Hydrolysis

Hydrolysis is a chemical reaction that releases sugars, which are normally linked together in complex chains, such as in ethanol production. In cellulosic ethanol production, hydrolysis reactions are used to break down cellulose and hemicellulose in biomass.

Typically, hydrolysis occurs during biomass pretreatment. In pretreatment, the hemicellulose fraction of the biomass is broken down into simple sugars. Hydrolysis occurs when a dilute acid is mixed with the biomass feedstock, causing a chemical reaction. When this chemical reaction occurs, the complex chains of sugars that make up the hemicellulose are broken up, releasing simple sugars. The complex hemicellulose sugars are converted to a mix of soluble five-carbon sugars?, xylose? and arabinose, and soluble six-carbon sugars?, mannose and galactose. A small portion of the cellulose is also converted to glucose in this step.

Enzymes can also be used in hydrolysis. When this occurs, cellulase enzymes are used to hydrolyze the cellulose fraction of the biomass. Companies such as Novozymes are involved in the development of cellulosic enzymes?.

During hydrolysis of cellulose, the remaining cellulose is hydrolyzed to glucose. In this enzymatic hydrolysis reaction, cellulase enzymes are used to break the chains of sugars that make up the cellulose, releasing glucose. Cellulose hydrolysis is also called cellulose saccharification?, because it produces sugars.