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Reed canary grass transportation costs – Reducing costs and increasing feasible transportation distances
biomass and bioenergy 33 (2009) 209–212
Available at www.sciencedirect.com
http://www.elsevier.com/locate/biombioe
Reed canary grass transportation costs – Reducing costs and increasing feasible transportation distances T. Lindha,*, T. Paappanena, S. Rinneb, K. Sivonena, M. Wihersaaric a
VTT, Technical Research Centre of Finland, P.O. Box 1603, FIN-40101 Jyva¨skyla¨, Finland YTY-konsultointi Oy, Teljintie 4, FIN-40530 Jyva¨skyla¨, Finland c University of Jyva¨skyla¨, P.O. Box 36, FIN-40014 Jyva¨skyla¨n yliopisto, Finland b
article info
abstract
Article history:
Reed canary grass is used in several heat and power plants in Finland and it is estimated
Received 3 August 2007
that about 70–80 plants could utilise reed canary grass as a co-firing fuel. Long-distance
Received in revised form
transport of reed canary grass forms a significant share of the production and delivery
21 May 2008
costs. Reed canary grass can be transported in bales or as loose matter. The density of the
Accepted 28 May 2008
matter and shape of the bales influence the load-size and the cost. At present it is
Published online 25 October 2008
impossible to obtain the full load-bearing capacity of a lorry even with bales, and with light bulk matter the obtainable load is less than one-third of the load-bearing capacity of
Keywords:
a lorry. By using Orkel local-baler it has been possible to obtain the largest load-sizes, but
Bioenergy
the total economy of the chain is not very good because the baling and chopping of bales
Energy crops
increase the total costs. If a full load-bearing capacity of a lorry (30–40 tonne) would be
Reed canary grass
obtained, the transportation costs would be reduced significantly compared to the present
Phalaris arundinacea
situation. Second alternative would be to mix reed canary grass with wood chips or peat
Transportation costs
before long-distance transport. At the moment feasible transportation distances are
Finland
relatively short. With briquettes the cargo space could be used more efficiently and the
Load-size
load-size of the transport could be increased. ª 2008 Elsevier Ltd. All rights reserved.
1.
Introduction
Reed canary grass (Phalaris arundinacea) is a perennial grass that naturally grows in Finland. Typical crop is 4.5–8 tonne dry solid ha1 which is about 22–38 MWh ha1 [1]. Cultivation of reed canary grass is growing rapidly in Finland because it is increasingly utilised as a solid fuel in heat and power plants. Because of its CO2 neutrality it is an attractive alternative for power plants under CO2 quota regulations. The cultivation area of reed canary grass in 2007 was estimated to be about 200 km2 (20 000 ha) which was 1% of the total cultivation area in Finland. The Ministry of Agriculture and Forestry has estimated that the area of reed canary grass could be 1000 km2
(100 000 ha, 2 TWh) in 2015. At present more than 20 plants have some experience in utilisation of reed canary grass. It is estimated that about 70–80 heat and power plants in Finland could utilise reed canary grass as a co-firing fuel [2]. In Finland co-firing usually means the addition of biomass to a peat fired unit [3,4]. Reed canary grass is co-combusted with fuels like peat, bark, sawdust and forest chips. Typical moisture content of these fuels is about 50% on total weight basis and boilers in power plants are designed for fuels with that moisture content. Moisture content of reed canary grass is much lower (15–25%). In terms of energy the maximum annual share of reed canary grass has nowadays been only about 1% of the
* Corresponding author. E-mail address: [email protected] (T. Lindh). 0961-9534/$ – see front matter ª 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biombioe.2008.05.019
210
biomass and bioenergy 33 (2009) 209–212
– Straw harvesting studies in 1995 and 1999 – Reed canary grass studies 1995–1997 and 2001–2005 – The development of reed canary grass fuel chain 2006–2008
30,00
Total costs, € MWh-1
total annual fuel energy input at power plants. The highest momentary shares have been around 15% of the total fuel energy (20–30% in volume). The most critical limiting factor at the plant is normally the fuel conveyor and feeding capacity which are designed for much energy denser fuels. The energy content of reed canary grass chop is only 0.3 MWh m3 while it is 0.6–1.1 MWh m3 for wood and peat. The production chain of reed canary grass needs further development in order to become more cost-efficient. Harvesting losses are high, at its best 20–40%, and 50–60% at the highest. Due to the low bulk density of the reed canary grass the transport is uneconomical, especially in the chopped form. The efficiency of the transport of bales as cylindrical bales, which is the most common form of bales, is also relatively low. The prevailing agricultural choppers and industrial crushers of power plants are in most cases unsuitable for chopping of bales for fuel purposes. In plant processing the light and straw-like chopped reed canary grass can cause problems. In most plants the reed canary grass can be applied for mixed combustion with peat and wood chips. This, however, requires proper mixing of the fuels either at the loading stage or at the reception and processing stage of the plant. Loose harvesting produces shorter reed canary grass chaff than when shredding bales. Shorter chaffs are easier to mix with other fuels and the flow in the power plants’ equipments is better. But storing loose chaff takes significantly more space than storing bales. Stored reed canary grass must be covered very well especially if it is in loose form. In Denmark fixed roofed central storehouses are used for storing straw. This kind of fuel terminals could be one way of storing reed canary grass bales in Finland. There have been several studies concerning reed canary grass production chain and costs in different stages of the production chain at the VTT [5–8].
