High pressure assist-alkali pretreatment of cotton stalk and physiochemical characterization of biomass.
Ground cotton stalks were pretreated with sodium hydroxide (NaOH) at concentrations of 1-4% (w/v), pressures of 30-130 kPa, durations of 15-75 min, and liquid/solid ratios of 10:1-30:1. Modeling of the high pressure assist-alkali pretreatment (HPAP) of cotton stalk was attempted. The levels of NaOH concentration, pressure, and duration were optimized using a Box-Behnken design to enhance the cellulose content of treated solid residue. The optimum pretreatment conditions were as follows: liquid/solid ratio, 20:1; pressure, 130 kPa; NaOH concentration, 3.0%; duration, 40 min. During the conditions, cellulose content of pretreated cotton stalk residue was 64.07%. The maximum cellulose conversion of 45.82% and reducing sugar yield of 0.293 g/g upon hydrolysis were obtained. Significant differences were observed in biomass composition and physiochemical characteristics between native and alkali-treated biomass. High NaOH concentration and pressure were conducive to lignin dissolution and resulted in increased cellulose content and conversion.
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China. Electronic address: dushuangkui@hotmail.com.
Shuang-kui
SK
Du
Xinna
X
Zhu
Hua
H
Wang
Dayun
D
Zhou
Weihua
W
Yang
Hongxia
H
Xu
D000704:Analysis of Variance; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002482:Cellulose / Q000032:analysis; D055598:Chemical Phenomena / Q000187:drug effects*; D003368:Gossypium / Q000187:drug effects*; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D011312:Pressure; D015203:Reproducibility of Results; D012972:Sodium Hydroxide / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014866:Waste Products / Q000032:analysis*; D014961:X-Ray Diffraction
D014866:Waste Products; D012972:Sodium Hydroxide; D002482:Cellulose
Box–Behnken design; Cotton stalk; Enzymatic hydrolysis; High pressure assist-alkali pretreatment (HPAP)