New research conducted by two separate research groups at Uppsala University suggests that isoprene, produced by blue-green algae, could be a promising solution for developing fossil-free fuels for aircraft. These studies, published in Photochemical & Photobiological Sciences and Bioresource Technology, highlight the potential of using genetically modified cyanobacteria, which have been engineered to produce isoprene using solar energy and carbon dioxide from the air.
The researchers have combined a photobiological-photochemical method to produce synthetic sustainable aviation fuel. They have modified cyanobacteria by incorporating an enzyme from the Eucalyptus tree, enabling them to synthesize isoprene. This approach utilizes sunlight as the energy source for the production of isoprene and subsequent conversion into larger hydrocarbons resembling conventional aviation fuels.
To determine the most suitable starting material for the photochemical reaction, the research groups investigated a range of small hydrocarbons, including isoprene, produced through biotechnological means. The results indicated that the molecular structure of a hydrocarbon impacts its efficiency in undergoing the photochemical reaction.
While the production yield of isoprene from cyanobacteria remains relatively low, the researchers also explored cultivation conditions that could enhance productivity. They found that exposing the cyanobacteria to violet light and higher temperatures increased their productivity. Additionally, the presence of isoprene improved the heat tolerance of the cyanobacteria, enabling their survival at higher temperatures. This finding could be advantageous for large-scale production utilizing sunlight.
Overall, the research outcomes offer promising prospects for replacing fossil fuels in aviation. However, further development is required to establish an industrial process by 2040, which is the ultimate goal in realizing this technology’s potential.
Source: Swedish Research Council