Microorganisms Fed with Toxic Gas to Produce Biofuel

(University of Borås/Phys.Org) Today, various processes are used to convert organic waste into biogas. By combining two different processes, it is possible to obtain even more of valuable substances such as hydrogen and methane. The key is to make the most of the microorganisms that do the work.

Forest waste containing lignocellulose is a material that microorganisms do not break down very easily.

In his research project, doctoral student Konstantinos Chandolias shows that it is possible to get around the problem and at the same time obtain a higher amount of valuable gases such as hydrogen and methane that are used for the production of biofuels and other valuable substances.

"By linking two types of process platforms, one for gasification and one for fermentation, which are currently used in the industry separately to produce substances such as ethanol, methanol, and ammonia, it is possible to process this waste that is so challenging to break down. In the gasification process, syngas (synthetis gas), a mixture containing hydrogen and carbon monoxide in particular, is formed. By allowing the syngas to begin the fermentation process, it is possible to obtain an even greater amount of hydrogen or methane. Carbon monoxide, which is toxic, acts as food for the microorganisms that produce hydrogen and methane," explains Konstantinos Chandolias.

"We have used a special type of bioreactor (reverse membrane bioreactor) which means that the microorganisms can be retained inside the reactor. They are trapped in a kind of membrane rather than floating around freely in the reactor. While the microorganisms are thus protected from harmful substances, the membranes let the substances, such as methane, hydrogen, and various acids produced by the organisms, through." READ MORE