Volume 13 (2015)
  Number 2

Journal full text: Vol 13 No 2

Contents


Pages

277-286 A. Bārdulis, D. Lazdiņa, M. Daugaviete, A. Bārdule, U. Daugavietis andG. Rozītis
Above ground and below ground biomass in grey alder Alnus incana (L.) Moench. young stands on agricultural land in central part of Latvia
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Above ground and below ground biomass in grey alder Alnus incana (L.) Moench. young stands on agricultural land in central part of Latvia

A. Bārdulis*, D. Lazdiņa, M. Daugaviete, A. Bārdule, U. Daugavietis andG. Rozītis

Latvian State Forest Research Institute ‘Silava’, Rigas street 111, LV2169 Salaspils, Latvia; *Correspondence: andis.bardulis@silava.lv

Abstract:

Young grey alder stands under 10 years of age that are growing on abandoned agricultural lands in Central Latvian lowlands were selected for this study. In the framework of the research the biomass of the trees was studied and an equation was developed for grey alder stands on abandoned agricultural lands. An allometric equation for the different biomass fractions of grey alder was developed. Tree biomass is characterised by a power model with a single independent variable (DBH), which also indirectly substitutes for the effect of the stand age. The model is adapted to each fraction by changing its ratio values. The determination coefficient of the model is high, varying from R2 = 0.89 to R2 = 0.94, and the confidence level of the model is 95%. The biomass of particular fractions is defined by a power regression, with the tree stem diameter at the height of 1.3 m used as an argument. In young grey alder stands on abandoned agricultural lands the majority, 64%, of root fractions is composed of coarse roots, followed by the stump fraction and fine roots, 28% and 8%, respectively. For aboveground biomass the largest fraction is stem, which constitutes 75% of the total aboveground biomass, while the share of branches is 25%.

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287-293 B. Dalecka, M. Strods and L. Mezule
Production of fermentation feedstock from lignocellulosic biomass: applications of membrane separation
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Production of fermentation feedstock from lignocellulosic biomass: applications of membrane separation

B. Dalecka*, M. Strods and L. Mezule

Riga Technical University, Faculty of Civil Engineering, Department of Water Science and Technology, Azenes 16/20-263, LV1048 Riga, Latvia; *Correspondence: brigita.dalecka@gmail.com

Abstract:

The development of cost-efficient, highly productive technologies for fermentation feed production from lignocellulose biomass is still a challenge. In this paper, the production of fermentable sugars from lignocellulosic biomass using hydrolysis techniques with membrane separation systems is studied. The research was conducted on both a laboratory and pilot level to evaluate and optimize the efficiency of the proposed technology. The results demonstrated that UF and NF permeate recovery increased efficiency, and the highest sugar recovery rates were obtained when secondary waste recirculation was introduced after NF and UF, reaching an almost 40% yield from all produced sugars.

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294-302 V. Dubrovskis and I. Plume
Anaerobic digestion of vegetables processing wastes with catalyst metaferm
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Anaerobic digestion of vegetables processing wastes with catalyst metaferm

V. Dubrovskis* and I. Plume

Latvia University of Agriculture, Faculty of Engineering, Institute of Agriculture Energetics, 5, Cakstesblvd, LV3001 Jelgava, Latvia *Correspondence: vilisd@inbox.lv

Abstract:

There are 54 active biogas plants in Latvia today. It is necessary to investigate the suitability of various biomasses for energy production. Maize is the dominating crop for biogas production in Latvia. The cultivation of more varied crops with good economical characteristics and a low environmental impact is thus desirable. One of the ways for improving biogas yield in Latvian conditions is using biological catalysts. This paper explores the results of the anaerobic digestion of vegetables’ processing wastes using the new biological catalyst Metaferm. The digestion process was investigated in view of biogas production in sixteen 0.7 l digesters operated in batch mode at the temperature of 38 ± 1.0 °C. The average methane yield per unit of dry organic matter added (DOM) from the digestion of onions was 0.433 l g–1DOM; with 1 ml ofMetaferm: 0.396 l g–1–1DOM, and with 2 ml of Metaferm: 0.394 l gDOM . The average methane yieldfrom the digestion of carrots was 0.325 l g–1–1DOM; with 1 ml of Metaferm: 0.498 l gDOM , and with2 ml of Metaferm: 0.426 l g–1DOM. The average additional methane yield per unit of dry organicmatter from the digestion of 50%:50% mixed onions and carrots was 0.382 l g–1DOMwith 2 mlof Metaferm. The average additional methane yield per unit of dry organic matter from the digestion of cabbage leftovers was 0.325 l g–1–1DOM; with 1 ml of Metaferm: 0.375 l gDOM , andwith 2 ml of Metaferm: 0.415 l g–1DOM. The average additional methane yield per unit of dryorganic matter from the digestion of potato cuttings was 0.570 l g–1DOM; with 1 ml ofMetaferm: 0.551 l g–1–1DOM, and with 2 ml of Metaferm:0.667 l gDOM . The average additionalmethane yield per unit of dry organic matter from the digestion of 50%:50% mixed cabbages and potatoes was 0.613 l g–1DOMwith 2 ml of Metaferm. All investigated vegetable wastes canbe successfully cultivated for energy production under agro-ecological conditions in Latvia. Adding the catalyst Metaferm increased methane yield, except for onions.

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303-310 T. Ivanova, M. Kaválek,, B. Havrland, M. Kolaříková and P. Skopec
Comparison of technologic parameters of pellets and other solid fuels produced from various raw materials
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Comparison of technologic parameters of pellets and other solid fuels produced from various raw materials

T. Ivanova¹, M. Kaválek¹,*, B. Havrland¹, M. Kolaříková¹ and P. Skopec²

¹Czech University of Life Sciences Prague, Faculty of Tropical AgriSciences, Kamycka 129, CZ16521 Prague 6 – Suchdol, Czech Republic
²Czech Technical University in Prague, Faculty of Mechanical Engineering, Zikova 1903/4, CZ16636 Prague 6, Czech Republic *Correspondence: michal.kavalek@seznam.cz

Abstract:

The article relates results of experiments and problem studies, the main goal of which was comparing four alternatives of solid biofuels suitable for heating private houses by low-power boilers. The results were obtained by burning of selected biofuels in an automatic pellet boiler specifically designed for combustion of pelletized fuels with high ash content. The emissions were set up related to the mass of burnt fuels and to the fuels’ net calorific value (specific emissions), they were measured and analysed. Based on the emission concentration measurements and stoichiometric calculations, the fuel gas emissions’ properties and boiler efficiency were compared at a range of power outputs of 7.5 kW, 12.5 kW and 18.5 kW. With regard to fuel properties and boiler outputs, the emissions of carbon monoxide (CO) were determined as well as emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2) were measured and compared too. The results permitted to formulate conclusions that the wood pellets were having the lowest values of measured emissions, whereby Jatropha seed cakes showed several times higher emissions in comparison with emissions from wood pellets, oil palm shells and wheat straw pellets, where the last one is a typical representative of the agricultural biomass with relatively high nitrogen content and as was shown higher emissions of NOX as compared to wood pellets. Oil palm shells measured emissions were relatively similar to wood pellets emissions, especially concerning emissions of SO2 and CO. All tested materials were having very low combustible sulphur contents and therefore the specific SO2 emissions were negligible at all these fuels. A very important finding was that the amount of emissions was dependent on boiler output, where with the output decreasing the amount of emissions was growing. The other linkage – dependence of the boiler efficiency on power output was also proved in the present paper.

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311-317 T. Ivanova, А. Muntean, V. Titei, B. Havrland and M. Kolarikova,
Energy crops utilization as an alternative agricultural production
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Energy crops utilization as an alternative agricultural production

T. Ivanova¹, А. Muntean², V. Titei³, B. Havrland¹ and M. Kolarikova¹,*

¹Czech University of Life Sciences Prague, Kamycka 129, CZ16521 Prague 6, Czech Republic; *Correspondence: kolarikova@ftz.czu.cz
²The State Agrarian University of Moldova, Mirceşti 42, Chișinău 2049, Republic of Moldova 3Botanical Garden of the Academy of Sciences of Moldova, Padurii 18, Chisinau 2002, Republic of Moldova

Abstract:

Nowadays an increasing attention is given to the production and use of solid biofuels as an alternative to traditional fossil fuels. The common raw material for the production of solid biofuels is a biomass of vegetal origin, which is mainly represented by waste and secondary agricultural products as well as forest or wood residues. Unfortunately, these types of materials do not always meet the quality requirements for the production of biofuels in the form of pellets and briquettes. This is primarily due to the fact that much of the agricultural wastes have low calorific value, high ash content, low density, etc. and at the end all these facts also negatively affects the price of biofuels. In addition, an intensive use of agricultural waste as a raw material for the purpose of biofuels’ production could have a negative impact on soil fertility. Based on abovementioned disadvantages of agricultural biomass, there is a big potential in utilization of alternative biomass such as energy crops. Several energy crops from the same biological family Asteraceae were selected for the research purposes. The main focus of this article is evaluation and comparison of the main solid biofuels’ properties, which were measured according to European and International standards. Assessment of an energy potential of selected crops for the Republic of Moldova is presented here as well.

