CSIRO releases report into biodiesel GHG emissions

The CSIRO yesterday released a report which investigates the impact of biodiesel use on greenhouse gas emissions, when compared to standard diesel fuel. At 126 pages, the report is slightly too large to have a quick read through during a break, so here’s the executive summary of the executive summary:

• Canola-based biodiesel emits 3.5 times more GHG emissions (measured in grams of CO2-equivalent) during its production than diesel fuel, known as the “upstream” section of the life cycle. However, total life cycle emissions are reduced by 49% when using canola-based B100, as the crops absorb carbon dioxide.
• Tallow, or animal fat, has upstream emissions 50% higher than those of diesel, but life cycle emissions 76% lower than diesel.
• The emissions from plantation-based palm oil depend on the age of the plantations being used. If the plantation is established before 1990, the emissions “associated with land clearing are not counted…under present methods of carbon accounting”, so upstream emissions are only 25% higher than those from diesel and life cycle emissions are 80% lower. Newer palm oil plantations, however, have upstream emissions 50 to 136 times higher than diesel, and life cycle emissions 8 to 21 times higher.
• Used cooking oil, being a waste product, has almost no upstream emissions, resulting in a life cycle emissions saving of 87% when compared to diesel.
• 2 per cent blends (B2) lower emissions by 1.7% at most, with standard Australian B2 fuels reducing emissions by 0.92% to 1.47%, depending on the source of biodiesel.

Also of note is that the extra-low-sulfur diesel (XLSD) used as the baseline in these calculations actually produces slightly more carbon dioxide than standard low-sulfur diesel (ULSD), due to the additional processing required. The lower sulfur content generates fewer smog-forming and hazardous pollutants; it is worth noting that the use of biodiesel also significantly reduces sulfur-based pollutants, though.

Luke at Envirofuel makes the point that the report is commissioned by Caltex, who supply biodiesel in 2, 5 and 20 per cent blends. According to Caltex CEO Des King, the company does not use palm oil “unless it can be shown to be sustainable to the satisfaction of key stakeholders in the countries it is produced”.

The full report can be viewed at the CSIRO website.

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