Tag Archives: biomass

474-482 M. Križan, K. Krištof, M. Angelovič, J. Jobbágy and O. Urbanovičová
Energy potential of densified biomass from maize straw in form of pellets and briquettes
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Energy potential of densified biomass from maize straw in form of pellets and briquettes

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

University of Agriculture in Nitra, Faculty of Engineering, Department of Machines and Production Biosystems, Tr. A. Hlinku 2, SK94976 Nitra, Slovakia
*Correspondence: koloman.kristof@uniag.sk

Abstract:

The aim of the study was the evaluation and comparison of energy potential of briquettes and pellets produced from the maize straw and woody biomass based on various diameters of pellets. By experimental measurements a calorific value and ash content was observed. Calorific value was measured by laboratory calorimeter IKA C 6000 (IKA® Works, Inc., USA) and laboratory combustion chamber Lindberg/Blue M (Thermo Fisher Scientific, Inc., USA). Individual calorific values and ash content was observed and subsequently confronted to obtain differences with replication. The analysis showed that calorific value of pellets with diameter 6 mm ranged from 16.99 MJ kg-1 to 17.80 MJ kg-1. Calorific value of pellets with 8 mm diameter ranged from 16.63 MJ kg-1 to 17.20 MJ kg-1. However, compared calorific value of briquettes ranged from 14.99 MJ kg-1 to 15.66 MJ kg-1. Further analysis showed that ash content of samples varied as well and it’s even affected by diameter of pellets. While ash content of pellets with diameter 6 mm was observed as 4.9% of total volume in case of pellets with 8 mm it was observed at value 5.5%. Briquettes produced from maize straw have ash content at value 5.4%. In contrary, ash content of woody biomass was significantly higher, 11% of volume, specifically. At the basis of observed parameters it can be concluded that maize straw densified in form of briquettes and pellets have a great energy potential which is comparable and competitive with currently used materials for production of briquettes and pellets.

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593-603 I. Vitázek, J. Tulík and J. Klúčik
Combustible in selected biofuels
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Combustible in selected biofuels

I. Vitázek*, J. Tulík and J. Klúčik

Slovak University of Agriculture in Nitra, Faculty of Engineering, Department of Transport and Handling, Tr.A. Hlinku 2, SK949 76 Nitra, Slovak Republic
*Correspondence: ivan.vitazek@uniag.sk

Abstract:

The aim of the research was to determine the moisture, combustible and ash content in selected biofuels, in dependence on temperature by the means of gravimetric method. For this purpose, the furnace Nabertherm L9/11/SW/P330 was used. Analyzed samples consisted of crushed biomass which is used in small heat sources (e.g. spruce wood, cherry wood, apple wood, black locust wood) with bark and without additives. Biomass for larger heat sources (woodchips cuttings from coniferous trees), sawdust mix (plum, cherry, walnut, apricot, apple) and pellets (90% spruce and 10% fir) were also analyzed. The results are processed graphically and enable to characterize the tested fuels. The highest content of combustible was found in spruce wood sample without bark (99.889%), the lowest content of combustible indicated cuttings from coniferous trees (88.402%). Gravimetric experiments were supplemented by DSC measurement of selected samples on calorimeter Toledo DSC822e. The graphic courses of reactions are provided up to 500 °C.

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

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

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

Abstract:

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

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1956–1970 M.A. Luna-delRisco,, K. Orupõld, I. Diaz-Forero and M. González-Palacio
Influence of chemical composition on the biochemical methane potential of agro-industrial substrates from Estonia
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Influence of chemical composition on the biochemical methane potential of agro-industrial substrates from Estonia

M.A. Luna-delRisco¹,*, K. Orupõld², I. Diaz-Forero³ and M. González-Palacio¹

¹ Universidad de Medellin, Faculty of Engineering, Energy Engineering,
Carrera 87 # 30 – 65, P.O. 050026 Medellin, Colombia
² Estonian University of Life Sciences, Faculty of Agricultural and Environmental
Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia
³ Servicio Nacional de Aprendizaje – SENA, Center for Design and Manufacture of
Leather, BIOMATIC Research Group, Calle 63 # 58B – 03, P.O. 055413 Itagüí,
Colombia
*Correspondence: mluna@udem.edu.co

Abstract:

