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A sustainable mallee woody crop industry will require optimised farming and delivery systems. This may comprise mallee biomass supply on its own, or mallee integrated with other farming systems. Optimum planting and management arrangements will differ markedly for each scenario. Competition for soil moisture is important and will depend on local climate and soils. Row layout, tree spacing and age at harvest will impact harvesting efficiency. Since harvesting and transport will be the major cost in mallee supply to the processor, designing the layout to maximise harvest efficiency and minimise cost is of critical import. Considerable capital has already been expended on establishing more than 13 000 Ha of mallee in Western Australia. Many of these alley plantings will be too old to harvest economically with a chipper harvester and alternative systems (e.g. feller-buncher) will be needed to control competition with existing cereal crops. It is likely that biomass supply to a processor will comprise block plantings close to the processor, supplemented by existing feedstock from dispersed alley plantings where appropriate. Block cultivation may comprise closely spaced alleys (10-30m) on marginal land close to the processor. Spacing will be site specific and determined by soil moisture competition and yield. Harvest and transport logistics must be considered in determining layouts. Harvesting efficiency will be improved when the concentration of biomass per metre of row is maximised and distance between belts is minimised. Where mallee planting is not intended for biomass removal, consideration will need to be given to protocols for carbon credits. Mallee planting provides vegetative biodiversity in a wheat monoculture and the collateral benefits of this biodiversity and associated environmental dividend needs to be quantified. Improvements to the productivity and profitability of the mallee farming systems will require further R&D to improve biomass yield, tree presentation for cost effective harvesting and better integration with other farming systems. Farming systems need to be implemented that not only enhance economic and environmental performance in the farming sector, but also match value chain requirements for overall efficiency. Harvesting Systems Chapter 2 demonstrated that sugarcane harvesting and transport systems have many similarities with mallee systems. In particular whole-of-crop sugarcane harvesting with all material (cane and trash) transported to the sugar mill has close synergies with mallee harvesting system. The sugar industry has shown the importance of considering whole-of-system performance to ensure components of the supply chain work efficiently as an integrated system. The prototype mallee harvester provides an opportunity to evaluate machine performance and assess critical parameters across the supply chain. The current harvester performs the basic functions of gathering, severing stems at ground level, feeding all the woody and leafy biomass through a chipper system and delivering the chipped product into infield transport. There is no debarking or separation of leafy biomass from woody biomass during the process. The current system is limited by available power which impacts pour rate, a critical factor in the delivered biomass cost and future prototypes will need to address this. Manoeuvrability, mobility and associated soil compaction issues will need to be considered in the selection of the tracked or wheeled configuration harvester. The prototype harvester, in trials to date, has achieved a pour rate of up to 38t/hr for a short period. A continuous machine pour rate greater than 50 t/hr will be required for a viable harvesting system. 173
Biomass bulk density has a large impact on transport system performance. Bulk density changes with tipping and transport, and the associated impact on product handling has not been determined for mallee material. Similarly, the effect of product composition (chip, leaf, twigs) on bulk density will be important although the influence on biomass composition appears to be minor. However the quality of the chipping process – the quality of cut – could potentially have a significant impact upon material handling properties, and possibly some influence upon bulk density. There are significant losses from mechanical harvesting of sugarcane during chopping of billets and separation of trash. There is no quantitative data on mallee harvesting losses but preliminary observations suggest they should be low since there are is no separation of the product on the harvester. Transport efficiencies may be improved by leaving residue materials such as bark and twigs behind in the paddock, however separation on the harvester has a low chance of success and will result in a more complex machine design and product losses in field. Given sufficient value for residues, for example as a bioenergy feedstock, transporting the mixed biomass will be the best option. Use of semi-mobile equipment to undertake product separation at nodes close to the biomass source and then transport of different products to different markets would be an option. Sugarcane harvester field efficiencies are typically 50%, whereas for mallee, modelling indicates field efficiencies could be 70-80%. This is the consequence of long row lengths and slow harvesting speed, resulting in a reduced number of times the harvester needs to turn per hour of operation and per tonne harvested. The dispersed nature of the mallee crop will have a significant effect upon field efficiency, with yields per paddock hectare of less than five green tonnes per hectare, and typically around one green tonne per hectare. In-field haul distances will be relatively long and vary widely over short periods, which will make the logistics of harvesting and hauling complex. To simplify this part of the process, the introduction of a shunt truck between the haulouts and the road transport is under consideration, as it should allow the harvester and its associated haulouts to work closely together and introduce important flexibility into the farm operations. Harvest timing is restricted to the winter and spring seasons in Australian sugar cane, whereas mallees could, with some qualifications, be harvested all year. This changes the scale of operations significantly, in that a one million tonne per season sugar mill processes at the rate of about two million tonnes a year. In comparison, a large bioenergy conversion factory might require about 100,000 to 200,000 green tonnes of biomass over a whole year. While mallee road transport logistics will consequently be relatively simple, the dispersed mallee crop and long in-field transport distances will make on-farm logistics relatively complex and expensive. Extensive use of sugar cane logistics and harvester monitoring systems will help the new mallee industry. The mallee industry will also benefit from the comparatively stable nature of the harvester delivered product. Green biomass can be stored for periods of a few days, and after upgrading and drying the finer components of the biomass, storage for a number of weeks should be feasible. This is a significant point of difference with sugar cane, which has cut-to-crush intervals of only hours, which makes the logistics of a mill’s supply chain complex. Payment systems and business structures vary in sugar cane and provide a range of models from which a new mallee industry will be able to choose. The new industry has the opportunity to set itself up so that responsibilities and rewards are properly aligned and the value added along the supply chain can be appropriately shared amongst the participants – to increase the size of the cake for the benefit of all. At equivalent pour rates, the cost of sugarcane harvesting is less than half that of the estimated cost of mallee harvesting. The actual cost of mallee harvesting is unknown but modelling a hypothetical 174
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Sustainable Biomass Supply Chain fo
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Foreword This report provides an as
