Tag Archives: renewable energy

344–358 A. Brunerová, M. Brožek and M. Müller
Utilization of waste biomass from post–harvest lines in the form of briquettes for energy production
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Utilization of waste biomass from post–harvest lines in the form of briquettes for energy production

A. Brunerová*, M. Brožek and M. Müller

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Science and anufacturing Technology, Kamýcká 129, CZ165 00 Prague, Czech Republic *Correspondence:brunerova@tf.czu.cz

Abstract:

A great amount of herbal waste biomass is produced nowadays during agriculture crop processing; also during ‘post–harvest lines’ operations. Such waste biomass occurs in the bulk form, thus, is not suitable for direct combustion; it can be improved by using of briquetting technology. Therefore, present paper provides chemical, mechanical and microscopic analyses of waste biomass originating from post–harvest lines and briquettes produced from it. Namely, waste biomass originated from production of oat (Avena sativa) – husks, wheat (Triticum spp.) – husks and poppy (Papaver somniferum) – straw and seed pods and mixture of all mentioned were investigated. Unprocessed materials were subjected to microscopic and chemical analysis and subsequently produced briquette samples were subjected to determination of its mechanical quality. A satisfactory level of moisture and ash content was observed, as well as, materials energy potential; oat – 17.39 MJ kg-1, wheat – 17.04 MJ kg-1, poppy – 14.48 MJ kg-1. Also microscopic analysis proved suitability of all feedstock materials within evaluation of geometrical shapes of their particles. However, evaluation of briquette mechanical quality unsatisfactory results. Process of briquetting revealed unsuitability of oat feedstock for briquette production; other materials proved following values of volume density and mechanical durability (in sequence): wheat – 1,023.19 kg m-3, 89.1%; poppy – 1,141.43 kg m-3, 94.7%; mixture – 972.49 kg m-3, 62.7%. In general, only poppy briquettes achieved requested mechanical quality level for commercial briquette production. However, undeniable advantage of investigated materials is the form they occurred in; no further feedstock preparation (drying, crushing) was needed.

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456–467 M. Križan, K. Krištof, M. Angelovič and J. Jobbágy
The use of maize stalks for energy purposes and emissions measurement during their combustion
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The use of maize stalks for energy purposes and emissions measurement during their combustion

M. Križan, K. Krištof*, M. Angelovič and J. Jobbágy

University of Agriculture in Nitra, Faculty of Engineering, Department of Machines and Production Biosystems, Tr. A. Hlinku 2, SK949 76 Nitra, Slovakia
*Correspondence: koloman.kristof@uniag.sk

Abstract:

Biomass is an ideal renewable energy with advantages of abundance resources and neutral in greenhouse gas circulation. Majority of this energy could have been used directly in agriculture itself. The rest of the biomass for other parts of industry or even communal parts could be made available as a refined and densified biomass available for direct combustion in form of bales. The objective of the work was a monitoring of possibilities of maize cortical use for energy purposes during combustion. Emissions measurement from the combustion of maize phytomass was performed by measuring device TESTO 350 M/XL. During the combustion of packages with the moisture of 18% and 38% was monitored and the effect of moisture on the content of gas emissions of CO, CO2, NO, NO2 as well as the percentage of residual O2 in the flue gas after combustion. All values of monitored emission limits were in current normative limits defined in Collection of Laws no. 356/2010. All emissions limits are in accordance to monitored standards for CO, CO2, NO, NO2, but on the other hand it should be noted that the more favourable results are based on combustion of cortical with moisture of 18% than at 38%. The issue of maize cortical harvesting considering machinery, technological and economical viewpoint within the Slovak republic but also worldwide is poorly understood and therefore these issues should be the subject of further research.

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1101–1106 A. Mäkiranta, B. Martinkauppi and E. Hiltunen
Seabed sediment – a natural seasonal heat storage feasibility study
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Seabed sediment – a natural seasonal heat storage feasibility study

A. Mäkiranta*, B. Martinkauppi and E. Hiltunen

University of Vaasa, Faculty of Technology, Electrical Engineering and Energy Technology, P.O. Box 700, FI-65101 Vaasa, Finland
*Correspondence: anne.makiranta@uva.fi

Abstract:

The new discovery among renewable energy resources, seabed sediment, has been utilised as a heat source for 42 houses in Vaasa since 2008. Sediment heat is annually loaded by the Sun. In this study the amount of annually charged energy is estimated. The difference of sediment temperatures between the coldest and the warmest month during the year is a key value in the approximation of the loaded energy. Sediment temperatures are measured once per month via optical cable by distributed temperature sensing (DTS) method. The monitoring period is three years, 2014–2016. The estimation of incoming energy (575 MWh) versus known exploited energy (560 MWh) is reasonable. Despite of the extraction this seasonal heat storage in the seabed of the Baltic Sea seems to reload well annually.

