New fuels, who dis?

Welcome back to the Strawman, the newsletter that’s like the friend who’s always down to go on a last minute holiday. Hol’ up - where we going?

Today we’re doing something a little different - yesterday we spoke about new regulations on aviation fuels and the push to make an emissions-heavy industry greener. Today, we’re diving into the world of Sustainable Aviation Fuels (or SAFs) to see what’s on the horizon.

A dirty past

Before we dive into the new and exciting, it’s worth knowing where we’re starting. The majority of commercial aircraft today use conventional jet fuel, derived from crude oil - the same crude oil that’s also refined to give us petrol and diesel for our cars.

Jet fuel isn’t just a single chemical - rather, it’s a mixture of chemical compounds. The issue? Burning this mixture results in significant greenhouse gases meaning this is a prime target for legislation, as we saw yesterday.

Staying SAF

Because jet fuel is a mixture of compounds, you can add chemically similar compounds to this mixture without having a major impact on performance. This is the basic principal behind SAFs - you can mix a more economically friendly fuel with the old one, and use it in current flights - no new-fangled technology needed.

It’s like that one time your parents were out the house and you tried the vodka - and then filled it up with water so no one would notice. Difference is, with SAFs, no one does notice.

Understandably for airlines, it’s a preferred solution - rather than having to change or upgrade the planes they’ve spent billions on, they get to keep them and change the fuel.

As the push for SAF in commercial flights lifts off, how these “sustainable” fuels are made is coming under scrutiny. Currently, there are two main ways of making SAFs:

Renewable biomass and feedstocks

Take a bunch of used cooking oil, waste, corn grains and oil seeds and what do you get?

Sustainable aviation fuel. Admittedly with some steps in between.

This is what most people refer to when talking about SAFs.

e-SAF or PtL

e-SAF or Power-to-Liquid (PtL) is a newer kind of SAF where you combine hydrogen separated from water with carbon from industrial waste processes; giving you the relevant compounds that could be used in fuel.

While PtL currently has a higher cost compared to other SAFs, the cost is expected to decrease significantly by 2050, with projections indicating that PtL could account for 42-57% of total SAF production.

Other solutions on the horizon

The aviation industry also has other solutions nipping at SAFs heels: battery powered or hydrogen powered flight being the big ones.

These are both early on in their development - but like that kid getting on the bicycle for the first time, with enough encouragement they’ll get there.

That’s all for today’s newsletter - now, the Strawman’s got a flight to catch (and best believe I’m asking the pilot about the fuel mix).

Adios, and see you tomorrow!