KEY POINTS:
The Biofuel Bill is working its way through the parliamentary process with the aim of requiring a fraction of all fuel sold in New Zealand to be produced from biological sources.
This will result in more fuel produced from renewable or sustainable materials, which will have less environmental impacts than mineral petroleum - both when extracted and in emissions released into the atmosphere.
There are concerns some of the biological sources may not be as renewable, sustainable and environmentally friendly as first thought. Specifically, some food crops have been used for fuel production and forests have been cleared to plant fuel crops - though not in New Zealand, yet.
Because of this, the Biofuel Bill is being modified to ensure that future biofuels in New Zealand do not cause such adverse side effects.
With these concerns considered in the legislation, and with the added economic pressure of continually escalating petrol prices, there are many good reasons to move towards biofuels at the pump.
However, the most important fuel to benefit from the legislation, which is often overlooked, is diesel.
Substitution of diesel fuel with biodiesel is of more importance than gasoline substitution because of diesel's practically universal use in public transport and the food production, processing and distribution sectors. Most people should be able to walk to the supermarket to buy their food but the food cannot be delivered to the supermarket without the truck and the fuel.
The European Union, in particular, has progressed a long way in the introduction of biodiesel. However, because of concerns over the crops used to produce biodiesel, the EU is now seriously reconsidering the issues. Britain recently produced an official review which urged a slowdown in the planned adoption of biofuels, including biodiesel.
But in New Zealand, we have the luxury of being able to produce biodiesel from a common waste from our agriculture sector - tallow.
Tallow is a byproduct of the meat processing industry. It has been estimated it could supply up to 3 per cent of our current diesel fuel use. Once processed into a fuel-grade product, it can be used in unmodified diesel engines when blended at up to 5 per cent in conventional diesel fuel.
New Zealand already has the required standards specification for the quality of such fuels in place. This ensures there will be no adverse effects on engines from using such blends.
It could also be possible to use higher blends in selected fleets, where the vehicles could be monitored to ensure there were no problems with these higher concentrations.
It would be a synergistic sustainable use to have the cattle trucks running on fuel made from the beasts that they carry.
We have the advantage of having local companies dealing with tallow refining.
The University of Auckland has also developed new biodiesel manufacturing technology and patented it, which reduces the reaction time to produce biodiesel from many minutes to only a few seconds. This has the potential to make the production process even more economical.
In order to expand the production of biodiesel further, we need to look for other feedstock in the future. One alternative is to plant fast-growing trees for the production of non-edible oil for use as feedstock. In the long term, we could also harness oil produced by algae for the production of biodiesel.
All of these options present an exciting future for New Zealand to be a world leader in producing its own sustainable, environmentally-friendly biodiesel.
* Associate Professor Robert Raine is a member of the engineering faculty at the University of Auckland.