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318-327 H. Kahr, M. Pointner, K. Krennhuber, B. Wallner and A. Jäger
Lipid production from diverse oleaginous yeasts from steam exploded corn cobs
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Lipid production from diverse oleaginous yeasts from steam exploded corn cobs

H. Kahr, M. Pointner, K. Krennhuber, B. Wallner and A. Jäger*

University of Applied Sciences Upper Austria, School of Engineering and Environmental Sciences, Stelzhamerstraße 23, 4600 Wels, Austria *Correspondence: Heike.Kahr@fh-wels.at

Abstract:

Corn cob hydrolysate was used as substrate for growth and lipid accumulation via oleaginous yeast species. A mass based suspension of 10 g 100 g-1 corn cob hydrolysate contained 26.0 g L-1 glucose, 8.5 g L-1 xylose. The inhibitor concentrations were 0.16 g L-1 acetic acid, 1.50 g L-1 formic acid, 0.48 g L-1 HMF and 0.06 g L-1 furfural. These conditions reduced the cell growth of non-adapted yeast. Successful adaptation of the tested yeasts over several generations in corn cob hydrolysate was performed. The adapted yeast Candida lipolytica produced 19.4 g 100 g -1 lipids in relation to the dry weight in 7.5 g 100 g-1 dry matter corn cob hydrolysate in fed batch mode. The scale up was done up to a volume of 2.5 litres – here lipid accumulation up to 17.5 g 100 g-1 was demonstrated with the quantitative GC/FID analyses. Predominantly oleic acid, palmitic acid, linoleic and palmitoleic acid were produced. This lipid spectrum is suitable for biodiesel production.

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328-336 M. Kolarikova, T. Ivanova,, P. Hutla and B. Havrland
Economic evaluation of hemp (Cannabis sativa) grown for energy purposes (briquettes) in the Czech Republic
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Economic evaluation of hemp (Cannabis sativa) grown for energy purposes (briquettes) in the Czech Republic

M. Kolarikova¹⋅², T. Ivanova¹,*, P. Hutla² and B. Havrland¹

¹Czech University of Life Sciences, Faculty of Tropics and Subtropics, Department of Sustainable Technologies, Kamycka 129, CZ16521 Prague 6, Czech Republic
²Research Institute of Agricultural Engineering, p.r.i., Drnovska 509, CZ16100 Prague 6, Czech Republic *Correspondence: ivanova@ftz.czu.cz

Abstract:

Depletion of fossil fuels and their environmental risks have brought to the foreground energy crops as a possible source of bioenergy. Industrial hemp (Cannabis sativa L.) has been suggested for production of solid biofuels (briquettes) due to good physic-mechanical properties as well as positive energy and combustion characteristics. This study determined economic potential of hemp briquettes production in the Czech Republic. A field trial was conducted in 2009–2014 in Prague in order to compare biomass yield (BY) of hemp varieties Bialobrzeskie (B) and Ferimon (F) harvested in autumn and spring period. Based on obtained results this study determined production costs of hemp briquettes (CZK t-1), revenue (CZK t-1) and rate of return (%) for four scenarios (B, F harvested in autumn and B, F harvested in spring). Briquettes production costs ranged from 4,015 CZK t-1 to 4,707 CZK t-1 for B in spring and B in autumn, respectively, due to 30% lower biomass yield in spring harvest. Results indicated that hemp briquettes production was not profitable if the selling price was the same as the price of wood briquettes and with BY obtained in experiment (7.18–10.7 t ha-1 of dry matter). Briquettes production in autumn made profit of 9% for B and 7% for F when subsidies for hemp cultivation were considered. In current conditions in the Czech Republic, utilization of hemp for briquettes production did not prove to be economically feasible.

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337-347 P. Kuttner,, A.D. Weißböck, V. Leitner and A. Jäger
Examination of commercial additives for biogas production
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Examination of commercial additives for biogas production

P. Kuttner¹,*, A.D. Weißböck¹, V. Leitner² and A. Jäger¹

¹University of Applied Sciences Upper Austria, 4600 Wels, Austria
²Energy Institute at the Johannes Kepler University Linz, 4040 Linz, Austria *Correspondence: paul.kuttner@fh-wels.at

Abstract:

The formation of biogas from biomass is a complex process with a multitude of variable process parameters. Stability of biogas production and production rate can be vastly improved by keeping these parameters close to their optimum. One possibility to achieve this is by use of additives. In Germany alone there currently are over 250 additives on the market which demonstrates the demand for optimisation of biogas plants. The effects of these additives are hardly investigated and can only be evaluated by costly, time consuming tests (e.g. continuous anaerobic digestion experiments). A new, fast and easy to handle method was developed to evaluate some of the effects of additives. To verify the method trace elements, organic acids, FOS/TAC, ions and cations were quantified. Three additives were tested: The addition of a commercial zeolite increased biogas production by 15%. Calcium carbonate increased performance by 8% after 16 days. No negative effect on biogas production could be observed for the addition of 0.03 and 0.06 g l-1 of iron(III) chloride, commonly used to reduce hydrogen sulphide concentration in biogas.

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348-353 R. Lauhanen,, J. Ahokas and J. Esala
Direct and indirect energy input in the harvesting of Scots pine and Norway spruce stump-root systems from areas cleared for farmland
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Direct and indirect energy input in the harvesting of Scots pine and Norway spruce stump-root systems from areas cleared for farmland

R. Lauhanen¹,*, J. Ahokas² and J. Esala¹

¹Seinäjoki University of Applied Sciences, School of Food and Agriculture, Ilmajoentie 525, FI60800 Ilmajoki, Finland
²University of Helsinki, Faculty of Agriculture and Forestry, Koetilantie 5, Helsinki, Finland *Correspondence: risto.lauhanen@seamk.fi

Abstract:

The aim of this study was to find the net energy and energy ratios for the recovery of Scots pine and Norway spruce stump-root systems when clearing land for cultivations. The energy analyses were carried out for direct and indirect energy under Finnish conditions. In the base study case for direct energy input; the net energy yields for stump-root system harvesting were 446–698 GJ ha-1, and the energy ratios were 22–33. In the case of indirect energy input the net energy yields were 440–692 GJ ha-1, and the energy ratios were 17–26. The proportion of indirect energy was low, because the amount of operating hours annually was high. When calculating indirect energy, only the energy input of machine manufacturing was used, since there was no data on the indirect energy used for repair and maintenance of the machines. The energy assessment for repairing and maintenance operations for heavy forest machines and vehicles in bioenergy procurement will need to be assessed.

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354-360 U. Neimane,, M. Zadina, L. Sisenis, B. Dzerina and A. Pobiarzens
Influence of lammas shoots on productivity of Norway spruce in Latvia
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Influence of lammas shoots on productivity of Norway spruce in Latvia

U. Neimane¹,*, M. Zadina¹, L. Sisenis², B. Dzerina¹ and A. Pobiarzens³

¹Latvian State Forest Institute ‘Silava’, Rigas 111, LV2169 Salaspils, Latvia
²Latvia University of Agriculture, Forest Faculty, Akademijas 11, LV3001 Jelgava ,Latvia
³Forest Competence Centre, Dzerbenes 27, LV1006 Riga, Latvia *Correspondence: una.neimane@silava.lv

Abstract:

The Norway spruce is widely spread in Eastern Europe and it is managed mainly for the production of sawlogs, though its logging residues are now increasingly used for the production of wood chips for bioenergy. The growth of the Norway spruce is and will be affected by climatic changes; one of the possible effects might be an increase in the frequency of trees with lammas shoots. Therefore, the aim of this study was to assess the influence of lammas shoots on the length of height increment of young Norway spruce in Latvia. Tree height and height increment was repeatedly measured and the presence of lammas shoots, bud flushing grades and frost injuries were assessed in two young (8–13 years) open-pollinated progeny tests in the central part of Latvia (56°46´N, 24°48´E). The mean portion of trees with lammas shoots in one experiment was 6% at the end of 8th growing season. In another experiment, it was 8.7%, 26.9% and 8.1% at the end of 10th, 11th and 13th growing seasons, respectively; 32.3% of trees had lammas shoots at least in one of three seasons. Faster growing and earlier flushing trees had a significantly higher frequency of lammas shoots. Lammas shoots increased the length of annual height increment by 10 to 14 cm, resulting in a 14–20% taller tree height at the age of 13 years. The reduction of height increment as a result of frost damages for very early flushing trees was less pronounced for trees with lammas shoots than without them.

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361-371 R. Pecenka and T. Hoffmann
Harvest technology for short rotation coppices and costs of harvest, transport and storage
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Harvest technology for short rotation coppices and costs of harvest, transport and storage

R. Pecenka* and T. Hoffmann

Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Max-Eyth-Allee
100, 14469 Potsdam, Germany;
*Correspondence: rpecenka@atb-potsdam.de

Abstract:

The lack of knowledge regarding cost-efficient design of whole production chains as
well as the availability of powerful harvest machinery are some of the main obstacles for
competitive production of bioenergy from short rotation coppices (SRC) at practice. In general,
two different harvest lines are available: the cut-and-chip and the cut-and-store lines. Whereas
the cut-and chip line provides wood chips which have to be stored until next heating season, the
product for intermediate storage of the cut-and-store line are whole trees. Both process lines have
major differences not only in harvesting, but also in transport, storage and process losses leading
to different costs of the end product wood chips. On basis of data from several SRC harvest
campaigns, production costs for wood chips have been calculated to identify best practice
solutions taking the following factors into account: chip size determined by the harvest system,
storage including related costs and losses, field size and shape as well as transport to storage.
According to the results, mower-chippers and forage harvesters can provide wood chips at lowest
production costs (43…45€ tdm-1) if field shape is favourable for harvest operations. Under less
favourable field conditions costs are approx. 7 to 14% higher. Highest production costs have to
be accepted if whole trees are harvested with a shoot harvester (64 to 72 € tdm-1). The reduction
in storage losses and storage costs are not sufficient to compensate higher machine costs for
harvest and additional comminution with mobile chippers from forestry

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372-381 S. Pehme and E. Veromann
Environmental consequences of anaerobic digestion of manure with different co-substrates to produce bioenergy: A review of life cycle assessments
Abstract |
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Environmental consequences of anaerobic digestion of manure with different co-substrates to produce bioenergy: A review of life cycle assessments

S. Pehme* and E. Veromann

Estonian University of Life Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia; *Correspondence: sirli.pehme@emu.ee

Abstract:

Consequential life cycle assessment approach is needed to assess the environmental impacts of increase in biogas production. To see the full impacts of anaerobic co-digestion all possible environmental consequences caused by this change, i.e. the impacts of changed management and possible substitution impacts of substrates, should be taken into account. Generally anaerobic digestion of manure shows great environmental benefit instead of managing it conventionally, especially for the global warming potential. Environmental performance of co-digestion depends strongly on the initial use of the substrate. Co-digestion with wastes/residues has a great potential to produce bioenergy and reduce global warming potential. Co-digestion with land dependant special energy crops increases the bioenergy output but also increases the environmental impacts due to the need to substitute the substrate and thus should be avoided or limited.

