Bacteria grown for gas generation

Karolien Vanbroekhoven, programme manager of separation and conversion technologies at VITO in Boeretang, said other groups around the world are looking into hydrogen production out of biomass, but her team’s work is unique because it focuses on dark fermentation, a process that does not use light as an energy source.

The fermentation process requires solid organic waste enriched with wastewater. The organic compounds of this biomass act as a carbon source for bacterial growth and a source of energy for their metabolism.

’Since they do not require light energy, they can constantly produce hydrogen from organic compounds throughout the day and night,’ said Vanbroekhoven.

The organic biomass is fed into a bioreactor, similar to an anaerobic digester, but specially designed for removing hydrogen.

’If hydrogen is not removed efficiently and fast from the reactor, the process stops,’ she added. ’Typically, both a mixture of at least hydrogen and carbon dioxide are produced and removed by stripping and combining with gas separation membranes.’