title: Two-stage, acetic acid-aqueous ammonia, fractionation of empty fruit bunches for increased lignocellulosic biomass utilization.
abstract: Fractionation of EFB was conducted in two consecutive steps using a batch reaction system: hemicellulose hydrolysis using acetic acid (AA; 3.0-7.0 wt.%) at 170-190°C for 10-20 min in the first stage, and lignin solubilization using ammonium hydroxide (5-20 wt.%) at 140-220°C for 5-25 min in the second stage. The two-stage process effectively fractionated empty fruit bunches (EFB) in terms of hemicellulose hydrolysis (53.6%) and lignin removal (59.5%). After the two-stage treatment, the fractionated solid contained 65.3% glucan. Among three investigated process parameters, reaction temperature and ammonia concentration had greater impact on the delignification reaction in the second stage than reaction time. The two-stage fractionation processing improved the enzymatic digestibility to 72.9% with 15 FPU of cellulase/g of glucan supplemented with 70 pNPG of β-glycosidase (Novozyme 188)/g-glucan, which was significantly enhanced from the equivalent digestibility of 28.3% for untreated EFB and 45.7% for AAH-fractionated solid.
authors.affiliation: Department of Applied Chemical Engineering, Dankook University, Cheonan, Chungnam 330-714, Republic of Korea.
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Applied Chemical Engineering, Dankook University, Cheonan, Chungnam 330-714, Republic of Korea.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Environmental Engineering, Kongju National University, Cheonan, Chungnam 330-717, Republic of Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Applied Chemical Engineering, Dankook University, Cheonan, Chungnam 330-714, Republic of Korea. Electronic address: kkoh@dankook.ac.kr.
authors.forename: Kyeong Keun
authors.initials: KK
authors.lastname: Oh
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D000641:Ammonia / Q000737:chemistry*; D018533:Biomass; D002480:Cellulase; D005591:Chemical Fractionation; D005638:Fruit / Q000737:chemistry*; D005936:Glucans; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D014867:Water
chemical_list: D005936:Glucans; D014867:Water; C036909:lignocellulose; D000641:Ammonia; D008031:Lignin; D002480:Cellulase; D019342:Acetic Acid
keywords: Acetic acid hydrothermal (AAH); Enzymatic digestibility; Pretreatment; Weak acid; Weak alkali