Clean Fuel Revolution

The primary roadblock to a more sustainable future for earth and aerospace travel is global carbon emissions and their harmful impacts on the climate.  

In two centuries, increases in greenhouse gases (e.g., CO2) triggered modern climate changes through the accelerated rise in global temperatures, disruptions in weather and hydrological patterns, as well as the meltdown of the cryosphere leading to rising sea levels, and more. The compounding nature of these environmental effects creates an urgent timeline threatening the long-term habitability of the planet. As a result, with the aim to limit global warming to 1.5 degrees Celsius, the aerospace and aviation industry set a goal to achieve net-zero carbon dioxide emissions by 2050. This goal, though ambitious, is attainable with the right commitments. The aerospace industry must rely on multi-stakeholder actions, collaboration among all sectors, recent technologies, and policies to support said technologies.  

SAF (sustainable aviation fuel) holds significance as the single most critical pathway towards net-zero for the aviation world. It has the advantage of being a drop-in substitute for conventional jet fuel in current aircraft; because they are chemically identical, no modifications to current aircraft are necessary. Though it still produces tailpipe emissions because it is made from renewable feedstock (waste oils, agricultural residues) rather than newly extracted fossil oils, it also serves to recycle existing carbon in the atmosphere. It could decrease greenhouse gas emissions by up to 80% when compared to conventional jet fuel. With these benefits, we must wonder why the transition has not been made yet. This brings us to the major hurdles surrounding SAF, and most other “green” energy or fuel options.  

Since SAF is new in the industry, its production and demand are not on par with traditional jet fuel; this is due to its excessive cost of production and procurement. SAF is 2 to 4 times more expensive than conventional jet-fuel, and it will become more expensive to produce in the future. The current cheapest way of producing it through HEFA (Hydroprocessed Esters and Fatty Acids) is a short-term solution that will plateau eventually due to land use limits as well as potential competition with food supplies. Future pathways like synthetic e-fuels and alcohol-to-jet are the most effective, yet most complex methods. Despite all this, the industry is moving forward and doing all it can to catch up. Currently, SAF makes up only about 1% of the fuel market, but with more than 140 projects underway worldwide to increase its production and the EU’s new mandates of 2% fuel blends, the supply is doubling every year. 

Similarly, cleaner alternatives to rocket fuel are also in an important stage of development. In the same way SAF is made from sustainable waste, many biofuels tasked with replacing RP-1 (a highly refined form of kerosene extensively used in rocket propellants) are derived from widely available agricultural materials and waste matter. These are adapted specifically for the high energy needs of space flight in creative and innovative ways. Companies like Skyrora and CleanJoule are creating bio-derived kerosene from unrecyclable plastic wastes and forestry wastes, close enough to standard kerosene to act as drop-in replacements. Others like BluShift Aerospace have succeeded in launching test rockets using solid biofuels sourced from farms. Furthermore, other projects rely on even more unique approaches such as using cracked ammonia as a biofuel or even genetically modified bacteria engineered to brew a new fuel type with an energy density far higher than standard petroleum.  

Despite all the wonders being developed, many wonder if the shift away from RP-1 is necessary considering what a small portion of aeronautical activity space flight represents, making its impact on the environment marginally small in comparison to other sectors. However, considering the anticipated growth of space flight and the subsequent increase in carbon emissions of the industry, it could be a worthwhile, proactive move towards more sustainable and accessible launch services. The need to be ahead of the industry is further stressed by the shift towards mass-producing and launching large-scale satellite networks, as they have in many ways begun to reshape the aerospace economy.  

As commercial entities increase in number and many rush to populate low Earth Orbit, rapid deployment schedules are fueling the urgent unprecedented demand for cost-effective and reliable launch solutions. The work done by companies like Blushift, Skyrora and the scientists at the Lawrence Berkeley National Laboratory matters greatly to the future. 

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