Enhancement of alkaline-oxidative delignification of wheat straw by semibatch operation in a stirred tank reactor


Alicia Hernández-Guzmán1, Ivette Michelle Navarro-Gutiérrez1, Perla Araceli Meléndez-Hernández1, Javier Ulises Hernández-Beltrán2, Héctor Hernández-Escoto1*

1Universidad de Guanajuato, Departamento de Ingeniería Química, Laboratorio de Análisis de Bio-Procesos Industriales, Noria Alta s/n, Guanajuato 36050, Mexico.
2Universidad Autónoma de Coahuila, Facultad de Ciencias Biológicas, Laboratorio de Biorremediación, Carretera Torreón-Matamóros Km. 7.5, Torreón, Coahuila 27000, Mexico.


This paper compares a semi-batch operation and a conventional one of an alkaline oxidative pretreatment of
wheat straw carried out in a stirred tank reactor. For the pretreatment, different concentrations of biomass (6%
up to 12% w/v) and two different particle sizes (mesh #40–60 and #>60) were experimented. The performance
of processes was evaluated through the analysis of lignocellulosic composition of the biomass, and the
enzymatic hydrolysis of pretreated biomass using the Cellic® CTec2 enzyme complex by Novozymes®. The
process time of semi-batch operation is significantly lower than the batch one and enables a higher load of
biomass, showing a delignification yield between 55 and 60%. In the first 5 h of reaction time, the enzymatic
hydrolysis experiments reached their maximum yields of 72 and 66% according to reducing sugars conversion
when using the mesh #>60 mesh and #40–60, respectively.