Same ethanol process - different steps
The process to convert cellulosic biomass into ethanol is similar to other bioethanol production processes - with a few key differences: the need for pretreatment and a different procedure during hydrolysis/fermentation.
Pretreatment
Pretreatment is important; it’s one of the most costly process steps in cellulosic ethanol conversion and is one of the most difficult to perfect. The various pretreatment methods differ significantly from one another in reaction conditions, process efficiency, complexity, and impact on the rest of the process. But all pretreatments can effectively increase the enzymatic accessibility of biomass by certain mechanisms.
Download more information about pretreatment
Hydrolysis
Hydrolysis is the process step that provides the enzymes in a biochemical process to break down the substrate into more accessible carbohydrates, so that the yeast can ferment into ethanol. For starch-based ethanol production, the industry standard has been a simultaneous saccharification and fermentation (SSF), where hydrolysis occurs in the same process step as fermentation. Novozymes' research has shown, for cellulosic ethanol conversion, that a separate hydrolysis step provides advantages over the inhibitors and suboptimal enzyme conditions created in the SSF process.
Fermentation
Novozymes has conducted sophisticated modeling to provide insight into the process of balancing the SSF & SHF conditions, and established the Fast Fermentation concept. In this concept, enzyme hydrolysis time is extended and fermentation time is compressed, creating a potential way to make SHF work and to share the cost forecast in cellulosic conversion processes. To learn more, please view the recorded webinar on our Fast Fermentation concept.
Read more about Novozymes' cellulosic biofuel solutions