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359–368 A. Brunerová, J. Malaťák, M. Müller, P. Valášek and H. Roubík
Tropical waste biomass potential for solid biofuels production
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Tropical waste biomass potential for solid biofuels production

A. Brunerová¹*, J. Malaťák², M. Müller¹, P. Valášek¹ and H. Roubík³

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ165 00 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 00 Prague, Czech Republic
³Czech University of Life Sciences Prague, Faculty of Tropical AgriSciences, Department of Sustainable Technologies, Kamýcká 129, CZ165 00 Prague, Czech Republic
*Correspondence: brunerova@tf.czu.cz

Abstract:

Subsequent utilization of waste biomass in developing countries occurs at poor level, despite the  act, that it has great potential in solid biofuel production. Densified waste biomass is utilized for  direct combustion, therefore, its suitability (energy potential, chemical composition) must be determined in attempt to protect environment and reduce air pollution. Main aim of present research was to determine suitability of waste biomass originating from production of rice (Oryza sativa), Date fruit (Phoenix dactylifera L.) and Jatropha fruit (Jatropha curcas) for solid biofuel production. Within a moisture, ash and volatile matter contents, major chemical elements (C, H, N, O) and net calorific value (NCV) were determined. Rice waste analysis proved low NCV (14.33 MJ kg–1) and high ash content (20.74%), which presented problems during combustion. Jatropha fruit waste (cake) analyses exhibited outstanding NCV (24.44 MJ kg–1) caused by residual oil content. Within major elements analysis a low content of oxygen (26.61%) was proved (recommended). Date fruit waste exhibited average NCV (16.40 MJ kg–1). However, high oxygen content (44.01%) was defined as limiting factor. Overall evaluation proved greatest suitability for Jatropha fruit waste (cake), followed by Date fruit waste and lowest potential was determined for Rice waste. However, investigated plants are not cultivated for energy production purposes, thus, observed results achieved satisfactory level of their suitability for solid biofuel production.

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322–328 M. Bloch-Michalik and M. Gaworski
Agricultural vs forest biomass: production efficiency and future trends in Polish conditions
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Agricultural vs forest biomass: production efficiency and future trends in Polish conditions

M. Bloch-Michalik* and M. Gaworski

Department of Production Management and Engineering, Warsaw University of Life Sciences, PL02-787 Warsaw, Nowoursynowska str. 164, Poland
*Correspondence: marta_michalik@sggw.pl

Abstract:

Biomass is one of the main sources of renewable energy with rapidly growing trend in the European Union countries. The technical potential of biomass energy in Poland is one of the highest in Europe, estimated at approximately 900 PJ/year. Solid biomass is the primary Polish RES and the share in the structure of production in Poland amounted to almost 77% in 2015. The most common types of biomass are waste raw materials from crop fields and forests.
The paper presents current potential of the biomass of two basic types, i.e. agricultural and forest material, based on the analyses developed with the scenario forecast of future use in Poland. Detailed considerations include differences in efficiency of agricultural and forest biomass production. To develop the efficiency aspects some indices were proposed to compare potential of energy production basing on different kind of biological material.

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1720-1729 T. Vaimann, A. Rassõlkin, A. Kallaste and M. Märss
Feasibility study of a local power supply system for sparsely populated areas in Estonia
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Feasibility study of a local power supply system for sparsely populated areas in Estonia

T. Vaimann¹²*, A. Rassõlkin¹, A. Kallaste¹² and M. Märss¹³

¹Tallinn University of Technology, Faculty of Power Engineering, Department of Electrical Engineering, Ehitajate tee 5, EE19086 Tallinn, Estonia
²Aalto University, School of Electrical Engineering, Department of Electrical Engineering and Automation, PO Box 13000, FI00076 Aalto, Finland
³Estonian University of Life Sciences, Institute of Technology, Department of Energy Engineering, Fr.R. Kreutzwaldi 56/1, EE51014 Tartu, Estonia
*Correspondence: toomas.vaimann@ttu.ee

Abstract:

The paper analyzes the reasonability of using an off-grid hybrid power supply system or in other words a local grid for sparsely populated areas as well as the necessary components selection and price development of such system. Typical consumers are selected and all estimations and calculations are based on them. Consumer profiles are set and analyzed as well as different elements of the local power supply grid and the possibility of connecting to the traditional grid. Estonian example is used in this paper as the country lies relatively north and has some remote areas, where local power supply grids can be implemented. All prices in the paper are derived from the Estonian example. Necessity of further study is proposed.

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1191–1199 A. Mäkiranta, J.B. Martinkauppi and E. Hiltunen
Correlation between temperatures of air, heat carrier liquid and seabed sediment in renewable low energy network
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Correlation between temperatures of air, heat carrier liquid and seabed sediment in renewable low energy network

A. Mäkiranta*, J.B. Martinkauppi and E. Hiltunen

University of Vaasa, Faculty of Technology, Electrical Engineering and Energy Technology, P.O. Box 700, FI-65101 Vaasa, Finland
*Correspondence: anne.makiranta@uva.fi

Abstract:

The low energy network based on renewable seabed sediment heat has been monitored for several years in Vaasa, Finland. In this study the temperatures of air, heat carrier fluid and seabed sediment are compared to each other and correlations between them are investigated. In this study data from one year 2014, was used. Correlations between these subjects clearly exist. The sizing of installed network seems to be correct; no overuse was detected.

