Peroxide−Acetic Acid Pretreatment To Remove Bagasse Lignin Prior to Enzymatic Hydrolysis

Abstract

This paper presents results on the features of bagasse pretreatment with peroxide and acetic acid (peroxide-HAc) aiming at selective removal of lignin to enhance enzymatic hydrolysis. Surface response methodology was employed to study the effects of major process parameters on delignification and to establish a model for the prediction of lignin removal in the process. Enzymatic hydrolysis following the pretreatment was conducted to evaluate the enhancement of biohydrolysis by the pretreatment. Results revealed that peroxide-HAc pretreatment of bagasse retained most of the carbohydrate constituents, although the delignification rate was low. Peroxide-HAc concentration, temperature, and time demonstrated significant effects on bagasse lignin removal. The relationship between lignin removal and the process parameters could be well described by a mathematical model derived from the experimental data. After treatment with 69.1% peroxide-HAc at 80°C for 26.5 h, 97.08% of lignin could be removed while keeping 68.24% hemicelluloses intact. Over 93.58% of carbohydrate in treated bagasse could be hydrolyzed with exoglucanase in a dosage of 138 FPU/g carbohydrates at 35°C within 48 h. It was thus demonstrated that treated bagasse has a much higher response toward enzymatic hydrolysis than its untreated counterpart.

Organosolv fractionating pre‐treatment of lignocellulosic biomass for efficient enzymatic saccharification: chemistry, kinetics, and substrate structures

“…Increasing pre‐treatment temperature could dramatically shorten the pre‐treatment time with a glucose yield higher than 90% . In situ synthesis of peracetic acid by AA and H 2 O 2 during pre‐treatment has been also found to efficiently increase cellulose digestibility . Similarly, AA‐H 2 O 2 concentration, temperature, and reaction time demonstrated significant effects on bagasse lignin removal.…”

Pretreatment strategies for delignification of sugarcane bagasse: a review

“…Sulfuric acid is the most commonly used acid in the pretreatment of sugarcane bagasse (Lavarack and Griffin 2002) but other reagents such as hydrochloric, nitric and phosphoric acids can also be used (Rodríguez-Chong et al 2004;Gámez et al 2006). The use of acetic acid and hydrogen peroxide has been reported by Tan et al (2010) as a method for removing lignin prior to bagasse enzymatic hydrolysis. According to Chen et al (2011), the pretreatment using dilute sulfuric acid has been considered as one of the most cost-effective methods.…”

Evaluation of microorganisms performance in hemicellulosic hydrolyzate detoxification and sugarcane bagasse lignin removal for ethanol production

“…In addition, a synergism might be related to lignin redistribution and hemicellulose removal and dissolution into the solvent due to these two processes occurring in the early stages of pretreatment (PINGALI et al, 2010). As reported by several authors, a hydrolyzate rich in pentose sugars with a small amount of D-glucose and other degradation compounds along with a solid fraction are the product of the acid hydrolysis (GARCÍA et al, 2014;MARTIN et al, 2007;ROCHA et al, 2011;SAHA et al, 2005;SUN;CHENG, 2005;TAN et al, 2010). Therefore, hemicellulose is susceptible to acid hydrolysis due to its branched structure, accompanied by amorphous region of cellulose.…”

“…Some examples are acid hydrolysis (BONDESSON; GALBE; ZACCHI, 2013;ROCHA et al, 2011;SAHA et al, 2005;SUN;CHENG, 2005;TAN et al, 2010) and alkaline hydrolysis (SINGH; BAJAR; BISHNOI, 2014), ozonolysis (LI et al, 2015;TRAVAINI et al, 2013), ionic liquids (DADI;…”

“…It was found that lignin did not solubilize in the acid during this process. Tan et al (2010) showed that a mixture of acetic acid and peroxide under high temperature (60-80 o C) might be used as a hydrolytic agent to break down the lignin from the vegetable biomass with low amounts of hemicellulose removal. In the context of the present study, nitric acid and acetic acid contribute to the structural changes of the vegetal biomass even under the mild conditions used and are therefore not indicated to remove the mycelia from the biologically pretreated SCB as was suggested by .…”