Batch trials were carried out to evaluate the Biochemical Methane Potential (BMP) of 61 different substrates collected from agricultural farms and industrial sites in Estonia. Tests were performed in 500 mL plasma bottles at 36°C. The highest methane yield from all tested substrates was obtained from unconsumed dairy products (557 ± 101 L kg-1 VS) while the lowest was obtained from animal slurries (238 L kg-1 VS ± 42). From tested energy crops, foxtail millet achieved the highest methane yield (320 L kg-1 VS). Silages from different crops presented methane yields from 296 ± 31 L CH4 kg-1 VS to 319 ± 19 L CH4 kg-1 VS. The influence of chemical composition and kinetic rate constants (k) on methane potential was analyzed. Anaerobic digestibility of selected agro-industrial substrates was markedly influenced by their organic content, i.e. total proteins and lignin concentrations. Rate constants were found to correlate negatively with hemicellulose, cellulose and lignin (p < 0.05). Results from this study suggest that an appropriate characterization of the chemical composition of the substrates is important not only for predicting BMP and the kinetics rates, but also for identifying possible inhibitors during the anaerobic digestion process. Results on the BMP and national availability of studied substrates indicate that herbal biomass and agro-industrial residues are promising substrates for biogas production in agricultural biogas facilities in Estonia.

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

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

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

Abstract:

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

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848–858 V. Rooni, M. Raud and T. Kikas
Technical solutions used in different pretreatments of lignocellulosic biomass: a review
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Technical solutions used in different pretreatments of lignocellulosic biomass: a review

V. Rooni, M. Raud and T. Kikas*

Estonian University of Life Sciences, Institute of Technology, 56 Kreutzwaldi Str., EE 51014 Tartu, Estonia
*Correspondence: timo.kikas@emu.ee

Abstract:

Bioethanol production from lignocellulosic biomass has attracted a lot of attention as one of the most promising alternative to liquid fossil fuels. Over the last decades a lot of research has been done to find the optimal methods & devices to produce bioethanol from all kind of lignocellulosic biomass. A traditional three-step production process is used to produce bioethanol from lignocellulosic biomass – pretreatment, enzymatic hydrolysis, & fermentation. Today, the high cost of the pretreatment prevents bioethanol from competing with petrol. In this review article, the positive & negative aspects of different pretreatment methods & patented devices are investigated & analysed. Based on the analysis several options on how to lower lignocellulosic biomass pretreatment costs & how to increase the competitiveness of bioethanol are proposed.

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1674–1685 J. Maga and K. Krištof
Effect of drill machine operating speed on quality of sowing and biomass yield
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Effect of drill machine operating speed on quality of sowing and biomass yield

J. Maga and K. Krištof*

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:

The paper is focused on the study and evaluation of quality of the seeding of seeds and its effect on the biomass yield. The aim was to evaluate the space arrangement of the seeds by using of polygon method on one field with the repetition for different forward speeds of the drill machine. For the evaluation there were used digital photographs, which were taken during repeated measurements of the each value of the forward speed after sprouting of crop. These images have been used in order to determine the shape and size of the surface area belonging to the plant. Own software TfPolyM was used for the image analysis. The shape of the polygons belonging to the individual plants was expressed by values of the shape factor Tf. This factor characterises the suitability the shape of polygon surface related to the individual plant. By comparing of the values of the shape factors for different forward speeds of the drill machine we can determine the optimal value of the forward speed from the point of seed placement uniformity in horizontal level. During harvest of the crop there was analysed the variability of the biomass yield in relation to values of the forward speed used during seeding. The most suitable values of shape factor Tf (0.8519) was recorded for speed of drill machine set on 12 km h-1. For other tested speeds 8, 10, 15 km h-1 were recorded lower values of shape factor 0.7994, 0.8173 and 0.8449, respectively. In determination of biomass production for drill machine speed 12 km h-1 the greatest yield from 1 m2 was observed. Subsequently, for speeds 8 and 10 km h-1 was lower about 4.26% and 1.83%, respectively. For tested speeds of drill machinery 15 km h-1 and above was observed only a small descent of yields about 0.6%. Fluctuation in yields affected by working speed then demonstrates fluctuation in sowing rate. It was also observed that the working speed of sowing machinery also affect the amount of yield directly. However, in case of lowest yield of straw recorded it was observed even 20% decrease in yield of grains.

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725–732 D. Černý, J. Malaťák and J. Bradna
Influence of biofuel moisture content on combustion and emission characteristics of stove
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Influence of biofuel moisture content on combustion and emission characteristics of stove

D. Černý*, J. Malaťák and J. Bradna

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague, Czech Republic
*Correspondence: david.cerny@dotacenazeleno.cz

Abstract:

 The research aim was to study the effect of moisture in solid fuel on combustion in a stove and its emissions. Analysed samples were from spruce woodchips. Four samples were prepared with different moisture contents and furthermore spruce wood was used as a reference sample. Combustion device used was a stove with a fixed fire grate. Studied parameters were ambient temperature, temperature of flue gases, coefficient of excess air, and contents of oxygen and carbon monoxide in flue gases. Laboratory measurement was performed on an analyser of flue gases whose function is based on electro-chemical converters. Measured values were first converted to a referential oxygen content in flue gases. Evaluation of these values was then made by regression analyses. The course of combustion process and its quality can be seen well in functional dependence of carbon monoxide on excess air coefficient. The area of combustion was the smallest with the least moist sample (3.2%) and increases with increasing moisture. A sample with high moisture (31.1%) was already causing the fire to gradually extinguish. Because flue gas temperature is in the same range for all samples, the overall efficiency of the stove decreases sharply with fuel moisture due to specific heat of flue gases. It has been thus confirmed that fuel moisture content has a substantial influence on combustion, especially in the chosen combustion device, which has been verified by comparison with the reference fuel.