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include business development (new p
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Acknowledgments The authors would l
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4.1 Product Options and Supply Chai
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Table 4.2 Assessment of current val
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Figure 3.4 Tracked rigid self-prope
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Executive Summary What the report i
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• Biomass production potential of
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• As the Industry expands, the mo
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Harvesting, transport and storage s
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Biomass processing, supply chain pl
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Key barriers to biomass industries
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Crop-Biomass Production Production
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Figure 1.1 The cropping and pasture
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Table 1.1 Mallee species used for p
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1.1.4 Growth Cycle Mallee System Ma
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northern New South Wales (where it
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Almost 80% of the industry now cuts
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Bark has relatively high ash but as
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Carbon sinks Planting of mallees to
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Table 1.5(a) State Land area devote
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out the fluctuations in farm income
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Mallee system Most of the mallee bi
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inconclusive result may have been d
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For a sustainable woody crop indust
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changed significantly since they we
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Figure 2.2 Biosystems Engineering p
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Whole-of-crop harvesting represents
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During the last decade the harvesti
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single row, as this would improve t
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2.2.2.2 Weight Sugar System The Aus
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Table 2.1 Harvester Comparison Tabl
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The quality of cut may be less impo
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ate than a 170 tonne/ha crop of sta
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Dry Leaf 6.1 - 3.5 17.0 58.9 53.2 T
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Bulk density will be a key consider
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Table 2.4 EM levels in cane supply
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L/T L/T 60 0.97 0.71 80 0.92 0.66 1
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Total 7.5-26 16.5 Mallee System The
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• waiting for mill delivery of em
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perhaps at 10 - 20 km intervals. Th
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transport arrangements, harvest gro
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contractors and growers, and the fa
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experience of the sugar industry wi
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Table 2.11 Alternative harvest paym
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onto the harvester. BR+F still send
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Repairs and maintenance 2.10 Capita
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Figure 2.14 and Table 2.14 describe
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Sichter et al. (2005)), harvest and
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Transport efficiencies may be possi
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3. Transport and Storage Systems Tr
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same time, the potential problems o
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Figure 3.3 Articulated self-propell
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• The harvester will not have any
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Figure 3.7 Gross mass compared with
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external factors dramatically impac
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Figure 3.11 The effect of haulout t
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3.3 Road Transport 3.3.1 Configurat
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Figure 3.15 shows an example of the
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Road distance one way < 20 km 70 km
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Haul distance is largely outside th
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3.6 Recommendations The nature of t
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• The strategy offered lower tota
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sugarcane billets are such that wit
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• Transfer the whole tree product
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Figure 4.5(b) Energy balance of con
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2010). Table 4.2 presents a summary
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4.4.2 Activated charcoal Activated
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Nett Product Value ($/t) $475.00 $
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Table 4.9 presents an estimation of
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• Oil from leaf @ $2/kg • Synth
Page 145 and 146: • The mallee oil would be extract
Page 147 and 148: 5. Industry and Business Structures
Page 149 and 150: is conducted into tariff levels on
Page 151 and 152: Bx is % brix in first expressed jui
Page 153 and 154: Hildebrand (2002) estimated that th
Page 155 and 156: also has a flow on effect to the sp
Page 157 and 158: Sugar Industry Illustrative Example
Page 159 and 160: with super size multi-lift bins ove
Page 161 and 162: farmer vs. harvester) is the next l
Page 163 and 164: 6. Supply Chain Planning and Manage
Page 165 and 166: Figure 6.1 Building blocks of the s
Page 167 and 168: weighed against the costs of operat
Page 169 and 170: • There is close contact between
Page 171 and 172: 6.4 Planning, Management Tools and
Page 173 and 174: • Harvest and transport logistics
Page 175 and 176: interface. The system allows users
Page 177 and 178: Case Study 6.2 - Model Application
Page 179 and 180: Relationships between sectors and p
Page 181 and 182: 7. Supply Chain Modelling and Econo
Page 183 and 184: It was assumed that there was a fif
Page 185 and 186: Table 7.2 Scenario two capital equi
Page 187 and 188: Table 7.4 Fuel burn rates harvester
Page 189 and 190: Figure 7.5 Effect of capital equipm
Page 191 and 192: Figure 7.7 Effect of annual tonnes
Page 193 and 194: 30 1.8 7.0 12.3 17.5 50 1.1 4.3 7.6
Page 195: 8. Conclusions and Recommendations
Page 199 and 200: Vehicles used for infield haulout w
Page 201 and 202: This can be compared with harvest a
Page 203 and 204: While diversification can add value
Page 205 and 206: Appendix 1: Comparative Assessment
Page 207 and 208: and transport conditions. Billet le
Page 209 and 210: that cane production is the most pr
Page 211 and 212: on sugar only, other proceeds (mola
Page 213 and 214: References Agnew, J 2002. A Partici
Page 215 and 216: Enecon 2001. Integrated Tree Proces
Page 217 and 218: Keating, BA, Antony, G, Brennan, LE
Page 219 and 220: Ridge, DR and Linedale, AL, 1997. T
Page 221: Willcox, T, Hussey, B, Chapple, D a
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