Tag Archives: density

2226–2235 P. Zeman, V. Hönig, P. Procházka and J. Mařík
Dimethyl ether as a renewable fuel for diesel engines
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Dimethyl ether as a renewable fuel for diesel engines

P. Zeman¹, V. Hönig¹*, P. Procházka² and J. Mařík³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcka 129, CZ16521, Prague 6, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Economics, Kamýcka 129, CZ16521, Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcka 129, CZ16521, Prague 6, Czech Republic
*Correspondence: honig@af.czu.cz

Abstract:

The area of automotive fuel, or fuel components, which can be produced from biomass also includes dimethyl ether, otherwise known as DME. The issue of the use of DME as a fuel is one which has been monitored until recently. Biomass can also be used as the raw material for the production of DME. DME has therefore replaced the previously-used CFCs (chlorofluorocarbons), which are now banned for their role in dangerous levels of ozone depletion. With regard to its physical properties and combustion characteristics, it is currently expected that DME will soon apply significantly as a fuel in the municipal sector and in households, and as an alternative fuel for motor vehicles with diesel engines. DME is a suitable fuel for diesel engines and can be considered as one of the most promising diesel fuel replacements. DME is a suitable fuel for diesel engines mainly due to its low self-ignition temperature and good cetane figures. It is well miscible with most organic solvents and because the polar solvent is water-immiscible. The advantage is its high levels of purity, and its being free of sulphur, nitrogen, or metals. The physical properties of DME are very similar to the physical properties of LPG. DME requires relatively complex and costly fuel accessories, but the original compression ratio of the diesel engine is maintained. A diagram of the fuel system is illustrated in the paper. The paper analyses the dependence of vapour pressure on temperature, the dependence of the density on temperature, kinematic viscosity, the flash point, the boiling point, and the solubility of water. The objective is to evaluate this interesting energy source for applications in diesel engines.

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1227-1233 V. Hönig, L. Smrčka, R. Ilves and A. Küüt
Adding biobutanol to diesel fuel and impact on fuel blend parametres
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Adding biobutanol to diesel fuel and impact on fuel blend parametres

V. Hönig¹*, L. Smrčka², R. Ilves³ and A. Küüt³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcka 129, 16521 Prague 6, Czech Republic
²University of Economics, Faculty of Business Administration, Department of Strategy, W. Churchill Sq., 13067 Prague 3, Czech Republic
³Estonian University of Life Sciences, Institute of Technology, Kreutzwaldi 56, EE51014 Tartu, Estonia
*Correspondence: honig@af.czu.cz

Abstract:

One of the main arguments for the use of biofuels is environmental reason. Biofuels release significantly lower quantities of greenhouse gases (GHG) during the combustion opposed to conventional fossil fuels. Fatty acid methyl esters are commercially blended with diesel and bioethanol with gasoline. Biobutanol and bioethanol are using the same sources. Biobutanol can be used as a biofuel in internal combustion engines in the same manner as bioethanol. Application of biobutanol in diesel is rather marginal, but is definitely preferable in diesel engines in comparison with bioethanol. There are plenty of options to use biobutanol in diesel engines. The simplest are blends with diesel. Number of parameters can used to compare biobutanol with standard diesel. Fuel parameters are changing with the amount of butanol added. Maximum amount of butanol in diesel in order to prevent negative effects was assessed.

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207-220 A. Jasinskas, G. Rutkauskas, A. Dravininkas and A. Mieldažys
Vibratory thickening of grass mass
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Vibratory thickening of grass mass

A. Jasinskas¹, G. Rutkauskas¹, A. Dravininkas¹ and A. Mieldažys²

¹ Institute of Agricultural Engineering of Lithuanian University of Agriculture,Raudondvaris, LT-54132 Kaunas reg., e-mail: aljas@mei.lt
² Lithuanian University of Agriculture,Kaunas-Akademija, LT-53361, e-mail: ifps.katedra@lzuu.lt

Abstract:

Flat surface inertia type vibrators in which the excitation force for thickening grass mass is received by turning the unbalanced mass were analyzed and evaluated. Directed and undirected action vibrators were manufactured and tested. The amplitude frequency characteristics of pressed grass mass were evaluated using a directed action grass mass pressing vibrator. It was concluded that resonant frequency depends essentially only on mass toughness qualities, and changes from 7.0 Hz when there is fodder goat’s rue (Galega orientalis Lam) mass of greater toughness, up to 15 Hz when thickening chopped maize mass of lesser toughness. The amplitude of grass mass pressure during resonance depends only on the mechanical resistance of the pressed mass. The amplitude of excitation power of goat’s rue and its mixes during resonance increased from 2.5 to 3 times but efficiency of mass pressure reduced. The calculated coefficients of pressure enhancement were equal to 5.5-5.8 when vibratory thickeners were used for pressing grass mass. The established repression of pressure on plant mass layer, while pressing mass on the surface and from the bottom of container, was 3.0-7.5 when using the directed action vibrator, and 4.8 when using the undirected action version. After evaluating the application of various tractors and vibratory grass mass thickeners for grass mass pressing it was found that in both cases the received efficiency rates of grass mass layer were similar. However, while using vibratory grass mass thickeners, these rates were even higher than using a wheeled tractor T-25A. The efficiency of mass thickening by centrifugal-directed action vibrator was evaluated by using an experimental trial. The results indicated that during vibratory thickening the grass layer was thickened intensely for 5-10 min. Therefore, it is advisable to use vibrators of this type for thickening grass layers of 0.4-0.6 m thickness. This vibrator resulted in good density of chopped maize – after 20 min of thickening (2×200 kg) the density of 510 kg/m3 was achieved and while thickening the first mix of 200 kg layer after 10 min 571 kg m-3 density was achieved. The densities of dry matter were 143 kg m-3 and 161 kg m-3 respectively. The investigation of the forage quality showed that it met the requirements of the highest-class silage.

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