As the global aviation industry strives toward net-zero carbon emissions by 2050, sustainable aviation fuels (SAFs) derived from biobased feedstocks have emerged as a crucial pathway to decarbonization. While much of the existing research on SAFs has focused on environmental and technological aspects, limited attention has been paid to their broader sustainability dimensions, such as socioeconomic and human health impacts and supply-demand dynamics. This thesis addresses these gaps by providing an integrated assessment of the sustainability performance of biobased SAF production and supply chains, combining quantitative modelling with a holistic systems perspective.
The research first establishes that biobased SAF constitutes an emerging, complex sector that interacts with multiple industries and societal stakeholders. Given its developmental stage, assessing its full sustainability performance early on is vital for guiding policy and investment decisions. The thesis develops and applies methodological approaches to quantitatively evaluate underexplored sustainability dimensions, focusing on socioeconomic effects, life cycle human health impacts, and the balance between SAF supply and demand under future decarbonization scenarios.
The socioeconomic assessment employs a scenario-based Input-Output (IO) analysis, using Brazil’s projected SAF demand toward 2050 as a case study. The analysis demonstrates that biobased SAF production can generate substantial positive socioeconomic benefits, including net gains in employment and GDP. However, these benefits vary by feedstock type and conversion technology, highlighting the need for region-specific policies to optimize socioeconomic outcomes. Modest negative impacts on trade balance and fossil-sector employment are identified, for which proactive mitigation measures—such as retraining programs and labor reallocation—are recommended to ensure a just transition.
To complement the socioeconomic analysis, the thesis explores human health impacts through a comparative evaluation of six life cycle impact assessment (LCIA) methods. The results reveal that biomass conversion processes are the primary contributors to health-related impacts due to chemical use, energy consumption, and waste generation, followed by feedstock cultivation involving fertilizers and pesticides. The study concludes that no single LCIA method can universally capture human health effects in SAF systems; rather, the methodological choice should be context-specific, guided by study scope and regional conditions.
Further, a supply-demand analysis examines the potential of biobased SAF to meet the aviation sector’s decarbonization targets by 2050. Using European data and multiple scenarios, the findings suggest that sufficient SAF supply is only attainable if feedstock availability exceeds 60% of theoretical potential—an unlikely scenario given competition from other bio-based industries. The results underscore the regional variability in biomass distribution and the importance of aligning national and continental strategies.
Overall, the thesis concludes that biobased SAF holds significant promise in reducing greenhouse gas emissions—up to 75% compared to fossil jet fuel—while promoting socioeconomic development. However, its sustainability performance is highly context-dependent, influenced by technology choice, feedstock type, and policy design. The work advances an operational framework for integrated sustainability assessment that identifies trade-offs and synergies, supporting informed decision-making for SAF deployment. Beyond aviation, the methodological insights contribute to broader discussions on designing fair, effective, and context-sensitive transitions toward a sustainable bioeconomy.

The life cycle human health (HH) impacts related to aviation biofuels have been understood in a limited way. Life cycle impact assessment (LCIA) methods for assessing HH are often associated with a high level of uncertainty and a low level of consensus. As a result, it remains challenging to perform a robust assessment of HH impacts with a suitable LCIA method. This study aims to systematically compare six commonly used LCIA methods for quantifying HH impacts, in order to empirically understand the potential impacts of aviation biofuel production on HH and how the results are affected by the choice of methods. Three aviation biofuel production pathways based on different feedstocks (sugarcane, eucalyptus, and macauba) were analyzed and compared to fossil aviation biofuels, on the basis of a functional unit of 1 MJ aviation fuel. The majority of the LCIA methods suggest that, in respect to midpoint impacts, macauba-based biofuel is associated with the lowest impacts and eucalyptus-based biofuel the highest; whereas at endpoint level, the results are more scattered. The LCIA methods agree that biomass conversion into aviation biofuel, H2 production, and feedstock cultivation are major contributors to life cycle HH impacts. Additionally, we provide a guideline for determining an appropriate method for assessing HH impacts.

Derived from renewable feedstocks, aviation biofuel is generally perceived as inherently sustainable. However, its production involves a wide range of sectors and interacts with different actors in society. It is therefore important to understand and evaluate not only the environmental impacts of that process, but also its socioeconomic effects. At present, empirical studies assessing socioeconomic aspects of aviation biofuel are rare in scientific literature. The aim of this study, therefore, is to assess key effects of aviation biofuel production on employment, GDP, and trade balance. A scenarios-based Input-Output (IO) analysis was used to evaluate these socioeconomic effects, taking Brazilian aviation biofuel production to 2050 as an example. To address the uncertainty of IO analysis, we have proposed a stochastic simulation approach for the technical coefficients in the IO model. Four distinct scenarios were developed. In each, three potential combinations of technologies and feedstocks for producing aviation biofuel were evaluated: sugarcane via alcohol to jet (ATJ), macauba via hydro-processed esters and fatty acids (HEFA), and eucalyptus via Fischer-Tropsch (FT). Among other things, we found that the production of aviation biofuel would create around 12,000–65,000 jobs, while contributing US$200-1100 million to Brazil's GDP under different scenarios with different supply chains. The socioeconomic effects calculated deterministically were generally higher than the stochastic outcomes, which can be explained by factors such as technological learning and economic growth. Aviation biofuel production showed large positive net socioeconomic effects on employment and GDP, although some of the fossil sectors would be negatively affected. Overall, the macauba-HEFA chain (with the highest effects on employment and GDP, and the lowest effects on imports) seemed to be the most favorable of the scenarios studied, despite the relatively high level of uncertainty associated with it.

Aviation fuels derived from biomass are generally perceived as sustainable alternatives compared with their fossil counterparts. However, the production of jet biofuels will have impacts on environment, economy and society simultaneously. Despite that a large number of studies have evaluated environmental impacts or techno-economic feasibility of aviation biofuels, very few studies took social aspects into consideration. Thus, this study seeks to provide a social sustainability evaluation for aviation biofuels with a supply chain perspective. Three potential jet biofuel supply chains, based on different feedstocks, i.e. sugarcane, eucalyptus and macauba, were analyzed in the context of Brazil. The assessment is performed mainly with a process-based approach combined with input-output analysis. A set of social sustainability issues, including employment, working condition, labor right, gender equity and social development, were evaluated in a quantitative manner. The results show the three supply chains lead to differentiated levels of social effects. The macauba-based supply chain generates the highest number of jobs and highest GDP value, whereas the eucalyptus-based supply chain offers more employment opportunities for women. In comparison, the sugarcane-based supply chain has relatively moderate social effects. For future work, the assessment of social sustainability needs to cover a wider range of social issues, in order to extend the comprehension of social sustainability regarding biofuels. Additional research is suggested to bridge the methodological gaps in social sustainability assessment.