Volume 12 (2014)
  Number 2

Journal full text: Vol 12 No 2 305-430 , 431-588, 589-688

Contents


Pages

307-314 J. Čedík, M. Pexa, M. Kotek and J. Hromádko
Effect of E85 fuel on performance parameters, fuel consumption and engine efficiency – Škoda Fabia 1.2 HTP
Abstract |
Full text PDF (410 kB)

Effect of E85 fuel on performance parameters, fuel consumption and engine efficiency – Škoda Fabia 1.2 HTP

J. Čedík, M. Pexa, M. Kotek and J. Hromádko

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, 16521 Prague – 6 Suchdol, Czech Republic; e-mail: cedikj@tf.czu.cz, pexa@tf.czu.cz, kotekm@oikt.czu.cz, janhromadko@tf.czu.cz Abstract: This article deals with the effect of the E85 fuel on the performance parameters, specific fuel consumption and engine efficiency of a spark ignition engine Škoda Fabia 1.2 HTP and it is related to the article Effect of E85 Fuel on Harmful Emissions – Škoda Fabia 1.2 HTP. The measurement was performed on a test bench using a test cycle that simulates real traffic conditions and simultaneously the external rotation speed characteristics were measured. Three variants were chosen for burning E85 fuel. The first one was the usage of the E85 fuel without modifications on the engine control unit (variant 1 – E85), the second one was the usage of the E85 fuel with prolonged time of the injection by 28% (variant 2 – E85+) and the last third variant was the reference fuel petrol Natural BA95 (variant 3 – N95) for comparison. The results of the measurement showed a non-negligible decrease of the engine torque and power for both variants using E85 fuel. Further, there was a considerable increase of the specific fuel consumption for variants 1 and 2 (E85, E85+). Engine efficiency for the driving cycle increased for variants 1 and 2 (E85, E85+) approximately by one percent. For the external rotation speed characteristics the engine efficiency increased approximately by 5% for variant 1 – E85 and approximately by 2% for variant 2 – E85+. Key words: E85 fuel, performance parameters, fuel consumption, engine efficiency.INTRODUCTION

Abstract:

The increase in the usage of bioethanol as a fuel in Europe is significant (up to15% annually) (Beran, 2011). The reason could be the European Parliament and the European Council, which adopted the so called action plan concerning with the issue of biofuels in transport. In the action plan the strategy for achieving the planned 20% substitution of conventional liquid motor fuels with alternative fuels by 2020 is defined (Šebor et al., 2006). Furthermore according to the European Directive 2009/28/EC on the promotion of the use of energy from renewable sources and amending and subsequent repealing directives 2001/77/EC and 2003/30/EC the target is a 20% share of energy from renewable sources and a 10% share of energy from renewable sources in transport (EU Directive 2009/28/EC; Hromádko et al., 2009; Beran, 2011; Pirs & Gailis, 2013). The second reason could be the dependence of Europe on the imported crude oil products. European OECD countries were dependant on the imported crude oil in the year 2007 from about 65% and by 2030 the dependence could increase up to 83%. The transport in Europe is dependant on the crude oil products from about 98% (Šebor et al., 2006; IEA, 2009; Gnansounou, 2010). France is the major consumer of307

Key words:

,




315-322 J. Čedík, M. Pexa, M. Kotek and J. Hromádko
Effect of E85 Fuel on Harmful Emissions – Škoda Fabia 1.2 HTP
Abstract |
Full text PDF (318 kB)

Effect of E85 Fuel on Harmful Emissions – Škoda Fabia 1.2 HTP

J. Čedík, M. Pexa, M. Kotek and J. Hromádko

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, 16521 Prague 6, Suchdol, Czech Republic; e-mail: cedikj@tf.czu.cz, pexa@tf.czu.cz, kotekm@oikt.czu.cz, janhromadko@tf.czu.cz Abstract: This article deals with harmful emissions production by a spark ignition engine Škoda Fabia 1.2 HTP operating on E85 fuel. The measurement was performed on a test bench using a test cycle that simulates real traffic conditions. Three variants were chosen for burning E85 fuel and the first one was the usage of the E85 fuel without modifications of the engine control unit (variant 1 – E85), the second one was the usage of the E85 fuel with prolonged time of the injection by 28% (variant 2 – E85+) and the last third variant was reference fuel petrol Natural BA95 (variant 3 – N95) for comparison. The results of the measurement have shown that for the variant 1 – E85 there was a significant decrease in the emissions of CO and HC while increasing emissions of NOX especially at high load. For the variant 2 – E85+ there was a significant increase of the emissions of CO and HC, again especially at high load. Emissions of NOX have shown a decrease for this variant. CO2 emissions were approximately on the same level for both variants (E85, E85+) in comparison with the variant 3 – N95. Keywords: ethanol, E85 fuel, emissions production.INTRODUCTION

Abstract:

The increase in the usage of bioethanol as a fuel in Europe is significant (up to15% annually) (Beran, 2011). The reason could be the European Parliament and the European Council, which adopted the so called action plan concerning with the issue of biofuels in transport. In the action plan the strategy for achieving the planed 20% substitution of conventional liquid motor fuels with alternative fuels by 2020 is defined (Šebor et al., 2006). Furthermore, according to the European Directive 2009/28/EC on the promotion of the use of energy from renewable sources and amending and subsequently repealing directives 2001/77/EC and 2003/30/EC the target is a 20% share of energy from renewable sources and a 10% share of energy from renewable sources in transport (EU Directive 2009/28/EC; Beran, 2011;). The second reason could be the dependence of Europe on the imported crude oil products. European OECD countries were dependant on the imported crude oil in the year 2007 from about 65% and by 2030 the dependence could increase up to 83%. The transport in Europe is dependant on the crude oil products from about 98% (Šebor et al., 2006; IEA, 2009; Gnansounou, 2010). France is the major consumer of bioethanol in Europe with a 5.41% share of bioethanol on the market (in Sweden it is 5.14%) (Gnansounou, 2010).The most used fuel with higher share of bioethanol is the E85 fuel, which is madefrom 85% bioethanol and from 15% petrol. In comparison with the petrol the E85 fuel315

Key words:

, , , , , , , , ,




323-332 V. Hönig, and J. Hromadko
Possibilities of using vegetable oil to power diesel engines as well as their impact on engine oil
Abstract |
Full text PDF (829 kB)

Possibilities of using vegetable oil to power diesel engines as well as their impact on engine oil

V. Hönig¹,* and J. Hromadko²

¹Faculty of Agrobiology, Food and Natural Resources, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521 Prague – 6 Suchdol, Czech Republic; Correspondence: honig@af.czu.cz 2Faculty of Engineering, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521 Prague – 6 Suchdol, Czech Republic

Abstract:

The environmental advantages of biofuels cannot only evaluate the final production of pollutants resulting from the combustion of biofuels in the vehicle, but it is necessary to take into account the entire life cycle of fuels including the initial phase of production of raw materials through production to finally the fuel burning vehicle and how it affects the vehicle mechanisms. The Article describes the possibilities of powering diesel engines based on vegetable oils (RME, rapeseed oil) as an alternative to standard diesel fuel. It deals with the properties of biofuels and their potential use in the internal combustion engines by the structural adjustment of the fuel system or the combustion chamber. It also highlights the potential negative impacts of vegetable oils on the machine’s operability and the possibility of reducing the negative effects. The article is based on laboratory analysis of tribotechnical diagnostics. They describe the current state of oil, its primary and secondary pollution and wear of the machine. The important method is ferrography to which the main emphasis is focused. The experimental section analyzes the impact of biofuels on the quality of oil used to fill diesel engines, and establishes an optimal oil change interval. For minimization the negative effects of biofuels is tribotechnical diagnosis necessary part of fuels quality evaluation. Key words: rapeseed oil, RME, engine lubrication oil, construction change, tribotechnical diagnostic.INTRODUCTION

Key words:

, , ,




333-340 V. Hönig, M. Kotek and J. Mařík
Use of butanol as a fuel for internal combustion engines
Abstract |
Full text PDF (371 kB)