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382-395 K. Pitman, M. Raud and T. Kikas
Biochemical oxygen demand sensor arrays
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Biochemical oxygen demand sensor arrays

K. Pitman, M. Raud and T. Kikas*

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

Abstract:

Biochemical oxygen demand (BOD) is one of the most widely utilized parameters in water quality evaluation. BOD as a parameter illustrates the amount of organic compounds susceptible to biochemical degradation in the water. The BOD test lasts for at least 5–7 days or even up to 21 days. An incubation time this long is not acceptable for monitoring purposes or system control. In order to shorten the BOD measurement time, a multitude of biosensors have been proposed. Unfortunately, BOD biosensors have several limitations, such as short lifetime, limited substrate range, precision etc. Some of those limitations can be overcome by using microbial sensor-arrays. Such bioelectronic tongues can achieve the much wider substrate range usually attributed to multiculture sensors and still maintain the long lifetime of a single culture sensor. This is achieved by separating different cultures from each other in the array and using the signals of separate sensors to produce summarised information via statistical analysis. The purpose of this review is to give a short overview of BOD measurements and discuss the potential of using sensor-arrays for BOD measurements.

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396-404 J. Priekulis, A. Aboltins and A. Laurs
Amount of manure used for biogas production
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Amount of manure used for biogas production

J. Priekulis, A. Aboltins* and A. Laurs

Latvia University of Agriculture, Institute of Agricultural Machinery, Cakstes blvd. 5, LV3001 Jelgava, Latvia; *Correspondence: aivars.aboltins@inbox.lv

Abstract:

Methods for calculation of the amount of manure from every agricultural animal species and subgroup for production of biogas have been developed in compliance with the 2006 IPCC Guidelines. These methods can be applied for future forecasts if the amount of biogas produced in the country increases. It has been stated that in 2013 in Latvia for production of biogas mostly chicken and pig manure was used – correspondingly 33.7% and 26.7% from the amount of manure obtained from these animals. In the forecast for 2020, in turn, it is expected that the consumption of manure will be 31.9% of chicken manure and 31.5% of pig manure, from the amount of manure obtained from the corresponding group of animals.

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405-412 M. Raud, M. Tutt, J. Olt and T. Kikas
Effect of lignin content of lignocellulosic material on hydrolysis efficiency
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Effect of lignin content of lignocellulosic material on hydrolysis efficiency

M. Raud, M. Tutt, J. Olt and T. Kikas*

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

Abstract:

Lignocellulosic material is the most promising feedstock for bioethanol production; however, due to the varying physicochemical characteristics of different biomasses, it is necessary to select a biomass with a composition suitable for bioethanol production. For this purpose several different alternative non-food energy crops were chosen to investigate their suitability for bioethanol production, considering their cellulose, hemicellulose and lignin content. The traditional three-step bioethanol production process was used, where dilute acid was applied for biomass pre-treatment. Glucose and ethanol concentrations were measured during the process. Glucose and ethanol yields and hydrolysis efficiency were used to evaluate the suitability of different energy crops for bioethanol production. The results show that, with most biomass types, the glucose yield increases as the cellulose content in the biomass rises. However, a sharp decrease in hydrolysis efficiency was noted in the lignin content range of 7 to 9 g 100 g-1. The lower hydrolysis efficiency also resulted in a lower ethanol yield in the next step of the bioethanol production process for these samples.

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

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

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

Abstract:

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

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420-429 V. Skorupskaitė, V. Makarevičienė,, G. Šiaudinis and V. Zajančauskaitė
Green energy from different feedstock processed under anaerobic conditions
Abstract |

Green energy from different feedstock processed under anaerobic conditions

V. Skorupskaitė¹, V. Makarevičienė¹,*, G. Šiaudinis² and V. Zajančauskaitė³

¹Aleksandras Stulginskis University, Faculty of Forest Sciences and Ecology, Institute of Environment and Ecology, Studentų Str. 11, LT53361 Akademija, Kauno district, Lithuania; *Correspondence: virginija.skorupskaite@asu.lt
²Vėžaičiai Branch of Lithuanian Research Centre for Agriculture and Forestry, Gargždų str. 29, LT96216 Vezaiciai, Klaipėda district, Lithuania
³Klaipėda University, Faculty of Marine Technology, Department of technological process. Herkaus Manto Str. 84, LT92294 Klaipėda, Lithuania

Abstract:

The possible use of energy crops and aquaculture for bioenergy production has only recently become a research target, so there is little information on their properties and advantages. The aim of this study was to investigate the possible use of cup plant, as well as marine and freshwater algae (Scenedesmus sp. and Chlorella sp.) for biogas production. Research of a batch anaerobic digestion process at a mesophilic temperature were performed using wet wastewater sludge, cattle manure, fresh microalgae biomass and dry marine algae, cup plant biomass and mixtures of these materials. The highest biogas yield (541.28 ml g-1 VS) was obtained by using a new feedstock from the microalgae Scenedesmus sp. biomass. That yield was 1.4 times higher than the biogas yield from cattle manure and 15% lower than the biogas yield from wastewater sludge. It was found that adding microalgae biomass to a cattle manure substrate increases biogas production approx. 1.5 times. The highest methane concentration in biogas produced from microalgae ranges from 64.87% to 66.66% and exceeds the methane amount (64.26%) in biogas produced from wastewater sludge. The methane amount in biogas produced from cattle manure, cup plant and marine algae biomass is lower than 60%. In addition, it was found that it is possible to produce 5,092.3 m3 of biogas or 113 GJ of energy from 1 ha of harvested cup plant biomass.

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430-435 J. Smilga, M. Zeps, L. Sisenis, J. Kalnins, A. Adamovics and J. Donis
Profitability of hybrid aspen breeding in Latvia
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Profitability of hybrid aspen breeding in Latvia

J. Smilga¹, M. Zeps²⋅*, L. Sisenis³, J. Kalnins², A. Adamovics² and J. Donis²

¹Forest Competence Centre, Dzerbenes Str. 27, LV1006 Riga, Latvia
²Latvian State Forest Institute ‘Silava’, Riga Str. 111, LV2169 Salaspils, Latvia
³Latvia University of Agriculture, Forestry Faculty, Akademijas Str. 11, LV3001 Jelgava, Latvia *Correspondence: martins.zeps@silava.lv

Abstract:

Hybrid aspen (Populus tremuloides × P. tremula) has fast growth in climatic conditions of Northern Europe and relatively high wood quality. Therefore, breeding of it has been carried out in a number of Baltic Sea Region countries. Breeding requires notable financial investment; therefore, the aim of our study was to estimate the profitability of hybrid aspen breeding in Latvia and the factors affecting it. Financial analysis was based on the differential approach, that is, only the costs and benefits that differ between two compared alternatives – planting of hybrid aspen and natural regeneration of silver birch or common aspen – were compared. Differential gain in this case included additional monetary value of the above-ground parts of trees in planted hybrid aspen stands (values obtained from trials in Latvia); differential costs were the costs of tree breeding, plants, planting, cleaning and protection against browsing damages (repeated use of browser repellents or fencing). Profitability of hybrid aspen breeding was significantly affected by the size of the area planted annually, soil fertility (site index) and length of rotation period. The differential gain from investments in tree breeding and establishment and management of plantations (r = 3%), assuming that selected clones would be used for 15 years and 500 ha are planted annually, in comparison to natural regeneration of common aspen and to silver birch, was 662 EUR ha-1 and 1136 EUR ha-1, respectively. In contrast, if only 50 ha are planted annually, the respective figures were 588 and 756 EUR ha-1. If fencing was used for protection of the hybrid aspen plantation against browsing, the differential gain was positive only on the most fertile soils (site index Ia).

