Dialogue: Improving fuel quality key to clearing the air

By JACK HENDERSON

Aucklanders care about air quality - that is one certain outcome of the Auckland Regional Council's 0800 SMOKEY campaign.

Smoke incidents have been logged at more than 1000 vehicles a day. Rightly sick of breathing foul exhaust gases, we want vehicles to be fixed so they don't pollute. To achieve this state, taken for granted in European cities, four conditions need to be satisfied, with tuning our vehicles being one of them.

The ARC campaign is successfully focusing on that.

The Government has started work on the other three: prosecution for vehicles that emit visible smoke for more than 10 seconds, a rule that vehicles must comply with the (better) emissions standards of their countries of origin, and regulations to improve fuel quality. Of these, fuel quality improvements have been the least discussed so far, but are needed for any of the measures to work properly.

Marsden Pt fuel is low-tech, both petrol and diesel. It makes tuning difficult for both performance and cleanliness, damages exhaust-cleaning equipment, and produces harmful gases in higher quantities than petrol and diesel from other developed countries.

The main issue with petrol is the way that octane (RON) is enhanced. RON is a measurement of fuel's ability to resist detonation. 96 petrol ignites later than 91, but most cars these days are designed to run on 91, which is cheaper and cleaner (but not clean enough). RON is varied by differences in blending stock and isomers, and by refinery procedures. Octane was originally enhanced in New Zealand by lead, which is also a scavenging agent, but which was banned by regulation after its poisonous effects became known.

RON is now enhanced by the addition of aromatics in the stock: notably benzene and toluene, which are carcinogenic in themselves, and with combustion poisons which include relatively high levels of invisible carbon monoxide. Motorists will recall the early unleaded petrol, which had aromatic levels so elevated that it rotted fuel lines.

To protect public health, there has been a concerted move in Europe and America to screw down benzene levels, not yet followed in New Zealand. The cost to the motorist should be small, as it is mostly a fuel content issue, and will be unnoticeable compared with normal fluctuations.

With diesels the problem is very simple, but the solution more expensive: there is far too much sulphur in our diesel. Sulphur is part of crude oil and if it is not properly separated has a number of bad effects.

When diesel engines emit sulphur dioxide and sulphates, noxious in themselves, particles are formed into soot. More nitrogen oxides are also produced. The large volumes of soot make it impossible to fit new technology exhaust-cleaning equipment, so the exhaust goes unfiltered into the atmosphere. A 35 per cent reduction in particulate matter in diesel exhaust can be achieved by sulphur reduction alone, even without better tuning or emissions-control equipment. Diesel particulates have been strongly linked to lung cancer.

The sulphur level allowed in New Zealand diesel is 3000 parts a million.

In Europe, Japan and America, a 500 ppm level has been introduced, with the intention of getting it down to 50 ppm by mid-decade. That's 60 times better than the standard existing here. Technically, we need more sulphur extraction plants at Marsden Pt. These do not come cheap, but $200 million could achieve the new 50 ppm standard. It will be necessary to achieve this level to use the new diesel technologies and emissions-control equipment. There is no point in going for 500 ppm as an intermediate position - there are real economic and environmental advantages to going straight to 50 ppm.

The air quality and fuel efficiency gains should more than compensate for the cost of about 3c extra a litre until the plant is paid for. Looking at the amount of variation in fuel prices occurring at the moment, it is a small price to pay for clean diesel and cleaner air. It is also worth noting that there is no excise duty on diesel fuel.

Our fuel is underspecified not because of the business practices of the refining company, which are legal, but because of years of ineffective light-handed regulation, resulting from a belief that the market needs no intervention.

Yet everywhere in the world, oil companies have only moved where regulations exist. Now we are seeing some action. New Government policy is to complete a discussion document on fuel quality improvements by Christmas, under the Ministry of Economic Development, with regulations in force midway through next year. For the sake of our environment, we need to increase the quality of fuel, even if it costs just a little bit more: in the context of recent price rises, it is no disaster, but we will all notice the improvement in our air quality.

*Jack Henderson is Deputy Chair of the Auckland Regional Council's Transport Committee.