Producing biomass: Biomass types: Tree residue: Plantation residue
Residue from harvesting forest plantations includes the stem tops and branches left in landscapes after harvest.

Evaluating the economics

Harvest residues from hardwood and softwood plantations and native forests are considered to be a major potential source of biomass that can be used for energy and fuel.

An Australia Government report, Scoping biorefineries: temperate biomass value chains [PDF, 1.7 MB], says that large quantities of forestry biomass currently exist, and even larger amounts could be produced.

Tasmania, Victoria and New South Wales have the most forest biomass, the report says.

The key economic factors determining whether biorefineries are established to process and convert this biomass into fuels and energy are:
  • growing forests
  • harvesting and chipping
  • transporting.


Estimated costs and amounts of biomass from selected forests in Australia are provided in Chapter 3 of the report, as well as indicative costs associated with production, harvesting and transport.

The cost of collecting residues from harvesting operations is estimated to range from $34–$70 per tonne.
It is estimated that 35% of plantation biomass (above the ground) is harvest residue that can be used for energy or fuel.

The cost of transporting biomass 50–200 km is estimated to range from $12–$46 per tonne. For distances greater than 200 km, transport alone may represent more than 50% of total costs.

Factors affecting the going price of biomass residues include:
  • plant growth rates
  • availability of substitutes or product (biomass) replacement e.g. woodchip for crop residues
  • transport costs (distance, mode of transport, scale of transport loads, pre-treatment potential, fuel)
  • fit for purpose of the biomass (e.g. specific plants oils)
  • import potential of pulp as a precursor to transformation
  • the scale of the value add by the biorefinery (e.g. high value chemicals vs. energy vs. commodity chemicals).


In a 2014 Western Australia case study, AFORA (Australian Forest Operations Research Alliance) analysed the effect of 5 operational factors on the operating costs of a biomass supply chain:
  • energy demand
  • interest rate
  • moisture content
  • transport distance
  • truck payload.


AFORA’s industry bulletins and reports and industry tools are freely available.



For Australian forest growers, opportunities would arise from the development of a biorefinery industry. These opportunities are outlined in a Forest & Wood Products Australia report entitled Opportunities for Australian forest growers from the development of a biorefinery and/or biomaterials industry within Australia.



Calculating the amount of biomass in pinus radiata harvest residues is discussed in the RIRDC report, Determining biomass in residues following harvest in Pinus radiata forests in New South Wales. The report considers the financial costs of biomass production for generating bioenergy using discarded waste from tree harvesting.

It includes a case study from a pine forest in NSW. The report also makes general recommendations on how much biomass can be harvested without detriment to plantations.

Benefits

Plantations can be integrated into farm operations, and can be a form of farm forestry. Farm forestry can be a tool of land management, ensuring that agricultural land is both productive and kept in good condition.

Plantations can also be integrated into a range of different land uses.

How forest plantations affect agricultural land and water availability is discussed in Chapter 5 of the 2011 report of an inquiry into the future of the Australian forestry industry, Seeing the forest through the trees [PDF, 4.5 MB].

Careful siting of plantations in the landscape can maximise timber production while minimising impacts on catchment water yield, according to a CSIRO submission to the forestry report.

The benefits of farm forestry, both on-farm and for the local environment, according to the report, fall into three categories:

1) Land and water quality benefits
  • improving biodiversity and ecology
  • reducing windspeed
  • preventing and mitigating wind erosion
  • protecting crops and providing shelter for stock
  • producing seed and controlling pests
  • reducing evaporation
  • preventing and mitigating water erosion
  • addressing excess groundwater and dryland salinity
  • preventing and mitigating land degradation
  • sequestering carbon.


2) Economic benefits
  • opportunity for diversification
  • risk management
  • innovation
  • longer rotation crops for superannuation (more than 20 years)


3) Aesthetic benefits

Farm forestry means that a farm is a ‘nicer’ place to live and work.



Using forestry biomass and wood-waste products to generate energy is discussed in Chapter 7 of the report which looks specifically at:
  • biofuels – such as biodiesel, methane or ethanol
  • biomass – as direct fuel, such as for combustion
  • biochar
  • cogeneration
  • carbon sequestration.


Growing a mix of tree crops for bioenergy and other bioproducts, such as timber and woodchips, has several benefits for landowners, according to the 2011 RIRDC report, Bioenergy from native agroforestry: An assessment of its potential in the NSW Central Tablelands [PDF, 2.4 MB]. The report says that growing trees for biomass offers the possibility of:
  • using land profitably
  • achieving catchment targets for increasing native vegetation
  • conserving biodiversity
  • combating salinity and erosion
  • protecting water quality and mitigating some of the impacts of climate change.
The report makes recommendations for planners, government departments, energy providers (biomass consumers) and landowners to create a sustainable biomass industry. It also reports on species of use, and benefits of the species chosen.



An example of a forestry and sawmill residue feedstock project is described in Section 5.4 (page 73) of the report, A bio-energy roadmap for South Australia, which was prepared for the state government in August 2015.

The report also describes the technology options for producing energy from forestry and sawmill residues and outlines the main issues that need to be considered.