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436-441 M. Zeps,, L. Sisenis, S. Luguza, M. Purins, B. Dzerina and J. Kalnins
Formation of height increment of hybrid aspen in Latvia
Abstract |
Full text PDF (281 KB)

Formation of height increment of hybrid aspen in Latvia

M. Zeps¹,*, L. Sisenis², S. Luguza², M. Purins², B. Dzerina² and J. Kalnins³

¹Latvian State Forest Institute ‘Silava’, Riga Str. 111, LV2169 Salaspils, Latvia
²Latvia University of Agriculture, Forest Faculty, Akademijas Str. 11, LV3001 Jelgava, Latvia
³Forest Competence Centre, Dzerbenes Str. 27, LV1006 Riga, Latvia *Correspondence: martins.zeps@silava.lv

Abstract:

Annual increment of hybrid aspen exceeds that of other tree species (including common aspen) in Baltic States. Notable (several-fold) differences in productivity between clones have been detected and therefore tree breeding programs are established to select the best genotypes (clones) for large-scale propagation. In order to aid the selection as well as understand the potential changes in growth of hybrid aspen as a result of climatic changes, it is important to analyse the intra-annual growth dynamics. Therefore aim of our study was to assess height growth intensity of hybrid aspen and factors affecting it. Weekly measurements of height increment were carried out through the third growing season of trees in two plantations, consisting of 19 clones (10 ramets per clone), on abandoned agricultural land in western (Mazirbe, 56° 36´ N, 24° 30´ E) and central (Vecumnieki, 57° 40´ N, 22° 19´ E) part of Latvia. Mean height growth period of hybrid aspen ranged from 119 ± 8.9 days for late flushing clones to 137 ± 8.6 days for early flushing and was tightly (r = 0.69) linked to total length of height increment. Mean height growth intensity during this period for respective groups of clones ranged from 7.7 ± 3.04 mm day-1 to 11.7 ± 2.93 mm day-1. Growth intensity (and height increment) was significantly affected by genotype (clone) and in both sites tightly (r = 0.57…0.84) linked with daily mean temperature, but not with precipitation. Increasing temperature in future might boost the productivity of hybrid aspen plantations, especially with early flushing clones.

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445-454 K. Balina,, M. Balode, L. Muzikante and D. Blumberga
Impact of synthetic hormone 17α-ethinylestradiol on growth of microalgae Desmodesmus communis
Abstract |
Full text PDF (359 KB)

Impact of synthetic hormone 17α-ethinylestradiol on growth of microalgae Desmodesmus communis

K. Balina¹,*, M. Balode²⋅³, L. Muzikante² and D. Blumberga¹

¹Riga Technical University, Institute of Energy Systems and Environment, Azenes Str. 12/1, LV1048 Riga, Latvia; *Correspondence: karina.balina@rtu.lv
²Latvian Institute of Aquatic Ecology, Daugavgrivas 8, LV1048 Riga, Latvia
³University of Latvia, Faculty of Biology, Department of Hydrobiology, Kronvalda Boulevard 4, LV1010 Riga, Latvia

Abstract:

Microalgae has recently attracted much attention as a feedstock for biogas. Using wastewater as microalgae nutrition is a way how to produce algal biomass with low cost and minimum impact on environment. However, wastewater often is polluted with chemicals like pharmaceuticals which are among the commonly used chemicals in everyday life. The present study was aimed at the toxicity evaluation of a commonly used synthetic hormone, 17α-ethinylestradiol, using freshwater green algae Desmodesmus communis as a biotest organism. Parameters like healthy cell number and photosynthetic activity were determined and used to assess the toxicity. Lowest Observed Effect Concentration (LOEC) and 50% Effective Concentration (EC50) values were calculated for the parameters at different incubation times. It was found out that 17α-ethinylestradiol affects algal cell ability to grow, inhibits cell division and reduce photosynthetic processes in algal cells. Our research shows that inhibitory effect on growth of green algae D. communis start on concentration below 10 µg L-1 (4–8 µg L-1). Concentrations in the range of concentration 80–100 reduce growth by 50%, but concentrations 100–500 µg L-1 induce 100% reduction of growth rate and even calls initial algal cell destruction. Presence of EE2 in wastewater used for algal growth can affect productivity of a microalgae aquaculture.

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455-463 M. Bloch-Michalik and M. Gaworski
A proposition of management of the waste from biogas plant cooperating with wastewater treatment
Abstract |
Full text PDF (350 KB)

A proposition of management of the waste from biogas plant cooperating with wastewater treatment

M. Bloch-Michalik* and M. Gaworski

Department of Production Management and Engineering, Warsaw University of Life Sciences, Nowoursynowska str. 164, 02-787 Warsaw, Poland
*Correspondence: marta_michalik@sggw.pl

Abstract:

The energy policy relevant to ecological aspects in all EU members since couple of years is determined by renewable energy sources (RES) development. Specific activities related to the increase of the share of RES in national energy like certificates of origin, penalties and fees all together make up a kind of enforcement that would encourage society to searching new possibilities to generate energy in accordance to respect to the natural environment. Seeking alternatives to fossil energy sources is the best option to force the approaching energy crisis. The paper aimed at analysis of possibility in using the digestate coming from biogas plant which cooperating with wastewater treatment. In details, some aspects of underestimated energy potential of digestate was developed as well as energy flow in analysed technological solution to demonstrate that it is possible to close this balance circle. As a result of the undertaken considerations there are some suggestions how to adopt the treatment system to improve effectiveness of waste management in accordance with energy production.

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464-476 E. Dace and I. Muizniece
Modeling greenhouse gas emissions from the forestry sector – the case of Latvia
Abstract |
Full text PDF (360 KB)

Modeling greenhouse gas emissions from the forestry sector – the case of Latvia

E. Dace* and I. Muizniece

Riga Technical University, Institute of Energy Systems and Environment, Azenes street 12/1, LV1048 Riga, Latvia; *Correspondence: elina.dace@rtu.lv

Abstract:

A system dynamics model for assessing the greenhouse gas (GHG) emissions from forestry and forest land is presented in the paper. The model is based on the IPCC guidelines for national GHG inventories and includes the main elements of the forestry sector, i.e. changes in the living biomass, dead organic matter and soils. The developed model allows simulating various policies and measures implemented and decisions made, and their impact on change in the GHG emissions. Various scenarios of potential development in the medium-term planning were simulated till 2030 to assess their impact on the GHG emissions. It is found that the most sustainable option would be use of wood processing waste for production of e.g. wood chips or some added-value products. The case of Latvia is selected for simulations, as forests compose about 52% of the country’s area. Nevertheless, by changing specific parametric values the model can be adapted and applied for estimation and analysis of GHG emissions from forestry in other countries, as well.

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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
Abstract |
Full text PDF (839 KB)

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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485-493 E. Hiltunen, J.B. Martinkauppi, A. Mäkiranta, J. Rinta-Luoma and T. Syrjälä
Seasonal temperature variation in heat collection liquid used in renewable, carbon-free heat production from urban and rural water areas
Abstract |
Full text PDF (413 KB)

Seasonal temperature variation in heat collection liquid used in renewable, carbon-free heat production from urban and rural water areas

E. Hiltunen, J.B. Martinkauppi*, A. Mäkiranta, J. Rinta-Luoma and T. Syrjälä

University of Vaasa, Faculty of Technology, Electrical Engineering and Energy Technology, Wolffintie 34, FI65200 Vaasa, Finland *Correspondence: Birgitta.Martinkauppi@uva.fi

Abstract:

A renewable energy source called sediment energy is based on heat collection with tubes similar to those used in ground energy and is installed inside a sediment layer under water body. In this paper, an investigation of temperature behaviour of heat carrier liquid is made during several years to evaluate utilization of sediment energy. This is done by evaluating temperature variations of heat carrier liquid and its correlation to air temperature. This increases advancement of knowledge how the temperature of the sediment recovers from the heat collection. The temperature variation of the liquid seems to correlate with the mean monthly air temperature. The selected methods clearly indicate that sediment energy seems to be yearly renewable because there is a clear correlation between air temperature and heat carrier liquid temperature.

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485-493 E. Hiltunen, J.B. Martinkauppi, A. Mäkiranta, J. Rinta-Luoma and T. Syrjälä
Seasonal temperature variation in heat collection liquid used in renewable, carbon-free heat production from urban and rural water areas
Abstract |
Full text PDF (413 KB)

Seasonal temperature variation in heat collection liquid used in renewable, carbon-free heat production from urban and rural water areas

E. Hiltunen, J.B. Martinkauppi*, A. Mäkiranta, J. Rinta-Luoma and T. Syrjälä

University of Vaasa, Faculty of Technology, Electrical Engineering and Energy Technology, Wolffintie 34, FI65200 Vaasa, Finland *Correspondence: Birgitta.Martinkauppi@uva.fi

Abstract:

A renewable energy source called sediment energy is based on heat collection with tubes similar to those used in ground energy and is installed inside a sediment layer under water body. In this paper, an investigation of temperature behaviour of heat carrier liquid is made during several years to evaluate utilization of sediment energy. This is done by evaluating temperature variations of heat carrier liquid and its correlation to air temperature. This increases advancement of knowledge how the temperature of the sediment recovers from the heat collection. The temperature variation of the liquid seems to correlate with the mean monthly air temperature. The selected methods clearly indicate that sediment energy seems to be yearly renewable because there is a clear correlation between air temperature and heat carrier liquid temperature.

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494-499 P. Kic
Hot-air distribution in the floor heating
Abstract |
Full text PDF (358 KB)

Hot-air distribution in the floor heating

P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, CZ16521 Prague 6, Czech Republic;
Correspondence: kic@tf.czu.cz

Abstract:

The aim of this paper is to present results of measurement of hot-air floor heating system. The energy from fireplace directly heats the house near to the chimney and partly is distributed by the special ventilation under the floor in the whole heated room. The main principle is based on specially designed accumulative floors, consisting of a set of special chambers, which enable to heated air from the fireplace to flow through them. The layer of concrete floor is installed on the surface of these chambers. Hot-air can be intensively distributed around the house with time shift, but the air flow is not uniform and some places are warmer or colder. The results of measurements in the building showed that the accumulation in the floor compensates temperature differences. The result of proper application of this type of heating is a stable thermal comfort and saving of heating costs. Based on the results of measurements, practical recommendations for the design, installation and use of these types of heating were summarised in the conclusions.