Use of butanol as a fuel for internal combustion engines

V. Hönig¹*, M. Kotek² and J. Mařík²

¹Faculty of Agrobiology, Food and Natural Resources, CULS-Czech University of Life SciencesPrague,Kamycka129,16521,Prague 6,CzechRepublic;
*Correspondence: honig@af.czu.cz
²Faculty of Engineering, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521, Prague 6, Czech Republic

Abstract:

Abstract: Currently, the focus of the research and development is devoted to the wider use of fuels of plant origin focused on the possibility of producing a higher quality and use of motor fuel other than bioethanol. BioButanol is thus not only a promising alternative fuel for gasoline, but also a possible replacement for bioethanol as a fuel for internal combustion engines for transportation. Butanol can be produced virtually with the same ingredients as bioethanol, but in terms of fuel property, it is a preferable alternative to bioethanol. The efficient technology for its production by direct fermentation of simple sugars by fermentation, enzymatic hydrolysis or modified polysaccharides is currently the subject of intensive research work. The paper presents fuel properties of butanol and simultaneously compared with the properties of gasoline and bioethanol. It also specifies the advantages and disadvantages of its use both in mixtures and in its pure form. The article also reviews the experimental analysis of emissions in the driving cycle fuel consumption of butanol. Mixtures of butanol – gasoline 5%, 30%, 50%, 85% and 100% were selected as a fuel without further additions as compared to the automotive gasoline and ethanolic E85. Switching to fuel based butanol in FFVs is not a technical problem, particularly based on the comparison with its demonstrable benefits over bioethanol. The development of renewable sources of carbohydrates from agricultural crops butanol can also help reduce imports of petroleum fuels in support of agriculture, availability of drinking water and an increase employment in the region.

Key words:

, , , ,




341-350 R. Ilves, A. Küüt, T. Kikas and J. Olt
Influence of the drop size of bioethanol fuel in air-fuel mixture on combustion process of spark ignition engine
Abstract |
Full text PDF (570 kB)

Influence of the drop size of bioethanol fuel in air-fuel mixture on combustion process of spark ignition engine

R. Ilves*, A. Küüt, T. Kikas and J. Olt

Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, EE51014 Tartu, Estonia; *Correspondence: risto.ilves@emu.ee

Abstract:

Abstract: Bioethanol is widely used as a fuel in spark ignition engines. Brazil and USA are among the largest producers of bioethanol in the world. In order to widen the use of bioethanol as a fuel in spark ignition engines, the combustion process has to be improved. This can be accomplished by dosing bioethanol air-fuel mixture into the engine. Thus, the smaller drop size of the fuel can be achieved than in the air-fuel mixtures formed in regular fuel supply systems. Decreasing the size of the fuel drops decreases evaporation time of the air-fuel mixture and therefore, increases the combustion velocity of the air-fuel mixture. This article gives an overview of using 96.4% bioethanol as a fuel in spark ignition engines when the fuel drop size in the air-fuel mixture directed to cylinder is smaller than in the air-fuel mixture formed in regular fuel supply systems. Results indicate that by decreasing the fuel drop size in the air-fuel mixture, fuel consumption of the engine decreased, while heat-release rate and the combustion velocity of the air-fuel mixture increased. Key words: bioethanol, fuel drop size, spark ignition engine, heat-release rate, combustion pressure.INTRODUCTIONSince developing the Otto-cycle engine by N.A. Otto, formation of the air-fuelmixture in the spark ignition engines has considerably improved. In the homogeneous mode, used in Otto-cycle engines, the entire combustion chamber is filled with the air-fuel mixture. In the newest technology, direct injection engines, the fuel is injected directly into the engine’s cylinder. Thus, not entire combustion chamber is filled with air-fuel mixture. The advantage of forming a stratified air-fuel mixture close to the spark plug electrode is that it can be ignited even at relative air-fuel ratio

Key words:

, , , , ,




351-358 M. Lukeš, M. Kotek and M. Růžička
Transport demands in suburbanized locations
Abstract |
Full text PDF (939 kB)

Transport demands in suburbanized locations

M. Lukeš*, M. Kotek and M. Růžička

Faculty of Engineering, Czech University of Life Sciences Prague, ¹⁶⁵ ²¹ Prague ⁶ –Suchdol, Czech Republic;
*Correspondence: lukesm@tf.czu.cz

Abstract:

The aim of this paper is to describe the suburban residents’ transport demands from the viewpoint of consumption costs in the case of regular commuting. The surveyed suburbs have different transport patterns, because these suburbs are influenced by the catchment area of the city of Prague that is a dominant city of the region, and many of the suburban settlements do not behave as traditional municipalities. Most of the existing transport links are carried out in relation to the city of Prague on radially oriented roads. The traffic intensity is often at the roads’ full capacity or the roads are even congested along the ride to the city. These congestions have a negative impact on the city’s environment and increase the consumption costs of passenger car transport as well. This contribution describes the transport demands based on the traffic surveys that were carried out within ¹⁵ suburban settlements during the morning peak hours and during ordinary working days. These selected settlements are located at different distances from the city and include different types of buildings and build-up areas. Thus, the authors gained a high quality sample for statistical assessment. On the basis of traffic surveys, the authors found the total amount of transport demands which were generated by selected settlements. The obtained results have proved the low competitiveness of public transport in suburban conditions from the viewpoint of travelling speed and transport costs as well, because there are no competitive advantages in this issue.

Key words:

, , , ,




359-366 J. Mařík, M. Pexa,, M. Kotek and V. Hönig
Comparison of the effect of gasoline – ethanol E85 – butanol on the performance and emission characteristics of the engine Saab 9-5 2.3 l turbo
Abstract |
Full text PDF (365 kB)

Comparison of the effect of gasoline – ethanol E85 – butanol on the performance and emission characteristics of the engine Saab 9-5 2.3 l turbo

J. Mařík¹, M. Pexa¹,*, M. Kotek¹ and V. Hönig²

¹Faculty of Engineering, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521 Prague 6, Czech Republic; *Correspondence: pexa@tf.czu.cz 2Faculty of Agrobiology, Food and Natural Resources, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521 Prague 6, Czech Republic

Abstract:

Due to the increasing environmental demands of the European Union for reducing emissions, it is necessary to utilize biofuels at the expense of the conventional fossil fuel BA95. Biofuels in spark-ignition engines usually use ethanol at a ratio of up to 85% to 15% of the conventional fuel BA95. Such a fuel is known as E85. Butanol also has very similar properties to ethanol. Ethanol is a higher alcohol. For comparison, ethanol and butanol fuels with conventional fuels were chosen for the vehicle Saab 9-5, turbo-charged 2.3l. This vehicle is completely adapted to operation on ethanol fuel (broad adaptation control unit, suitable sealing elements, fuel pump, etc.). The engine performance and emissions were monitored when operating on these fuels as compared to the conventional fuels BA95. It can be stated that the engine reached higher performance parameters when operating on ethanol and butanol fuels. This is due to the fact that the control unit increases the fuel supply during operation on biofuels (lower calorific value of fuel). There is no lean combustion and the possible damage to the engine during long-term operation. From the perspective of bootable showing, butanol fuel has worse parameters compared to ethanol fuel and conventional fuels.

