The catalan Forest Biomass Production Chains

Transcripción

PROFORBIOMED
PROMOTION OF RESIDUAL FORESTRY BIOMASS
IN THE MEDITERRANEAN BASIN
The catalan Forest Biomass Production
Chains - a vision from outside
July 2013
Ignacio López Vicens (coord.)
Dimitris Athanassiadis
Eduardo Tolosana
Rubén Laína
This publication is co-financed
financed with ERDF within the Project “PROFORBIOMED, Promotion of Forest Biomass
in the Mediterranean Basin” No. Ref. (1S-MED
(1S
10-009).
The sole responsibility for the content of this publication lies with the authors. It does not necessarily reflect
the opinion of the European Communities or the MED Programme.
The European Commission is not responsible for any use that may be made of the information contained
therein.
The analysed production chains
The two most important forest production chains for bioenergy are two, which may be called highvolume and high-quality. Chains’ cost depends on amount of biomass per ha extracted and average diameter of felled trees. This should be considered in thinnings’ scheduling. Furthermore, to
reduce re-allocation cost, surface of havesting site or overall amount to be extracted should reach
a minimum.
High-volume production chain
This chain is characterized by the high amounts of mobilized biomass and the high productivity of
all the processes in order for the producer to be able to reduce the costs as much as possible
without much regard to biomass quality.
Trees are felled and
-
the ones for energy, skidded (if forest not accessible to forwarder) to roadside and if
needed cross-cut into two parts for facilitating the next step
the ones for industrial material uses are processed at stump and skidded to roadside (if
forest not accessible to forwarder)
Energywood is forwarded to an intermediate storage. Industrial material wood is transported from
roadside to industry, but an intermediate storage may be done with forwarder.
Fuel wood is comminuted at the intermediate storage (a point accessible to trailers), and transported to a depot by truck. If chips are to be exported by ship, the terminal is the harbour itself.
The Catalan Forest Biomass Production Chains - a vision from outside
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Preparation
EXTRACTION
TRACKS OPENING
ACCESS
PERSONNEL
OF
ACCESS
MACHINERY
OF
Within the stand
FELLING
–
MOTOR MANUAL
TOPPING – ONLY
INDUSTRIAL
WOOD – MOTOR
MANUAL
DELIMBING – ONLY
INDUSTRIAL WOOD –
MOTOR MANUAL
BUCKING – LIGHT,
PRIOR TO EXTRACTION
- MANUAL
EXTRACTION OF
FULL-TREE
FULL-STEM
WITH FARM TRACTOR
At roadside
CROSS CUTTING into TWO
PARTS of WHOLE TREES
STACKING WITH
FARM TRACTOR
CLASSIFICATION
TRANSPORT/HAULAGE OF
FULL TREES
WITH TRUCK or FORWARDER
FULL STEMS
WITH
TRUCK/FOREST
TRAILER or FORWARDER
At intermediate storage
SEASONING –
1 MONTH
SEASONING
CHIPPING
FOREST CHIPS
90 m3bv trailer
HAULAGE BY
TRUCK
At yard
STORAGE
OF
COMMINUTED
MATERIAL
TRANSPORT/DELIVERY OF
FOREST CHIPS
DIVERSE TRUCKS
Industrial enduser
Industrial end-user
Sawmill
Figure 1: chart for the high-volume production chain
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High-quality
quality (for household) production chain
This production chain pays more attention to the final quality of wood chips for small to medium
sized boilers. Therefore, having into account the current domestic demand, this chain produces
some 20.000 to 30.000 tones (as received) per year. This chain is an evolution of the conventional
production chain under the stem length system for the supply to sawmills and other wood indusindu
tries. The main difference to that chain is the straightness (bioenergy does not need straight logs,
increasing the costs) and the the distances to be covered (theoretically and necessarily shorter for
bioenergy), making it necessary to be very careful with the production costs and the efficiency and
an
productivity if there are no points of local consumption.
consumption
Trees are felled and processed at stump.
stump Logs are skidded to the forest road side, where a sorting
into round wood and fuel wood takes place.
There are then two different paths:
-
when fuelwood remains
emains in the area for the self-consumption of the forest owner
when fuelwood goes to a terminal for commercial trading
Self-consumption fuel wood is transported to and chipped at the domestic boiler site at the user’s
convenient time.
Trading fuelwood is transported to a terminal. After seasoning is chipped and screened, if required, and transported as chips to a small or medium domestic boiler.
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Preparation
EXTRACTION
TRACKS OPENING
ACCESS
PERSONNEL
OF
ACCESS
MACHINERY
OF
Within the stand
FELLING
–
MOTOR MANUAL
TOPPING
–
MOTOR MANUAL
DELIMBING
–
MOTOR MANUAL
At roadside
EXTRACTION OF
STEM
WITH
FARM
TRACTOR
At intermediate storage
SEASONING
STACKING
CLASSIFICATION
FULL-STEM
At yard
SEASONING
CHIPPING
STORAGE
OF
COMMINUTED
MATERIAL
SCREENING
TRANSPORT/DELIVERY OF
WOOD CHIPS
DIVERSE TRUCKS
MID- TO SMALL-END USER
Sawmill
Figure 2: graphical chart for the high-quality production chain
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Reference data
Some partial data has been collected and prepared with the collaboration of the external experts.
Time-study measurements produced the results shown in Table 1.
Table 1: reference data about some processes involved in the HQ/HV production chains
Process
Felling
Chain (High-quality or Highvolume)
Productivity or capacity
HQ/HV
3,0 odt/h
(E15)
1,7 odt/h
(E15)
Delimbing
HQ
-
Topping
HQ
-
Extraction* with skidder
HQ/HV
FT – 2,7 odt/h (E15)
Extraction* with farm
tractor
HQ/HV
FT - 1,7 odt/h (E15)
Extraction* with forwarder
HQ/HV
FT – 4,2 odt/h (E15)
Chipping
HV
Drum chipper, screen of
80x80 mm – 9 - 25 odt/h E15
HQ
Drum chipper, screen of 30 x
30 mm – 7,1 odt/h E15
HQ
Payload trailer: 12-15 odt
Truck transport - stem
S – 2,2 odt/h (E15)
CTL – 5,3 odt/h (E15)
Payload rigid truck: 6 – 7 odt
Truck transport fulltree
HV
Payload rigid truck 4 odt
Truck transport wood
chips
Primarily HV
Payload trailer: 90 m3bv, some
17-18 odt