2.
Production costs
The production costs of reed canary grass can be divided into five cost factors: productive value of the field, foundation of the growth, annual fertilisation, harvesting and storage, longdistance transport to users and chopping. The costs of each production stage consist of investments made in machinery and work costs. Long-distance transport of reed canary grass forms a significant share of the production and delivery costs (Fig. 1). Transportation costs will be discussed more accurately in Section 3. There is no significant difference between the production costs of loose harvesting and baling methods. The balers commonly employed are not equipped with chopping unit.
20,00 15,00 10,00 5,00 0,00 Bales, mobile crusher
Bales, plant crusher
Loose
Chopping of bales
Ann.fertilization
Long dist. transport
Cultivation
Harvesting
Land value
Fig. 1 – Costs (V MWhL1) in different stages of production chain of reed canary grass. The crop yield used in these calculations is 6 tonne dry solid haL1 in a year and transport distance is 70 km.
Hence shredding and chopping of bales must be carried out, for example, at a power plant [9].
3.
Transportation costs
There are several factors which influence the price of the reed canary grass transport. Load-size of a lorry is an important factor influencing the costs of transportation. Reed canary grass can be transported in bales or as bulk matter. The density of the matter and shape of the bales influence the load-size and the cost. In Finland transport equipment of peat can be used for transport of loose matter and logging residue trucks for transport of bales.
3.1. Most of these studies have been carried out with other research facilities and companies. This article combines some of the results of these studies.
25,00
Load-sizes
At present it is impossible to obtain the full load-bearing capacity of a lorry even with bales, and with light bulk matter the obtainable load is less than one-third of the load-bearing capacity of a lorry. In Finland useful load of a lorry can be up to 40 tonne. Common load volume of a peat lorry is about 120– 150 m3 which is about 107 MWh of peat. VTT investigated load-sizes by inquiring transportation entrepreneurs and by comparing the results with the theoretical calculations. The amounts of reed canary grass, loadable into a lorry, were calculated on the basis of the results (Table 1). Obtaining of these load-sizes requires that loading succeeds optimally, and that the density of bales is good. Load-size and transport distance have an effect on transportation costs (Fig. 2). By using Orkel-local-baler (chop-bales in Fig. 2) it has been possible to obtain largest load-sizes, but the total economy of the chain is not very high because the baling costs increase the total costs. If the full load-bearing capacity of a lorry (30–40 tonne, 35 tonne in Fig. 2) would be obtained, the transportation costs would be reduced significantly compared
211
biomass and bioenergy 33 (2009) 209–212
Table 1 – Amount of reed canary grass in lorry transports. Bale volume (m3)
Total mass (tonne)
Energy (MWh)
60–64 48–52 60–66
150 81.4–86.9 101.8–110.3 121–133.1
10.5 14.7 18.3 21.8
40 56 70 82
44–50
114–129.6
20.5
77
98
101.8
28.5
108
Bales
Bulk matter Cylindrical bales 1.2 m Cylindrical bales 1.5 m Large cubical bales 1.2 0.7 2.4 m Large cubical bales 1.2 0.9 2.4 m Local-balersa
a Bales made by Orkel local-baler of precision-chopped reed canary grass [10].
