Effect of Pretreatment Reagent and Hydrogen Peroxide on Enzymatic Hydrolysis of Oak in Percolation Process

Abstract

The effect of pretreatment reagent and hydrogen peroxide on enzymatic digestibility of oak was investigated to compare pretreatment performance. Pretreatment reagents used were ammonia, sulfuric acid, and water. These solutions were used without or in combination with hydrogen peroxide in the percolation reactor. The reaction was carried out at 170°C for the predetermined reaction time. Ammonia treatment showed the highest delignification but the lowest digestibility and hemicellulose removal among the three treatments. Acid treatment proved to be a very effective method in terms of hemicellulose recovery and cellulose digestibility. Hemicellulose recovery was 65-90% and digestibilities were >90% in the range of 0.01-0.2% acid concentration. In both treatments, hydrogen peroxide had some effect on digestibility but decomposed soluble sugars produced during pretreatment. Unlike ammonia and acid treatments, hydrogen p~roxidein water treatment had a certain effect on hemicellulose recovery as well as delignification. At 1.6% hydrogen peroxide concentration, both hemicellulose recovery and digestibility were about 90%, which were almost the same as those of 0.2% sulfuric acid treatment. Also, digestibility was investigated as a function of hemicellulose removal or delignification. It was found that digestibility was more directly related to hemicellulose removal rather than delignification.

Effects of cellulase and xylanase enzymes on the deconstruction of solids from pretreatment of poplar by leading technologies

“…Supplementation of cellulase with xylanase has been reported to enhance glucose release from pretreated biomass solids 36–38. Studies reported in the literature showed that glucose release is enhanced by xylose removal,39–46 and it has been argued that removing the hemicellulose coating on cellulose and/or its linkages with cellulose increases cellulose accessibility. However, Weimer et al47 suggested that intimate association of hemicellulose and cellulose does not inhibit cellulose digestion.…”

Bioethanol production from ammonia percolated wheat straw

“…A peroxide pretreatment enhance enzymatic conversion through oxidative delignification and a decrease in cellulose crystallinity [10]. Increased lignin solubilization and cellulose availability were observed after a peroxide pretreatment of wheat straw [11], Douglas fir [12], and oak [13]. Ozonation is another attractive pretreatment method that does not leave strong acidic, basic, or toxic residues in the treated material [14].…”

Pretreating wheat straw by the concentrated phosphoric acid plus hydrogen peroxide (PHP): Investigations on pretreatment conditions and structure changes

“…Taking the typical feedstock of corncob as an example, approximately 75% lignin was removed, and only 38% hemicellulose was removed (Su et al, 2015). Besides, H 2 O 2 supplementation (1.6%) in the diluted sulfuric acid (0.1%) was investigated to pretreat oak at 170°C, in which hemicellulose removal was improved, and delignification was not increased much (Kim et al, 2001). Thus, the reactions of hemicellulose and lignin with PHP were uniquely different with those of the alkaline hydrogen peroxide and the diluted acid plus H 2 O 2 .…”