Tag Archives: ash content.

2229-2241 I. Vitázek, R. Majdan and M. Mojžiš
Volatile combustible release in biofuels
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Volatile combustible release in biofuels

I. Vitázek*, R. Majdan and M. Mojžiš

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:

Plant biomass consists of varied materials. Biomass is used for different purposes, but it is most frequently burnt in modern combustion devices for heat production. The quality of solid biofuels depends on the total content of combustibles while the volatile combustible content affects the combustion process. The aim of the paper is to determine the exact content of the biofuel components by the means of the gravimetric method – namely volatile combustible, ash and moisture content – and to evaluate the process of volatile combustible release as a function of temperature during the experiment. The device Nabertherm L9/11/SW/P330 type with accessory was used to carry out the experiments. Various biofuel samples were examined, namely wood (9 kinds), wood cuttings and wood chips (2 kinds), pellets (4 kinds), sawdust (1 kind), compared to less traditional fuels (DDGS and RME – 2 kinds) and wood coal (1 kind). The tables and graphs present the experimental results, which allow evaluation of the components content in different biofuels and provide characteristics of the process of volatile combustible release in analysed fuels. Spruce wood without bark showed the highest content of combustible (99.89%). Sawdust of fruit trees contains the highest proportion of volatile combustible (93.978%) and releases the combustible at the highest rate (15.25 mg h-1).

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2146-2155 E. Pannacci and S. Bartolini
Effect of nitrogen fertilization on sorghum for biomass production
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Effect of nitrogen fertilization on sorghum for biomass production

E. Pannacci* and S. Bartolini

University of Perugia, Department of Agricultural, Food and Environmental Sciences, Borgo XX Giugno, 74, IT06121 Perugia, Italy
*Correspondence: euro.pannacci@unipg.it

Abstract:

Two field experiments were carried out in 2005 and 2006 in central Italy in order to evaluate the effects of different nitrogen (N) application rates (0, 50 100 and 150 kg ha-1) on flowering date, plant height, biomass production and partitioning (leaves, panicles and stems) and biomass quality of a sorghum hybrid (H133). Sorghum showed a high potential in terms of biomass production without N fertilization (18.5 t ha-1 of d.m. in 2005 and 26.6 t ha-1 of d.m. in 2006). The rate that maximized the biomass production was 100 kg ha-1 of N, increasing the biomass dry weight by 23.8% in 2005 and 18.8% in 2006, with respect to unfertilized sorghum; higher N rates are not advisable in order to avoid increasing fertilization costs and environmental impact without benefit of greater biomass production. The two highest N rates when combined with low water availability appeared to increase the rate of plant development, causing earlier flowering and increasing the percentage of panicles in total biomass. Higher heating value (HHV), lower heating value (LHV) and ash concentration of biomass varied among N rates, with values of HHV and LHV lower for unfertilized sorghum (17.6 and 16.7 MJ kg-1 d.m., respectively) than when N was applied (from 19.0 to 19.7 and from 18.1 to 18.8 MJ kg-1 d.m., respectively); on the contrary, ash concentration was greater for unfertilized sorghum (7.5% d.m.) than for fertilized sorghum (from 5.8 to 6.7% d.m.). This research showed the high potential of sorghum in terms of biomass production also when cultivated with limited irrigation and fertilization inputs. The biomass dry yield obtained by one hectare of sorghum crop without N nitrogen fertilization (i.e. 22.6 t ha-1 of d.m., average of 2005 and 2006 values) produces the same energy, by thermal utilisation, of 9.3 toe, that is equivalent to energy produced by 10,385 L of diesel fuel or 11,097 m3 of methane fuel. This aspect increases the certainty of the energetic and environmental sustainability of sorghum crop.

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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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259–268 D. Streikus, A. Jasinskas, M. Arak, E. Jotautienė1, R. Mieldažys, S. Čekanauskas and Z. Jankauskienė
Investigations of fibre plants preparation and utilization of solid biofuels
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Investigations of fibre plants preparation and utilization of solid biofuels

D. Streikus¹, A. Jasinskas¹*, M. Arak², E. Jotautienė1, R. Mieldažys¹, S. Čekanauskas³ and Z. Jankauskienė⁴

¹Aleksandras Stulginskis University, Faculty of Agricultural Engineering, Institute of
Agricultural Engineering and Safety, Kaunas-Akademija, Studentu str. 15A, LT-53361
Kaunas r., Lithuania
²Estonian University of Life Sciences, Institute of Technology, Fr.R. Kreutzwaldi 56,
EE51014 Tartu, Estonia
³Aleksandras Stulginskis University, Experimental Station, Kaunas-Akademija,
LT-53361 Kaunas r., Lithuania
⁴Lithuanian Research Centre for Agriculture and Forestry, Upyte Experimental Station,
Linininku str. 3, Upyte, LT-38294 Panevezys r., Lithuania
*Correspondence: algirdas.jasinskas@asu.lt

Abstract:

Presented research results of technological-technical means and operations for solid biofuel preparation: chopping, milling, pelleting and burning of fibre plants – 3 sorts of fibre hemp (Beniko, Bialobrzeskie and Epsilon 68) and fibre nettle (sown in 60 x 60 cm). These fibre plants were grown in the experimental fields of Lithuanian Research Centre for Agriculture and Forestry, Upytė Experimental Station, and in Aleksandras Stulginskis University were investigated the technical means of these plants preparation and usage for energy purposes. It was used the standard methodology for solid biofuel preparation of fibre plants, and was investigated the technique for plant chopping, milling and pelleting. There were determined fibre plant mill fractional composition while usage the hummer miller prepared mill. There were determined the fibre plant pellet quality indicators – moisture content and bulk density. The fibre plant pellet moisture content ranged from 6.4% to 8.8%, and pellet density reached 1,082.7–1,186.2 kg m-3 DM (dry matter). Pellet elemental composition, ash content and calorific value were determined at the Lithuanian Energy Institute. The ash content after the burning of fibre plant pellet was not high and varied from 3.6 to 5.9%. Determined net calorific value of fibre hemp and fibre nettle dry mass was relatively high 17.2–17.5 MJ kg-1, it was close to calorific value of some wood species.

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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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