Energy, economic and environmental (3E) analysis for the renewable jet fuel production process

Abstract

Blending conventional petroleum jet fuel with renewable fuel obtained from hydro-processing of cooking oil wastes can significantly reduce the carbon footprint of the aviation sector. Renewable jet fuel (RJF) remains for the most part more expensive than conventional jet fuel and the life-cycle emissions reduction depends on the feedstock. For promoting mass production of used cooking oil (UCO) based jet fuel, a 3E (energy/exergy, environmental and economic) analysis of a simulated processing plant is carried out. Hydrogen is the main component in the two-step process: hydro-processing and hydro-cracking/isomerization. Hydrogen production and exergy destruction in the process significantly influence the life-cycle emissions of the RJF. The low exergy efficiency of the process units where significant heat transfer occurs generates an increase in the price of the products. Results show a life-cycle carbon dioxide emissions reduction from 41 % to 81 % when combusting the hydro-processed jet fuel instead of conventional jet fuel. The minimum fuel selling price could be very close to conventional jet fuel (about 18 % more expensive) if an effective cooking oil wastes collection system is in place. Moreover, when implementing a carbon tax above $37/tCO 2 the price becomes equal to conventional jet fuel. UCO is the most sustainable feedstock as there is no competition with the food market and the environmental benefits justify government spending for promoting mass production.