregnating agent and the impregnation process of the sorption material were selected. Subsequently, the properties of the original and impregnated materials and their sorption capacity were determined for varies concentrations of carbon dioxide in the model gas mixture. The measurement results were compared with the static carbon dioxide sorption capacity measurement. Sorption capacities were tested at 30 °C. Additionally were also tested the thermal regeneration of carbon dioxidesaturated materials by temperatures of 30 °C and 60 °C.

4/2018 - pages 100 - 104DOI: 10.35933/paliva.2018.04.01

A review on dual fluidized bed steam gasification of pelletized solid biofuel

Van Minh Duong, Johannes Schmid, Hermann Hofbauer

Agricultural feedstock can be a sustainable biofuel option when they perform significant calorific value and high ash deforming temperature recorded. An appropriate gasification system particularly designed for solid biofuel provides an opportunity for combined heat and power generation in gas engine or gas turbine. In further, high calorific product gas, practically free of nitrogen, can be utilized for the Fischer-Tropsch synthesis of liquid biofuels and also for production of bio synthetic natural gas or other related gaseous products. The report provides an overall review on the dual fluidized bed steam gasifier performance on feedstock pellets at temperatures between 760 °C and 810 °C. Calcite (250 - 600 μm) with mainly CaCO3 in compositions and olivine sand (100 - 300 μm) were used as bed material for the reactor. Mass and energy balances were established on the base of stationary process simulations with IPSEpro. Physio-chemical characterization of solid biofuels were analysed and their ash fusion were evaluated. The interference on steady state operation in term of bed material agglomeration effects was discussed. Various tests on solid biofuels and further investigation on co-gasification of biomass are recommended before further scale-up.

4/2018 - pages 105 - 112DOI: 10.35933/paliva.2018.04.02

International research of the application of flue ashes for CO2 sorption

Marek Staf, Barbora Miklová

The paper provides basic information on the presently realized international project addressing the use of fly ashes, separated by ESPs of power plants and heating plants, for reduction of carbon dioxide emissions. The consortium of participants includes research organizations from Greece, Czech Republic, Germany and Poland. The sample base is continuously collected across the listed countries. Experiments, which aim is evaluation of the sorption properties at various conditions (t, p, flue gas composition etc.), are divided among cooperating partners. Within the research activities the ways, providing cheap sorbents, derived from a waste and massively produced materials, but enabling to economically separate carbon dioxide, are searched. Post combustion CO2 capture from flue gas is considered as a target application of the sorbents. Among other things the paper summarizes data on analytical and experimental methods that are used in the course of the project to characterize the sample base, to measure sorption properties and to improve them. Besides the laboratory methods, including XRF analysis, BET surface measurement, laboratory sorption apparatuses and so on, the article briefly mentions also a pilot scale unit. Its installation is currently realized in order to verify the results obtained during the laboratory tests.

4/2018 - pages 113 - 121DOI: 10.35933/paliva.2018.04.03

Laboratory pyrolysis and combustion of poorly treatable biowastes

Pavel Straka, Olga Bičáková

Pyrolysis of two types of biowaste whose use and processing are problematic, orange peel and apricot stones, provided a gas with a lower heating value of 11–14 MJ/m3, which can be, after improving, further used as the energetic gas. The obtained bio-oils exhibited a higher heating value of 30–32 MJ/kg and may be used as fuel oils; considering the large number of organic substances present in these oils, they can be alternatively utilized as a source of chemicals. Moreover, the pyrolysis further produced 27–29 wt.% of solid carbonaceous residue with a higher heating value of 33–35 MJ/kg, so, it may be used as auxiliary fuel for common solid fuels. Considered biowastes were further combusted and utilization of ashes obtained was investigated. It was found that ashes from the types of wastes studied can be used for the preparation of fertilisers for agricultural lands, because they contain significant amounts of essential elements – phosphorus, potassium and magnesium as well as calcium and sulphur.

4/2018 - pages 122 - 127DOI: 10.35933/paliva.2018.04.04

Impact of a reduced supply of hydrogen on the activity of hydrodesulphurization catalyst

Nikola Bringlerová, Aleš Vráblík, Radek Černý, Blanka Zbuzková, Jana Hamerníková
The article deals with the effect of the hydrogen supply failure on the activity of hydrodesulphurisation (HDS) catalyst. The hydrodesulphurization of the atmospheric gas oil with the addition of 10% light cycle oil mixture was performed using two identical parallel reactors. In the first reactor, the hydrotreating was performed under the standard reaction conditions (reaction temperature of 350 °C, 4.5 MPa pressure and the volumetric ratio of hydrogen to the feedstock 300 m3.m-3). In the second reactor, the hydrogen flow failure and pressure reducing for 2 hours was repeatedly simulated (reaction temperature 350 °C, pressure of 0.5 MPa and the volumetric ratio of hydrogen to the feedstock 50 m3.m-3). The repeated hydrogen and pressure reducing were performed during the reactor operation under the standard reaction conditions where the sulphur content in the products was 10 This way, the effect of reduced hydrogen supply on the hydrodesulphurisation catalyst activity and the quality of products was studied. As a result of the reduction in hydrogen flow, there was a higher content of coke deposited on the catalyst and drop in its catalytic activity, which had to be compensated by increasing the reaction temperature.
The properties of liquid products fulfilled the limits of ČSN EN 590. The content of nitrogen and PAH were slightly influenced by the deactivation procedure. The samples taken immediately after the deactivation step contained higher level of 4,6-dimethyldibenzothiophene, 4-methyldibenzothiophene a 4,6-diethyldibenzothio-phene
4/2018 - pages 128 - 135DOI: 10.35933/paliva.2018.04.05

Marine Fuels after 2020 II

Aleš Vráblík, Radek Černý

Nowadays it is clear that the changes caused by the sulphur cap 2020 will be reflected into the whole refinery sector – from crude oil retailers, refineries, fuel traders, additive manufacturers to end-users. Last year, the article (Marine fuels after 2020 in Paliva) dealing with this issue was published but it is necessary to continuously refine and update partial estimates. For these reasons, this article is summarizing the current situation and the predicted development after 2020 is presented. It seems that the key role for the coming period will be the production of the so-called 0.5 % fuel containing max 0.5 wt% of sulphur. Expected consumption of 0.5 fuel will be higher by 40 %. However, it is clear that alternative fuels, such as methanol or LNG, are a promise for the future, especially with regard to further planned legislative constraints. Last but not least, hybrid systems that combine current engines with alternative technologies will also play an unforgettable role.

4/2018 - pages 136 - 139DOI: 10.35933/paliva.2018.04.06

technical support editor-in-chief