* values are assessed from experiences in different conditions
FT: full-tree system, S: stem system, CTL: cut-to-length system
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Improvement potential and bottlenecks
In both production chains, some processes need improvements. Particularly, all the processes
related to the movement of biomass are the ones detected as a bottleneck. These processes with
most improvement potential are extraction and haulage.
Photographs 1:: extraction of stems and full trees (skidding) with farm tractor : Author: Ignacio López
Photograph 2: haulage of full-trees
trees to intermediate storage area for chipping:: Author: Ignacio López
Extraction of full-trees
trees or tree sections to road side or intermediate storage area,
area with a latter combination with a partial haulage either with forwarder or with truck may constitute too many steps
for this operation.
Felling
elling and processing should be mechanized whenever possible, since it greatly facilitates subsu
sequent extraction operations.
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Photograph 3: motor-manual delimbing and topping in an integral harvest of round- and energy-wood. Author:
Ignacio López
For better quality and cleaner biomass, skidding logs on the ground should be avoided. It could
even be used a farm tractor, but with crane and trailer.
Photograph 4: the risk of contamination when skidding and staking is relatively high. Author: Ignacio López
The role of operational research in the development of the forest biomass market
In the near future, the most likely drivers of the evolution of the forest bioenergy market will be the
increase of the fossil fuel prices and the need of sustainable fuels. Also, the increase of the
awareness of the possibilities of forest biomass for heat production will increase its demand.
The exportation of forest fuels is also perceived as driver of this growth.
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However, there is some agreement that in any case, the procurement of forest biomass for energy
should also be focused on its sustainability, and the general public should also be aware of and
ask for that. Public institutions should therefore promote campaigns for the dissemination about
efficiency and costs associated to the use of forest fuel in front of fossil fuels.
Operational research should therefore focus on the following issues, in order of importance (starting with highest):
-
-
-
productivity and economical profitability: by guaranteeing the economical profit to harvesting contractors it is possible to guarantee the sustainability of this economical activity,
and indirectly it also promotes reaching of environmental and energy/carbon balance purposes.
environmental impact: how are forest reacting to biomass extraction systems is the key
question to answer and how these affect forest fire risk. Operational and ecological research must be linked in this field.
energy/carbon balance: this issue is highly related to the life cycle assessment of forest
fuels and is of key importance for comparing this one to fossil fuels. This is another key
topic for operational research.
Social impact – employment and its quality – is also considered an important issue, but to a lesser
degree.
Proposals for improvements
For the high-volumes production chain a forwarder (or adapted farm tractor with crane and trailer)
would be the best option for hauling off tree parts, logs up to 8/10 m or small whole trees or full
stems.
Photograph 5: example of an adapted farm tractor with crane and trailer for forwarding. Author: Ignacio López
Mechanized harvesting would be an important improvement, especially if there are other industrial
wood destinations and/or the use of branches and tops is planned. This should be specially con-
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sidered in good terrain conditions (reduced slope mainly). Forwarder would be the best option for
hauling off logs up to 10 m or small full stems.
Small forwarder with a hydraulic compression system would be the best option for hauling off tree
parts, logs up to 8/10 m or small whole trees or full stems. Also, feller-bunchers should be tested in
order to evaluate improvements in the extraction phase.
Photographs 6: left: a trailer with compression system. Right: a feller-buncher and a bunch of full-trees. Author:
Ignacio López
With respect to transportation, this could be improved by using new trucks that are more productive and consume less fuel. This is of special importance since a Catalan transport contractor has
informed about a consumption of ca. 8 litres / 10 km, when figures from Nordic countries are ca. 6
litres / 10 km.
For chipping at the roadside and if there are small amounts of biomass in each stand, a chipper
truck is recommended (according to experience in Italy and Sweden).
Photograph 7: Chipper truck. Source: Stora Enso
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In addition to all these proposed innovations and technological possibilities, some issues should be
considered at the time of drafting forest management plans, especially extraction and haulage.
These ideas could be (and not limited to):
-
better cost-effective estimations of the available energy resource at stand level (there are
often errors over 25%)
better planning of intermediate storage areas for full trees
considering more intensive thinning for the extraction of bioenergy
Conclusions
Although it may seem that the Catalan forest production chains are at their optimal range in terms
of productivity, external experts have suggested several improvements that should be tested in
order to reinforce the competitiveness of the sector.
Intrinsic issues, such as forest yields and accessibility, need to be taken into account for each of
the suggested improvements, as well as extrinsic issues such as the legal situation of the marketplace, fossil fuel prices, etc.
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The catalan Forest Biomass Production Chains

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