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494-499 P. Kic
Hot-air distribution in the floor heating
Abstract |
Full text PDF (358 KB)

Hot-air distribution in the floor heating

P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, CZ16521 Prague 6, Czech Republic; e-mail: kic@tf.czu.cz

Abstract:

The aim of this paper is to present results of measurement of hot-air floor heating system. The energy from fireplace directly heats the house near to the chimney and partly is distributed by the special ventilation under the floor in the whole heated room. The main principle is based on specially designed accumulative floors, consisting of a set of special chambers, which enable to heated air from the fireplace to flow through them. The layer of concrete floor is installed on the surface of these chambers. Hot-air can be intensively distributed around the house with time shift, but the air flow is not uniform and some places are warmer or colder. The results of measurements in the building showed that the accumulation in the floor compensates temperature differences. The result of proper application of this type of heating is a stable thermal comfort and saving of heating costs. Based on the results of measurements, practical recommendations for the design, installation and use of these types of heating were summarised in the conclusions.

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500-510 V. Kirsanovs and A. Žandeckis
Investigation of fuel effect on biomass gasification process using equilibrium model
Abstract |
Full text PDF (271 KB)

Investigation of fuel effect on biomass gasification process using equilibrium model

V. Kirsanovs* and A. Žandeckis

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

Abstract:

Gasification is one of the most promising technologies of converting biomass into energy. Different type of biomass can be used for gasification process since there are no strict limitations for parameters of used fuel. Various types of biomass are used in Latvia for production of energy. Wood fuels make up the main part of used biomass in Latvia. However, many non-wood biomass types are available as well. This study presents the comparison of wood and non-wood biomass use in gasification process. Biomass gasification model based on thermodynamic equilibrium was used to simulate gasification process with various biomass types. All input parameters were constant in model except fuel properties. In general gasification process was simulated with seven types of biomass – draff from beer production, common reed, middling from oats and wheat sieving, straw from grain cultivation, buckwheat hulls, rapeseed by-product from biofuel production, as well as wood. These non-wood biomass types are available in Latvia. Produced syngas calorific value and gasification process efficiency are taken as the indicators to examine the gasification performances using various biomass types. The regression model was proposed to describe relation between fuel properties and efficiency of the gasification process. Results show that non-wood biomass can be successfully used for gasification process. Ash content growth in the fuel promotes temperature decrease in the reactor. Fuel chemical composition has effect on the produced syngas composition and heating value.

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500-510 V. Kirsanovs and A. Žandeckis
Investigation of fuel effect on biomass gasification process using equilibrium model
Abstract |
Full text PDF (271 KB)

Investigation of fuel effect on biomass gasification process using equilibrium model

V. Kirsanovs* and A. Žandeckis

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

Abstract:

Gasification is one of the most promising technologies of converting biomass into energy. Different type of biomass can be used for gasification process since there are no strict limitations for parameters of used fuel. Various types of biomass are used in Latvia for production of energy. Wood fuels make up the main part of used biomass in Latvia. However, many non-wood biomass types are available as well. This study presents the comparison of wood and non-wood biomass use in gasification process. Biomass gasification model based on thermodynamic equilibrium was used to simulate gasification process with various biomass types. All input parameters were constant in model except fuel properties. In general gasification process was simulated with seven types of biomass – draff from beer production, common reed, middling from oats and wheat sieving, straw from grain cultivation, buckwheat hulls, rapeseed by-product from biofuel production, as well as wood. These non-wood biomass types are available in Latvia. Produced syngas calorific value and gasification process efficiency are taken as the indicators to examine the gasification performances using various biomass types. The regression model was proposed to describe relation between fuel properties and efficiency of the gasification process. Results show that non-wood biomass can be successfully used for gasification process. Ash content growth in the fuel promotes temperature decrease in the reactor. Fuel chemical composition has effect on the produced syngas composition and heating value.

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511-519 K. Kļaviņa, K. Kārkliņa and D. Blumberga
Charcoal production environmental performance
Abstract |
Full text PDF (344 KB)

Charcoal production environmental performance

K. Kļaviņa*, K. Kārkliņa and D. Blumberga

Riga Technical University, Faculty of Power and Electrical Engineering, Institute of Energy Systems and Environment, Āzenes st. 12/1-616, LV1048 Riga, Latvia; *Correspondence: krista.klavina@rtu.lv

Abstract:

Charcoal is a well-known material obtained through thermal conversion of different types of biomass in an anoxic environment. The greatest share of the overall charcoal amount is produced in inefficient batch pyrolysis chambers. Thus contribution in an in-depth charcoal production process research for process optimization is of great importance. In this study an industrial experiment of charcoal production in a continuous up-to-date retort is performed. The selected industrial object has a high level of automation and process control. The retort is connected to a continuous monitoring system that records and stores the process parameter values. Apart from the process control parameter measurements attention has to be paid to the charcoal production plant pollution as this industry often gets contradictory attention towards its environmental performance. The air pollution is evaluated by air quality measurements at the production facility site. The obtained experimental results from an industrial facility with a state-of-the-art technology give an opportunity to evaluate the potential of the charcoal industry to be a sustainable player in the renewable energy market.

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511-519 K. Kļaviņa, K. Kārkliņa and D. Blumberga
Charcoal production environmental performance
Abstract |
Full text PDF (344 KB)

Charcoal production environmental performance

K. Kļaviņa*, K. Kārkliņa and D. Blumberga

Riga Technical University, Faculty of Power and Electrical Engineering, Institute of Energy Systems and Environment, Āzenes st. 12/1-616, LV1048 Riga, Latvia; *Correspondence: krista.klavina@rtu.lv

Abstract:

Charcoal is a well-known material obtained through thermal conversion of different types of biomass in an anoxic environment. The greatest share of the overall charcoal amount is produced in inefficient batch pyrolysis chambers. Thus contribution in an in-depth charcoal production process research for process optimization is of great importance. In this study an industrial experiment of charcoal production in a continuous up-to-date retort is performed. The selected industrial object has a high level of automation and process control. The retort is connected to a continuous monitoring system that records and stores the process parameter values. Apart from the process control parameter measurements attention has to be paid to the charcoal production plant pollution as this industry often gets contradictory attention towards its environmental performance. The air pollution is evaluated by air quality measurements at the production facility site. The obtained experimental results from an industrial facility with a state-of-the-art technology give an opportunity to evaluate the potential of the charcoal industry to be a sustainable player in the renewable energy market.

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520-525 T. Prodanuksand D. Blumberga
Methodology of demand side management Study course. experience of case studies
Abstract |
Full text PDF (216 KB)

Methodology of demand side management Study course. experience of case studies

T. Prodanuks*and D. Blumberga

Riga Technical University, Faculty of Power and Electrical Engineering, Institute of Energy Systems and Environment, Azenes street 12-K1, LV1043 Riga, Latvia; *Correspondence: toms.prodanuks_1@rtu.lv

Abstract:

The role of environmental and energy security issues due to political issues are increasing and this stimulates governments to review sustainable energy strategies. One of the ways to reach the targets set by many countries for cuts in greenhouse-gas emissions, free competition and security of supply is energy efficiency. Energy efficiency can be achieved by demand side management (DSM) programs. DMS requires regular and intensive work with energy users and it makes a platform for introduction of DSM strategies in engineering education. The paper discusses the integration models of DSM in the engineering education, analyses the components significant for ensurance of sustainable engineering education and energy efficiency and climate change targets. Based on analysis a methodology for of integration of DSM is developed. Methodology shows how to introduce environmental specialists, students and municipality employees with demand side management in public buildings and how to evaluate efficiency of such integration. Methodology is analysed through several case studies and conclusions and recommendations developed.

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520-525 T. Prodanuks and D. Blumberga
Methodology of demand side management Study course. experience of case studies
Abstract |
Full text PDF (216 KB)

Methodology of demand side management Study course. experience of case studies

T. Prodanuks* and D. Blumberga

Riga Technical University, Faculty of Power and Electrical Engineering, Institute of Energy Systems and Environment, Azenes street 12-K1, LV1043 Riga, Latvia; *Correspondence: toms.prodanuks_1@rtu.lv

Abstract:

The role of environmental and energy security issues due to political issues are increasing and this stimulates governments to review sustainable energy strategies. One of the ways to reach the targets set by many countries for cuts in greenhouse-gas emissions, free competition and security of supply is energy efficiency. Energy efficiency can be achieved by demand side management (DSM) programs. DMS requires regular and intensive work with energy users and it makes a platform for introduction of DSM strategies in engineering education. The paper discusses the integration models of DSM in the engineering education, analyses the components significant for ensurance of sustainable engineering education and energy efficiency and climate change targets. Based on analysis a methodology for of integration of DSM is developed. Methodology shows how to introduce environmental specialists, students and municipality employees with demand side management in public buildings and how to evaluate efficiency of such integration. Methodology is analysed through several case studies and conclusions and recommendations developed.

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526-532 K. Rugele,, G. Bumanis, L. Mezule, T. Juhna and D. Bajare
Application of industrial wastes in renewable energy production
Abstract |
Full text PDF (353 KB)

Application of industrial wastes in renewable energy production

K. Rugele¹⋅²,*, G. Bumanis³, L. Mezule¹, T. Juhna¹ and D. Bajare³

¹Riga Technical University, Faculty of Civil Engineering, Department of Water Engineering and Technology, Kalku 1, LV1047 Riga, Latvia
²Riga Technical University, Faculty of Materials Science and Applied Chemistry, Institute of General Chemical Engineering, Kalku 1, LV1047 Riga, Latvia,
³Riga Technical University, Faculty of Civil Engineering, Department of Building Materials and Products, Kalku 1, LV1047 Riga, Latvia *Correspondence: kristine.rugele@rtu.lv

Abstract:

This research focuses on the industrial waste application as raw materials to create composite material and its characterisation for their possible application in anaerobic digestion. As the limitation of effective biogas digestion process is associated with inhibition of the some elements and acidification of biodegradable organic matter, therefore a highly porous alkaline composite material was evaluated in this research as buffer capacity increasing material. Batch experiments were provided with composite material additive in anaerobic digesters. Results indicate that alkaline composite materials in anaerobic digesters treated acidic whey could increase BMP up to 22%, but pH value could be kept in the optimal range (7.2–7.4) to ensure the effective digestion process.

