Project highlights

  • An Excellent opportunity to conduct a new but urgently required research area for achieving the UK’s net zero target in 2050. Currently only one crop-based biomass certified sustainable aviation fuel is available out of eight conversion process certified to use in aviation by ICAO.
  • Although there is a limited possibility for crop based SAF within first generation biomass SAF (WEF, 2020) due to green waste sources, the opportunity cost of current land use, and pressure on food production. Increasing biomass supply from cover-crops and unused land or alternative crop systems (intercropping or multi-cropping) could offer positive externalities in terms of rural development, soil fertility and biodiversity (Bybee-Finley & Ryan, 2018).
  • A Comprehensive systematic approach with a combination of environmental technology, life cycle assessment (GREET model), cost benefit analysis, and air transport economics and modelling will be employed across different SAF scenarios.
  • There is no sustainable aviation fuel facility in the UK yet, although it is an essential contributor to decarbonise the air transport and tackle the Climate change. The work will contribute largely to lead the UK as a world leader by commercialising this technology at the early stage.


This research aims to provide quantitative insight into the role that biofuels can play in decarbonising aviation by taking a system approach for SAF’s entire life cycle by focusing on the production phase in the UK agriculture.

Sustainable aviation fuel (SAF) is receiving intense consideration so as to reduce overall CO2 emissions in the short and medium term for achieving the UK’s net zero target in 2050. There are three main challenges for SAF to be successfully implemented: (1) expense (currently USD80-160 per gallon), and (2) feedstock availability, and (3) overall sustainability. In particular, cost of SAF is heavily dependent on the availability and cost of sustainable feedstock. The domestic production required to achieve the UK net zero target by increasing up to 40% of total fuels by 2030 (Sustainable Aviation, 2018). Using biofuels for SAF would require a stable, large supply of biomass, which have only a small impact on land use, water use, and biodiversity (ICAO, 2017). Therefore, the whole life cycle must be assessed to see if SAFs are truly sustainable.  Particularly, the crop based SAF’s land use change (LUC) emission is a key determinant of the LCA, which is highly dependent upon the situation in which the feedstock is cultivated (Staples et al., 2014), including indirect LUC (WEF, 2020). However, increasing biomass supply from cover-crops and unused land or alternative crop systems (intercropping or multi-cropping) could offer positive externalities in terms of rural development, soil fertility and biodiversity (Bybee-Finley & Ryan, 2018).

In this project the following research questions will be addressed:

  1. What are the specific criteria for SAF? What are the challenges and issues in the UK?
  2. Is it possible to produce sufficient feedstock sustainably in the UK?
  3. How can the different possible production process be improved?
  4. What is the total environmental load for SAF over its life cycle and how can it be minimised?
  5. What is the total cost and benefit for all stakeholders and society?
  6. How can SAF be introduced to meet the UK next zero carbon target and other societal needs?

diagram showing stages in the life cycle assessment of CO2 with accompanying cost benefit analysis

Figure 1: Sustainable Aviation Fuel in air transport system


Cranfield University


  • Climate and Environmental Sustainability


Project investigator

Dr Chikage Miyoshi, Cranfield Environment Centre ([email protected])


How to apply


This research aims to assess the viability of SAF by taking a Life Cycle Assessment (LCA) approach as an entire air transport system. Three models are principally involved: land-use models, LCA, and cost benefit analysis (CBA). First, the critical and systematic state of art literature review will be conducted. Then, for the production phase, different land-use models are taken to investigate the agricultural productivity improvement without impacting or displacing existing food production. It attempts to keep a balanced agro-ecosystem: greater crop diversity promoting resilience.  The required amount of SAF will be estimated by forecasting air transport traffic and carbon emissions for UK aviation. Sensitivity analysis will be conducted to assess the trade-off between conventional jet fuel and SAF. Furthermore, cost and benefit analysis will be conducted in Net Present Value by considering all stakeholders’ views including the externalities (CO2, tax revenue, and labour opportunities).

Training and skills

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.

The statistical analysis skills are required for conducting econometric model. Moreover, LCA and CBA knowledge are crucial.  A possible 10 days work replacement can be awarded in the partner industry.  Advanced course of CENTA2 is useful to obtain the skill to handle a big data. Some modules of MSc in environmental engineering course and Geographical information management course can be taken.

Partners and collaboration

The possible partners could be International Consolidated Airline Group (IAG), London Heathrow Airport, and Sustainable Aviation. Sustainable Aviation is an organisation to aim the development of sustainable air transport ‘s benefit for targeting the net zero in 2050. Both IAG and LHR are core members of this group.

IAG has committed to invest $400m in sustainable aviation fuels over the next 20 years, and will establish a SAF facility at Heathrow with Shell in 2021. The Head of Sustainability at IAG, Mr Johnathan Counsel is a Visiting professor at Cranfield University.

