TECHNOLOGY: Natural Gas

Using Synthetic Biology to Leverage
Potential of Natural Gas

Tapping unconventional gas sources, particularly shale gas, will be essential to meeting future global demands for liquid fuel and other energy. In the US, the ability to replace petroleum demand with the increased availability of domestic natural gas supplies from shale would be a major advance in energy independence and national security.  

Natural gas is a mixture of several hydrocarbon gases, including methane (between 70% and 90%), ethane, propane, butane and pentane, as well as carbon dioxide, nitrogen and hydrogen sulphide. Natural gas is referred to as “wet” when hydrocarbons other than methane are present, “dry” when it is almost pure methane, and “sour” when it contains significant amounts of hydrogen sulphide.  Stranded gas is a form of natural gas that is inaccessible for physical or economic reasons.

New technology solutions enabling broader use of the components of natural gas to meet energy demand are needed.  Current chemical approaches such as Fischer-Tropsch to convert gas to liquids are poorly suited to practical capture and use of stranded, unconventional gas sources even after more than 80 years of development and optimization. In addition, gas transport today requires costly and lengthy construction of pipelines. Reducing methane levels in the atmosphere could also have environmental benefits, as methane’s contribution to global greenhouse effects are more than 20 times greater than carbon dioxide per molecule.  Modern synthetic biology provides a powerful new approach to the challenge of efficiently using domestic natural gas reserves for more than combustion on site. 

Comparison of Biofuel Platform Efficiency

Carbon
Feedstock
MW %C Conversion Method Theoretical
Diesel
Yield (g/g)
CO2 44 27% Photosynthesis 21%
Sugar/
Biomass
~180 40% Fermentation
31%
Pyrolysis 47%
CH4 16 75% Fermentation 59%

refinery at night