Saccharification of lignocellulose

Scale-up of the hydrolysis process in the stirred reactor.
Scale-up of the hydrolysis process in the stirred reactor.
Hydrolysis of the fibre fraction.
Hydrolysis of the fiber fraction.

The lignocellulose pulping process produces the (solid) cellulose fiber and the supernatant of the pulping solution, which among other things contains hemicellulose.

In the next step, the monomeric sugars are obtained from cellulose or hemicellulose. For this purpose, enzyme mixtures of cellulases or hemicellulases are used, which synergistically break down cellulose and hemicellulose into the sugars they contain (glucose or xylose).

Powerful stirred reactor for hydrolysis of cellulose and hemicellulose to monomeric sugars

The uniform mixing of the enzymes in the pulp mass is of great importance for an optimal space-time yield of the hydrolysis process. To ensure this, we at the Fraunhofer IGB have developed a high-performance stirred reactor system that is characterized by its special stirrer geometry and is therefore suitable for mixing cellulose fiber pulp with up to 20 percent solids content. In this way we were able to achieve yields of > 100 g/kg glucose. A maximum yield of 70 percent over 48 hours was achieved with a minimum enzyme dosage.

This was followed by the design and construction of the reactor for the pilot plant in Leuna at Fraunhofer CBP.

Applications of lignocellulose-based sugars

The sugar solutions obtained are suitable for various applications. Glucose, for example, can be used as a substrate by a large number of microorganisms in fermentations.

The digestion solution rich in hemicelluloses can also be used for the fermentation of certain microorganisms, which was also part of the work at the Fraunhofer IGB. The digestion process may cause the digestion solution to contain toxic degradation products, which must be removed before use.


  • Hahn T, Nothacker M, Kövilein A, Beck A, Zibek S (2019) Stirrer speed adaption is beneficial for liquefaction of cellulose. Chimica Oggi-Chemistry Today, vol 37(6)
  • Hahn T, Haitz F, Zibek S (2015) Enzymatic hydrolysis of solid substrates Critical notes and experimental guidelines for improvements. Chimica Oggi-Chemistry Today, vol 33.
  • Ludwig D, Buchmann M, Hirth T, Rupp S, Zibek S (2014) High solids enzymatic hydrolysis of pretreated lignocellulosic materials with a powerful stirrer concept. Appl Biochem Biotechnol, vol 172. doi:10.1007/s12010-013-0607-2

Reference projects

AERTOs biobased economy (BBE)


The aim is to drive forward the development of a biobased economy in Europe and to remove certain technical hurdles in the new value chains. Furthermore, cooperation between the individual European RTOs (Research and Technology Organisations) involved is to be intensified.

Lignocellulose biorefinery


The aim is to develop and establish a process for the complete material utilization of all lignocellulose components by obtaining biobased products based on cellulose, hemicellulose and lignin within a biorefinery.


Duration: January 2010 – December 2013