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641–649 A. Adamovics, S. Ivanovs and V. Stramkale
Investigations about the impact of norms of the fertilisers and cultivars upon the crop capacity biomass of industrial hemp
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Investigations about the impact of norms of the fertilisers and cultivars upon the crop capacity biomass of industrial hemp

A. Adamovics, S. Ivanovs* and V. Stramkale

Latvia University of Agriculture, Liela iela 2, LV 3001 Jelgava, Latvia
*Correspondence: semjons@apollo.lv

Abstract:

Field trials were carried out in 2012–2014, on the Research and Study Farm ‘Pēterlauki’ of the Latvia University of Agriculture. Eleven sorts of industrial hemp (Cannabis sativa L.) – ‘Bialobrzeskie’, ‘Futura 75’, ‘Fedora 17’, ‘Santhica 27’, ‘Beniko’, ‘Ferimon’, ‘Felina 32’, ‘Epsilon 68’, ‘Tygra’, ‘Wojko’ and ‘Uso 31’ were sown in a sod calcareous soil (pHKCl 6.7, P 52 mg kg-1, K 128 mg kg-1, the organic matter content 21–25 g kg-1). The total seeding rate was 50 kg ha-1. The plots were fertilised as follows: N-120, P2O5– 90, K2O- 150 kg ha-1. Hemp was sown in the middle of May, in 10 m2 plots, triplicate. Hemp was harvested when the first matured seeds appeared. The biometrical indices, the height and stem diameter, the harvesting time, the amount of fresh and dry biomass and the fibre content were evaluated.
Yield of dry matter on average comprised 15.06 t ha-1, depending on the cultivars. Cultivation year and cultivar notably affected hemp biomass yield. In 2012, the highest yield of dry biomass was produced from cultivars ‘Futura 75’ (21.33 t ha-1) and ‘Tygra’ (20.87 t ha-1), the lowest – from ‘Bialobrzeskie’ (11.95 t ha-1). Significantly higher average yield of dry biomass was obtained from cultivars ‘Futura 75’ (17.76 t ha-1), ‘Tygra’ (16.31 t ha-1), ‘Wojko’ (15.51 t ha-1) and ‘Epsilon 68’ (15.28 t ha-1), the lowest – ‘Bialobrzeskie’ and ‘Uso 31’ (13.53 t ha-1). Meteorological conditions influenced the dry biomass yield.
The aim of this study was find productive cultivar of industrial hemp (Cannabis sativa L.) and clarify nitrogen fertiliser rates impact for biomass production in Latvia.

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525–532, J. Malaták, J. Bradna and J. Velebil
Combustion of briquettes from oversize fraction of compost from wood waste and other biomass residues
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Combustion of briquettes from oversize fraction of compost from wood waste and other biomass residues

J. Malaták*, J. Bradna and J. Velebil

Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague, Czech Republic
*Correspondence: malatak@tf.czu.cz

Abstract:

This article aims to determine experimentally the energy potential of samples from oversize compost fraction formed into briquettes. Theoretical combustion characteristics of the briquettes are determined and are compared with a reference fuel. Elemental analysis and stoichiometric calculations were performed for the samples. Classical grate combustion device with manual fuel supply was chosen for combustion tests. Flue gas temperature and emission parameters, such as the emission levels of carbon monoxide, carbon dioxide and nitrogen oxides, were monitored by a multi-purpose flue gas analyzer Madur GA-60. Dependence of these parameters on air input was followed.
Elemental analyses and stoichiometric calculations of individual samples indicate favourable properties of the energy compost for further energy utilisation, namely the gross calorific value of 16.42 MJ kg-1. Excess air was causing high losses through heat of the flue gas during the experiments on combustion device. This fact occurred in a situation when the temperature of flue gas leaving the chimney reached high levels. The excess air coefficient also significantly influenced emissions of carbon dioxide and monoxide and nitrogen oxides in the flue gas. The trends are analysed statistically and are expressed by regression equations. The results can serve in practice for optimization of combustion processes in grate boilers with manual feed of the fuel.

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