Bioethanol production from sodium hydroxide – dilute sulfuric acid pretreatment of rice husk via simultaneous saccharification and fermentation

Abstract

Abstract. Degradation of lignin from lignocellulosic biomass plays a main key role in converting of lignocelluloses to bioethanol. The pretreatment of lignocelluloses is needed to enhance the fermentable sugars production from enzymatic hydrolysis. This research studied the effect of dilute sulfuric acid pretreatment on the ethanol production using alkaline-dilute acid pretreatment. This research used two stages of the pretreatment process. The first stage used NaOH solution with ratio of rice husk and NaOH solution (1:10 w/v). On the second stage, five concentrations of sulfuric acid of 1 to 5% at temperature of 121 o C and various heating times (30-90 min) were investigated. The ethanol production from pretreated rice husk was conducted by the simultaneous saccharification and fermentation (SSF) for various SSF times of 72-160 hr. The experimental results indicated that an increase in concentration of sulfuric acid capable to destroy the lignocellulosic structure of rice husk. The highest value of cellulose content was achieved about 88.84 % for acid pretreated material at H 2 SO 4 concentration of 2% in 90 minutes. The lignin reduction ranged from 47.46% to 79.29%. The highest ethanol concentration obtained was 13.68 g/L for the SSF time of 120 hours and the sulfuric acid concentration of 3 %.

Enhancing Bioethanol Production from <em>Azolla filiculoides</em> through Optimization of Pretreatment and Culture Conditions with <em>Saccharomyces cerevisiae</em>

“…Therefore, 0.75 M sulfuric acid concentration was chosen as the acid component in the acid α-amylase combined pre-treatment, for further optimization studies for Azolla filiculoides substrate (Figure 05). When simultaneous saccharification and fermentation procedures using the commercial cellulase enzyme (Novozyme) were done, a significantly higher ethanol concentration (13.68 g/L) was obtained from rice husk by Saccharomyces cerevisiae, when 3% sulfuric acid concentration was used (Novia et al, 2017). Extreme acidity may cause sugar degradation during the fermentation process and would lead to an unfavorable effect on sugar conversion (Kefale et al, 2012;Nutawan et al, 2010).…”

Effect of Dilute Acid - Alkaline Pretreatment on Rice Husk Composition and Hydrodynamic Modeling with CFD

“…Programs on energy utilization have been sustained by nding other kinds of renewable energy. Several studies relating to the conversion of lignocellulose biomass as a raw material to produce bioethanol have been implemented (Chen et al, 2011;Hermansyah et al, 2015;Karimi et al, 2006;Novia et al, 2017;Sudiyani et al, 2017;Xavier et al, 2010).…”

“…The fundamental processes that occur in the pretreatment process have been investigated. Numerous researches (Novia et al, 2007(Novia et al, , 2017Cundari, 2016) are being applied to advance the computational methods appropriate for pairing the many crucial characteristics of chemistry and physics in a procedure that is e ective enough for explaining the pretreatment problems. CFD modeling can o er a huge scope of information for the design of pretreatment reactor.…”