to the present situation. The energy content of a full load would be even higher than that of peat and wood chips. The easiest way to reduce the transportation costs and simultaneously the total costs is to use a large cubical baling press which makes it possible to produce loads of as high mass and volume as possible. By cylindrical bales of certain size the cargo space can remain incomplete, because it is not possible to make over-high loads. It is possible to increase the density of loads up to a certain limit only by using a baler of the right type. In theory one alternative would be to make loose, but still compact small briquettes. The construction of briquettes would correspond to the construction of peat and wood chips, and simultaneously the problems of power plant processing of the fuels would be eliminated. Theoretically, the briquette production would be profitable, but there would be problems in obtaining briquette manufacture of sufficient capacity. Second alternative would be to mix reed canary grass with wood chips or peat before long-distance transport. By these almost the full load-bearing capacity would be obtained by using load-space of 120 m3. The transport of pure peat would be even more profitable. But by using longer containers the
Table 2 – Prices used in profitability calculations of reed canary grass fuel use and transport distance. V ha1
Profits and costs Farming subsidy (subsidy area C2 year 2006, cattle farm) Price of the reed canary grass at the power plant Harvesting, the costs before transportation to the production site Crushing of bales Movable crusher Power plant crusher Transportationb Cylindrical bales (d ¼ 1.5 m) (s ¼ transport distance, km)
V MWh1
593
226
8
559a
125 75
4.4 2.65 ¼ 3.56 10(7) s3 1.48 10(4) s2 þ 5.38 10(2) s þ 1.55 ¼ 2.0 transport of bales
Bulk matter
The crop yield used in these calculations is 6 tonne dry solid ha1 in a year. a Pahkala et al. [11]. b Cost calculation model which includes fixed and variable costs of a truck.
transport costs of the mixture can be compared with that of peat. The economy of the transport of mixed fuels would, however, be better than that of light reed canary grass loads. One possible way was railway transport but it was not investigated.
3.2.
Distance and profitability
The profitability of transportation of reed canary grass was studied. All the costs and profits of production chain were taken into account. To calculate the profitability of reed
200 100
14
Profits-costs, € ha-1
Transport costs, € MWh-1
16
12 10 8 6 4
0
0
50
100
150
-100
200 III II
-200 I
-300
IV
-400
2 -500 0 10
50
100
150
One-way transport distance, km Bulk matter
Cylindrical bales d=1,5 m
Cylindrical bales d=1,2 m
One-way transport distance, km
200
35 t
I Transporting bulk matter II Transporting bales, crushing bales with movable crusher at the power plant III Transporting bales, crushing bales with fixed crusher at the power plant IV Baling, crushing vales at the farm, transporting bulk material
Large cubical bales
Fig. 2 – Transport costs of reed canary grass. The crop yield used in these calculations is 6 tonne dry solid haL1.
Fig. 3 – Subtraction of profits and costs of reed canary grass production chain as a function of transport distance to power plant [12].
212
biomass and bioenergy 33 (2009) 209–212
canary grass fuel use and transport distance the following prices were used (Table 2). Four different methods for transporting reed canary grass were compared (Fig. 3). The feasible transportation distance is from 20 to 120 km depending on the production method and the method of bale crushing. The worst option is to crush bales at the plantation and transport the bulk matter. This option combines these two most costly methods. Using bulk matter is cheapest if the transportation distance is less than 20 km. Baling increases the feasible transport distance but crushing increases the costs. Costs of movable crusher are higher than that of fixed crusher.
3.3.
Example plant
The Rauhalahti CHP plant in Jyvaskyla in Central Finland uses about 2 TWh of peat and wood fuels which are transported over an average radius of 100 km. There are 27 km2 of fallow land within a 70-km radius that could be used to cultivate reed canary grass [2]. At a productivity of 22 MWh ha1 a1 this area would satisfactorily supply about 3% (59.4 GWh) of the feedstock demand, while for a higher productivity of 38 MWh ha1 a1 this area would supply about 5% of the total demand.
4.
Conclusion
At the moment feasible transportation distances are relatively short. By increasing load-sizes transport costs can be reduced. New baling techniques with cubical baling are a feasible way to increase load-sizes. With cylindrical bales the load-sizes are about 50–70 MWh and with large cubical bales about 80 MWh. It is still less than a load-size of a peat or dry wood chips, which is over 100 MWh. Baling increases problems at the power plant where bales need to be crushed and the crushed matter has to be suitable for feeding systems and boiler. Presently most reed canary grass brought to heat and power plant is in baled form. There is not much loose form production in Finland. Reed canary grass in loose form could be mixed with peat or wood chips before transportation which reduces transportation cost in certain distances. Also crushing is unnecessary with loose material.