Key words:

, , , ,




367-372 M. Pexa and J. Mařík
The impact of biofuels and technical engine condition to its smoke – Zetor 8641 Forterra
Abstract |
Full text PDF (294 kB)

The impact of biofuels and technical engine condition to its smoke – Zetor 8641 Forterra

M. Pexa* and J. Mařík

Faculty of Engineering, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521 Prague 6, Czech Republic; *Correspondence: pexa@tf.czu.cz Abstract: The large number of vehicles necessitated the introduction of rules that focus in addition to traffic safety on the ecology of operation of the engine especially. Over time, the emission limits in amendments to regulations tightened, and this also applies to agriculture. One of the efforts of the EU is the introduction of biofuels precisely because, among other things, they have an impact on reducing emissions from the operation of internal combustion engines. Fatty acid methyl ester is promoted as the best substitute for diesel fuels, in the Czech conditions, namely rapeseed methyl ester (RME – Rapeseed Methyl Ester). The requirements for diesel fuel are established with the standard EN 590 and the requirements for RME with the standard EN 14 214. Efforts are made to promote replacement of the old fleet with the new. A large percentage of obsolete vehicles in poor condition still remain in use in small farms. In this paper, a comparison of a smoke combustion engine tractor Zetor 8641 Forterra when using fuels with different ratios of diesel and RME is provided. For comparison, a common test is performed in the technical emission (measurement of smoke on the principle of free acceleration). In order to assess the influence of the technical condition of an internal combustion engine and rapeseed methyl ester on smoke, gradually simulated faults of turbochargers, opening pressure and spray of pre-injection fuel injectors on a selected motor are used. The result showed that deteriorating technical condition of an internal combustion engine decreases the positive effect of rapeseed oil methyl ester blended into the fuel on smoke. Key words: biofuel, smoke, technical condition of the engine.

Abstract:

INTRODUCTION

Key words:

,




373-390 L. Podkuiko, K. Ritslaid, J. Olt and T. Kikas
Review of promising strategies for zero-waste production of the third generation biofuels
Abstract |
Full text PDF (464 kB)

Review of promising strategies for zero-waste production of the third generation biofuels

L. Podkuiko*, K. Ritslaid, J. Olt and T. Kikas

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, 51014 Tartu, Estonia; *Correspondence: lara.podkuiko@emu.ee

Abstract:

Biodiesel obtained from microalgae is considered a promising alternative to conventional diesel fuel. However, it has been proposed that cultivation of algae for the sole purpose of making biodiesel is neither economically efficient nor sustainable. Nevertheless, there are several ways in which microalgae can be utilized to their full potential. One possibility is to view the cultivation and utilization of microalgae as a complex process that includes wastewater treatment, carbon dioxide sequestration, production of nutritional supplements, biofuels etc. The aim of this paper is to review the most promising possibilities of combining different cultivation strategies/technologies with the coproduction of high value products (e.g. Ω-fatty acids) and biofuels (algal diesel, ethanol and biogas).

Key words:

, , ,




391-396 M. Pointner, P. Kuttner, T. Obrlik, A. Jäger and H. Kahr
Composition of corncobs as a substrate for fermentation of biofuels
Abstract |
Full text PDF (225 kB)

Composition of corncobs as a substrate for fermentation of biofuels

M. Pointner*, P. Kuttner, T. Obrlik, A. Jäger and H. Kahr

University of Applied Sciences Upper Austria, Wels Campus, Stelzhamerstr. 23, 4600 Wels, Austria; *Correspondence: manuel.pointner@fh-wels.at

Abstract:

Lignocellulosic residues as for instance corncobs can be used as substrates for the production of biofuels. The corncobs are usually pre-treated in a thermal-physical step (steam explosion) before enzymatic hydrolysis. The pre-treatment process increases the accessibility of the raw material for the hydrolysis. The products of the hydrolyses are used as substrates for the fermentation of bio-ethanol. As an alternative, the hydrolysates could be used for the fermentation of oleaginous yeasts. These yeasts produce and accumulate lipids from glucose during growth. For the energetic use in the form of bio-diesel, the lipids can be converted into fatty acid methyl esters (FAME) in the same way as vegetable oils. The fibre composition of the raw material was determined in regard to the proportions of cellulose, hemicellulose und lignin. It was investigated whether different corn varieties show varying compositions. The fibre compositions before the pre-treatment of ten different varieties of corncobs (from locations in Upper Austria) were determined. No significant differences were observed (cellulose: 38.8% ± 2.5%, hemicellulose: 44.4% ± 5.2%, lignin: 11.9% ± 2.3% in the dry matter).

Key words:

, , , ,




397-406 M. Raud, R. Kesperi, T. Oja, J. Olt and T. Kikas,
Utilization of urban waste in bioethanol production: potential and technical solutions
Abstract |
Full text PDF (231 kB)

Utilization of urban waste in bioethanol production: potential and technical solutions

M. Raud¹, R. Kesperi¹, T. Oja², J. Olt¹ and T. Kikas¹,*

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, EE51014 Tartu, Estonia; *Correspondence: timo.kikas@emu.ee 2Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE51014 Tartu, Estonia

Abstract:

In urban forestry and greening millions of tons of lignocellulosic waste is produced every year. Although lignocellulosic materials are considered one of the most promising feedstock for the bioethanol production, biomass from urban greening and forestry goes unused. Aim of this research was to investigate the potential of such waste biomass for bioethanol production. Woody and non-woody vegetation from different sources was investigated: old and fresh leaves, and mixed waste from urban greening which contained grass, twigs, and leaves. Cellulose, hemicellulose and lignin contents in the samples were determined using fibre analysis. Dilute acid was used for pre-treatment at temperature of 130°C in order to compare yields from different methods. Thermochemical pre-treatment was followed by enzymatic hydrolysis and fermentation. Produced glucose and ethanol contents were measured using electrochemical analyser. Waste from urban greening had the highest cellulose content of 22.96% and gave the best glucose and ethanol yields, 154.5 g kg-1 and 62.5 g kg-1, respectively when the sample was pre-treated with dilute H2SO4. In addition, map analysis was used to assess the area manageable by urban forestry and greening in the city of Tartu to estimate the potential of greening and forestry waste as a substrate for bioethanol production that could be used as a fuel in city’s public transportation system. In conclusion, it was shown that the waste from urban greening and forestry is a very promising raw material for biofuel production considering its localization and high cellulose content.

Key words:

, , ,




407-416 K. Sirviö,, S. Niemi, V. Vauhkonen and E. Hiltunen
Antioxidant studies for animal-based fat methyl ester
Abstract |
Full text PDF (330 kB)

Antioxidant studies for animal-based fat methyl ester

K. Sirviö¹,*, S. Niemi¹, V. Vauhkonen² and E. Hiltunen¹

¹University of Vaasa, Faculty of Technology, PL 700, FIN-65101 Vaasa, Finland; *Correspondence: Katriina.Sirvio@uwasa.fi 2UPM Research Center, FI-53200 Lappeenranta, Finland

Abstract:

The aim of this study was to test an antioxidant, BioSineox, for animal-based fat methyl ester, AFME, in order to determine the optimal concentration of this antioxidant for meeting the six-hour oxidation stability requirement as set in the EN 14214:2010 standard. Oxidation stability was measured using a Biodiesel Rancimat 873, which meets the requirements of the EN 14112 standard. The variety of raw materials used in the production of methyl esters, i.e. biodiesels, renders a variety of fatty acid profiles. Consequently, the reaction of biodiesels with various antioxidants must be individually tested for each combination. Before the antioxidant is added during the manufacturing process, it must be tested in laboratory conditions. As the main result of this study it can be stated that the process requires a relatively high (2,000 ppm) BioSineox concentration in order for the biodiesel to meet the six-hour oxidation stability requirement. In March 2013, the standard EN 14214:2010 was replaced by the EN 14214:2012. One of the changes was an increase in the oxidation stability requirement from 6 hours minimum to 8 hours minimum. To reach this target, the concentration of the antioxidant must be further increased.

