BETHLEHEM, Pennsylvania — For the first time, researchers from the Imperial College London and the University of Turku in Finland have utilized E. coli to generate renewable propane.
Particularly appealing due to its existing global market, propane is a cleaner fuel that is used in various applications ranging from central heating to conventional motor vehicles.
The potential for an environmentally sustainable process is constrained by the low unit cost of fuel. However, with this new promising procedure, Dr. Patrik Jones believes that it “opens up new possibilities for future sustainable production of renewable fuels that at first could complement, and thereafter replace fossil fuels like diesel, petrol, natural gas and jet fuel.”
Manipulating the bacteria, researchers were able to alter its original process of converting fatty acids into cell membranes to create engine-ready propane instead.
After using an enzyme called thioesterase that targets the fatty acids and interrupts the normal process, researchers used a second bacterial enzyme called CAR to convert butyric acid to butyraldehyde and then finished with an enzyme called aldehyde-deformylating oxygenase, or ADO, which is known to create hydrocarbons, to create propane.
Earlier attempts to utilize ADO for fuel production were not successful, but scientists found that by using electrons to stimulate the enzyme, its catalytic capability increased dramatically, enough to be used to ultimately produce propane.
The choice to develop propane as opposed to other sources of fuels is the ease in which it can be removed from the natural process and is viable for immediate use through the existing infrastructure. Furthermore, propane’s ability to transition from gas to liquid with relative ease makes it an easy fuel to transport.
Despite the promising discovery, it is a still quite some time before the process is commercially viable. The current process produces approximately a thousand times less than would be required for commercial use.
Algae can currently be used to make biodiesel, but is not commercially viable due to its high monetary and energy costs.
Jones of Imperial College London estimates the renewable propane process can be commercially viable within the next five years to 10 years.
The final goal of the research hopes to employ the process within photosynthetic bacteria and convert solar energy directly into chemical fuel.
Looking at the bigger picture, researchers have made great strides in searching for alternative greener processes for fuel production. Last year, scientists were successful in engineering E. coli to manufacture diesel.
For those suffering from climate change, the potential for a renewable process to replace the current system is particularly promising.
– William Ying
Sources: Nature Communications, Imperial, Think Progress, Forbes, Telegraph, Gizmodo
Photo: NBC News