Researchers at Berkeley Lab have created synthetic biofuels using bacteria with an energy density significantly higher than jet fuel. The new fuel candidate molecules are known as polycyclopropanated fatty acid methyl esters (POP-FAMEs), and they’re made up of seven sets of cyclopropane rings. These are rings of three carbon atoms bonded into triangular shapes, which forces the bonds into a 60-degree angle. The strains of that sharp angle holds high potential energy that can be released during combustion.
Berkeley claim energy density of over 50 megajoules per litre (13,800 Wh/kg). Gasoline’s energy density is around 32 MJ/L, while common jet and rocket fuels top out around 35 MJ/L (12,000 Wh/kg)
Challenge – Cost
There has been no commercial production, and key element is the cost of the production system.
The aircraft industry is a major contributor to carbon emissions and while battery-powered aircraft are in development, long haul aircraft may need alternative energy to power flight.
R&D on Synthetic Biofuels Using Bacteria
There has been a long history of R&D using E. coli along with a huge investment by companies into production into synthetic proteins and fats. The use of bacteria to produce food proteins is a major disruption globally that many are unaware of. For a recent publication see Adegboye, M.F., Ojuederie, O.B., Talia, P.M. et al. Bioprospecting of microbial strains for biofuel production: metabolic engineering, applications, and challenges. Biotechnol Biofuels 14, 5 (2021). https://doi.org/10.1186/s13068-020-01853-2