Saccharification

Achieving maximum sugar yield

Many Factors Impact Final Yield

Saccharification, the process to depolymerize cellulose and hemicellulose into fermentable sugars, is a considerable cost component in the biochemical conversion of biomass and feedstock to bioproducts.

In developing a high-yielding saccharification process, we take into consideration a combination of several factors:

  • Biomass composition
  • Type of pretreatment
  • Dosage and efficiency of the hydrolytic catalyst or enzymes

Microbe Produces Ethanol from Switchgrass Without Pretreatment. Read article on science.energy.gov »

Integrating Upstream and Downstream Processes

Chemical pretreatment and saccharification are closely linked processes. While a particular pretreatment process might be effective against biomass recalcitrance, it may inhibit saccharification.

At ABPDU we place significant emphasis on the integration between pretreatment and saccharification to establish the optimum process parameters and selection of methodologies.

Our Equipment

Saccharification Process Options

Cocktail Optimization of Enzymes
As the severity factor of the pretreatment process decreases, the sugar yield after enzymatic hydrolysis also decreases. Hence the requirement for different types of enzymes and their higher dosages to achieve maximum sugar yield from cellulose and hemicellulose fractions of the pretreated biomass. We offer a cocktail of enzymes such as cellulases, hemicellulases, and other accessory enzymes for complete hydrolysis.
High Solids Enzymatic Hydrolysis
Maintaining high solids concentrations throughout the biomass conversion process is important for final product yield with reduced intensity of the separation process. High substrate concentration allows for the production of a concentrated sugar solution, which, in turn, is beneficial in separation processes after fermentation. The extent to which solids loading can be increased in hydrolysis varies with the type of feedstock, pretreatment process, and enzyme/catalyst. At the ABPDU, we are able to generate cellulosic sugars up to 150 g/L concentration.
Solid/Liquid Separation
After saccharification, lignin-rich solid is separated from the sugar-rich aqueous phase using a decanter or basket centrifuge depending on the scale of the process.
Simultaneous Saccharification and Fermentation (SSF)
During saccharification, the enzyme or catalyst can be constrained by the presence of some inhibitors generated during pretreatment. The fermentation process can be combined with saccharification in an SSF process, where enzymes are applied simultaneously with the micro-organism. In such cases, the enzymatic action is maximized due to the presence of low amounts of the inhibitory product, as the sugar is being metabolized upon release. SSF is thought to be an ideal process for biochemical conversion of biomass to bioproducts.
Mass/Energy Balance
A mass balance, also called a material balance, is a meticulous accounting of material entering and leaving a system. Mass balance is essential to establish a process as it is required to calculated the actual conversion of feedstock, monitor process flow, identify bottle-necks in processes, and model large scale process in desired reactors. Similarly, an energy balance can be established across a process by assuming that net energy loss from a reactor is zero.

Related Papers, Articles, and Presentations

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