Tag Archives: energy

xxx M. Bappah, J. Bradna, J. Velebil and J. Malatak
The potential of energy recovery from by–products of small agricultural farms in Nigeria
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The potential of energy recovery from by–products of small agricultural farms in Nigeria

M. Bappah*, J. Bradna, J. Velebil and J. Malatak

Czech University of Life Sciences, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamycka 129, CZ16521 Praha 6–Suchdol, Prague, Czech Republic
*Correspondence: bappahmusa@gmail.com

Abstract:

Agricultural by–products are renewable energy sources from which essential amount of energy can be recovered, which can be used to replace the use of conventional fossil fuel, reduces the potential of greenhouse gas (GHG) emission and at the same time reduces deforestation, especially in rural areas. Energy values of biomass from small Agricultural farms, in particular waste generated from different tropical crops, viz; Maize, Millet, Rice, Sorghum and Groundnut were determined, to ascertain their potentials as alternative fuel sources for rural use. The materials were found to be of importance judging by their combustion potentials in all the forms investigated. The Energy values of the by-products considered ranged between 11.68 MJ kg-1 to 17.48 MJ kg-1 with Groundnut pods and millet husk having the highest and least respectively. Moisture and ash had effect on the energy values of these biomass. Our results are relevant to the problems posed by the management of farm residues in developing countries.

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xxx M. Dąbrowska, A. Świętochowski and A. Lisowski
Physicochemical properties and agglomeration parameters of biogas digestate with addition of calcium carbonate
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Physicochemical properties and agglomeration parameters of biogas digestate with addition of calcium carbonate

M. Dąbrowska*, A. Świętochowski and A. Lisowski

Warsaw University of Life Sciences, Department of Agricultural and Forestry Machinery,
Faculty of Production Engineering, Nowoursynowska 166, PL02-787 Warsaw, Poland
*Correspondence: magdalena_dabrowska@sggw.pl

Abstract:

The aim of the work was to determine the physical properties of digestate from biogas production – either with or without the addition of calcium carbonate and to determine the parameters of its compaction. The material for research was obtained from an agricultural biogas plant specialized in processing cattle manure, vegetable pomace, chicken manure and maize silage. The parameters of compaction of digestate were experimentally determined and its net calorific value was calculated based on the gross calorific value. Physical properties were determined according to standards. The moisture content of liquid digestate was 96%. Mechanical separation allowed to decrease the water content by 19% and addition of 20% of calcium carbonate by 30%. It was found that digestate with addition of calcium carbonate is not suitable to use for energy purposes, because of its low net calorific value (5.2–5.9 MJ kg-1), however it can be used for fertilizer purposes in relation to its chemical composition. Without  additives, the net calorific value was 14.9 MJ kg-1, but due to the high moisture content of the raw material it is unprofitable to dry it and burn. On the other hand, it was proved that it is possible to obtain pellets of appropriate density out of the digestate using 40 mm of the die height and 0.3 g of single portion of the material.

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1227–1234 I. Tipans, J. Viba, M. Irbe and S.K. Vutukuru
Analysis of non-stationary flow interaction with simple form objects
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Analysis of non-stationary flow interaction with simple form objects

I. Tipans, J. Viba, M. Irbe and S.K. Vutukuru*

Riga Technical University, Faculty of Mechanical Engineering, Transport and Aeronautics, Department of Theoretical Mechanics and Strength of Materials, Viskalu Street 36A, LV – 1006, Riga, Latvia
*Correspondence: vshravankoundinya1989@gmail.com

Abstract:

The paper is devoted to the analysis of a non-stationary rigid body interaction in a fluid flow. Initially, an approximate method for determining the forces due to fluid interaction with the rigid body is offered. For this purpose, the plane movement of a mechanical system with an infinite DOF (degrees of freedom) is reduced to 5 DOF motion: 3 DOF for the body and 2 DOF for the areas of compression and vacuum in fluid flow. Differential equations of non-stationary motion are formed by the laws of classical mechanics. The use of an approximate method has been quantified by computer modelling. The average difference in results was found to be small (< 5%). The analysis of the fluid (air) interaction is carried out for a rigid body of two simple geometries – flat plate and diamond. The results obtained are used to refine the parameters of the proposed approximate method that is addressed in the present study for fluid interaction with the non-stationary rigid body. Theoretical results obtained in the final section are used in the analysis of the movement of prismatic bodies in order to obtain energy from the fluid flow.