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526-532 K. Rugele,, G. Bumanis, L. Mezule, T. Juhna and D. Bajare
Application of industrial wastes in renewable energy production
Abstract |
Full text PDF (353 KB)

Application of industrial wastes in renewable energy production

K. Rugele¹⋅²,*, G. Bumanis³, L. Mezule¹, T. Juhna¹ and D. Bajare³

¹Riga Technical University, Faculty of Civil Engineering, Department of Water Engineering and Technology, Kalku 1, LV1047 Riga, Latvia
²Riga Technical University, Faculty of Materials Science and Applied Chemistry, Institute of General Chemical Engineering, Kalku 1, LV1047 Riga, Latvia,
³Riga Technical University, Faculty of Civil Engineering, Department of Building Materials and Products, Kalku 1, LV1047 Riga, Latvia *Correspondence: kristine.rugele@rtu.lv

Abstract:

This research focuses on the industrial waste application as raw materials to create composite material and its characterisation for their possible application in anaerobic digestion. As the limitation of effective biogas digestion process is associated with inhibition of the some elements and acidification of biodegradable organic matter, therefore a highly porous alkaline composite material was evaluated in this research as buffer capacity increasing material. Batch experiments were provided with composite material additive in anaerobic digesters. Results indicate that alkaline composite materials in anaerobic digesters treated acidic whey could increase BMP up to 22%, but pH value could be kept in the optimal range (7.2–7.4) to ensure the effective digestion process.

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533-538 M. Šeďová, P. Neuberger and R. Adamovský
Measurement and analysis of temperature changes of ground massif with Slinky heat exchanger
Abstract |
Full text PDF (280 KB)

Measurement and analysis of temperature changes of ground massif with Slinky heat exchanger

M. Šeďová*, P. Neuberger and R. Adamovský

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Mechanical Engineering, Kamýcká 129, CZ16521 Prague – Suchdol, Czech Republic; *Correspondence: sedova@tf.czu.cz

Abstract:

The article is describing temperature changes in the ground massif with Slinky heat exchanger. The exchanger serves as a heat source for a heat pump which is used for cold water warming and a heating of the administration building. The aim of the research is to analyse the influence of the Slinky heat exchanger to the temperature of the ground massif while extracting heat energy at the beginning and during the heating season, as well as beyond it. The temperature process of the ground massif is described near the exchanger, on a reference lot in burial depth of the heat exchanger and also in a depth of 0.2 m. The energy potential of the ground massif was evaluated using the temperature differences of ground massif in the area of the Slinky heat exchanger at the beginning and at the end of the heating season.

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533-538 M. Šeďová, P. Neuberger and R. Adamovský
Measurement and analysis of temperature changes of ground massif with Slinky heat exchanger
Abstract |
Full text PDF (280 KB)

Measurement and analysis of temperature changes of ground massif with Slinky heat exchanger

M. Šeďová*, P. Neuberger and R. Adamovský

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Mechanical Engineering, Kamýcká 129, CZ16521 Prague – Suchdol, Czech Republic; *Correspondence: sedova@tf.czu.cz

Abstract:

The article is describing temperature changes in the ground massif with Slinky heat exchanger. The exchanger serves as a heat source for a heat pump which is used for cold water warming and a heating of the administration building. The aim of the research is to analyse the influence of the Slinky heat exchanger to the temperature of the ground massif while extracting heat energy at the beginning and during the heating season, as well as beyond it. The temperature process of the ground massif is described near the exchanger, on a reference lot in burial depth of the heat exchanger and also in a depth of 0.2 m. The energy potential of the ground massif was evaluated using the temperature differences of ground massif in the area of the Slinky heat exchanger at the beginning and at the end of the heating season.

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541-549 J. Čedík,, M. Pexa, J. Mařík, V. Hönig, Š. Horníčková and K. Kubín
Influence of butanol and FAME blends on operational characteristics of compression ignition engine
Abstract |
Full text PDF (851 KB)

Influence of butanol and FAME blends on operational characteristics of compression ignition engine

J. Čedík¹,*, M. Pexa¹, J. Mařík¹, V. Hönig², Š. Horníčková² and K. Kubín³

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague 6, Czech Republic; *Correspondence cedikj@tf.czu.cz
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, CZ16521 Prague 6, Czech Republic
³Research Institute of Agricultural Engineering, p.r.i., Drnovská 507, CZ16101 Prague 6, Czech Republic

Abstract:

The issue of the use of alternative fuels in diesel engines is discussed in this paper. The purpose is to reduce the dependence of EU Member States on fuels of petroleum origin. One of the possibilities is the use of butanol produced from organic products. The use of pure butanol in diesel engines is not possible. However, it may be used as an additive for fuels of petroleum origin or adding to oil for improving the operating conditions of the engine. Successively 10, 30 and 50% n-butanol was used as an additive. Turbocharged combustion engine of the tractor Zetor 8641 Foretrra was used to the test. This engine was burdened using a dynamometer to the PTO. Performance parameters and fuel consumption of the engine were monitored during measurements. Performance parameters of the engine decreases and fuel consumption increases due to the properties of butanol. Cleansing properties of butanol which restrict carbonization on functional surfaces of the engine seems advantageous.

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541-549 J. Čedík,, M. Pexa, J. Mařík, V. Hönig, Š. Horníčková and K. Kubín
Influence of butanol and FAME blends on operational characteristics of compression ignition engine
Abstract |
Full text PDF (851 KB)

Influence of butanol and FAME blends on operational characteristics of compression ignition engine

J. Čedík¹,*, M. Pexa¹, J. Mařík¹, V. Hönig², Š. Horníčková² and K. Kubín³

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague 6, Czech Republic; *Correspondence cedikj@tf.czu.cz
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, CZ16521 Prague 6, Czech Republic
³Research Institute of Agricultural Engineering, p.r.i., Drnovská 507, CZ16101 Prague 6, Czech Republic

Abstract:

The issue of the use of alternative fuels in diesel engines is discussed in this paper. The purpose is to reduce the dependence of EU Member States on fuels of petroleum origin. One of the possibilities is the use of butanol produced from organic products. The use of pure butanol in diesel engines is not possible. However, it may be used as an additive for fuels of petroleum origin or adding to oil for improving the operating conditions of the engine. Successively 10, 30 and 50% n-butanol was used as an additive. Turbocharged combustion engine of the tractor Zetor 8641 Foretrra was used to the test. This engine was burdened using a dynamometer to the PTO. Performance parameters and fuel consumption of the engine were monitored during measurements. Performance parameters of the engine decreases and fuel consumption increases due to the properties of butanol. Cleansing properties of butanol which restrict carbonization on functional surfaces of the engine seems advantageous.

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550-557 V. Hönig,, Z. Linhart, J. Táborský and J. Mařík
Determination of the phase separation temperature and the water solubility in the mixtures of gasoline with biobutanol and bioethanol
Abstract |
Full text PDF (268 KB)

Determination of the phase separation temperature and the water solubility in the mixtures of gasoline with biobutanol and bioethanol

V. Hönig¹,*, Z. Linhart², J. Táborský¹ and J. Mařík³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamycka 129, CZ16521, Prague 6, Czech Republic; *Correspondence: honig@af.czu.cz
²Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Management, Kamycka 129, CZ16521, Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamycka 129, CZ16521, Prague 6, Czech Republic

Abstract:

Original hydrocarbon composition, volatility, compatibility with materials, calorific value and stability of the mixture in the presence of water are monitored usually. This paper deals with the stability of gasoline-biobutanol and gasoline-bioethanol mixtures in the presence of water. Biobutanol is better biofuel than bioethanol using the same raw materials. Different contents of alcohol and oxygenated cosolvents are evaluated. Experimental analysis are focused on the water solubility and phase stability. Solubility in water of butanol and ethanol mixtures is very similar. Butanol-gasoline mixture provides better phase stability upon contact with water or atmospheric moisture oppose to ethanol mixtures. Butanol also does not enter to the aqueous layer and fuel properties remain in phase separation preserved. Further, it was found that crystals occur at low temperatures after exclusion of water was seen. Moreover, the temperature of phase separation can affect the content of alcohol, water, hydrocarbon composition and cosolvents added. The only difference found between more beneficial butanol and less beneficial ethanol was ABE (Aceton–Butanol–Ethanol) fermentation with Clostridium Acetobutylicum allowing to ferment also saccharidic cellulose to biobutanol according to standard of second generation biofuels.

