Evaluating Alternative Fuels to Facilitate the Implementation of the Carbon Offsetting and Reduction Scheme for International Aviation

The aviation sector has contributed US$2.7trillion to the global growth domestic product (GDP). Despite this positive economic contribution, environmental concerns arise from the aviation sector. As a mode of transportation, aviation has a 12% share of CO₂ emissions from the sector. As a result, the ICAO has developed a market-based measures (MBM) scheme to mitigate CO₂ emissions. Incidentally, CORSIA is an MBM technique implemented by the ICAO in the form of an offsetting scheme. The offsetting requirements are accounted for using a combinatory approach of both sectoral and individual approaches. The sectoral approach measures the aviation emissions growth factor considering all the participating states under CORSIA. The individual approach accounts for the emission growth factor on an operator level. In order to reduce operators' obligation under CORSIA, the integration of reduction measures such as Alternative Jet Fuels (AJFs) may reduce the cost associated with CORSIA's offsetting requirements. Therefore, an intensive literature review collected data on the characteristics of AJFs and lifecycle emissions for each selected fuel. The studied fuels are categorised depending on their production pathways to Gas to Liquid (GTL), Oil to Jet (OTJ), Gas to Jet (GTJ), Sugar to Jet (STJ), Catalytic Hydrothermolysis Jet (CHJ), and Alcohol to Jet (ATJ). A multi-objective model developed is combined into a singular objective function to optimise the total fuel-related cost on operators under CORSIA. The objective function also considers the reclaiming possibility of offsetting requirements if a CORSIA's Eligible Fuels (CEF) is utilised. The results demonstrate that an increase in carbon price increases the total net cost of fuel purchasing and carbon taxing. However, including the reclaiming credit can reduce the total cost by 0.13% to 22.14%, assuming a carbon price range from 3 $/tonneCO₂ to 510 $/tonneCO₂.