Key words:

, , , ,




417-424 M. Tutt, T. Kikas, H. Kahr, M. Pointner, P. Kuttner and J. Olt
Using steam explosion pretreatment method for bioethanol production from floodplain meadow hay
Abstract |
Full text PDF (714 kB)

Using steam explosion pretreatment method for bioethanol production from floodplain meadow hay

M. Tutt¹*, T. Kikas¹, H. Kahr², M. Pointner², P. Kuttner² and J. Olt¹

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, EE51014 Tartu, Estonia; *Correspondence: marti.tutt@emu.ee 2Upper Austria University of Applied Sciences, Wels Campus, Stelzhamerstraße 23, 4600 Wels, Austria

Abstract:

This article investigates influence of the steam explosion pretreatment method at different temperatures on sugar conversion rates and bioethanol production efficiencies from floodplain meadow hay. Floodplain meadow hay is used as a raw material, because these semi-natural grasslands need regular maintenance to preserve their high biodiversity. So far, this biomass has been largely unused, but it could provide a good feedstock for bioethanol production. In this work, steam explosion pretreatment is used in combination with enzymatic hydrolysis. Effects of steam explosion pretreatment on the fibre content and cell wall structure are also studied. Results from fibre analysis show, that the floodplain meadow hay has very high lignin content of 24.16%, but relatively low cellulose content of 27.19%. Highest cellulose to glucose conversion rate of 234.6 g kg-1 and ethanol yield of 115.7 g kg-1 of biomass were achieved with the steam explosion pretreatment at 200°C. Scanning electron microscope (SEM) images show that pretreatment at 150°C does very little damage to plant cells, while steam explosion at 200°C disintegrates most of the plant cell walls and exposes cellulose fibres.

Key words:

, , ,




425-430 K. Veselá, M. Pexa and J. Mařík
The effect of biofuels on the quality and purity of engine oil
Abstract |
Full text PDF (254 kB)

The effect of biofuels on the quality and purity of engine oil

K. Veselá*, M. Pexa and J. Mařík

Faculty of Engineering, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521, Prague 6, Czech Republic; *Correspondence: kvesela@tf.czu.cz

Abstract:

The European Union aims to promote the use of biofuels and thus set a commitment to the expansion of biofuels in transport. Biofuels replace fossil fuels mainly in part, the creation of biodiesel. For gasoline engines, the most widely used biofuel is E85, a fuel containing 85% ethanol and 15% gasoline. The more bio-components are contained in a fuel, the more oil filling the combustion engine suffers. Therefore, in this paper, a comparison of the properties of oil filling when using fossil fuels (currently contains a small amount of the fuel ethanol) and the E85 biofuel is provided. The cars Saab 95 and 93 are monitored, namely the motors B235 R, B207 L, and B205 L. For each car, the total of 10 samples of engine oil were taken. One part of the samples was collected during operation of the internal combustion engine on the biofuel E85 and the second during operation of the internal combustion engine on the fossil fuel BA95. Both vehicles used the same engine oil, Mobil 1 0W-40, for lubrication of the internal combustion engine. The analyses of the engine oil are focused on the evaluation of the kinematic viscosity and density at 40 and 100°C.

Key words:

, ,




433-444 A. Allik, J. Uiga and A. Annuk
Deviations between wind speed data measured with nacelle-mounted anemometers on small wind turbines and anemometers mounted on measuring masts
Abstract |
Full text PDF (871 kB)

Deviations between wind speed data measured with nacelle-mounted anemometers on small wind turbines and anemometers mounted on measuring masts

A. Allik*, J. Uiga and A. Annuk

Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, EE51014 Tartu, Estonia; *Correspondence: alo.allik@emu.ee Abstract: This article focuses on the readings received from two different types of nacelle-mounted anemometers and their comparison with reference measurements on-site. The aim of the article was to evaluate the influence of the wind turbine rotors on the wind data measured with the nacelle-mounted anemometers. The measurements were made during a case study of two existing small wind turbines. The framework conditions in the analysed cases were similar: both analysed anemometers were mounted on small, 10 kW horizontal axis type wind turbines (HAWT-s) with active yaw and pitch control, and although the wind turbines were situated at different locations, the wind conditions of the measurement sites were relatively similar. The comparative wind speed data for the analysis was acquired in both cases from measurement masts that were installed in the proximity of the analysed anemometers on the basis of the standard EN 61400-12-1:2006. The anemometer readings were logged during measuring periods of two months and saved as 10 minute averages. Three anemometers and a wind direction sensor were used for the reference measurements on both sites. It was found that in both cases the operating state of the wind turbines (presumably the rotation of the rotor blades of the turbine) influenced the readings received from the nacelle-mounted anemometers to a statistically significant extent. The 10 minute average wind speeds of the nacelle-mounted anemometers were significantly lower than the means of the data acquired from the measuring mast anemometers. Despite the fact that the means did not coincide the correlations between the reference wind data and the nacelle-mounted anemometer readings were strong. In the analysed cases the readings from the ultrasonic anemometer were more similar to the reference measurements than the readings from the mechanical cup-anemometer. Key words: wind measurements, anemometers, accuracy, wind turbines.INTRODUCTION

Abstract:

Modern wind turbines with active yaw and pitch control rely in their operation onreal-time wind speed data, which is used for the automatic control operations. This requires constant wind speed measurements in the proximity of the wind turbine. Normally anemometers that are mounted on the nacelle of the wind turbine are used for acquisition of the necessary data. This occurs due to the fact that the anemometer has to be approximately on the same height with the wind turbine hub and installing a separate mast just for measurements is not reasonable. The problem lies in the fact that the wind turbine and especially the rotating rotor blades of the turbine influence the air flow that has to be measured. And thereby influence the results of the measurements.433

Key words:




445-454 R. Bindig, S. Butt and I. Hartmann
Application of high temperature catalysis to abate emissions from a small scale combustion system
Abstract |
Full text PDF (309 kB)

Application of high temperature catalysis to abate emissions from a small scale combustion system

R. Bindig, S. Butt* and I. Hartmann

DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH, 116 Torgauer St., 04347 Leipzig, Germany; *Correspondence: Saad.Butt@dbfz.de

Abstract:

A newly designed downdraft wood stove achieved low-emission heating by integrating an alumina-supported mixed metal oxide catalyst in the combustion chamber operated under high temperature conditions. Since the mixed metal oxide catalysts have been the center of attention regarding their applicability at high temperatures, a novel idea has been put into practice by integrating them in a small scale combustion system in order to mitigate the emissions. The alumina-supported mixed metal oxide catalyst reduced the volatile hydrocarbons, carbon monoxide and carbonaceous aerosols by more than 60%.

Key words:

, , , ,




455-468 G. Cimdina, I. Veidenbergs, A. Kamenders, J. Ziemele,A. Blumberga and D. Blumberga
Modelling of biomass cogeneration plant efficiency
Abstract |
Full text PDF (590 kB)

Modelling of biomass cogeneration plant efficiency

G. Cimdina, I. Veidenbergs, A. Kamenders, J. Ziemele,A. Blumberga and D. Blumberga*

¹Institute of Energy Systems and Environment of the Riga Technical University, Kronvalda bulvaris 1, LV-1010, Riga, Latvia; e-mail: dagnija.blumberga@rtu.lv

Abstract:

The paper presents the analysis of operation conditions of biomass cogeneration plant (CHP). The data set for analysis comprises the data measured on an hourly basis at the cogeneration plant in Jelgava. The volume of the data set is 467 modes. By means of statistical processing of the change in the plant’s specific fuel consumption, by applying the methods of regression analysis, the most important factors describing the operation of the equipment or independent parameters were identified. The relationship between the change in the plant’s specific fuel consumption and the parameters impacting it, is established by the regression equation obtained in data processing. According to the performed analysis: the change in the plant’s specific fuel consumption is determined by the following four statistically important parameters: boiler efficiency; power generation efficiency; heat production efficiency indicators and outdoor temperature. The specific fuel consumption rate, calculated using regression equation, is compared to the specific fuel consumption rate observed in the CHP during operation. The assessment of the percentage difference shows that the specific fuel consumption rates calculated using the equation are useful in describing the plant data and can also be used to estimate future fuel consumption. It was observed that the rate difference is within the margins of 3.6 to 6.7 per cent.

