By Luke Harrington
A press release by Z Energy on 3rd April 2014 marks the next step in alternative fuel developments in New Zealand. CEO Mike Bennetts announced a plan to invest $21 million toward a biodiesel manufacturing plant in Auckland, with a particular focus on tallow as the organic derivative of choice. Previous large-scale biofuel generation schemes have been met with varying levels of success in New Zealand (particularly the foray by Solid Energy in 2007) - this is actually acknowledged by Bennetts in the statement. Though this latest proposed operation will only make a small dent in the goliath that is fossil fuel demands for domestic transport, it is a promising step in the right direction – Z should be applauded for taking a leadership role in such an area.
The key ingredient to this proposal is the utilisation of tallow in the biodiesel production process. In essence, tallow is a rendered form of beef or mutton fat, and simply a by-product of the meat slaughter process. Like the use of woody waste biomass to meet the energy demands of the industrial sector, this method of utilising a by-product is a great way of maximising the efficiency of current industrial operations. In my opinion, such an initiative is analogous to car pooling in a city centre; a great way to reduce emissions without any detrimental trade-offs.
A key issue has afflicted the large scale production of biofuel in the past: feedstock crops would be grown on land that could otherwise provide food, leading to food supply reductions, price rises, increased pressure to clear land and higher rates of deforestation. Such problems are not applicable in this circumstance, which is fantastic. Motu was also involved in Scion research in 2009 on the potential for producing biofuel from wood – this technology is still evolving.
In the press release, Bennetts suggests the company will look to incorporate the biodiesel as five to twenty per cent blends, and some commercial customers have already expressed interest to take volume from Z’s initial production outputs. As of 2009, approximately 150,000 tonnes of tallow were produced annually in New Zealand, and could be converted easily and economically into high quality biodiesel (von Tunzelman, 2009). The 20 million litres of annual production proposed by the Z initiative will contribute only 0.5% to the estimated 4 billion litres of diesel used in New Zealand each year (MED estimates, 2013). However, it represents an important first step in encroaching on the high carbon emissions attributed to vehicle transport in New Zealand.
I am interested to see the energy requirements associated with the biodiesel production process. In order for this type of operation to be beneficial in the long term, the energy demands (and associated emissions) at the processing plant cannot exceed the benefits from using less mineral diesel. These numbers are not yet available, owing to the early stages of the project, but needs to remain a consideration. Furthermore, the economic impacts of the production process should not make the biodiesel too expensive for consumers to actually want to buy – it is estimated that a five per cent blend will increase the price by less than 2 cents a litre. Given that only commercial operators are the target consumers in the medium term, I don’t think this is a significant issue right now.