Comparison of Jet Fuel produced by Shale oil and Biomass:Manufacturing, Emission and Performance

摘要

The need for alternate fuels to power aviation both commercial and military arises from two main factors - energy security and environmental safe guards. Various researchers around the world are looking at alternate feedstock and methods to obtain drop in fuels keeping the environmental impact of the whole process in mind. The primary target for all these fuels is to satisfy physical and combustion characteristics of at least existing petroleum derived jet fuel - JP-8 and Jet A. Jet Fuel produced from shale oil was first proposed and investigated as a viable option in the 1970's by the United States Air Force (USAF). The program was dropped due to decrease in crude oil prices back then. There is a renewed interest in the use of oil shale as feedstock due present global situations. Various parameters such as specific gravity, flash point, freezing point, heat of combustion, smoke point, thermal stability, auto ignition temperature and emission characteristics were determined in these experiments. These experiments revealed the similarities and the parities with the then Jet fuel used by the USAF - JP-S and also looked at chemical composition of the shale oil derived jet fuel to explain their findings. With the present global competition for fossil fuel feedstock and increasing prices the energy security offered shale oil seems very attractive. The improved extraction efficiency along with lowering of the carbon footprint of the process has made shale oil a prospective feedstock. This paper also looks at the physical and combustion characteristics of 1. Biodiesel from hydroprocessing (HEFA) and transesterification and 2. Coal, gas and biomass derived synthetic liquid fuels as aviation fuels. The former is being used in various test runs and the latter already in commercial use in Johannesburg and makes comparison to find the better option. Finally we take a look at "well to wake" concept of a fuel life cycle to see how practical is their use on large scale and future requirements of the aviation industry to access the possibility of them as a long term alternate to petroleum derived jet fuel.