Tag Archives: alternative fuel

1218-1227 R. Rannaveski and M. Listak
Flash points of gasoline from Kukersite oil shale: Prediction from vapor pressure
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Flash points of gasoline from Kukersite oil shale: Prediction from vapor pressure

R. Rannaveski and M. Listak*

Tallinn University of Technology, School of Engineering, Department of Energy Technology, Ehitajate tee 5, EE19086 Tallinn, Estonia
*Correspondence: madis.listak@ttu.ee

Abstract:

The flash point of liquid fuels, especially of light distillates such as gasoline or naphtha, is an important parameter for the handling of such materials. In this work, flash points and volatility characteristics (vapor pressure, boiling point) of a number of shale gasoline samples with different volatilities were measured. The shale gasoline fractions were produced from Kukersite oil shale using solid heat carrier retorting technology. Several existing correlations for calculating flash points of hydrocarbons and petroleum fractions are evaluated, and the absolute average deviations were found to be between 1.1 to 20.9 °C. New, easy-to-use correlations are proposed for estimating flash points for oil shale based gasolines from volatility characteristic that are readily available. The correlation proposed in this work are based on the vapor pressure at 20 or 37.8 °C (100 °F), Reid vapor pressure (37.8 °C) or boiling point. The average absolute deviations for these correlations were 0.82 to 0.93 °C, meaning they are comparable to or better than existing methods developed for petroleum oils, which mostly use boiling point as the input parameter, when applied to gasoline from Kukersite oil shale.

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188-197 M. Obergruber, V. Hönig, P. Procházka and P. Zeman
Energy analysis of hydrogen as a fuel in the Czech Republic
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Energy analysis of hydrogen as a fuel in the Czech Republic

M. Obergruber¹, V. Hönig²*, P. Procházka³ and P. Zeman¹

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, CZ16521 Prague 6, Czech Republic
²University of Economics, Faculty of Business Administration, Department of Strategy, W. Churchill Sq., CZ130 67 Prague 3, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Economics, Kamýcká 129, CZ16521 Prague 6, Czech Republic
*Correspondence: vladimir.honig@vse.cz

Abstract:

The concept of ‘hydrogen economy’ dates back to the 1970s. It was first introduced as s response to the first oil crisis. In the context of the hydrogen economy, it is important to calculate how much hydrogen would be needed to power all motor vehicles in the Czech Republic. This is main topics of this paper. To calculate the amount of hydrogen, we used two different methods. One is based on thermodynamic laws and the other on normal operating conditions. Both approaches yielded comparable results. It was found out that even with the use of all the electricity produced in the Czech Republic in 2016, we would not be able to cover the amount of energy that is required for production. It would cover only 75% resp. 76% depending on the calculation method used. Eventually, the Czech Republic could buy necessary amount of hydrogen and it would cost between 11 and 29 billion euros which is between 6% and 16% of GDP of the Czech Republic. In the calculations, authors found out that most fuel is burnt in the passenger cars. Therefore, we made a sensitivity analysis to find out how much our results would differ if fuel consumption changed. It turns out that with an increase in consumption of 1 L per 100 km, hydrogen production coverage will decrease by about 4% (again with the use of all electricity produced in the Czech Republic).

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413-419 K. Skanderová, J. Malaťák and J. Bradna
Energy use of compost pellets for small combustion plants
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Energy use of compost pellets for small combustion plants

K. Skanderová, J. Malaťák* and J. Bradna

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ16521 Prague, Czech Republic; *Correspondence: malatak@tf.czu.cz

Abstract:

The purpose of this paper is to explore the thermal emission characteristics of alternative fuels gained from the composting process and intended for local energy use. The first goal is to determine the basic parameters of the examined samples (elemental analysis). The thermal emission parameters of the combustion device, such as the flue gas temperature and emission concentration of carbon monoxide, carbon dioxide and nitrogen oxides in relation to the operating conditions of the combustion device with an automatic feed fuel burner furnace are also considered. Pellets from oversized chips gained from the composting process and the pelleted mixtures of compost and spruce sawdust in the ratio 1:1 were burnt in the burner furnace. The resulting values of the samples’ individual elemental analyses indicate the optimal properties for further energy utilization. The amount of excess air generated during combustion, however, is high and this is also reflected in the great loss of flue gas sensible heat. The resulting parameters further prove that the excess air coefficient (n) depends on flue gas temperature, as well as carbon dioxide, monoxide and nitrogen oxides content in the flue gas. It was concluded during the combustion tests that the pollutants monitored in the flow did not reach the limit values. The scientific hypothesis of the author confirms that the stabilized dried mixture of plant biomass and appropriate biodegradable waste is suitable for biomass combustion. The available data suggest that the use of compost for energy purposes through combustion is possible, if biodried biomass is used, i.e., special products of composting processes are used in medium-sized and large combustion devices.

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