Acknowledgements This article is based on the results of several projects implemented at VTT Technical Research Centre of Finland. This work has been carried out under the project ‘‘Integrated European Network for Biomass Co-firing’’, NetBioCof, funded by European Union.
references
[1] Ma¨kinen T, Soimakallio S, Paappanen T, Pahkala K, Mikkola H. Liikenteen biopolttoaineiden ja peltoenergian kasvihuonekaasutaseet ja uudet liiketoimintakonseptit. [Greenhouse gas balances and new business opportunities for biomass-based transportation fuels and agrobiomass in Finland]. In: VTT research notes, vol. 2357; 2006. 134 pp. Available from:; 2006 [in Finnish]. [2] Flyktman M, Paappanen T. Ruokohelven ka¨ytto¨kapasiteettiselvitys. VTT Technical Research Centre of Finland PRO2105/05; 2005. 28 pp [in Finnish]. [3] Finnish Environment Institute. Finnish expert report on best available techniques in large combustion plants. The Finnish Environment 2001;458:143. [4] Ja¨rvinen T, Alakangas E. Co-firing of wood – fuel handling and co-combustion. VTT Technical Research Centre of Finland; 2001. p. 11. [5] Leinonen A, Lindh T, Paappanen T, Kallio E, Flyktman M, Hakkarainen J, et al. Cultivation and production of reed canary grass for mixed fuel as a method for reclamation of peat production area. In: An international symposium of peatland restoration and reclamation, 14–18 July, Duluth, Minnesota, USA: IPS; 1998. p. 120–4. [6] Lindh T, Paappanen T, Kallio E, Ka¨yhko¨ V, Kaipainen H, Hokkanen M, et al. Developing loose harvesting method and delivery methods for straw like biomasses to be used as mixed fuel. In: Salo R, editor. Production of biomass as raw material for fibre and energy. Final report, part II. Harvesting of reed canary grass and straw, production costs and combustion techniques. Publications of Agricultural Research Centre of Finland, Series A 85. Jokioinen: Agricultural Research Centre of Finland; 2000. p. 7–86 [English abstract]. [7] Paappanen T, Kallio E, Lindh T. Development of straw harvesting method for production of mixed fuel. Tutkimusselostus ENE32/T0024/2000. Technical Research Center of Finland. Final Report. In Finnish; 2000. 37 pþ2 app [English abstract]. [8] Lindh T, Ka¨rki J, Impola R, Paappanen T, Leino T, Kallio E, et al. The development of reed canary grass fuel chain. In: Bioenergy 2007, 3–6 September, Jyva¨skyla¨, Finland: Finbio. Publication 36; 2007. p. 329–36. [9] Lindh T, Paappanen T, Kallio E, Flyktman M, Ka¨yhko¨ V, Selin P, et al. Production of reed canary grass and straw as blended fuel in Finland. VTT Technical Research Centre of Finland. Available from: 2005. p.10. [10] Lo¨tjo¨nen T, Isolahti M. Korjuu paaleina edullisinta – kehitystyo¨ alentaa kustannuksia. Bioenergia 2006;5:21–3 [in Finnish]. [11] Pahkala K, Isolahti M, Partala A, Suokannas A, Kirkkari A-M, Peltonen M, et al. Ruokohelven viljely ja korjuu energian tuotantoa varten. 2. Korjattu painos. MTT Agrofood Research Finland 2005 [In Finnish]. [12] Paappanen T, Leinonen A, Kallio E, Kirjalainen T, Lindh T. Jahtavisnevan tuottajarenkaan toiminnan kehitta¨minen ruokohelven tuotannossa, loppuraportti. VTT Technical Research Centre of Finland PRO2/P2061/06; 2005. 22 pp [in Finnish].
