Aromatics in European Motor Fuels: Sources, Rationale and Strategies To Meet Year 2000/ 2005 Limits, Impact on Costs and CO₂ Emissions

European motor fuel specifications have changed dramatically in recent years. This has included a reduction of the benzene content of gasolines to less than 1%, the introduction of a maximum limit for total aromatics in gasolines and polyaromatics in diesel. Total aromatics in diesel are also indirectly limited by increasing cetane and decreasing density specifications. These new limits, associated to the improvements in vehicle emissions partly enabled by the reduced sulphur content of the fuels, have already reduced the contribution of road transport to total emissions and are set to further dramatically reduce this contribution in the coming decade. As vehicle exhaust after-treatments become more efficient, the absolute level of emissions decreases and the impact of the fuel quality becomes increasingly marginal. The already implemented and foreseen changes in motor fuel specifications have had and will have major consequences for refinery operations, affecting the whole product chain. They have and will require major investment programmes and also result in an overall increase in CO2 emissions. As competition for desirable components increases, the quality of the feed to petrochemicals is likely to worsen. As long as the spark ignition engine dominates the gasoline vehicle market, aromatics will play a vital role in providing both the quantity and high-octane quality of the required fuel. Further changes in road fuel quality would not give significant improvements in air quality but could have major implications in terms of refinery investments, global CO2 emissions as well as available volumes. 1. Evolution of EU Aromatic hydrocarbons are an integral part of motor fuels. In gasolines they provide the bulk of the specifications affecting aromat- octane rating, the fundamental quality for a spark-ignited engine. In diesel they are part of the ics in road fuels package of molecules found in the relevant virgin crude oil cuts and are also produced in catalytic and thermal cracking of heavier cuts. Over the years and particularly in the last decade, EU motor fuel specifications have been dramatically tightened. This has followed a general trend, supported mainly by concerns on the effect of road traffic on urban air quality. The USA, and more specifically California, has lead the world with regards to gasoline whereas diesel has also attracted great attention in Europe due to its much larger share of the personal car market. Table 1 summarises the main recent changes to EU specifications. BLOCK 2 - - FORUM 11 361