Integrated Power-to-Liquid systems can produce Sustainable Aviation Fuel with 21.43 gCO2eq/MJSAF GWP

Why It Matters

This research demonstrates a tangible method for decarbonizing the aviation sector by leveraging renewable energy and innovative capture and conversion processes. It provides designers and engineers with a validated system architecture and performance metrics for developing next-generation sustainable fuels.

Key Finding

An integrated system for producing sustainable aviation fuel using direct air capture and offshore wind power is technically viable and environmentally beneficial, achieving a GWP significantly lower than fossil jet fuel and meeting regulatory emission reduction targets, though it is economically intensive due to electricity demands.

Key Findings

• Carbon conversion efficiency of 88%, hydrogen conversion efficiency of 39.16%, and Power-to-liquids efficiency of 25.6%.
• Heat and water integration between refinery and DAC units significantly enhances energy performance and reduces fresh water demand.
• Minimum jet fuel selling price (MJSP) estimated at 5.16 £/kg, with operational expenditure (OPEX) dominated by electricity costs.
• Well-to-Wake (WtWa) global warming potential (GWP) of 21.43 gCO2eq/MJSAF, highly dependent on upstream wind electricity emissions.
• Stochastic LCA indicates GWP falls below the UK aviation mandate threshold for emissions reduction.
• WtWa water footprint of 0.480 l/MJSAF, with refinery cooling water and electricity's water footprint as main contributors.

Research Evidence

Aim: To assess the technical, economic, and environmental feasibility of a Power-to-Liquid (PtL) system for producing sustainable aviation fuel (SAF) using direct air capture and offshore wind power.

Method: Techno-economic and Life Cycle Assessment (LCA)

Procedure: A combined techno-economic and life cycle assessment was conducted on an integrated SAF production system. This system included direct air capture (DAC), an offshore wind farm, an alkaline electrolyser, and a refinery plant with reverse water gas shift and Fischer-Tropsch reactors. Key performance indicators such as carbon and hydrogen conversion efficiencies, energy performance, minimum jet fuel selling price (MJSP), global warming potential (GWP), and water footprint were calculated. Monte Carlo simulations were used for stochastic LCA.

Context: Sustainable aviation fuel production, renewable energy integration, chemical engineering, environmental impact assessment

Design Principle

Maximize resource efficiency through process integration and renewable energy utilization for sustainable fuel production.

How to Apply

Consider integrating direct air capture and renewable energy sources with established fuel synthesis processes to develop low-carbon alternatives for hard-to-abate sectors like aviation.

Limitations

The economic viability is highly sensitive to electricity prices and the cost of DAC technology. The upstream emissions of offshore wind electricity are a critical factor influencing the overall GWP.

Student Guide (IB Design Technology)

Simple Explanation: This study shows that we can make jet fuel from air and wind power that is much better for the planet than regular jet fuel. It works by capturing CO2 from the air, using wind energy to make hydrogen, and then combining them to create fuel. The main challenges are the cost of the equipment and the electricity needed.

Why This Matters: This research is important for design projects focused on sustainability and renewable energy, as it provides a real-world example of how complex systems can be designed to reduce environmental impact in a critical industry.

Critical Thinking: How might the scalability and cost-effectiveness of this PtL system be further improved to compete with conventional jet fuel prices?

IA-Ready Paragraph: The research by Rojas Michaga et al. (2023) provides a comprehensive techno-economic and life cycle assessment of a Power-to-Liquid system for sustainable aviation fuel (SAF) production. Their findings indicate that an integrated system combining direct air capture, offshore wind power, and advanced refining can achieve a global warming potential of 21.43 gCO2eq/MJSAF, significantly below conventional jet fuel and meeting regulatory mandates. This demonstrates the potential for such integrated systems to decarbonize aviation, though economic viability is contingent on electricity costs and capital expenditure for capture technologies.

Project Tips

• When evaluating sustainable energy systems, consider a holistic approach that includes technical, economic, and environmental factors.
• Investigate the potential for process integration to improve efficiency and reduce resource consumption in your design project.

How to Use in IA

• Reference this study when discussing the feasibility of alternative fuels or the environmental impact of energy-intensive processes in your design project.

Examiner Tips

• Demonstrate an understanding of the trade-offs between different sustainability metrics (e.g., GWP vs. cost) in your analysis.

Independent Variable: ["Integration of DAC, offshore wind, electrolyser, and refinery components","Heat and water integration strategies"]

Dependent Variable: ["Carbon conversion efficiency","Hydrogen conversion efficiency","Power-to-liquids efficiency","Minimum Jet Fuel Selling Price (MJSP)","Global Warming Potential (GWP)","Water footprint"]

Controlled Variables: ["Specific technologies used (e.g., alkaline electrolyser, Fischer-Tropsch reactor)","Upstream emissions of offshore wind electricity (as a variable influencing GWP)","UK aviation mandate thresholds"]

Strengths

• Comprehensive assessment combining technical, economic, and environmental factors.
• Utilizes advanced LCA methodology including stochastic analysis.
• Addresses a critical need for sustainable solutions in the aviation industry.

Critical Questions

• What are the potential environmental impacts of scaling up offshore wind farms and DAC technology?
• How do different electricity grid mixes affect the overall sustainability of PtL SAF production?

Extended Essay Application

• Investigate the feasibility of a similar integrated system for producing alternative fuels for other transport sectors, considering local resource availability and economic conditions.

Source

Sustainable aviation fuel (SAF) production through power-to-liquid (PtL): A combined techno-economic and life cycle assessment · Energy Conversion and Management · 2023 · 10.1016/j.enconman.2023.117427