A carregar...
Publicação
Carbon Footprint Assessment of Microalgal Biomass to Bio-jet Fuel in Mainland Portugal
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 183.88 KB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
The aviation industry, a significant contributor of greenhouse gases emissions in the
transportation sector, faces challenges meeting the decarbonization targets until 2050 through the
paradigm of electric mobility. The limitations of electrifying aviation emphasize the importance of
exploring alternative solutions, particularly biofuels. Hence, this study took part in the Move2LowC
project, exploring microalgae cultivation in industrial wastewater using industrial CO2 effluents,
microalgae harvesting, and its conversion through hydrothermal liquefaction (HTL), bio-oil
refining/upgrading to bio-jet fuel, and combustion in a jet engine, in mainland Portugal.
The primary goal was to determine the carbon footprint of microalgae to bio-jet fuel and other
useful refinery products, addressing two research questions (RQ): RQ1 – What is the carbon footprint
of converting 1 kg (dry cell weight) (FU) of microalgae into multi-product, in gCO2eq/FU?; and RQ2 –
What is the carbon footprint of obtaining and burning 1 MJ of bio-jet fuel (FU) from microalgae, in
gCO2eq/FU, and how can it achieve SAF (Sustainable Aviation Fuel) compliance?
A life cycle analysis (LCA) was undertaken, following ISO 14040/44 standards and global
warming potential at 100years (GWP100), incorporating experimental Move2LowC data, and from
literature and modeling through PRELIM. The system boundary considered cultivation, harvesting,
HTL, transport to refinery, refining/upgrading, transport to airport, and combustion, excluding
construction materials. RQ2 incorporated energy allocation to bio-jet fuel, to compare with CORSIA
guidelines. Alternative scenarios were analyzed, exploring the influence on GWP100 results of the
process units locations; bottled CO2 supplementation; heat recovery from HTL syngas; 100 % renewable
electricity; and different thermochemical processes’ yields.
Results indicated that the Move2LowC base-case scenario does not currently enable SAF
production, with a carbon footprint (161.45 gCO2eq/MJ bio-jet fuel) significantly exceeding that of
conventional jet-fuel. Electricity for cultivation and heat for HTL were major contributors. The scenario
analysis revealed opportunities for emission reduction through employing heat recovery and locating all
system at the same facilities. Combining these two measures, the best-case scenario could produce SAF
if electricity was zero emissions, even with lower bio-oil and bio-jet fuel yields.
This study highlights the importance of optimizing the Move2LowC process and, despite current
limitations, presents potential pathways for SAF compliance, including the decarbonization of the
Portuguese electricity mix by 2050.
Descrição
Tese de mestrado, Engenharia da Energia e Ambiente, 2024, Universidade de Lisboa, Faculdade de Ciências
Palavras-chave
Águas residuais Liquefação Hidrotérmica (HTL) Gás de síntese Simulação de refinaria (PRELIM) jet fuel sustentável (SAF) Teses de mestrado - 2024