scholarly journals OPTIMIZATION OF LIGNIN EXTRACTION FROM RICE HUSK BY ALKALINE HYDROGEN PEROXIDE USING RESPONSE SURFACE METHODOLOGY

2017 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Rice Husk ◽  
Alkaline Hydrogen Peroxide ◽  
Lignin Extraction

scholarly journals Optimization of Lignin Extraction Variables by Response Surface Methodology from Pine Saw Dust, and Quantification of Major Structural Units in Isolated Lignin Fraction

2021 ◽  
Vol 11 (4) ◽  
pp. 1739
Author(s):  
Muhammad Ajaz Ahmed ◽  
Jae Hoon Lee ◽  
Joon Weon Choi
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Quantum Coherence ◽  
Resonance Spectrum ◽  
Quadratic Model ◽  
Molecular Weights ◽  
Solids Loading ◽  
A Value ◽  
Lignin Extraction ◽  
Lignin Fraction

A synergistic combination of dioxane, acetic acid, and HCl was investigated for lignin extraction from pine wood biomass. After initial screening of reagent combination, response surface methodology (RSM) was used to optimize the lignin yield with respect to the variables of time 24–72 h, solids loading 5–15%, and catalyst dose 5–15 mL. A quadratic model predicted 8.33% of the lignin yield, and it was further confirmed experimentally and through the analysis of variance (ANOVA). Lignin at optimum combination exhibited features in terms of derivatization followed by reductive cleavage (DFRC) with a value of (305 µmol/gm), average molecular weights of 4358 and polydispersity of 1.65, and 2D heteronuclear single quantum coherence nuclear magnetic resonance spectrum (2D-HSQC NMR) analysis showing relative β-O-4 linkages (37.80%). From here it can be suggested that this fractionation can be one option for high quality lignin extraction from lignocellulosic biomass.

scholarly journals Modelling and optimization of zinc recovery from Enyigba sphalerite in a binary solution of hydrochloric acid and hydrogen peroxide

2020 ◽  
Vol 120 (11) ◽  
Author(s):  
I.A. Nnanwube ◽  
O.D. Onukwuli
Keyword(s):  
Genetic Algorithm ◽  
Hydrogen Peroxide ◽  
Response Surface Methodology ◽  
Hydrochloric Acid ◽  
Response Surface ◽  
Binary Solution ◽  
Infrared Analysis ◽  
Zinc Recovery ◽  
X Ray ◽  
Stirring Rate

SYNOPSIS This work focused on the prediction of optimal conditions for zinc recovery from sphalerite in a binary solution of hydrochloric acid and hydrogen peroxide. The sphalerite sample was characterized with X-ray fluorescence spectrometry (XRF), X-ray diffractometry, and Fourier transform infrared analysis (FTIR). The central composite design of response surface methodology (RSM) developed in Design Expert software and the genetic algorithm (GA) tool in matlab, were deployed for the optimization exercise. The leaching temperature, acid concentration, stirring rate, leaching time, and hydrogen peroxide concentration were defined as input variables, while zinc yield was the response. An ideal zinc yield of 90.89% could be obtained with a leaching temperature of 84.17°C, HCl concentration of 3.14 M, stirring rate of 453.08 r/min, leaching time of 107.55 minutes, and hydrogen peroxide concentration of 3.93 M using RSM; while a yield of 87.73% was obtained using GA. Analysis of the post-leaching residue revealed the presence of sulphur, zircon, fluorite, gahnite, anatase, and sylvite. Keywords: sphalerite leaching, genetic algorithm, optimization, response surface methodology.

Optimization of Production Conditions for Activated Carbons from Rice Husk by Potassium Carbonate Using Response Surface Methodology

2014 ◽  
Vol 1053 ◽  
pp. 303-310 ◽  
Author(s):  
Mian Wu Meng ◽  
Cong Liang Qi ◽  
Qing Ye Liu ◽  
Liang Lv ◽  
Hao Ai ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Adsorption Capacity ◽  
Response Surface ◽  
Rice Husk ◽  
Activated Carbons ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Activation Temperature ◽  
Nitrogen Adsorption Isotherm

A three-factor-three-level experiment was developed by the central composite design (CCD) and Response surface methodology to discuss the effects of concentration of K2CO3, activation temperature and time on the adsorption capacity of the activated carbon (AC) derived from the rice husk and to identify the key preparation parameters. The performance of the AC was characterized by nitrogen adsorption isotherm as Brunauer–Emmett–Teller (BET) and scanning electron microscope (SEM), respectively. The optimal parameters were obtained: Rice husk was soaked in K2CO3 solution (2.32 mol/L) with an impregnation ratio (rice husk: K2CO3=1:3) (wt. %), activated at 1239 K for 0.48 h. The results showed that iodine adsorption capacity of the AC was 1268.52 mg/g, the error between the models predicted (1356.98 mg/g) was only 6.2%. The AC has a large apparent surface area (SBET = 1312 m2/g), total pore volume (0.78 cm3/g) and average pore diameter (11.92 Å).

scholarly journals Optimization of Adhesion Strength and Microstructure Properties by Using Response Surface Methodology in Enhancing the Rice Husk Ash-Based Geopolymer Composite Coating

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2709
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Faizal Mustapha ◽  
Norkhairunnisa Mazlan ◽  
Mohd Ridzwan Ishak
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Composite Coating ◽  
Adhesion Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Offshore Structures ◽  
Interfacial Bonding ◽  
Curing Temperature ◽  
High Adhesion

As a result of their significant importance and applications in vast areas, including oil and gas, building construction, offshore structures, ships, and bridges, coating materials are regularly exposed to harsh environments which leads to coating delamination. Therefore, optimum interfacial bonding between coating and substrate, and the reason behind excellent adhesion strength is of utmost importance. However, the majority of studies on polymer coatings have used a one-factor-at-a-time (OFAT) approach. The main objective of this study was to implement statistical analysis in optimizing the factors to provide the optimum adhesion strength and to study the microstructure of a rice husk ash (RHA)-based geopolymer composite coating (GCC). Response surface methodology was used to design experiments and perform analyses. RHA/alkali activated (AA) ratio and curing temperature were chosen as factors. Adhesion tests were carried out using an Elcometer and a scanning electron microscope was used to observe the microstructure. Results showed that an optimum adhesion strength of 4.7 MPa could be achieved with the combination of RHA/AA ratio of 0.25 and curing temperature at 75 °C. The microstructure analysis revealed that coating with high adhesion strength had good interfacial bonding with the substrate. This coating had good wetting ability in which the coating penetrated the valleys of the profiles, thus wetting the entire substrate surface. A large portion of dense gel matrix also contributed to the high adhesion strength. Conversely, a large quantity of unreacted or partially reacted particles may result in low adhesion strength.

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