Novel bioreactor designs for rapid methane fermentation

Methane-based fermentation is fundamentally different from ‘traditional’ glucose-based fermentation for several reasons, including: the low solubility of methane in aqueous solution, the need to co-feed multiple (explosive) gasses at high mass transfer rates while simultaneously allowing efficient extraction of CO₂, and significant heat loads generated from the metabolism of the high-energy methane substrate.  These issues are more similar to those faced in ‘traditional’ chemical reactor design where many approaches to mitigate the above issues have been developed. 

The objective of this project is to develop key bioreactor technology to enable efficient methane-to-biofuel fermentation processes. Although sugar-based fermentation is well-established with a variety of off-the-shelf reactor technologies available, relatively little effort has been expended to address gas-fed fermentations. Gas-fed fermentations present a number of unique challenges such as low rates of heat/mass transfer and accumulation of explosive gas mixtures. By utilizing the project team’s unique expertise in reactor design in the chemical industry and in methanotroph fermentation, we plan to develop specialized reactors that can serve as the basis for the production of a variety of fuels and chemicals via bioconversion of methane. Redesign of the bioreactor will be performed using computational fluid dynamics.  A bench-scale prototype will be built and tested using Calysta’s target strain to demonstrate operating parameters and performance metrics.

This bioreactor technology will position methane as a new biological feedstock for the domestic, cost-competitive production of biofuels. Importantly, the project team will make this technology available to the research community at large via partnering and toll manufacturing.