THIOTEQ bioreactor

From BioMineWiki

Jump to: navigation, search

Bioreactor: Biological stage

In the THIOTEQ process, the process water no longer flows through the bioreactor. Consequently, a sulfur source must be added (next to the energy source) to make hydrogen sulfide. A good source is elemental sulfur instead of sulfate because it requires only one quarter of the energy to convert elemental sulfur into sulfide compared to using sulfate. When acetic acid is used as electron donor, the conversion can be written as:

4 S0+ CH3COOH +2 H2O → 4 H2S + 2 CO2

This equation shows that four times more sulfide can be generated from the same amount of electron donor compared to sulfate reduction. The biological process is carried out under ambient conditions which make it safe to operate. In addition, the process is self-controlling; high sulfide concentrations become inhibitory to the bacteria that subsequently stop producing but are not killed. Therefore, a dangerous runaway situation is impossible. The bacteria become active again when the sulfide is withdrawn from the bioreactor by the precipitation process. Finally, the sulfide inventory in the bioreactor is mostly maintained as ionic - and therefore dissolved - HS-. Little H2S is therefore released in case of a leak. The sulfide is available on demand within the capabilities as long as the sulfide demand is balanced by the addition of electron donor.

See also

Personal tools