Available at www.sciencedirect.com
http://www.elsevier.com/locate/biombioe
Reed canary grass transportation costs – Reducing costs and increasing feasible transportation distances T. Lindha,*, T. Paappanena, S. Rinneb, K. Sivonena, M. Wihersaaric a
VTT, Technical Research Centre of Finland, P.O. Box 1603, FIN-40101 Jyva¨skyla¨, Finland YTY-konsultointi Oy, Teljintie 4, FIN-40530 Jyva¨skyla¨, Finland c University of Jyva¨skyla¨, P.O. Box 36, FIN-40014 Jyva¨skyla¨n yliopisto, Finland b
article info
abstract
Article history:
Reed canary grass is used in several heat and power plants in Finland and it is estimated
Received 3 August 2007
that about 70–80 plants could utilise reed canary grass as a co-firing fuel. Long-distance
Received in revised form
transport of reed canary grass forms a significant share of the production and delivery
21 May 2008
costs. Reed canary grass can be transported in bales or as loose matter. The density of the
Accepted 28 May 2008
matter and shape of the bales influence the load-size and the cost. At present it is
Published online 25 October 2008
impossible to obtain the full load-bearing capacity of a lorry even with bales, and with light bulk matter the obtainable load is less than one-third of the load-bearing capacity of
Keywords:
a lorry. By using Orkel local-baler it has been possible to obtain the largest load-sizes, but
Bioenergy
the total economy of the chain is not very good because the baling and chopping of bales
Energy crops
increase the total costs. If a full load-bearing capacity of a lorry (30–40 tonne) would be
Reed canary grass
obtained, the transportation costs would be reduced significantly compared to the present
Phalaris arundinacea
situation. Second alternative would be to mix reed canary grass with wood chips or peat
Transportation costs
before long-distance transport. At the moment feasible transportation distances are
Finland
relatively short. With briquettes the cargo space could be used more efficiently and the
Load-size
load-size of the transport could be increased. ª 2008 Elsevier Ltd. All rights reserved.
1.
Introduction
Reed canary grass (Phalaris arundinacea) is a perennial grass that naturally grows in Finland. Typical crop is 4.5–8 tonne dry solid ha1 which is about 22–38 MWh ha1 [1]. Cultivation of reed canary grass is growing rapidly in Finland because it is increasingly utilised as a solid fuel in heat and power plants. Because of its CO2 neutrality it is an attractive alternative for power plants under CO2 quota regulations. The cultivation area of reed canary grass in 2007 was estimated to be about 200 km2 (20 000 ha) which was 1% of the total cultivation area in Finland. The Ministry of Agriculture and Forestry has estimated that the area of reed canary grass could be 1000 km2
(100 000 ha, 2 TWh) in 2015. At present more than 20 plants have some experience in utilisation of reed canary grass. It is estimated that about 70–80 heat and power plants in Finland could utilise reed canary grass as a co-firing fuel [2]. In Finland co-firing usually means the addition of biomass to a peat fired unit [3,4]. Reed canary grass is co-combusted with fuels like peat, bark, sawdust and forest chips. Typical moisture content of these fuels is about 50% on total weight basis and boilers in power plants are designed for fuels with that moisture content. Moisture content of reed canary grass is much lower (15–25%). In terms of energy the maximum annual share of reed canary grass has nowadays been only about 1% of the
* Corresponding author. E-mail address: [email protected] (T. Lindh). 0961-9534/$ – see front matter ª 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biombioe.2008.05.019
210
biomass and bioenergy 33 (2009) 209–212
– Straw harvesting studies in 1995 and 1999 – Reed canary grass studies 1995–1997 and 2001–2005 – The development of reed canary grass fuel chain 2006–2008
30,00
Total costs, € MWh-1
total annual fuel energy input at power plants. The highest momentary shares have been around 15% of the total fuel energy (20–30% in volume). The most critical limiting factor at the plant is normally the fuel conveyor and feeding capacity which are designed for much energy denser fuels. The energy content of reed canary grass chop is only 0.3 MWh m3 while it is 0.6–1.1 MWh m3 for wood and peat. The production chain of reed canary grass needs further development in order to become more cost-efficient. Harvesting losses are high, at its best 20–40%, and 50–60% at the highest. Due to the low bulk density of the reed canary grass the transport is uneconomical, especially in the chopped form. The efficiency of the transport of bales as cylindrical bales, which is the most common form of bales, is also relatively low. The prevailing agricultural choppers and industrial crushers of power plants are in most cases unsuitable for chopping of bales for fuel purposes. In plant processing the light and straw-like chopped reed canary grass can cause problems. In most plants the reed canary grass can be applied for mixed combustion with peat and wood chips. This, however, requires proper mixing of the fuels either at the loading stage or at the reception and processing stage of the plant. Loose harvesting produces shorter reed canary grass chaff than when shredding bales. Shorter chaffs are easier to mix with other fuels and the flow in the power plants’ equipments is better. But storing loose chaff takes significantly more space than storing bales. Stored reed canary grass must be covered very well especially if it is in loose form. In Denmark fixed roofed central storehouses are used for storing straw. This kind of fuel terminals could be one way of storing reed canary grass bales in Finland. There have been several studies concerning reed canary grass production chain and costs in different stages of the production chain at the VTT [5–8].