Key words:

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550-557 V. Hönig,, Z. Linhart, J. Táborský and J. Mařík
Determination of the phase separation temperature and the water solubility in the mixtures of gasoline with biobutanol and bioethanol
Abstract |
Full text PDF (268 KB)

Determination of the phase separation temperature and the water solubility in the mixtures of gasoline with biobutanol and bioethanol

V. Hönig¹,*, Z. Linhart², J. Táborský¹ and J. Mařík³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamycka 129, CZ16521, Prague 6, Czech Republic; *Correspondence: honig@af.czu.cz
²Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Management, Kamycka 129, CZ16521, Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamycka 129, CZ16521, Prague 6, Czech Republic

Abstract:

Original hydrocarbon composition, volatility, compatibility with materials, calorific value and stability of the mixture in the presence of water are monitored usually. This paper deals with the stability of gasoline-biobutanol and gasoline-bioethanol mixtures in the presence of water. Biobutanol is better biofuel than bioethanol using the same raw materials. Different contents of alcohol and oxygenated cosolvents are evaluated. Experimental analysis are focused on the water solubility and phase stability. Solubility in water of butanol and ethanol mixtures is very similar. Butanol-gasoline mixture provides better phase stability upon contact with water or atmospheric moisture oppose to ethanol mixtures. Butanol also does not enter to the aqueous layer and fuel properties remain in phase separation preserved. Further, it was found that crystals occur at low temperatures after exclusion of water was seen. Moreover, the temperature of phase separation can affect the content of alcohol, water, hydrocarbon composition and cosolvents added. The only difference found between more beneficial butanol and less beneficial ethanol was ABE (Aceton–Butanol–Ethanol) fermentation with Clostridium Acetobutylicum allowing to ferment also saccharidic cellulose to biobutanol according to standard of second generation biofuels.

Key words:

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558-567 V. Hönig,, M. Orsák, M. Pexa and Z. Linhart
The distillation characteristics of automotive gasoline containing biobutanol, bioethanol and the influence of the oxygenates
Abstract |
Full text PDF (613 KB)

The distillation characteristics of automotive gasoline containing biobutanol, bioethanol and the influence of the oxygenates

V. Hönig¹,*, M. Orsák¹, M. Pexa² and Z. Linhart³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamycka 129, CZ16521, Prague 6, Czech Republic; *Correspondence: honig@af.czu.cz
²Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamycka 129, CZ16521, Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Management, Kamycka 129, CZ16521, Prague 6, Czech Republic

Abstract:

Bioethanol and fatty acid methyl esters are a regular part of the production of gasoline and diesel fuels, although in limited quantities. Introduction of bioethanol as part of automobile gasoline was associated with high production costs, technical and logistical problems. This article analyses changes of distillation curve of biobutanol and isobutanol as an alternative to bioethanol. Added alcohol to gasoline causes reduction of boiling point due to the formation of azeotrope. This phenomena of distillation curve are called Plato effect. Therefore, ethers (MTBE and ETBE) are added to fuel to affect the most central part of distillation curve. Especially, to decrease the distillation temperature oppose to gasoline without oxygenates of wide range of distilled volume. This article replaces simple universal models predicting properties of alcohol-gasoline mixtures. It was found that mixture of ETBE with bioethanol in gasoline the distillation curve summarise its effects. Butanol and MTBE influence distillation curve of gasoline only in values of its boiling points. Therefore, butanol is mixable with all listed fuel components without any additional addaptations.

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558-567 V. Hönig,, M. Orsák, M. Pexa and Z. Linhart
The distillation characteristics of automotive gasoline containing biobutanol, bioethanol and the influence of the oxygenates
Abstract |
Full text PDF (613 KB)

The distillation characteristics of automotive gasoline containing biobutanol, bioethanol and the influence of the oxygenates

V. Hönig¹,*, M. Orsák¹, M. Pexa² and Z. Linhart³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamycka 129, CZ16521, Prague 6, Czech Republic; *Correspondence: honig@af.czu.cz
²Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamycka 129, CZ16521, Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Management, Kamycka 129, CZ16521, Prague 6, Czech Republic

Abstract:

Bioethanol and fatty acid methyl esters are a regular part of the production of gasoline and diesel fuels, although in limited quantities. Introduction of bioethanol as part of automobile gasoline was associated with high production costs, technical and logistical problems. This article analyses changes of distillation curve of biobutanol and isobutanol as an alternative to bioethanol. Added alcohol to gasoline causes reduction of boiling point due to the formation of azeotrope. This phenomena of distillation curve are called Plato effect. Therefore, ethers (MTBE and ETBE) are added to fuel to affect the most central part of distillation curve. Especially, to decrease the distillation temperature oppose to gasoline without oxygenates of wide range of distilled volume. This article replaces simple universal models predicting properties of alcohol-gasoline mixtures. It was found that mixture of ETBE with bioethanol in gasoline the distillation curve summarise its effects. Butanol and MTBE influence distillation curve of gasoline only in values of its boiling points. Therefore, butanol is mixable with all listed fuel components without any additional addaptations.

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568-576 V. Hönig, M. Orsák and J. Táborský
The analysis of the influence of biobutanol and bioethanol mixture with ethers on the vapour pressure of gasoline
Abstract |
Full text PDF (303 KB)

The analysis of the influence of biobutanol and bioethanol mixture with ethers on the vapour pressure of gasoline

V. Hönig*, M. Orsák and J. Táborský

Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamycka 129, CZ16521 Prague 6, Czech Republic; *Correspondence: honig@af.czu.cz

Abstract:

In addition to widely known species automotive fuels that are currently on the market, there are many other chemicals which are used or can be used as fuels or fuel components for current automotive internal combustion engines. Implementation of such ingredients car brings a number of technical problems. The vapour pressure is the pressure in the system in which they are at a certain temperature gaseous and liquid phases in equilibrium. The addition of alcohols such as gasoline constituents significantly affects the volatility of the resulting mixture. The article is focused on assessing the addition of biobutanol as n–butanol or isobutanol vapour pressure compared to the already commonly used in bioethanol. Also included is the possibility to use ethers for influencing the vapour pressure of the resulting mixture. Part of the experiment is to assess the influence of the quantity and type of oxygenates and composition of gasoline. Based on the measured data it is clear that addition of alcohol to gasoline create complications. Effect biobutanol as possible alternatives is different than bioethanol. It is therefore necessary to take into account the influence of alcohol, even at low concentrations corresponding to the limit according to standard EN 228. Biobutanol compared bioethanol can be used as 100% fuel. For the low vapour pressure of the fuel experiment also aims to increase its value using pentane.

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568-576 V. Hönig, M. Orsák and J. Táborský
The analysis of the influence of biobutanol and bioethanol mixture with ethers on the vapour pressure of gasoline
Abstract |
Full text PDF (303 KB)

The analysis of the influence of biobutanol and bioethanol mixture with ethers on the vapour pressure of gasoline

V. Hönig*, M. Orsák and J. Táborský

Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamycka 129, CZ16521 Prague 6, Czech Republic; *Correspondence: honig@af.czu.cz

Abstract:

In addition to widely known species automotive fuels that are currently on the market, there are many other chemicals which are used or can be used as fuels or fuel components for current automotive internal combustion engines. Implementation of such ingredients car brings a number of technical problems. The vapour pressure is the pressure in the system in which they are at a certain temperature gaseous and liquid phases in equilibrium. The addition of alcohols such as gasoline constituents significantly affects the volatility of the resulting mixture. The article is focused on assessing the addition of biobutanol as n–butanol or isobutanol vapour pressure compared to the already commonly used in bioethanol. Also included is the possibility to use ethers for influencing the vapour pressure of the resulting mixture. Part of the experiment is to assess the influence of the quantity and type of oxygenates and composition of gasoline. Based on the measured data it is clear that addition of alcohol to gasoline create complications. Effect biobutanol as possible alternatives is different than bioethanol. It is therefore necessary to take into account the influence of alcohol, even at low concentrations corresponding to the limit according to standard EN 228. Biobutanol compared bioethanol can be used as 100% fuel. For the low vapour pressure of the fuel experiment also aims to increase its value using pentane.

Key words:

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577-584 T. Kotek,, M. Kotek, P. Jindra and M. Pexa
Determination of the optimal injection time for adaptation SI engine on E85 fuel using self-designed auxiliary control unit
Abstract |
Full text PDF (241 KB)

Determination of the optimal injection time for adaptation SI engine on E85 fuel using self-designed auxiliary control unit

T. Kotek¹,*, M. Kotek², P. Jindra² and M. Pexa¹

¹Czech University of Life Science Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague, Czech republic; *Correspondence: kotek@oikt.czu.cz
²Czech University of Life Science Prague, Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcká 129, CZ16521 Prague, Czech republic

Abstract:

Article deals with problems of the operation of spark ignition combustion engine on high-percentage of blend bioethanol. The aim of the experiment was to find the optimal value of injection time of the engine injection valves with respect to the adaptive ability of the original engine control unit (ECU) when using a special auxiliary control unit (ACU) was adjusted injection time. Special dynamic driving cycle has been designed to assess the effects of prolonged injection time on the adaptive abilities of the ECU that stemmed from a real recording vehicle’s rides with the same engine as was used in conducted experiments. The results proved that by changing the extension of the period of injection occurs a gradual adaptation of the original ECU, but this adaptation is gradual and underway predominantly in modes functional closed-loop control, thus in modes of low to medium of loads. Results of the experiment provide determination of the efficient frontier of the percentage extension injection time with regard to adaptive abilities of original ECU.

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577-584 T. Kotek,, M. Kotek, P. Jindra and M. Pexa
Determination of the optimal injection time for adaptation SI engine on E85 fuel using self-designed auxiliary control unit
Abstract |
Full text PDF (241 KB)

Determination of the optimal injection time for adaptation SI engine on E85 fuel using self-designed auxiliary control unit

T. Kotek¹,*, M. Kotek², P. Jindra² and M. Pexa¹

¹Czech University of Life Science Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague, Czech republic; *Correspondence: kotek@oikt.czu.cz
²Czech University of Life Science Prague, Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcká 129, CZ16521 Prague, Czech republic

Abstract:

Article deals with problems of the operation of spark ignition combustion engine on high-percentage of blend bioethanol. The aim of the experiment was to find the optimal value of injection time of the engine injection valves with respect to the adaptive ability of the original engine control unit (ECU) when using a special auxiliary control unit (ACU) was adjusted injection time. Special dynamic driving cycle has been designed to assess the effects of prolonged injection time on the adaptive abilities of the ECU that stemmed from a real recording vehicle’s rides with the same engine as was used in conducted experiments. The results proved that by changing the extension of the period of injection occurs a gradual adaptation of the original ECU, but this adaptation is gradual and underway predominantly in modes functional closed-loop control, thus in modes of low to medium of loads. Results of the experiment provide determination of the efficient frontier of the percentage extension injection time with regard to adaptive abilities of original ECU.

