Small-scale stirred-tank reactors for enzymatic hydrolyses of suspended plant materials

Peter Riedlberger, doctoral thesis Technische Universität München, 2012

A large number of experimental studies is required in the development of efficient processes for the enzymatic hydrolysis of biomass. A new impeller was designed for homogenization of suspended particles and subsequently characterized to make use of a parallel stirred-tank reactor system on a milliliter-scale. Scale-up of enzymatic hydrolysis processes to the liter-scale was shown to be possible if the same mixing numbers are applied. This was successfully demonstrated with enzymatic hydrolyses of microcrystalline cellulose, wheat straw and granulated corn stover with a solid content of up to 20 % and particle sizes in the millimeter range. After optimization of the reaction conditions for hydrolysis making use of the parallel operated stirred-tank reactors 40 % (w/w) of alkaline pretreated corn stover was released as glucose and 30 % (w/w) as xylose within 24 h. With final sugar concentrations of more than 120 g/L a subsequent usage of hydrolyzed plant biomass is thus feasible as substrate for fermentation processes.

Publications

• Riedlberger P, Brüning S, Weuster-Botz D (2013): Characterization of stirrers for screening studies of enzymatic biomass hydrolyses on a milliliter-scale. Bioproc Biosys Eng 36: 927-935.
• Riedlberger P, Weuster-Botz D (2012): New miniature stirred-tank bioreactors for parallel study of enzymatic biomass hydrolysis. Bioresource Technol 106: 138-146.