31. It is common internationally that low level biodiesel blends are required to meet the petroleum diesel specifications as they are considered interchangeable with diesel. It is recommended that retail biodiesel blends in New Zealand are required to meet the diesel specifications set out in the PPSR (Schedule 3). The following outlines the amendments necessary to Schedule 3.
Maximum allowable biodiesel content
32. It is recommended that the maximum allowable biodiesel to be blended with diesel for retail sale is 5% by volume (using test method EN 14078), and that this biodiesel must meet the B100 specifications. It is considered that biodiesel blends containing up to 5% by volume may be used in any diesel engine without modification, and thus a 5% limit is common internationally (e.g. Europe, Japan, United States, Canada, and is currently being proposed in Australia).
33. Several submitters do not support a limit of 5% by volume biodiesel in diesel for retail sale. These submitters want the flexibility to retail higher blends, which would enable greater demand for biodiesel, potentially providing more scope for a domestic industry, and give greater choice to consumers. However, there is a lack of vehicle manufacturers who will support biodiesel blends above 5% by volume. Allowing for the retail sale of higher biodiesel blends increases the chance of vehicle operability problems occurring, particularly while compatibility awareness is low, which could impact on consumer confidence in biofuels. As noted above, non-retail biodiesel blends will be able to contain any proportion of biodiesel.
Amendments to test methods
34. It is recommended that the particulates (otherwise known as total contamination) test method is amended from ASTM D6217 to IP 440. The current test method is not applicable to biodiesel blends. The majority of submitters support this amendment.
35. It is recommended that the test method ASTM D6890 is allowed as an alternative test method for cetane number. The current test method requires the use of a cetane engine which is relatively rare and old technology that is expensive and difficult to operate. Cetane index is commonly used for petroleum diesel, but this test method is not applicable to biodiesel blends. The majority of submitters support this amendment.
36. It is recommended that the water content test method be amended from ASTM D6304 to IP 438. This test method has greater precision and uses the same equipment.
Cold Flow Properties in Auckland/Northland
37. The current cold flow property4 requirements in the PPSR for summer and winter diesel apply to all areas of New Zealand. It is recommended that the Cloud Point5 (CP) for summer in Auckland and Northland (as defined in the PPSR) be relaxed from +4ºC to +6ºC. A review of the climate data showed that the current requirement is too stringent for these regions, which are warmer on average than the rest of New Zealand. Relaxing the CP specification in Auckland/Northland will also facilitate the blending of biodiesel into existing diesel stocks in this region, reducing the need for a separate diesel blendstock. In general, blending biodiesel into diesel at the 5% by volume level increases the CP of the fuel by 2 to 3ºC.
38. Whilst Auckland and Northland are warm regions, the cold flow requirements here need to take into consideration those who travel from Auckland to cooler areas, such as the central volcanic plateau, on the same tank of diesel. Climate data indicates that there is a risk of waxing in the central volcanic plateau with diesel that meets the current regulated CP for summer (+4°C), let alone a relaxed CP. However, the regulated cold flow performance requirements do not aim to ensure all diesel is protected from waxing in all parts of the country in all seasons. Instead they specify absolute minimums and set an overriding ‘fit for common purpose' requirement. In practice, the oil companies manage the cold flow performance of diesel to suit the given region and season, often applying more stringent requirements than in the PPSR.
39. The majority of submitters supported a relaxation of the CP requirements in summer provided that this is justified by climate data. Gull New Zealand Ltd do not, however, support having geographically different cold flow requirements, as they believe that it will place them at a disadvantage against the four major oil companies. Gull only draws fuel from one source (i.e. Mount Maunganui), and to continue to supply areas north and south of Auckland all fuel will need to meet the most stringent requirements (i.e. +4ºC). Whereas the four major oil companies will have the option to supply separate stock to Auckland/Northland. The higher the cloud point, the lower the cost of the diesel. A report by Hale & Twomey (2006) into specification waivers for biofuel blends indicated that the cost for oil companies of producing diesel with cold flow properties 2ºC lower would be about NZ 0.2c/l.
Filter Blocking Tendency
40. It is recommended that B5 blends for retail sale be required to meet all of the specifications for retail diesel, which includes a limit for Filter Blocking Tendency (FBT). The FBT test measures the filterability of fuel in order to ascertain what affect it will have on vehicle operability. It was included in the PPSR in 2002 in response to problems encountered with diesel fuel dosed with a cold flow improver. While it is a sensitive test method, petroleum diesel supplies have had no problem meeting the limit of 2.5. Australia is the only other jurisdiction that includes an FBT requirement in the diesel specifications (with a tighter limit of 2.0).
41. Some recent testing in New Zealand of biodiesel blends produced from either tallow or palm oil has shown the unexpected formation of particulate aggregates at room temperature which are causing the blends to often fail the FBT limit. Not enough is known at this time as to the cause of the poor FBT results. There have also been problems with fuel filter clogging from biodiesel blends in the United States. As a response to this, the United States is currently considering including a filterability test in its standard.
42. Several submitters are of the view that the FBT requirement should not apply to biodiesel blends due to the sensitivity of the test and the problems fuel made from tallow is experiencing in meeting this specification. However, there is not enough evidence to suggest that a FBT limit above 2.5 would not have a negative impact on vehicle operability. To build and maintain consumer confidence in biodiesel, and to protect the integrity of the biodiesel and fuel industry as a whole, it would be prudent to require biodiesel blends to meet the current FBT requirement until it is better known what the affects of a higher limit are on vehicle operability. Certain biodiesel manufacturing technology seems to have better results than others at producing product with satisfactory filterability properties. Thus, the filterability issues are not necessarily seen as being a limiting factor for domestic tallow biodiesel production.