Key words:

, ,




469-478 A. Jansons, S. Zurkova, D. Lazdina and M. Zeps
Productivity of poplar hybrid (Populus balsamifera x P. laurifolia) in Latvia
Abstract |
Full text PDF (415 kB)

Productivity of poplar hybrid (Populus balsamifera x P. laurifolia) in Latvia

A. Jansons*, S. Zurkova, D. Lazdina and M. Zeps

Latvian State Forest Research Institute ‘Silava’, Rigas 111, LV-2169 Salaspils, Latvia; *Correspondence: aris.jansons@silava.lv

Abstract:

Fast growing poplar clones have been widely used for biomass production in Southern Europe; however, there is insufficient information about the growth of poplar in north-eastern Europe that might hamper its wider use. The aim of the study was to assess the productivity of poplar hybrid and its potential for biomass productions. Material for the study was collected in 14 stands (age 54–65 years) located in the central and western part of Latvia (56–57°N, 22–23°E), which were established on fertile drained mineral soil (Mercurialiosa mel.) and mineral soil with normal moisture regime (Oxalidosa and Aegopodiosa). Tree diameter and height were measured and biomass was estimated using equation developed based on 24 sample trees. Mean tree diameter and height in stands on mineral soil varied greatly (from 29 ± 1.6 cm to 45 ± 3.9 cm and from 24 ± 0.9 m to 31 ± 0.8 m, respectively); however in stands on drained mineral soil mean diameter and height was 42 ± 2.1 cm and 27 ± 0.7 m, respectively. Mean diameter and height of poplar was 16.7–25.1% higher compared with Norway spruce and these differences were statistically significant (p-value < 0.05), differences with common aspen were not significant. The number of fallen and standing dead trees, reaching up to 14–46% from the number of living trees, indicated aging and intense self-thinning. Mean annual volume increment of all stands was 11.8 m3 ha-1 y-1 (in some of stands reaching 21.0 m3 ha-1 y-1), corresponding to 4.2–9.8 t of dry matter per year. Thus, the results suggest that poplar could be an efficient species for production of bioenergy.

Key words:

, , ,




479-490 S.N. Kalnins, S. Valtere, J. Gusca and D. Blumberga
Combined management response and indicator based evaluation methodology of implementation of environmental management system at a wood pellet production industry
Abstract |
Full text PDF (252 kB)

Combined management response and indicator based evaluation methodology of implementation of environmental management system at a wood pellet production industry

S.N. Kalnins*, S. Valtere, J. Gusca and D. Blumberga

Institute of Energy Systems and Environment of the Riga Technical University, Kronvalda bulvaris ¹, LV-¹0¹0 Riga, Latvia;
*Correspondence: silvija-nora.kalnins@rtu.lv

Abstract:

The sustainability factor stimulates industrial companies to be more active and precise in improving their performance in relation to energy efficiency and environmental indicators. One of the more widespread practises to introduce improvements in energy efficiency and environmental processes is through energy and environmental management systems. However until now, there is a lack of practical studies assessing the role of environmental management systems to the improvement of the wood fuel production sector. The paper describes an analysis of lessons learned based on combined management-response and indicator based analysis on the introduction of environmental management systems (in accordance with ISO ¹⁴00¹:²00⁴) in an industrial enterprise. The chosen subject of this research is a wood pellet production facility located in Latvia. The research can be applied as a guideline for entrepreneurs in wood fuel production industry that are planning to implement energy and environmental management systems.

Key words:

, , ,




491-498 E. Kamendere,, A. Zandeckis, A. Kamenders, J. Ikaunieks and C. Rochas
Mechanical ventilation with a heat recovery system in renovated apartment buildings
Abstract |
Full text PDF (618 kB)

Mechanical ventilation with a heat recovery system in renovated apartment buildings

E. Kamendere¹,*, A. Zandeckis¹, A. Kamenders¹, J. Ikaunieks² and C. Rochas¹

¹Institute of Energy Systems and Environment, Faculty of Power and Electrical Engineering, Riga Technical University, Kalku street 1, LV-1658 Riga, Latvia; *Correspondence: edite.kamendere@rtu.lv 2Ekodoma Ltd., Noliktavas Street 3, LV-1010 Riga, Latvia

Abstract:

Renovation of existing buildings offers a great opportunity to reduce energy consumption, but often it also reduces indoor air quality, as buildings which were originally designed for natural ventilation are made highly air tight. A solution to the problem would be a mechanical ventilation system, but several problems are experienced when implementing it – no place for installing air ducts, cold air inflow or additional energy needed for incoming air preheating. Ventilation using heat recovery units is the one method out of many other energy saving measures. The advantage of using heat recovery units is energy saving, and as a result, savings on costs of the operation of the ventilation system. This paper describes the renovation carried out in 4-storey apartment buildings. In the course of the study, two buildings were analysed, both belonging to the series buildings of the Soviet Era (103 series), built in 1970 using the same materials, the same construction solutions. The renovation was carried out by one company, using the same materials and the same renovation principles for both buildings. The only difference after the renovation is that a new centralized mechanical ventilation system with a heat recovery unit is installed in one of the buildings, while in the second building the natural ventilation system is preserved. The arrangement of the mechanical ventilation system is rather innovative as the ventilation ducts in the building for fresh air supply are integrated into the facade’s insulation layer and enter the living room through the wall directly behind heating radiators. The main questions studied in the course of the research are the efficiency of the mechanical ventilation system heat recovery, the building’s air tightness, and the overall system efficiency.

Key words:

, , ,




499-510 V. Kirsanovs, A. Žandeckis, I. Veidenbergs, I. Blumbergs, M. Gedrovičs andD. Blumberga
Experimental study on optimisation of the burning process in a small scale pellet boiler due to air supply improvement
Abstract |
Full text PDF (637 kB)

Experimental study on optimisation of the burning process in a small scale pellet boiler due to air supply improvement

V. Kirsanovs*, A. Žandeckis, I. Veidenbergs, I. Blumbergs, M. Gedrovičs andD. Blumberga

Riga Technical University, Institute of Energy Systems and Environment, Kronvalda blvd. ¹, Riga, LV-¹0¹0 Latvia;
*Correspondence: vladimirs.kirsanovs@rtu.lv

Abstract:

The specific weight of biomass and pellets in thermal energy production has recently started to increase rapidly. The continually growing price of fossil fuels and European Union requirements to increase the share of renewable energy in thermal energy production are the main reasons of the biomass specific weight increase. Unfortunately, Latvia uses only a small part of the country’s existing biomass potential for the time being. A growth of the amount of biomass utilisation for energy production can be foreseen in the future, because such type of energy production has a number of advantages, one of which is the lesser amount of emissions that arise during the combustion process. However, the amount of emissions that arise during the combustion of wood pellets can get lower due to optimisation of the combustion process. Air supply is one of the main factors which have effect on the heat loss, boiler efficiency, and emissions levels. The main goal of this study is to optimise the pellet combustion process in a small scale pellet boiler due to the air supply improvement. Experimental research of the combustion process of a pellet boiler with nominal capacity ²⁵ kW was carried out during the work. First at all, the effect of changes in the amount of air supplied to the boiler combustion process was determined. Then, approbation of two methods for combustion process improvement was made. The first method was based on flame dissipation, but the second method included the opposite method – flame concentrating. However, the main task of both methods applied was to improve the process of mixing air and fuel. It was important to reduce the rate of air supplied, too. Four different gratings were used for dissipation of the flame. Cylinders without and with a spiral for flow swirl were used for flame concentration. The results of the study show that both methods, in general, have a positive impact on the combustion process.

Key words:

, , , , , , , , , ,




511-518 K. Klavina, A. Cinis and A. Zandeckis
A study of pressure drop in an experimental low temperature wood chip dryer
Abstract |
Full text PDF (387 kB)

A study of pressure drop in an experimental low temperature wood chip dryer

K. Klavina*, A. Cinis and A. Zandeckis

Riga Technical University, Institute of Energy Systems and Environment, Kronvalda blvd. 1, LV-1010 Riga, Latvia; *Correspondence: krista.klavina@rtu.lv

Abstract:

The use of wood materials, and logging residues in the energy sector is growing rapidly, and will follow the same trend in the following years in the entire EU. This development is related to the target of 20% renewable energy share in the primary energy consumption. Thus it is very important to increase the value of fresh wood materials by application of drying technologies. Drying allows increasing the efficiency and flexibility of combustion, transportation, and storage processes. The goal of this research is to study wood chip drying process in low temperature conditions as a promising solution for the use of low exergy energy sources, such as solar energy, geothermal, and waste heat. Low temperature drying processes typically require high parasitic consumption of electrical energy that is required to provide the air change in the wood chip body, but allows reduction of heat loss. This study was developed to collect experimental information required for designing, optimization and operation of low temperature dryers. Experimental setup was used to study wood chip drying process in controlled laboratory conditions. Air pressure loss is settled as the dependent variable. Thickness of wood chip layer and airflow rate were changed between the experiments. A comprehensive analysis of the obtained monitoring data is carried out.