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634-645 O.L. Akangbe, R. Adamovský and F. Mošna
Optimising cold compressive recovery of oil from the seeds of Sesame (Sesamum indicum L.)
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Optimising cold compressive recovery of oil from the seeds of Sesame (Sesamum indicum L.)

O.L. Akangbe¹*, R. Adamovský¹ and F. Mošna²

¹Czech University of Life Sciences, Faculty of Engineering, Department of Mechanical Engineering, Kamýcka 129, CZ16521 Praha 6 – Suchdol, Prague, Czech Republic
²Czech University of Life Sciences, Faculty of Engineering, Department of Mathematics, Kamýcka 129, CZ16521 Praha 6 – Suchdol, Prague, Czech Republic
*Correspondence: akangbe@tf.czu.cz

Abstract:

Effects of the time rate of deformation and aspect ratio on mechanical response and performance in single cycle cold compression scheme were investigated for bulk sesame seeds and response forms fitted using forward stepwise multiple regression technique. The degree of deformation was dependent on the time rate of its induction and the equipment’s aspect ratio. Energy requirement correlated positively with deformation rate and aspect ratio. Energy expenditure was however more efficient with larger aspect ratios than with smaller ones, given the associated volume energy demands. Strain resistance correlated positively with each of the two influence factors. The time rate of deformation was the most important predictor of oil yield and performance. All the fitted forms had highly significant effects in predicting the responses investigated with 76.7–99.6% of the behaviours of the system explained. The results are valid within the ranges of the influence parameters investigated.

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22-40 F. da Borso, C. Di Marzo, F. Zuliani, F. Danuso and M. Baldini
Harvest time and ensilage suitability of giant reed and miscanthus for bio-methane production and characterization of digestate for agronomic use
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Harvest time and ensilage suitability of giant reed and miscanthus for bio-methane production and characterization of digestate for agronomic use

F. da Borso, C. Di Marzo, F. Zuliani, F. Danuso and M. Baldini*

Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Via delle Scienze, 206, IT33100 Udine, Italy
*Correspondence: mario.baldini@uniud.it

Abstract:

In many countries, biogas plants are mainly fed by livestock slurry and dedicated crops, including maize, which still represents one of the main energy crops utilized. Many concerns are now arising on environmental impact due to the high water consumption, chemical fertilizer and pesticide requirements and on adverse effect of maize as energy crop on the price of food and feed commodities. For these reasons two perennial crops, in particular miscanthus (Miscanthus x giganteus) and giant reed (Arundo donax L.), were cultivated at very low input and evaluated for their bio-methane yield at different harvest times and ensilage suitability, in a north-eastern area of Italy. Moreover, considering the agronomic use of the obtained digestate as fertilizer, this has been characterized by the content of heavy metals. Both multi-annual crops have proved highly productive in biomass especially with a harvest time in autumn, at which a satisfactory completion of the silage process without additives was observed. Conversely, bio-methane yield per hectare were not satisfactory with respect to the reference crops such as maize. The low BMP attained showed the main bottleneck of the methanisation of ensiled giant-reed and miscanthus, which is represented by fiber composition with high degree of lignification. The simulation use of digestate obtained as fertilizer in vulnerable areas, could lead to slightly exceed the levels allowed by the legislation of some European countries with regard of heavy metals as Cu, Zn and Cd.

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760–766 E. Kucuktopcu, B. Cemek and P. Banda
Determination of poultry house indoor heating and cooling days using degree-day method
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Determination of poultry house indoor heating and cooling days using degree-day method

E. Kucuktopcu*, B. Cemek and P. Banda

University of Ondokuz Mayis, Faculty of Agriculture, Department of Agricultural Structures and Irrigation, TR 55139 Samsun, Turkey
*Correspondence: erdem.kucuktopcu@omu.edu.tr

Abstract:

In poultry production, degree-day values are used as fundamental design parameters considered among others in determining the extent of heating and cooling of poultry housing. In this study, heating and cooling data values for each of broiler production period were determined using the degree-day method. The total length of the experiment was 123 days which corresponds to 3 growing periods. The inside and outside air temperatures of the poultry house were measured using air temperature data loggers positioned at different points and heights within and outside broiler house. Knowledge of heating and cooling day values is important as it necessitates the provision and maintenance of ideal bird’s production conditions and ensuring the economic viability of the enterprise through optimized energy consumption.

