Due to the presence of H2S, all sour gas streams must be treated before being released into the environment. Physiochemical processes are typically used to remove sulfur from the gas stream and recover it. However, this is unsustainable due to the usage of either high temperatures, high pressures, and complex and/or toxic chemical requirements. As the world transitions to renewable energy, sulfur availability will also begin to decrease as the majority is produced as a by-product of the fossil fuel industry. The project aims to remove H2S from gas streams using the biotechnological desulfurization process and recover it as biologically produced elemental sulfur. The current biological process produces thiosulfate and sulfate as by-products, both of which are unwanted due to their consumption of caustic and bleed stream formation. Recently, it was discovered that sulfide oxidizing bacteria (SOB) are able to remove sulfide in anaerobic conditions and reduce oxygen in sulfide-free condition. This ability known as shuttling capacity can be further enhanced when the SOB are grown in alternating “anaerobic-sulfide rich” and “aerobic-sulfide-free” conditions.
The underlying mechanisms for the shuttling capacity are not understood, therefore, a multi-scale approach is needed to understand this ability. New methods will be developed to determine if the shuttling capacity can be quantified and optimized for the recovery of sulfur. It is hypothesized that understanding the shuttling capacity will lead to more efficient process schemes.