Key words:

, ,




519-526 M. Kolarikova,, T. Ivanova, B. Havrland and K. Amonov
Evaluation of sustainability aspect – energy balance of briquettes made of hemp biomass cultivated in Moldova
Abstract |
Full text PDF (208 kB)

Evaluation of sustainability aspect – energy balance of briquettes made of hemp biomass cultivated in Moldova

M. Kolarikova¹,*, T. Ivanova¹, B. Havrland¹ and K. Amonov²

¹Faculty of Tropical AgriSciences, Czech University of Life Sciences, Kamycka 129, 12641Praha 6, Czech Republic; 2Central Bohemia University, Pod Vodarenskou vezi 4, 18200Praha 8, Czech Republic *Correspondence: kolarikova@ftz.czu.cz

Abstract:

Biomass is currently a significant source of energy mainly for its availability and high potential. Energy crops suitable for energy purposes must have a positive energy balance within the whole production cycle. Industrial hemp (Cannabis sativa L.) has a high yield in a short period of time and reaches a gross calorific value similar to that of wood. Two hemp cultivars were experimentally sown in the Republic of Moldova in order to determine the yield and energy balance for utilization of solid fuels in the form of briquettes. Briquettes were considered to be used in small – scale boilers for heating purposes with a thermal efficiency of 80%. Hemp harvested as a green plant in autumn was left under a roof for losing moisture, to keep yield as high as possible and left the field for another crop in rotation system. The energy balance included all forms of inputs – energy of human labor, energy in fuels, in seeds and in the machines during the technological process according to common practises in Moldova. Energy Return on Energy Invested (EROEI), due to the large share of manual labor and agricultural practices without using of fertilizers, exceeded the value of 12.6. This means that it is classified as very suitable for energy purposes. Hemp appears to be a promising energy crop in temperate climate and it is able to contribute solving the energy situation in Moldova.

Key words:

, , , ,




527-542 I. Laicāne, A. Blumberga, M. Rošā and D. Blumberga
Determinants of household electricity consumption savings: A Latvian case study
Abstract |
Full text PDF (454 kB)

Determinants of household electricity consumption savings: A Latvian case study

I. Laicāne*, A. Blumberga, M. Rošā and D. Blumberga

Institute of Energy Systems and Environment, Faculty of Power and Electrical Engineering, Riga Technical University, Kronvalda boulevard ¹, LV–¹0¹0 Riga, Latvia;
*Correspondence: ilze.laicane@rtu.lv

Abstract:

In order to assess the potential for energy efficiency in households it is important to understand the implications for household electricity consumption by analyzing the factors that impact consumption. Moreover some recent studies suggested that changes in household electricity consumption are more likely to be explained by user behavioural aspects than technical solutions. This paper examines the influence of household’s personal, demographic, socio–economic, the stock and use of electrical appliances, structural characteristics, external factors (such as weather, location etc.) by analysing data obtained from a smart metering pilot project currently being implemented in ⁵00 Latvian households. The preliminary results show a decrease of the electricity consumption in ²0¹³ (April–December) by ²³% for the target group and ⁵% for the control group. The aim of the study is to introduce a novel model for assessing electricity consumption and savings achieved in households. The main tasks of this study is to examine the main characteristics determining electricity consumption savings, in particular, to evaluate the extent of smart metering influence on electricity consumption savings by using linear regression model.

Key words:

, , ,




543-552 D. Lazdiņa, A. Bārdulis, A. Bārdule, A. Lazdiņš, M. Zeps and Ā. Jansons
The first three-year development of ALASIA poplar clones AF2, AF6, AF7, AF8 in biomass short rotation coppice experimental cultures in Latvia
Abstract |
Full text PDF (577 kB)

The first three-year development of ALASIA poplar clones AF2, AF6, AF7, AF8 in biomass short rotation coppice experimental cultures in Latvia

D. Lazdiņa*, A. Bārdulis, A. Bārdule, A. Lazdiņš, M. Zeps and Ā. Jansons

Latvian State Forest Research Institute Silava, 111 Rigas str., LV2169 Salaspils, Latvia; *Correspondence: dagnija.lazdina@silava.lv

Abstract:

Hybrid aspen and willows are the fastest growing tree species used for biomass production in short rotation coppice (SRC) cultures in Latvia. Poplars are suitable for cultivation in Latvia, however, their potential for this purpose as SRC in Latvia and North Eastern Europe has not yet been investigated. There is an increasing interest in using poplar clones to establish short rotation plantations. The aim of this study is to analyse the productivity of the Italian poplar clones AF2, AF6, AF7, AF8 and their potential use for biomass production, as well as the effect of fertilization on the development and survival of trees. The experimental plot consisted of drained mineral soil with the initial spacing of trees ranging from 9,000 to 10,000 trees ha-1 (1.5 m x 0.7–0.5 m). Weed management has been carried out on the plantation once per season every year. Four management methods were tested – control (no fertilization), fertilization with waste water sludge 10 t DM ha-1, wood ash 6 t ha-1, mineral fertilizer NPK (12:5:14) 100 kg ha-1. In the second year, the height of the trees ranged from 0.2 to 2.64 m, on average 1.12 ± 0.005 m. The annual increments during the third year ranged from 0.01–2.14 m, on average 0.787 ± 0.004 m. At the end of the third season, the tree diameters at breast height of all clones varied greatly from 0.36 cm to 4.4 cm. The trees reached average diameters of 1.48 ± 0.007 cm; the tree heights ranged from 0.36 m to 4.24 m and were 1.99 ± 0.01 m, on average at the end of the third season. Depending on the clone and treatment, the amount of fresh biomass was 1.57–10.67 t ha-1(planting density 10,000 trees), and one fifth of the biomass, on average, was located in branches. Sewage sludge fertilizer contributed to the development of the micropatogen Venturia sp., resulting in lower initial retention and delayed development. Mineral fertilizers were the most effective. No animal and frost damages were observed. Overall, the results indicate a significant potential for us for using poplar for bioenergy production, with the optimal rotation age for bioenergy production being more than 3 years.

Key words:

, , ,




553-562 M. Märss,, A. Annuk, A. Allik and J. Uiga
AC-link based new microgrid system for research of local power flow management
Abstract |
Full text PDF (884 kB)

AC-link based new microgrid system for research of local power flow management

M. Märss¹⋅²,*, A. Annuk¹, A. Allik¹ and J. Uiga¹

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, EE51014 Tartu, Estonia 2Tallinn University of Technology, Department of Electrical Engineering, Ehitajate tee 5, EE19086 Tallinn, Estonia; *Correspondence: maido.marss@emu.ee

Abstract:

This paper gives an overview of a distributed energy technology laboratory, where diverse approaches are studied to effectively integrate distributed generation into power systems. The laboratory is equipped with small-scale power generation devices including wind turbine (3.5 kW), PV array (2.5 kW), synthetic energy generator (3.6 kW) and also batteries, ultra capacitor, programmable load (6.2 kW), weather station, power flow and power quality control and monitoring system. The laboratory is used for researching and applying energy-management technics to control energy storage and increasing power reliability and power quality in small-scale generation units. On-site measured data of power consumption and production can be linked to the laboratory and simulated online with synthetic energy generator and programmable load. It is also possible to scale the measured data and model systems with variable sizes. As a result the stability of variable systems can be tested with different storage capacities and load management techniques.

