Optimization of Dilute Acid Hydrolysis of Corn Stover for Separate Production of Xylose and Glucose by Response Surface Methodology

2012 ◽  
Vol 608-609 ◽  
pp. 298-301
Author(s):  
Su Li Zhi ◽  
Jing Yang ◽  
Yan Yao ◽  
Shu Ting Zhang ◽  
Xue Bin Lu

Dilute sulfuric acid pretreatment of corn stover was used to obtain a solution of high concentration of xylose from the hemicellulosic fraction and a relatively low concentration of glucose, which not only saved the hemicellulase but also made a full use of corn stover. Then the study considered the selectivity (xylose-glucose ratio) as an important parameter to optimize the hydrolysis conditions. The results optimized by response surface methodology (RSM) showed that the optimum conditions for pretreatment were found to be H2SO4 concentration of 2.4% and reaction time of 100min at 100°C. Under these conditions, 78.8% of xylose yield was achieved and the glucose yield was lower than 11.6%. To confirm these results, the optimum condition was performed and the actual results of xylose yield and glucose yield were 78% and 11.3%.

2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.


Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 787 ◽  
Author(s):  
Saleem Ethaib ◽  
Rozita Omar ◽  
Mustapa Kamal Siti Mazlina ◽  
Awang Biak Dayang Radiah

This study aims to evaluate the sugar yield from enzymatic hydrolysis and the interactive effect pretreatment parameters of microwave-assisted pretreatment on glucose and xylose. Three types of microwave-assisted pretreatments of sago palm bark (SPB) were conducted for enzymatic hydrolysis, namely: microwave-sulphuric acid pretreatment (MSA), microwave-sodium hydroxide pretreatment (MSH), and microwave-sodium bicarbonate (MSB). The experimental design was done using a response surface methodology (RSM) and Box–Behenken Design (BBD). The pretreatment parameters ranged from 5–15% solid loading (SL), 5–15 min of exposure time (ET), and 80–800 W of microwave power (MP). The results indicated that the maximum total reducing sugar was 386 mg/g, obtained by MSA pretreatment. The results also illustrated that the higher glucose yield, 44.3 mg/g, was found using MSH pretreatment, while the higher xylose yield, 43.1 mg/g, resulted from MSA pretreatment. The pretreatment parameters MP, ET, and SL showed different patterns of influence on glucose and xylose yield via enzymatic hydrolysis for MSA, MSH, and MSB pretreatments. The analyses of the interactive effect of the pretreatment parameters MP, ET, and SL on the glucose yield from SPB showed that it increased with the high MP and longer ET, but this was limited by low SL values. However, the analysis of the interactive effect of the pretreatment parameters on xylose yields revealed that MP had the most influence on the xylose yield for MSA, MSH, and MSB pretreatments.


Author(s):  
Abimael I. Ávila-Lara ◽  
Jesus N. Camberos-Flores ◽  
Jorge A. Mendoza-Pérez ◽  
Sarah R. Messina-Fernández ◽  
Claudia E. Saldaña-Duran ◽  
...  

Author(s):  
Xiaoxu Song ◽  
Meng Zhang ◽  
Z. J. Pei ◽  
A. J. Nottingham ◽  
P. F. Zhang

Response surface methodology was used to study the effects of parameters namely, time, temperature, and solid content and to optimize the process conditions for the minimum energy consumption in dilute acid pretreatment. Box-Behnken design using response surface methodology was employed. Effects of time and temperature are significant at the significant level of α = 0.05. Longer time and higher temperature result in higher power energy consumption. The best optimal values of the process conditions are time 14–21 min and temperature 129–139 °C.


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