The catalan Forest Biomass Production Chains
Transcripción
The catalan Forest Biomass Production Chains
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 2 2 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 TRANSPORT/HAULAGE OF FULL STEMS WITH TRUCK/FOREST TRAILER or FORWARDER At intermediate storage SEASONING – 1 MONTH SEASONING CHIPPING TRANSPORT/HAULAGE OF 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 The Catalan Forest Biomass Production Chains - a vision from outside 3 3 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. The Catalan Forest Biomass Production Chains - a vision from outside 4 4 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 TRANSPORT/HAULAGE OF 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 The Catalan Forest Biomass Production Chains - a vision from outside 5 5 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 The Catalan Forest Biomass Production Chains - a vision from outside 6 6 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. The Catalan Forest Biomass Production Chains - a vision from outside 7 7 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. The Catalan Forest Biomass Production Chains - a vision from outside 8 8 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- The Catalan Forest Biomass Production Chains - a vision from outside 9 9 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 The Catalan Forest Biomass Production Chains - a vision from outside 10 10 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. The Catalan Forest Biomass Production Chains - a vision from outside 11 11