Key words:

, , , ,




563-574 P. Pikk and A. Annuk
Case study of increasing photovoltaic energy solar fraction in a conventional office building in northern latitudes
Abstract |
Full text PDF (397 kB)

Case study of increasing photovoltaic energy solar fraction in a conventional office building in northern latitudes

P. Pikk* and A. Annuk

Department of Energy Engineering, Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, EE51014, Tartu, Estonia; *Correspondence: priit.pikk@emu.ee

Abstract:

Current trends in planning office buildings are moving towards reducing primary energy consumption for heating, hot water heating and cooling. Availability of the solar energy resource and the low temperatures in northern latitudes from early spring until autumn provide the possibility to use photovoltaic (PV) energy for heating, cooling and other energy needs. This article calculates the heating, cooling, hot water and electricity demand of an office building with a glass facade of 65% of the total wall area. The calculated annual total energy consumption is 120 kWh m-2. To reduce the heat and electricity consumption from district heating and the power network, PV modules are integrated into the roof and facade and the solar fractions of the PV energy of the four energy loads (heating, cooling, hot water, and electricity) are found. Optimization of the PV module tilt angles on the facade and roof results in the maximum solar fraction for cooling, heating, preparing hot water, and electricity consumption, 98.4%, 32.1%, 71.7%, and 51.6% respectively. For total load, the calculated maximum solar fraction is 49.8%.

Key words:

, , , ,




575-588 J. Pubule, A. Kamenders, S. Valtere and D. Blumberga
Cleaner production in biowaste management
Abstract |
Full text PDF (351 kB)

Cleaner production in biowaste management

J. Pubule*, A. Kamenders, S. Valtere and D. Blumberga

Riga Technical University, Institute of Energy Systems and Environment, Kronvalda boulv. ¹, LV-¹0¹0 Riga, Latvia;
*Correspondence: jelena.pubule@rtu.lv

Abstract:

The article provides a study concerning possible future developments in biowaste management in Latvia. In the article, planning, impact assessment, implementation and improvement phases, as well as the required improvements in these phases of biowaste management, are analysed. Furthermore, the problems faced by the energy sector with resource scarcity and energy dependency from one side, and waste management and EU targets for the minimization of the deposited amount of biodegradable waste, from the other side, are presented. The possibility to reach targets concerning the share of renewable energy sources through the use of biowaste resources and possible impacts are presented. During the research, principles of cleaner production in waste management were created and analyzed. The paper presents new assessment methods based on a combination of different methods for the impact assessment of the waste sector, and the implementation of cleaner production in biowaste management.

Key words:

, , , ,




589-602 S. Rancane, K. Makovskis, D. Lazdina, M. Daugaviete, I. Gutmane and P. Berzinš
Analysis of economical, social and environmental aspects of agroforestry systems of trees and perennial herbaceous plants
Abstract |
Full text PDF (442 kB)

Analysis of economical, social and environmental aspects of agroforestry systems of trees and perennial herbaceous plants

S. Rancane¹*, K. Makovskis², D. Lazdina², M. Daugaviete², I. Gutmane¹ and P. Berzinš¹

¹LLU Research Institute of Agriculture, Zemkop bas instituts 7, Skr veri, Latvia
2Latvia State Forest Research Institute Silava, Rigas 11, Salaspils, Latvia; *Correspondence: 1sarmite.rancane@inbox.lv

Abstract:

The aim of this study was to determine the economic, social and environmental aspects, that promote choosing an agroforestry system and continuing agricultural production instead of simple afforestation of agricultural land. Material for the study was collected in an experimental demo field located in the central part of Latvia (56°41 N and 25°08 E) established in the spring of 2011, nearby Skr veri. Two legumes – fodder galega (Galega orientalis Lam.) ‘Gale’, poor-alkoloid lupine (Lupinus polyphyllus L.) ‘Valfrids’ and two perennial grass cultivars – reed canary grass (RCG) (Phalaris arundinacea L.) ‘Bamse’ and festulolium (x Festulolium pabulare) ‘Felina’ were sown between the tree rows and in monoculture on drained mineral soil. Four different fertilisation treatments for herbaceous plants – control (without fertiliser), mineral fertilisers, wastewater sludge and wood ash were used. Biomass, seed yield, agricultural management cost have been investigated since the establishment of experiment in 2011. Potential benefits from growing herbaceous plants for seed, biomass production and possible future income from tree wood and non-wood goods were calculated. Management cost of agroforestry system, plantation forest and traditional sowing were analyzed. The growth of herbaceous plants for seed production together with hybrid aspen in agroforestry system during a 5 year period has a positive balance with all types of fertilisers. The growth of herbaceous plants in a monoculture for biomass production in a 3 year period had a positive balance for all types of organic fertilisations at both cutting frequencies. Positive balance by applying mineral fertiliser was achieved only at two-cut cutting regime.

Key words:

, , , , , ,




603-610 J. Ružbarský, M. Müller and P. Hrabe
Analysis of physical and mechanical properties and of gross calorific value of Jatropha curcas seeds and waste from pressing process
Abstract |
Full text PDF (630 kB)

Analysis of physical and mechanical properties and of gross calorific value of Jatropha curcas seeds and waste from pressing process

J. Ružbarský¹*, M. Müller² and P. Hrabe²

¹Technical University of Košice, Faculty of Manufacturing Technologies, Department of Technological Systems Operation, Štúrova 31, Prešov 08001, Slovak Republic;
*Correspondence: juraj.ruzbarsky@tuke.sk
²Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Science, Kamýcká 129, 16521 Prague, Czech Republic

Abstract:

The  research  was  performed  with  an  aim  to  investigate  physical  and  mechanical properties and a gross calorific value of Jatropha curcas seeds and particular products (waste) of  a  pressing  process.  Sizes  of  seeds,  an  energy  which  is  necessary  for  pressing  an  oil  and  a setting  of  the  gross  calorific  value  were  tested  parameters.  Tests  were  performed  at  Jatropha Curcas seeds of a brown colour (that means gnaw). The pressing process waste amounts up to 80%. The proportion of the kernel mass to the coat mass is 1:0.62. From the research results it follows that the coat mass is 37.60%. The seed coat belongs among interesting material owing to  the  gross  calorific  value.  For pressing  the  whole  seeds  it  is  necessary  of  about  30%  higher energy than for pressing the kernels of Jatropha curcas.

Key words:

, , , , ,




611-622 V. Suzdalenko, M. Gedrovics and V. Vitolins
Experimental pilot device for thermal analysis of biomass co-firing
Abstract |
Full text PDF (577 kB)

Experimental pilot device for thermal analysis of biomass co-firing

V. Suzdalenko*, M. Gedrovics and V. Vitolins

Institute of Energy Systems and Environment, Riga Technical University, Kronvalda boulevard 1, LV-1010 Riga, Latvia; *Correspondence: Vera.Suzdalenko@rtu.lv

Abstract:

The share of biomass in the transformation sector of Latvia accounts for only 15%, at the same time natural gas share in transformation sector is about 80%. Nonetheless, an ongoing natural gas price growth stimulates its full replacement with biomass. The goal of the research was to construct an experimental pilot device, where could be possible to combust biomass with gaseous fossil fuel. The pilot device was equipped with the following measurement instruments: thermocouples for local temperature measurements and gas analyzer for measurements of flue gas composition, temperature, and combustion efficiency.

Key words:

, , ,




623-632 V. Suzdalenko, M. Gedrovics, Vigants E. and L. Lieplapa
Integrated analysis of biomass co-firing with gaseous fossil fuel. Environmental criteria analysis
Abstract |

Integrated analysis of biomass co-firing with gaseous fossil fuel. Environmental criteria analysis

V. Suzdalenko*, M. Gedrovics, Vigants E. and L. Lieplapa

Institute of Energy Systems and Environment, Riga Technical University, Kronvalda boulevard 1, LV-1010, Riga, Latvia; *Correspondence: Vera.Suzdalenko@rtu.lv

Abstract:

The goal of the research described in the paper is to study co-firing of wood pellets and gaseous fossil fuel, evaluating the influence of co-firing on efficiency, produced energy volumes, and emission production. In order to achieve the set aim and objectives a special pilot device for wood pellets and propane/butane co-firing was constructed in an accredited laboratory. The results of the experimental research allow running a complete analysis of co-firing and evaluating the influence of magnetic field on efficiency, produced heat energy volumes, and emission production. The research has a high practical significance and is aimed to increase the level of wood biomass use for energy production as well as to ensure its effective application.