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941–951 O.L. Akangbe and D. Herak
Mechanical behaviour of selected bulk oilseeds under compression loading
Abstract |
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Mechanical behaviour of selected bulk oilseeds under compression loading

O.L. Akangbe and D. Herak*

Czech University of Life Sciences, Faculty of Engineering, Department of Mechanical Engineering, Kamycka 129, Praha 6 – Suchdol, CZ16521 Prague, Czech Republic
*Correspondence: herak@tf.czu.cz

Abstract:

Cold pressing or compressive mechanical expression of oil from bulk oilseeds without thermal treatments or appreciable thermal effects facilitates the preservation of quality in expressed oils and enhances their stability in storage. Mechanical response of bulk oilseeds during cold expression which are vital to equipment design vary with crops and are not completely understood. Mechanical behaviours of bulk seeds of camelina, pumpkin and sesame relevant to cold pressing were investigated at moisture contents of 7.04, 8.60 and 6.06% (d.b.), 80 mm pressing depth and a compressive force of 100 kN, applied uniformly at 10 mm min-1. Deformation varied with incremental force and among crops at peak compression. Deformations in Camelina, Sesame and Pumpkin seeds were 40.2, 41.6 and 50.9 mm at peak compression. Oil point pressures of Sesame, Camelina and Pumpkin seeds were 3.83, 7.49 and 8.83 MPa, respectively. Oil recovery at the applied load was similar in Camelina and Sesame but significantly lower in pumpkin seeds. Volume energy requirement for the expression of oil from camelina, pumpkin and sesame seeds were 2.56, 1.72 and 1.46 MJ m-3, respectively. An assessment of the pressed cake after oil expression revealed that the materials were capable of further deformation under compression.

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477-484 M. Dzikevics, A. Blumberga and D. Blumberga
Conceptual design of experimental solar heat accumulation system with phase change materials
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Conceptual design of experimental solar heat accumulation system with phase change materials

M. Dzikevics*, A. Blumberga and D. Blumberga

Riga Technical University, Faculty of Power and Electrical Engineering, Institute of Energy Systems and Environment, Azenes 12/1, LV1048 Riga, Latvia; *Correspondence: mikelis.dzikevics@rtu.lv

Abstract:

The research on solar heating systems often is faced with choice of carrying out experiments in real systems with changing parameters or to use modelling software with constant parameters but many undefined parameters or assumptions. The design of experimental system for simulating solar heat accumulation is proposed in this paper. The proposed design allows testing of phase change materials which provide higher thermal density compared to water. Results from computational fluid dynamic simulations carried out by other studies have been analysed for implementation into designing of the tank. All of these factors have been taken into account to create a system that resembles real case and can simulate for a long periods of time.

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596-603 D. Marčev, M. Růžička, M. Lukeš and M. Kotek
Energy consumption of commuting from suburban areas
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Energy consumption of commuting from suburban areas

D. Marčev*, M. Růžička, M. Lukeš and M. Kotek

¹University of Life Sciences Prague, Faculty of Engineering, Department of Vehicles ang ground transport, Kamýcká 129, CZ16521 Prague, Czech Republic; *Correspondence: marcev@tf.czu.cz

Abstract:

The process of suburbanization begun half a century later in the Czech Republic in comparison to Western Europe. It has given rise to similar changes in the individual behaviour of potential residents, resulting in different land use and the emergence of new requirements involving technical and transport infrastructures. Many factors that characterize suburban land use, e.g., density of population (households), free access to public facilities, availability of transport modes, etc., are closely associated with energy consumption, specifically in transport. Suburban development affects not only transportation inside expanding suburban municipalities but also their surroundings, e.g., the cumulative effect of traffic intensity increasing on roads radially oriented towards the city centre has been observed in recent years. The construction of manufacturing facilities, logistic and commercial complexes, entertainment centres, etc. continues within the suburban areas and it tends to significantly increase traffic movements (e.g., in tangential directions towards the core of the city). The current capacity of transport infrastructures does not correspond to the increased vehicle intensity (even not only during peak hours) and it does not guarantee an adequate quality for transport operation. The results of performed traffic surveys proved that morning traffic intensity (during peak hours) on the roads (of 2nd. or 3rd. class) leading to the city centre has doubled in the last five years. These results mean that transport energy consumption has increased enormously. Transport energy consumption is higher than usually expected in these cases. The energy consumption (fuel consumption) determined according to a vehicle’s homologation does not take into account the conditions that may affect driving style in a negative manner, e.g., slow driving, traffic congestions road, vertical alignment and tortuous roads. The mean consumption was 9.2 (l 100 km-1) on the selected trail sections –that is 1.66 more than the combined consumption figure presented by car producers. The selected sections make up 54% of the total trail length. This ‘local consumption’ is linked with higher emission production, details are available below. The author compared specific fuel consumption per 100 km and found that real consumption is evidently always higher than the quantities claimed to be correct by car producers in view of mixed modes. The same has been found by, e.g. Marique & Reiter, 2012 and other authors. The conclusions of the research are potentially relevant and should be used in a spatial planning or decision making processes to prevent ‘urban sprawl’ and the accompanying high energy consumption. Suburban development should go hand in hand with the construction of new transport infrastructures and high-quality public transport.

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596-603 D. Marčev, M. Růžička, M. Lukeš and M. Kotek
Energy consumption of commuting from suburban areas
Abstract |

Energy consumption of commuting from suburban areas

D. Marčev*, M. Růžička, M. Lukeš and M. Kotek

¹University of Life Sciences Prague, Faculty of Engineering, Department of Vehicles ang ground transport, Kamýcká 129, CZ16521 Prague, Czech Republic; *Correspondence: marcev@tf.czu.cz

Abstract:

The process of suburbanization begun half a century later in the Czech Republic in comparison to Western Europe. It has given rise to similar changes in the individual behaviour of potential residents, resulting in different land use and the emergence of new requirements involving technical and transport infrastructures. Many factors that characterize suburban land use, e.g., density of population (households), free access to public facilities, availability of transport modes, etc., are closely associated with energy consumption, specifically in transport. Suburban development affects not only transportation inside expanding suburban municipalities but also their surroundings, e.g., the cumulative effect of traffic intensity increasing on roads radially oriented towards the city centre has been observed in recent years. The construction of manufacturing facilities, logistic and commercial complexes, entertainment centres, etc. continues within the suburban areas and it tends to significantly increase traffic movements (e.g., in tangential directions towards the core of the city). The current capacity of transport infrastructures does not correspond to the increased vehicle intensity (even not only during peak hours) and it does not guarantee an adequate quality for transport operation. The results of performed traffic surveys proved that morning traffic intensity (during peak hours) on the roads (of 2nd. or 3rd. class) leading to the city centre has doubled in the last five years. These results mean that transport energy consumption has increased enormously. Transport energy consumption is higher than usually expected in these cases. The energy consumption (fuel consumption) determined according to a vehicle’s homologation does not take into account the conditions that may affect driving style in a negative manner, e.g., slow driving, traffic congestions road, vertical alignment and tortuous roads. The mean consumption was 9.2 (l 100 km-1) on the selected trail sections –that is 1.66 more than the combined consumption figure presented by car producers. The selected sections make up 54% of the total trail length. This ‘local consumption’ is linked with higher emission production, details are available below. The author compared specific fuel consumption per 100 km and found that real consumption is evidently always higher than the quantities claimed to be correct by car producers in view of mixed modes. The same has been found by, e.g. Marique & Reiter, 2012 and other authors. The conclusions of the research are potentially relevant and should be used in a spatial planning or decision making processes to prevent ‘urban sprawl’ and the accompanying high energy consumption. Suburban development should go hand in hand with the construction of new transport infrastructures and high-quality public transport.

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