An Experimental Strategy for the Manufacture of Aviation Fuel 2010-01-1878

Air travel has continued to increase dramatically and all indications are that the rapid rate, approximately 4% per annum, will continue into the foreseeable future. One major barrier to this growth is related to fuel. There exist major technical challenges in supplying fuels and in reducing exhaust pollutants. Transport propulsion is dependent on limited sources, mainly fossil fuels, which have a peak production predicted to be around 2005, and crude oil sources are limited and will eventually run out. Commercial air transport is responsible for around 700 million tons of jet-fuel derived CO₂ today, about 2.31% of total anthropogenic carbon dioxide, future forecasts of aviation growth show CO₂ emissions from the sector rising rapidly and inexorably to more than 1 billion tons by 2025 and this is unlikely to be acceptable. The future rate of gains in 15-20% aviation fuel efficiency (excluding dramatic improvement in fuel efficiency since the first commercial turbine aircraft which entered service in the 1960s) is not sufficient, nor likely to be matched into the future, to offset the growth rate of air travel (about 5.3% per year between 2000 and 2007, resulting in an increase of passenger traffic of 38%) particularly as many of the relatively easy technical improvements have already been incorporated. Any growth in air travel will lead to higher fuel demand. This will require the problem of meeting fuel requirements to be addressed including crude oil availability and cost, oil security, and concerns about global warming and climate change. For the growth of air travel to continue fuel alternates for aviation have to be found.

Biokerosene manufactured from vegetable oils is expected to have similar properties to conventional kerosene. The fuel is one of the candidates for aviation fuels due to its renewability and its availability, and its ability to mix with the traditional fuel. The source of materials for these is more widely, and thus reliably available when compared with their fossilized counterparts. Vegetable oils consist of long-chain fatty acid alkyl esters organic compounds and can be derived from a broad variety of renewable resources such as soybean, grape, jatropha, and algae oils. The oils have high viscosity, high freezing points, poor thermal stability compared to conventional kerosene, at this state, the oils cannot be viable fuels for aviation. Therefore, the sources of fuels need to be converted into biokerosene through techniques like pyrolysis and hydrodeoxygenation. This paper gives an overview of alternative aviation fuel applications, the production of biokerosene aviation fuels, and outlines the first stage of our efforts to develop an experimental strategy for the manufacture of biokerosene from vegetable oil sources by pyrolysis that could presents a solution to the fuel shortage in the future.