Key words:

, , ,




633-644 H. Vigants,, P. Uuemaa, I. Veidenbergs and D. Blumberga
Cleaner pellet production – an energy consumption study using statistical analysis
Abstract |
Full text PDF (438 kB)

Cleaner pellet production – an energy consumption study using statistical analysis

H. Vigants¹,*, P. Uuemaa², I. Veidenbergs¹ and D. Blumberga¹

¹Department of Electrical Power Engineering, Riga Technical University, Kronvalda bulv.1, LV-1010 Riga, Latvia; *Correspondence: haralds.vigants@rtu.lv 2Department of Electrical Power Engineering, Tallinn University of Technology, Ehitajate tee 5, EE19086 Tallinn, Estonia

Abstract:

This study investigates and analyses the methodology for introducing cleaner wood pellet production. A statistical model is developed for the energy consumption analysis. Efficiency indicators have been chosen which allow determining the impact on the production process. The developed model can be used in other similar type of industries. This study has processed large empirical data with statistical methods in order to establish the efficiency indicators. The modelled results enable to define the indicators which lead to higher efficiency and hence to the cleaner production. Key words: Energy efficiency, energy optimization, improvement of the production process, industrial process.INTRODUCTION

Key words:




645-654 J. Ziemele, I. Pakere,, N. Talcis, G. Cimdi a, . V gants, I. Veidenbergsand D. Bluberga
Analysis of wood fuel use development in Riga
Abstract |
Full text PDF (468 kB)

Analysis of wood fuel use development in Riga

J. Ziemele¹, I. Pakere¹,*, N. Talcis², G. Cimdi a¹, . V gants¹, I. Veidenbergs¹and D. Bluberga¹

¹Institute of Energy Systems and Environment, Riga Technical University, Kronvalda Bulv. 1, LV-1010 Riga, Latvia; *Correspondence: ieva.pakere@rtu.lv 2JSC ‘Rigas Siltums’, C su iela 3a, LV-1016 R ga, Latvia

Abstract:

Use of wood fuel is a sustainable solution of district heating system development for the countries which do not have fossil fuel reserves, but have rich forest resources. The study analyses the options for wood fuel use in Latvia’s capital, Riga. The STATGRAPHICS Forecasting and regression analysis modelling tools were used to develop two possible forecasting curves showing the trend of wood fuel use until the year 2020. The results show that the share of the amount of heat produced by wood fuel in Riga could reach 25% of total heat demand if the current trend continues.

Key words:

, , ,




657-662 A. Aan and M. Heinloo
Analysis and synthesis of the walking linkage of Theo Jansen with a flywheel
Abstract |
Full text PDF (398 kB)

Analysis and synthesis of the walking linkage of Theo Jansen with a flywheel

A. Aan* and M. Heinloo

Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi ⁵⁶, EE⁵¹0¹⁴ Tartu, Estonia;
*Correspondence: aare.aan@emu.ee

Abstract:

This paper presents the results of cinematic and dynamic calculations of Theo Jansen’s walking linkage on the worksheet of Mathcad. To validate the cinematic calculations, a video clip with simulation of the motion of Theo Jansen’s mechanism is composed. The synthesis of a flywheel for Theo Jansen’s linkage input link to decrease the fluctuation in its rotation is considered in detail.

Key words:

, , ,




663-672 S.N. Kalnins, S. Valtere, J. Gusca, K. Valters, K. Kass and D. Blumberga
Cooperative problem-based learning approach in environmental engineering studies
Abstract |
Full text PDF (481 kB)

Cooperative problem-based learning approach in environmental engineering studies

S.N. Kalnins, S. Valtere, J. Gusca, K. Valters, K. Kass and D. Blumberga*

Institute of Energy Systems and Environment of the Riga Technical University, Kronvalda bulvaris 1, LV-1010, Riga, Latvia;
*Correspondence: dagnija.blumberga@rtu.lv

Abstract:

Market  requirements  and  competition  in  the  job  market  set  the  necessity  for  an engineering  specialist  capable  of  not  only  analysing  the  theory  of  a  situation  but  also  able  to transfer theoretical knowledge into practise. In order to lessen the degree to which students are isolated  from  those  real-life  situations  with  which  they  will  be  working  with  daily  upon graduating,  it  is  important  to  integrate  a  problem-based  learning  approach  based  on  the  study course.  The  paper  describes  a  Cooperative  Problem-Based  Learning  Approach  used  in Environmental Engineering Studies and provides progress analysis about 8 years of experience in organizing the course.

Key words:

, , , ,




673-680 P. Maijala, M. Närvä and A. Pasila
Farm-to-table concept: How the industry and commerce are integrated to the academic education system
Abstract |
Full text PDF (256 kB)

Farm-to-table concept: How the industry and commerce are integrated to the academic education system

P. Maijala*, M. Närvä and A. Pasila

School of Food and Agriculture, Seinäjoki University of Applied Sciences, P.O. Box ⁴¹², ⁶0³²0 Seinäjoki, Finland;
*Correspondence: Pekka.Maijala@seamk.fi

Abstract:

The academic education within the complete farm-to-table concept was brought together at the Seinäjoki University of Applied Sciences (Seinäjoki UAS), combining the schools of Agriculture, Food and Biotechnology engineering and Hospitality management as school of Food and Agriculture. By a close cooperation, the schools of primary production, food engineering, and commerce & marketing, establish a way to efficiently facilitate the learning process of the students, and help them to obtain knowledge of all stages in the production of food. Accomplished employees with multiple skills and good understanding of the complete food chain are in greater demand. This is particularly evident in case of SMEs. Large companies may rely more on specialists. The good knowledge of marketing and sales, as well as the product development and the logistics are further areas that possess room for improvement in many companies located in South Ostrobothnia region. Furthermore, companies evaluate sustainability and ethical responsibility as values of greatest significance. From the educational perspective, a comprehensive theoretical knowledge accompanied by well-organized practical training periods is important. Approaches to tighten up the interactions between the education at Seinäjoki UAS school of Food and Agriculture and the enterprises in southern Ostrobothnia region are further evaluated. Education implementing projects is becoming regularly utilized in the student curricula at UAS. Students learn cooperativity, sharing and taking responsibility, and they learn to take initiatives and to solve problems – important skills in real working environment. Re-grouping students with different acts as an innovative and motivating force for students and gives an option for companies to introduce themselves. Novel technological solutions for data collection and analysis, based on mobile laboratory equipment and other systems, open up new possibilities for education within the farm-to-table concept.

Key words:

, , ,




681-686 V. Siirak, P. Tint and A. Traumann
Some practical applications of e-learning in OHS and ergonomics in higher education
Abstract |
Full text PDF (237 kB)

Some practical applications of e-learning in OHS and ergonomics in higher education

V. Siirak*, P. Tint and A. Traumann

Department of Work Environment and Safety, Tallinn University of Technology, Ehitajate tee 5, EE19086 Tallinn, Estonia;
*Correspondence: virve.siirak@ttu.ee

Abstract:

Abstract. The  computer  based  e-learning  in  Moodle  environment  and  other  computer applications in the teaching of occupational health and safety (OHS) are investigated. The social constructivist  learning  theory  is  effective  method  for  teaching  and  learning  of  OHS  and ergonomics  issues  in  the  university  education.  The  computer  programme  for  determination  of the  safety  level  at  enterprise  is  presented.  The  simple  computer  applications  are  very  suitable educational  tools  for  e-learning  of  OHS  and  ergonomics.  They  could  be  also  used  by  the employers  of  small  and  medium-sized  enterprises.  The  scope  of  practical  applications  of  e-learning in OHS and ergonomics in higher education is analysed on the basis of the scientific literature and analysing the methods used in the EU.

Key words:

, ,