Future Aviation Fuels – The Petroleum Industry Responds to the Challenge 800769
The growth of air traffic continues whilst the supply of petroleum fuels is expected to become more difficult with different applications competing intensively for the available products. The choice of crude oils available for refining is restricted so that the flexibility of refineries to meet the demands for products with restrictive specifications is reduced.
In order to maximize the long-term supply of aviation fuel it is foreseen that alternative sources of liquid fuel will need to be developed as well as the employment of as wide a range as possible of a variety of petroleum crudes. In the paper, factors that may in some cases limit the quantity of appropriate fuels are reviewed, with a description of Research and Development activities directed towards investigating the possible relaxation of particular specification items.
Refinery patterns are increasingly being geared, by various conversion techniques, to the production of maximum quantities of distillate fuels at the expense of the heavier fractions of the crude oil. Whilst these distillates may be somewhat more aromatic and olefinic in character than aviation users have been used to hitherto, they can be treated by various methods involving the use of hydrogen to yield products meeting even the tightest specification; however the treatment cost is high and the product yield deficient.
The effect of various hydrocarbon fractions and pure hydrocarbons on the combustion and low temperature properties of fuels has been investigated as well as their effects on the thermal stability of the fuels. The conclusions reached and deductions made in relation to aircraft and engine performance are described.
The paper concludes with consideration of the problems to be faced with fuels derived from alternative sources such as oil sands and shale oils and a reference to the potential financial and supply problems facing hydrogen as an aircraft fuel.