2.
Production costs
The production costs of reed canary grass can be divided into five cost factors: productive value of the field, foundation of the growth, annual fertilisation, harvesting and storage, longdistance transport to users and chopping. The costs of each production stage consist of investments made in machinery and work costs. Long-distance transport of reed canary grass forms a significant share of the production and delivery costs (Fig. 1). Transportation costs will be discussed more accurately in Section 3. There is no significant difference between the production costs of loose harvesting and baling methods. The balers commonly employed are not equipped with chopping unit.
20,00 15,00 10,00 5,00 0,00 Bales, mobile crusher
Bales, plant crusher
Loose
Chopping of bales
Ann.fertilization
Long dist. transport
Cultivation
Harvesting
Land value
Fig. 1 – Costs (V MWhL1) in different stages of production chain of reed canary grass. The crop yield used in these calculations is 6 tonne dry solid haL1 in a year and transport distance is 70 km.
Hence shredding and chopping of bales must be carried out, for example, at a power plant [9].
3.
Transportation costs
There are several factors which influence the price of the reed canary grass transport. Load-size of a lorry is an important factor influencing the costs of transportation. Reed canary grass can be transported in bales or as bulk matter. The density of the matter and shape of the bales influence the load-size and the cost. In Finland transport equipment of peat can be used for transport of loose matter and logging residue trucks for transport of bales.
3.1. Most of these studies have been carried out with other research facilities and companies. This article combines some of the results of these studies.
25,00
Load-sizes
At present it is impossible to obtain the full load-bearing capacity of a lorry even with bales, and with light bulk matter the obtainable load is less than one-third of the load-bearing capacity of a lorry. In Finland useful load of a lorry can be up to 40 tonne. Common load volume of a peat lorry is about 120– 150 m3 which is about 107 MWh of peat. VTT investigated load-sizes by inquiring transportation entrepreneurs and by comparing the results with the theoretical calculations. The amounts of reed canary grass, loadable into a lorry, were calculated on the basis of the results (Table 1). Obtaining of these load-sizes requires that loading succeeds optimally, and that the density of bales is good. Load-size and transport distance have an effect on transportation costs (Fig. 2). By using Orkel-local-baler (chop-bales in Fig. 2) it has been possible to obtain largest load-sizes, but the total economy of the chain is not very high because the baling costs increase the total costs. If the full load-bearing capacity of a lorry (30–40 tonne, 35 tonne in Fig. 2) would be obtained, the transportation costs would be reduced significantly compared
211
biomass and bioenergy 33 (2009) 209–212
Table 1 – Amount of reed canary grass in lorry transports. Bale volume (m3)
Total mass (tonne)
Energy (MWh)
60–64 48–52 60–66
150 81.4–86.9 101.8–110.3 121–133.1
10.5 14.7 18.3 21.8
40 56 70 82
44–50
114–129.6
20.5
77
98
101.8
28.5
108
Bales
Bulk matter Cylindrical bales 1.2 m Cylindrical bales 1.5 m Large cubical bales 1.2 0.7 2.4 m Large cubical bales 1.2 0.9 2.4 m Local-balersa
a Bales made by Orkel local-baler of precision-chopped reed canary grass [10].
to the present situation. The energy content of a full load would be even higher than that of peat and wood chips. The easiest way to reduce the transportation costs and simultaneously the total costs is to use a large cubical baling press which makes it possible to produce loads of as high mass and volume as possible. By cylindrical bales of certain size the cargo space can remain incomplete, because it is not possible to make over-high loads. It is possible to increase the density of loads up to a certain limit only by using a baler of the right type. In theory one alternative would be to make loose, but still compact small briquettes. The construction of briquettes would correspond to the construction of peat and wood chips, and simultaneously the problems of power plant processing of the fuels would be eliminated. Theoretically, the briquette production would be profitable, but there would be problems in obtaining briquette manufacture of sufficient capacity. Second alternative would be to mix reed canary grass with wood chips or peat before long-distance transport. By these almost the full load-bearing capacity would be obtained by using load-space of 120 m3. The transport of pure peat would be even more profitable. But by using longer containers the
Table 2 – Prices used in profitability calculations of reed canary grass fuel use and transport distance. V ha1
Profits and costs Farming subsidy (subsidy area C2 year 2006, cattle farm) Price of the reed canary grass at the power plant Harvesting, the costs before transportation to the production site Crushing of bales Movable crusher Power plant crusher Transportationb Cylindrical bales (d ¼ 1.5 m) (s ¼ transport distance, km)
V MWh1
593
226
8
559a
125 75
4.4 2.65 ¼ 3.56 10(7) s3 1.48 10(4) s2 þ 5.38 10(2) s þ 1.55 ¼ 2.0 transport of bales
Bulk matter
The crop yield used in these calculations is 6 tonne dry solid ha1 in a year. a Pahkala et al. [11]. b Cost calculation model which includes fixed and variable costs of a truck.