In Tasmania, 3.3 million tonnes of biomass could be sourced for bioenergy from sustainable forestry, with nearly 70% coming from private land, according to a 2013 study that compared Tasmanian and European forests: Forest biomass for energy: Current and potential use in Tasmania and a comparison with European experience.

The biomass could come from:
  • native forest regrowth
  • plantations
  • wood-processing residues.
Economic, ecological and social implications of using forest biomass for energy are also described.

Supply chain

Forest biomass supply chains have been well defined and researched in Europe and are operating effectively to convert forest biomass to commercial products—including an alternative energy source. Work is needed to adapt these systems to Australian forest operating conditions.

The supply chain is a particular barrier for producers of harvest residues to be able to supply power stations for co-firing.

This report by RIRDC, Facilitating the adoption of biomass co-firing for power generation, looks specifically at these barriers.

There are barriers for producers of residues from agriculture, agroforestry, forest plantation and native forests. The report also provides information on supply chain logistics and costs with specific concern for supplying power stations with the residue for co-firing.



AFORA’s freely available industry bulletins and reports and industry tools also offer information on supply chain.

Growing a plantation

Plantations must be carefully and actively managed over their life-cycle to produce particular timber and wood-products: this management is commonly referred to as ‘silviculture’. There is considerable silvicultural expertise in Australia, but, as discussed in Chapter 8 of the 2011 Australian Government report, Seeing the forest through the trees [PDF, 4.5 MB], Australia relies on foreign-trained forestry professionals.

The length of time a tree is grown before being harvested is commonly referred to as the rotation length. A plantation goes through a cycle of planting, growing, harvesting, and then replanting. The length of time between planting and replanting may be from 10 years up to 70 or 80 years. This is commonly referred to as the ‘rotation length’.

Both softwoods and hardwoods can be grown for short- and long-rotation: in general, short-rotation (perhaps 10 to 15 years) suits trees that are to be chipped or pulped, and long-rotation (more than 20 years) suits trees that are to be grown for sawlogs.

The pros and cons of short- and long-term rotations, in the context of Australia’s timber and wood product needs, are described in Chapter 5 of Seeing the forest through the trees [PDF, 4.5 MB].

Harvesting and transporting residue

The method of harvesting trees can have a large affect on the costs and benefits of using plantation residue for biomass production.

Bioenergy Australia’s 2012 publication, Bioenergy in Australia: Status and Opportunities [PDF, 9.1 MB], reviews methods and options for:
  • harvesting
  • removing
  • transporting
  • drying biomass fuel.


European biomass harvesting technologies have been reviewed for their application in Australia in a 2010 report produced by the CRC for Forestry.

The report summarises the advantages and disadvantages of various biomass systems used in Europe and notes their possible application in the Australian forestry industry, with a particular focus on recovery of harvesting residue for use in energy generation.



AFORA’s freely available industry bulletins and reports and industry tools also offer information on harvesting, collecting and transport options.



A Canadian guidebook, Biomass truck and resource road standards, provides a tool to determine which biomass truck configurations could travel successfully on new or existing resource road networks. Although this report is Canadian based, it is a useful reference for biomass operations within the Australian forest products industry.

It gives examples of existing biomass truck configurations and their suitability to different road conditions, based on:
  • truck configuration
  • road grade, width, surface material
  • horizontal curve radius, and vertical alignment.

Contacts

Dr. Mohammad Reza Ghaffariyan

University of the Sunshine Coast

Maroochydore DC, Queensland, 4558 Australia,
Phone: +61 7 5456 5447

mghaffar@usc.edu.au
David Hall

Energy Developments and Resources (EDR)

4 Glenneth Court, Bonny Hills NSW 2445,
Phone: +61 (0)2 6585 5368

david.hall@energydr.com.au
Martin Moroni

Private Forests Tasmania

30 Patrick Street, Hobart 7000,
Phone: 0361654073

admin@pft.tas.gov.au
Simon Penfold – Woody Biomass

African Mahogany Australia / Australian Bioenergy Partners

12 Churchill Court, East Brighton, Vic 3187,
Phone: 0488009843

Simon.penfold@ambrazil.com.au
Giles Perryman – Refgas Australia

Refgas Australia

Dunsborough, WA. 6281,
Phone: 0447 393 363

refgas@askwm.com
Fabiano Ximenes

Forest Science - Department of Industry - Lands

level 12, 10 Valentine Ave, Parramatta NSW 2150,
Phone: 0458760812

fabiano.ximenes@dpi.nsw.gov.au
Col Stucley

Enecon

Suite 5, 651 Canterbury Road, Surrey Hills, Victoria 3127
Phone: +61 (03) 9895 1250

cstucley@enecon.com.au
David Coote

University of Melbourne

Parkville, Vic 3010
Phone: 0419 509 822

dccoote@mira.net
Mohammad Reza Ghaffariyan

Forest Industries Research Centre (FIRC) University of the Sunshine Coast

Sippy Downs, Qld 4556
Phone: 07 5456 5447

mghaffar@usc.edu.au
John Meadows

Forest Industries Research Centre, University of the Sunshine Coast

Sippy Downs, Qld 4556
Phone: 0437 536 865

meadows@usc.edu.au