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650–660 A. Ayhan
Biogas potential from animal waste of Marmara Region-Turkey
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Biogas potential from animal waste of Marmara Region-Turkey

A. Ayhan

University of Uludag, Faculty of Agriculture, Department of Biosystems Engineering,
TR16059, Nilüfer, Bursa, Turkey; e-mail: aayhan@uludag.edu.tr

Abstract:

The purpose of this study was to determine the biogas production capacity from animal wastes in Marmara region of Turkey for the years 2005–2014. The wastes from the cattle and hen in the region were considered the resource for biogas production taking the number of animals and the collectability of the wastes into the account. Three scenarios were evaluated to estimate the biogas capacity by assuming that 100% (theoretical potential), 50%, and 25% of the total animal waste could be used for biogas production in the region. For theoretical biogas production from cattle wastes, the greatest potential in the year 2014 was calculated for Balıkesir province with 145.53 Mm3, followed by Çanakkale, Bursa, Sakarya, and other seven provinces. Balıkesir had the highest biogas potential in 2014 from the poultry waste, too, followed by Sakarya, Kocaeli, Bursa, and other seven provinces. Biogas potential (100%) of Marmara region increased by 15% from 2005 to 2014 with 1,242.17 Mm3 in 2014. The heat and electrical energy equivalents of the biogas were found to be 7,453.02 GWh and 2,608.56 GWhe, respectively. In the other two scenarios, depending on the utilization rate of theoretical biogas potential: biogas amount, heat and electric power values were determined proportionally.

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327–336 A. Brunerová, J. Pecen, M. Brožek and T. Ivanova
Mechanical durability of briquettes from digestate in different storage conditions
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Mechanical durability of briquettes from digestate in different storage conditions

A. Brunerová¹*, J. Pecen², M. Brožek¹ and T. Ivanova²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Material Science and Manufacturing Technology, Kamýcká 129, CZ 165 00 Prague,
Czech Republic
²Czech University of Life Sciences Prague, Faculty of Tropical AgriSciences,
Department of Sustainable Technologies, Kamýcká 129, CZ 165 00 Prague,
Czech Republic
*Correspondence: brunerova@tf.czu.cz

Abstract:

A present research was conducted to determine mechanical durability of digestate briquettes and potential influence of different storage condition. Experiments were performed on briquette samples produced from digestate feedstock with moisture content of 8.2%, ash content of 10.9% and gross calorific value of 17.15 MJ kg-1 by hydraulic piston press with working pressure of 18 MPa with external diameter 50 mm and length 40–60 mm. Briquette samples were divided into two groups and stored inside and outside building. Both groups were subjected to five experimental testing during specific time period from May until late November 2014. Mechanical durability of each briquette was measured after every testing, subsequently overall mechanical durability of specific groups was calculated. Results showed the lowest mechanical durability after first measurement: 98.85% for Group 1 and 98.95% for Group 2. The biggest change in mechanical durability was observed between first and second testing, values of following measurements were approximately equal. The highest mechanical durability was achieved after fifth testing: 99.65% for Group 1 and 99.63% for Group 2. It implied mechanical durability equal to 99.44% for Group 1 and 99.45% for Group 2 in average. Research proved very high mechanical durability which corresponds to the highest category of this quality indicator given by standard EN ISO 17225-1. Difference between mechanical durability of groups stored in different conditions was considered as minor. Thereby briquettes made from digestate are not only secondary product of proper waste management, effectively modified fertilizer but as was found by results of this research it is also suitable fuel with outstanding mechanical properties.

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999-1006 M. Repele, A.Paturska, K. Valters and G. Bazbauers
Life cycle assessment of bio-methane supply system based on natural gas infrastructure
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Life cycle assessment of bio-methane supply system based on natural gas infrastructure

M. Repele*, A.Paturska, K. Valters and G. Bazbauers

Institute of Energy Systems and Environment, Riga Technical University, Kronvalda Boulevard 1, Riga, LV1010, Latvia; *Correspondence: mara.repele@rtu.lv

Abstract:

Many sites for biogas production in Latvia currently do not have sufficient heat load to provide power production in co-generation mode. The alternative to relatively inefficient power production could be production of bio-methane which is known as one of the most important renewable option for gas supplies. After removal of contaminants bio-methane is of quality of natural gas and can be delivered to power plants and industry using the natural gas supply infrastructure. For analysis of environmental benefit of using bio-methane the environmental impact of the proposed solution has to be assessed. The aim of the study is to make life cycle assessment of the system for bio-methane supply to industrial plant via the natural gas grid. The analysed system includes bio-methane production and transport to the natural gas pipeline including the infrastructure. Functional unit was 1 MWh of bio-methane energy injected into the natural gas transmission pipeline. Life-cycle model was created and analysed with software ‘SimaPro’. ReCiPe and Eco-Indicator’99 were used as characterization methods to analyse the life-cycle environmental impacts. Results show the influence and contribution level expressed in mid-point categories as well as in a single-score indicator. The largest impact is created by use of fossil energy sources in production of bio-methane. The results can be used to design renewable energy supply systems and for the comparison of alternatives.

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