Further details

If you wish to apply to the project, applications should include:

  • A CV with the names of at least two referees (preferably three and who can comment on your academic abilities

Applications to be received by Friday 2nd June 2023.

Possible timeline

Year 1

Target: Obtain the fundamental knowledge and skill for conducting this research

In this period, a student has an opportunity to learn the core knowledge of both environmental and air transport agenda for establishing the foundation of this research.  Specific targets are below:

  • Conduct the critical and systematic review of environmental policy, development, and issues in the air transport as well as SAFs.
  • To understand the theory and mechanism of market based mechanism, and relation to the carbon price for decarbonising the air transport,
  • To obtain the knowledge and skill for traffic demand forecasting (statistical and econometric modelling) as well as Life cycle assessment (GREET model, BioGrace Tools, etc) in particular for ICAO methodology by state of the art review.
  • To start design the system framework by considering the definition of each component, agent, stakeholders, key parameters, and assumption required.

Year 2

Target: understanding of the state of art technique and the market

A student will start the core part of analysis after establishing the foundation during the previous years.

Understand the market and products

  • Conduct the market analysis and collect the required data for traffic forecasting (socio economic, demographic, and traffic variables), LCA (GREET model and BioGrace Tools) and CBA (e.g. capital cost, operating cost, commodity price), and design the system framework for linking each methodology. Scope of analysis (period, boundary, key parameters and component) will be defined.
  • Conduct the air transport traffic forecasting in UK by segmenting each market (UK domestic, EU-UK, and UK long haul international) for short term (2021-2023), midterm (2021-2030), and long term (2021-2050), and estimate the possible CO2 emissions produced by utilising Cranfield air transport carbon calculator.
  • Service definition: Define specifics for the products and services delivered by the project, and establish the case for analysis

Design the system framework and define components and key variables for analysis 

  • Develop prototype framework and tools for assessing biofuel crop systems (and land-use change) with remote sensing, the traceability and certification methods and the decisions support tool. Test against historical and new data. Communicate results and seek feedback through iterative process.

Year 3

Year 3-4:

Target: assessing the validity of SAF by LCA and CBA

As the finishing phase of PhD, a student will finalise analysis, test, validate and reassess the results. The interpreted outputs will be incorporated into the solutions to achieve the research questions 4,5, and 6.

  • Based on the outputs of multi crop production model, LCA and CBA will be conducted. Key parameters or component, and assumptions might be required to be modified.
  • The outputs of LCA and CBA will be validated, and the risk assessment will be conducted by several scenario and sensitivity analysis according to the change of key variables.
  • The outputs can be also reviewed by the internal and external expert in the industry and discussed the possible challenge and development and benefit for the UK. A roadmap for moving from proof-of-concept to commercial product is also presented.

Further reading


  • Bybee-Finley, K.A.; Ryan, M.R. (2018) Advancing Intercropping Research and Practices in Industrialized Agricultural Landscapes. Agriculture 8, 80.
  • Fukui, H., Miyoshi, C. (2017) The impact of aviation fuel tax on fuel consumption and carbon emissions: The case of the US airline industry.  Transportation Research Part D (Transport and the Environment), 50, pp. 234-253.
  • Miyoshi, C., Fukui. (2018) Measuring the rebound effects in air transport: The impact of jet fuel prices and air carriers’ fuel efficiency improvement of the European airlines. Transportation Research Part A. Policy and Practice, 112, pp. 79-84.
  • Miyoshi, C., Ruiz Ibanez, E. (2016) Are fuel-efficient aircraft worth investing in for non-Annex country airlines? An empirical analysis of Kenya Airways with an aircraft appraisal cost-benefit analysis model. Transport Policy, 47, pp. 41-54.
  • Miyoshi, C., Rietveld, P. (2015) Measuring equity effects of carbon charge on car commuters: A case study of Manchester Airport. Transportation Research Part D. (Transport and the Environment), 35, pp.  23-39.
  • Moreira, M., A.C. Gurgel, and J. E. A. Seabra. (2014) Life cycle greenhouse gas emissions of sugar cane renewable jet fuel. Environmental Science & Technology 48,
  • Staples, M.D., Malina, R., Olcay, H., Pearson, M.N., Hileman, J. I., Boies, A., Barret, S.R.H. (2014) Lifecycle greenhouse gas footprint and minimum selling price of renewable diesel and jet fuel from fermentation and advanced fermentation production technologies. Energy & Environmental Science, 7, pp. 1545-1554.

Web page with an author:


The financial difficulty in the aviation industry could be the largest challenge in terms of financial support to this project. However, CORSIA is implemented in 2021, and the interest to SAF is growing rapidly.

For the academic side, the traffic demand forecasting might be challenging due to the large uncertainty because of the COVID-19. For more robust assessment, additional (costly) data might be required.