Parratt & Associates Scoping Biorefineries: Temperate Biomass Value Chains

3.2 Regional assessments

A limited number of regional assessments of biomass feedstocks have been published. The results from two of these are summarised in Table 3-2. They have generally been undertaken to determine the potential contribution of bioenergy for a specific region or biomass resource. They provide a useful indication of the amount of biomass potentially available at a specific location that could be sourced from a biorefinery.

The Central Highlands Study undertaken by SED Consulting covered agricultural, forestry, municipal and industrial waste streams as well as short rotation coppice plantings⁹⁴. This study indicated that harvest residues from forests in the region could provide 70–86 kt/y prior to 2013 (based on the estimated amount of material within 50 km of the regional centre) and 145–171 kt/y in the longer term (based on the amount within 100 km of the regional centre). These figures represent 6–7% of the total figure from the CSIRO National Assessment, while those for crop stubble (140–560 Mt/y) represent around 10% of the CSIRO study⁹⁵. There is also no indication of whether they refer to dry or wet mass or, if the latter, the assumed moisture or energy content of the biomass.

The study identified several potential options for bioenergy generation from this material. These included a 12 MW capacity moving grate furnace boiler fuelled by municipal solid waste, and a 25 MW fluidised circulating bed furnace fuelled by woody biomass. The authors calculated that the combined output of both boilers would amount to 8–12 MW of electricity, with 25–28 MW of heat energy also available for industrial and process heat.

The University of NSW (UNSW) undertook a second published regional assessment for the Murrumbidgee Irrigation Area⁹⁶. The study concentrated on animal and food processing waste, but also reported on the availability of stubble in the region. Their study determined that rice straw was the only stubble available, as cereal stubble is predominantly either retained or used locally as animal feed. The amount of rice straw utilised was estimated to be 25% of the total rice straw available (the remainder is retained in the soil). The UNSW assessment calculated that 96,768t of rice straw would be used as animal bedding. The study also calculated that 2,796t would be used as household garden waste.

Table 3-2: Estimates of biomass availability for energy or fuel from regional case studies

^97^98Biomass type		Central Highlands kt/y			Murrumbidgee Irrigation Area kt/y
^99^100Crop stubble		140–560	^,		97
Forest residues
^101	Current	20–24			NDA
	Future (Post 2013)	70–163	^105		NDA
Sawmill residues		11	^105		NDA
Mallee energy crops		NDA			NDA
^102^103Municipal and industrial waste		23	^,		2.8
Total
	Current	194-618			100
	Future	244-757			NDA

(NDA = No data available.)