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585-595 M. Lukeš, M. Kotek and M. Růžička
The energy consumption of public transit under rural and suburban conditions
Abstract |
Full text PDF (739 KB)

The energy consumption of public transit under rural and suburban conditions

M. Lukeš*, M. Kotek and M. Růžička

¹Czech University of Life Sciences Prague, Faculty of Engineering, Kamýcká 129, CZ16521 Prague, Czech Republic; *Correspondence: lukesm@tf.czu.cz

Abstract:

The aim of paper is to investigate an energy consumption of public transit focused on regular commuting from suburban locations. Surveyed suburban settlements have become a part of ‘urban sprawl’ process in the suburbanized hinterland of Prague’s city. The transport links are strongly influenced by the catchment area of Prague’s city that has a dominant position in surveyed region and the most of the existing transport links are carried out in relation to the Prague’s city on radially oriented roads. The traffic intensities are often on a roads’ full capacity during peak hours or the roads are even congested alongside a ride to the city. The 10 suburban settlements were selected for the purpose of the fuel consumption investigation. Authors have focused on the journeys carried out during the morning peak hours of the ordinary working days when the transport demands are saturated. The fuel consumption investigation has involved the journeys by public transit (commuter bus) and by passenger car. Obtained results have proved possibilities of significant fuel consumption savings under condition that the bus transit preference would be effectively used. The energy efficiency of bus public transit allows to achieve the similar energy consumption per passenger as an ordinary passenger car has at a low occupancy rate of bus.

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585-595 M. Lukeš, M. Kotek and M. Růžička
The energy consumption of public transit under rural and suburban conditions
Abstract |
Full text PDF (739 KB)

The energy consumption of public transit under rural and suburban conditions

M. Lukeš*, M. Kotek and M. Růžička

¹Czech University of Life Sciences Prague, Faculty of Engineering, Kamýcká 129, CZ16521 Prague, Czech Republic; *Correspondence: lukesm@tf.czu.cz

Abstract:

The aim of paper is to investigate an energy consumption of public transit focused on regular commuting from suburban locations. Surveyed suburban settlements have become a part of ‘urban sprawl’ process in the suburbanized hinterland of Prague’s city. The transport links are strongly influenced by the catchment area of Prague’s city that has a dominant position in surveyed region and the most of the existing transport links are carried out in relation to the Prague’s city on radially oriented roads. The traffic intensities are often on a roads’ full capacity during peak hours or the roads are even congested alongside a ride to the city. The 10 suburban settlements were selected for the purpose of the fuel consumption investigation. Authors have focused on the journeys carried out during the morning peak hours of the ordinary working days when the transport demands are saturated. The fuel consumption investigation has involved the journeys by public transit (commuter bus) and by passenger car. Obtained results have proved possibilities of significant fuel consumption savings under condition that the bus transit preference would be effectively used. The energy efficiency of bus public transit allows to achieve the similar energy consumption per passenger as an ordinary passenger car has at a low occupancy rate of bus.

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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.

Key words:

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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.

Key words:

, , , ,




604-612 M. Müller, V. Šleger, M. Pexa, J. Mařík and Č. Mizera
Evaluation of stability of elastomer packing exposed to influence of various biofuels
Abstract |
Full text PDF (695 KB)

Evaluation of stability of elastomer packing exposed to influence of various biofuels

M. Müller¹, V. Šleger², M. Pexa³⋅*, J. Mařík³ and Č. Mizera²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ16521 Prague 6, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Mechanical Engineering, Kamýcká 129, CZ16521 Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague 6, Czech Republic; *Correspondence: pexa@tf.czu.cz

Abstract:

The aim of the European Union Member States is to reduce dependence on fuels derived from oil. For this reason, significant attention is paid to the use of organic products as a substitute or an additive in the fuel of petroleum origin. The usage of biofuels in conventional combustion engines is not easy due to the different properties of the products. The aim of the research was to determine the effect of biofuels on mechanical properties of O-rings type ACM (polyacrylate elastomer). The research was evaluated by the change of density, Shore A hardness, permanent deformation CS, tensile strength and deformation after exposure in the test environment for a period of 15 months. Comparing the O-rings immersed in standard diesel fuel it is clear that similar behaviour of the hardness shows are sunflower oil and canola oil. RME – Rapeseed Methyl Ester 20% and oil from Jatropha has a negative effect on the increase in hardness. Comparing the O-rings immersed in standard diesel fuel it is evident that except RME – Rapeseed Methyl Ester 20% other fuels have negative influence on permanent deformation CS.

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604-612 M. Müller, V. Šleger, M. Pexa, J. Mařík and Č. Mizera
Evaluation of stability of elastomer packing exposed to influence of various biofuels
Abstract |
Full text PDF (695 KB)

Evaluation of stability of elastomer packing exposed to influence of various biofuels

M. Müller¹, V. Šleger², M. Pexa³⋅*, J. Mařík³ and Č. Mizera²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ16521 Prague 6, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Mechanical Engineering, Kamýcká 129, CZ16521 Prague 6, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague 6, Czech Republic; *Correspondence: pexa@tf.czu.cz

Abstract:

The aim of the European Union Member States is to reduce dependence on fuels derived from oil. For this reason, significant attention is paid to the use of organic products as a substitute or an additive in the fuel of petroleum origin. The usage of biofuels in conventional combustion engines is not easy due to the different properties of the products. The aim of the research was to determine the effect of biofuels on mechanical properties of O-rings type ACM (polyacrylate elastomer). The research was evaluated by the change of density, Shore A hardness, permanent deformation CS, tensile strength and deformation after exposure in the test environment for a period of 15 months. Comparing the O-rings immersed in standard diesel fuel it is clear that similar behaviour of the hardness shows are sunflower oil and canola oil. RME – Rapeseed Methyl Ester 20% and oil from Jatropha has a negative effect on the increase in hardness. Comparing the O-rings immersed in standard diesel fuel it is evident that except RME – Rapeseed Methyl Ester 20% other fuels have negative influence on permanent deformation CS.

Key words:

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613-620 M. Pexa, J. Čedík,, J. Mařík, V. Hönig, Š. Horníčková and K. Kubín
Comparison of the operating characteristics of the internal combustion engine using rapeseed oil methyl ester and hydrogenated oil
Abstract |
Full text PDF (772 KB)

Comparison of the operating characteristics of the internal combustion engine using rapeseed oil methyl ester and hydrogenated oil

M. Pexa¹, J. Čedík¹,*, J. Mařík¹, V. Hönig², Š. Horníčková² and K. Kubín³

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague 6, Czech Republic; *Correspondence: cedikj@tf.czu.cz
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, CZ16521 Prague 6, Czech Republic
³Research Institute of Agricultural Engineering, p.r.i., Drnovská 507, CZ16101 Prague 6, Czech Republic

Abstract:

The issue of the use of alternative fuels in diesel engines is discussed in this paper. The purpose is to reduce the dependence of EU Member States on fuels of petroleum origin. One of the possibilities is the use of oils from biological materials. The use of the oil in standard engines is not usually possible. The engine modification or the fuel modification is necessary. Esterification or hydrogenation of oils can be used as the fuel modification. Impact of these changes on the operational characteristics of a turbocharged internal combustion engine is observed in the paper. The internal combustion engine of the tractor Zetor Foretrra 8641 was used for testing. This engine was burdened using a dynamometer to the PTO. Performance and fuel consumption of the engine were monitored during measurement. As fuels the 100% rapeseed methyl ester and 100% hydrogenated oil was elected. Based on the results we can say that the operating parameters of the internal combustion engine does not change significantly when using these fuels.

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613-620 M. Pexa, J. Čedík,, J. Mařík, V. Hönig, Š. Horníčková and K. Kubín
Comparison of the operating characteristics of the internal combustion engine using rapeseed oil methyl ester and hydrogenated oil
Abstract |
Full text PDF (772 KB)

Comparison of the operating characteristics of the internal combustion engine using rapeseed oil methyl ester and hydrogenated oil

M. Pexa¹, J. Čedík¹,*, J. Mařík¹, V. Hönig², Š. Horníčková² and K. Kubín³

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department for Quality and Dependability of Machines, Kamýcká 129, CZ16521 Prague 6, Czech Republic; *Correspondence: cedikj@tf.czu.cz
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, CZ16521 Prague 6, Czech Republic
³Research Institute of Agricultural Engineering, p.r.i., Drnovská 507, CZ16101 Prague 6, Czech Republic

Abstract:

The issue of the use of alternative fuels in diesel engines is discussed in this paper. The purpose is to reduce the dependence of EU Member States on fuels of petroleum origin. One of the possibilities is the use of oils from biological materials. The use of the oil in standard engines is not usually possible. The engine modification or the fuel modification is necessary. Esterification or hydrogenation of oils can be used as the fuel modification. Impact of these changes on the operational characteristics of a turbocharged internal combustion engine is observed in the paper. The internal combustion engine of the tractor Zetor Foretrra 8641 was used for testing. This engine was burdened using a dynamometer to the PTO. Performance and fuel consumption of the engine were monitored during measurement. As fuels the 100% rapeseed methyl ester and 100% hydrogenated oil was elected. Based on the results we can say that the operating parameters of the internal combustion engine does not change significantly when using these fuels.

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