Natural bacteria are used to ferment the sugars from the wood.
In most industrial and commercial fermentation systems, yeast is used to convert sugars into alcohol.
In AHB initiative, we use an efficient fermentation process with naturally occurring acetogenic bacteria instead of yeast. Due to this change, a higher percentage of the biomass is used as fuel instead of releasing CO2.
The sugar stream produced from the hydrolysis of the poplar chips is fermented with the bacteria, which ferment the sugars to an intermediate chemical, acetic acid, without producing CO2 as a by-product. As a result the process is nearly 100% carbon efficient, with some carbon being used for cell reproduction. In contrast, fermenting with yeast loses about half of the sugars as the greenhouse gas CO2.
Where does the carbon go?
Using bacteria instead of yeast, 100% of the carbon in the fermentation product is used for fuel.