transport costs of the mixture can be compared with that of peat. The economy of the transport of mixed fuels would, however, be better than that of light reed canary grass loads. One possible way was railway transport but it was not investigated.
3.2.
Distance and profitability
The profitability of transportation of reed canary grass was studied. All the costs and profits of production chain were taken into account. To calculate the profitability of reed
200 100
14
Profits-costs, € ha-1
Transport costs, € MWh-1
16
12 10 8 6 4
0
0
50
100
150
-100
200 III II
-200 I
-300
IV
-400
2 -500 0 10
50
100
150
One-way transport distance, km Bulk matter
Cylindrical bales d=1,5 m
Cylindrical bales d=1,2 m
One-way transport distance, km
200
35 t
I Transporting bulk matter II Transporting bales, crushing bales with movable crusher at the power plant III Transporting bales, crushing bales with fixed crusher at the power plant IV Baling, crushing vales at the farm, transporting bulk material
Large cubical bales
Fig. 2 – Transport costs of reed canary grass. The crop yield used in these calculations is 6 tonne dry solid haL1.
Fig. 3 – Subtraction of profits and costs of reed canary grass production chain as a function of transport distance to power plant [12].
212
biomass and bioenergy 33 (2009) 209–212
canary grass fuel use and transport distance the following prices were used (Table 2). Four different methods for transporting reed canary grass were compared (Fig. 3). The feasible transportation distance is from 20 to 120 km depending on the production method and the method of bale crushing. The worst option is to crush bales at the plantation and transport the bulk matter. This option combines these two most costly methods. Using bulk matter is cheapest if the transportation distance is less than 20 km. Baling increases the feasible transport distance but crushing increases the costs. Costs of movable crusher are higher than that of fixed crusher.
3.3.
Example plant
The Rauhalahti CHP plant in Jyvaskyla in Central Finland uses about 2 TWh of peat and wood fuels which are transported over an average radius of 100 km. There are 27 km2 of fallow land within a 70-km radius that could be used to cultivate reed canary grass [2]. At a productivity of 22 MWh ha1 a1 this area would satisfactorily supply about 3% (59.4 GWh) of the feedstock demand, while for a higher productivity of 38 MWh ha1 a1 this area would supply about 5% of the total demand.
4.
Conclusion
At the moment feasible transportation distances are relatively short. By increasing load-sizes transport costs can be reduced. New baling techniques with cubical baling are a feasible way to increase load-sizes. With cylindrical bales the load-sizes are about 50–70 MWh and with large cubical bales about 80 MWh. It is still less than a load-size of a peat or dry wood chips, which is over 100 MWh. Baling increases problems at the power plant where bales need to be crushed and the crushed matter has to be suitable for feeding systems and boiler. Presently most reed canary grass brought to heat and power plant is in baled form. There is not much loose form production in Finland. Reed canary grass in loose form could be mixed with peat or wood chips before transportation which reduces transportation cost in certain distances. Also crushing is unnecessary with loose material.
Acknowledgements This article is based on the results of several projects implemented at VTT Technical Research Centre of Finland. This work has been carried out under the project ‘‘Integrated European Network for Biomass Co-firing’’, NetBioCof, funded by European Union.
references
[1] Ma¨kinen T, Soimakallio S, Paappanen T, Pahkala K, Mikkola H. Liikenteen biopolttoaineiden ja peltoenergian kasvihuonekaasutaseet ja uudet liiketoimintakonseptit. [Greenhouse gas balances and new business opportunities for biomass-based transportation fuels and agrobiomass in Finland]. In: VTT research notes, vol. 2357; 2006. 134 pp. Available from: