abstract
Second-generation bioethanol production's main bottleneck is the need for a costly and technically difficult pretreatment due to the recalcitrance of lignocellulosic biomass (LCB). Chemical pulping can be considered as a LCB pretreatment since it removes lignin and targets hemicelluloses to some extent. Chemical pulps could be used to produce ethanol. The present study aimed to investigate the batch ethanol production from unbleached Kraft pulp of Eucalyptus globulus by separate hydrolysis and fermentation (SHF). Enzymatic hydrolysis of the pulp resulted in a glucose yield of 96.1 +/- 3.6% and a xylose yield of 94.0 +/- 7.1%. In an Erlenmeyer flask, fermentation of the hydrolysate using Saccharomyces cerevisiae showed better results than Scheffersomyces stipitis. At both the Erlenmeyer flask and bioreactor scale, co-cultures of S. cerevisiae and S. stipitis did not show significant improvements in the fermentation performance. The best result was provided by S. cerevisiae alone in a bioreactor, which fermented the Kraft pulp hydrolysate with an ethanol yield of 0.433 gg(-1) and a volumetric ethanol productivity of 0.733 gL(-1)h(-1), and a maximum ethanol concentration of 19.24 gL(-1) was attained. Bioethanol production using the SHF of unbleached Kraft pulp of E. globulus provides a high yield and productivity.
keywords
BIOETHANOL PRODUCTION; EUCALYPTUS-GLOBULUS; SACCHAROMYCES-CEREVISIAE; LIGNOCELLULOSIC BIOMASS; FERMENTING YEAST; FERMENTATION; PRETREATMENT; CONVERSION; HARDWOOD; GLUCOSE
subject category
Energy & Fuels
authors
Branco, RHR; Amandio, MST; Serafim, LS; Xavier, AMRB
our authors
Ana Maria Rebelo Barreto Xavier
Assistant Professor
Luísa Seuanes Serafim
Assistant Professor
Mariana Soraia Tomás Amândio
PhD Student
Rita Henriques Rebola Branco
MSc Studentacknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES.