scholarly journals CELLULOSE ACETATE PRODUCTION BY ACETYLATION OF CELLULOSE DERIVED FROM DATE PALM FRONDS

2020 ◽  
Vol 51 (3) ◽  
pp. 967-975
Author(s):  
Jassem & et al.
Keyword(s):  
Cellulose Acetate ◽  
Date Palm ◽  
Lignin Content ◽  
Organosolv Pretreatment ◽  
Acetate Production ◽  
Pretreatment Time ◽  
Pretreatment Temperature ◽  
Palm Fronds ◽  
Chloroform Methanol ◽  
High Lignin Content

Cellulose acetate (CA) is a biopolymer produced from fronds of date palm (type teperzal) which were taken from the Iraqi groves. The steps used to produce (CA); pretreatment, bleaching, acetylation and hydrolysis. Organosolv pretreatment method was used to remove high lignin content under mild and severe conditions using NaOH as a catalyst at the concentration (0.03) M. The conditions of Organosolv pretreatment were used: temperature (125 °C mild, 160 °C severe), pretreatment time 90 min, and ethanol: water ratio 40:60 wt/wt. The acetylation of cellulose with acetic acid was used to produce cellulose tri-(CTA) and di-(CDA) acetate for two ways: with treated and untreated fronds. The conditions of acetylation reaction were used: temperature (50-55) °C and time (1, 2 & 3) h. The product was characterized by the solubility test, titration method and Fourier transform infrared spectroscopy (FTIR). The results showed that the high percentage of lignin removed was (93%), the best degree of substitution (DS) for (CTA) and (CDA) were 3.01 and 2.60. As well as the excellent solubility percentages for (CTA) with chloroform and mixture of chloroform/methanol were 90% and 84%, respectively. While the solubility percentage for (CDA) with acetone was 95%, these result occurred at pretreatment temperature 160°C, pretreatment time 90 min and reaction time 3 h.

scholarly journals Delignification of Date Palm Fronds using Modified Organosolv Technique

2017 ◽  
Vol 13 (3) ◽  
pp. 1-9
Author(s):  
Yasmeen Salih Mahdi ◽  
Asem Hassan Mohammed ◽  
Alaa Kareem Mohammed
Keyword(s):  
Date Palm ◽  
Lignin Content ◽  
Statistical Experimental Design ◽  
Digestion Time ◽  
Stainless Steel Reactor ◽  
Pre Treatment ◽  
Design Type ◽  
Palm Fronds ◽  
Central Composite ◽  
High Lignin Content

Abstract   In this study, modified organic solvent (organosolv) method was applied to remove high lignin content in the date palm fronds (type Al-Zahdi) which was taken from the Iraqi gardens. In modified organosolv, lignocellulosic material is fractionated into its constituents (lignin, cellulose and hemicellulose). In this process, solvent (organic)-water is brought into contact with the lignocellulosic biomass at high temperature, using stainless steel reactor (digester). Therefor; most of hemicellulose will remove from the biomass, while the solid residue (mainly cellulose) can be used in various industrial fields. Three variables were studied in this process: temperature, ratio of ethanol to water and digestion time. Statistical experimental design type Central Composite Design (CCD) has been used to find a mathematical relationship between the variables and the remaining lignin percent as dependent variable. The results obtained in this study were represented by a polynomial mathematical equation of the second degree.  The results showed that the best digestion time was (80 minutes), which gave the best percent remaining concentration of lignin (3%) at temperature of 185oC and ratio of ethanol: water equal to 50: 50 wt/wt. In order to reduce digesting time, the effect of using different catalysts have been studied such as (NaOH, H2SO4, Ca (OH) 2) at low concentration (0.025, 0.025, 0.05M) respectively. It was found that the best catalyst is sodium hydroxide at concentration (0.025) mol/L which gave the same percent of  lignin 3% but with low digestion time about 30 min. Keywords: Biomass pre-treatment, delignification, lignin, organosolv, date palm fronds.

scholarly journals SYNTHYSIS OF RAYON FROM DATE PALM FRONDS

2018 ◽  
Vol 49 (6) ◽  
Author(s):  
Mahdi & et al.
Keyword(s):  
Sodium Hydroxide ◽  
Date Palm ◽  
Lignin Content ◽  
Statistical Experimental Design ◽  
Digestion Time ◽  
Palm Trees ◽  
Design Type ◽  
Palm Fronds ◽  
Central Composite ◽  
High Lignin Content

The artificial silk (Rayon) was produced from the fronds of date palms which was taken from date palm trees (type Al-Zahdi) from the Iraqi gardens. Two main parts of the frond, namely leaves and stalks were used in this study to produce rayon. The palm fronds were converted into a powder of 90-180 micrometers. Major steps were used to produce rayon; delignification, bleaching and finally dissolution. Modified organosolv method which uses organic solvent method was applied to remove high lignin content. Three variables were studied in the delignification process: temperature, the ratio of ethanol to water and digestion time. The results showed that the best percent of lignin removal was (97%) which occured at; digestion time (80 minutes), temperature (185oC) and the ratio of ethanol: water of 50: 50 wt/wt. Statistical experimental design type Central Composite Design (CCD) has been used to find a mathematical relationship between the variables and the remaining lignin percent as a dependent variable.  The effect of using different catalysts in delignification process  have been studied and found that the best catalyst is sodium hydroxide at the concentration (0.025) mole/L which gave the same percent removal of lignin (97%) but with low digestion time about 30 min. In the next step, the cellulose was dissolved using. NaOH with different concentrations (4%-12%) and the results showed that the optimum concentration of sodium hydroxide was 8% at temperature - 20oC. In order to improve cellulose dissolution, urea was added with proportion (6% NaOH + 4% urea). Finally, the cellulose was spinning with 10% H2SO4 to prepare rayon.

scholarly journals Enhanced Solid-State Biogas Production from Lignocellulosic Biomass by Organosolv Pretreatment

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Safoora Mirmohamadsadeghi ◽  
Keikhosro Karimi ◽  
Akram Zamani ◽  
Hamid Amiri ◽  
Ilona Sárvári Horváth
Keyword(s):  
Solid State ◽  
Rice Straw ◽  
Methane Production ◽  
Biogas Production ◽  
Lignin Content ◽  
Agricultural Waste ◽  
Ethanol Solution ◽  
Order Model ◽  
Organosolv Pretreatment ◽  
Pretreatment Temperature

Organosolv pretreatment was used to improve solid-state anaerobic digestion (SSAD) for methane production from three different lignocellulosic substrates (hardwood elm, softwood pine, and agricultural waste rice straw). Pretreatments were conducted at 150 and 180°C for 30 and 60 min using 75% ethanol solution as an organic solvent with addition of sulfuric acid as a catalyst. The statistical analyses showed that pretreatment temperature was the significant factor affecting methane production. Optimum temperature was 180°C for elmwood while it was 150°C for both pinewood and rice straw. Maximum methane production was 152.7, 93.7, and 71.4 liter per kg carbohydrates (CH), which showed up to 32, 73, and 84% enhancement for rice straw, elmwood, and pinewood, respectively, compared to those from the untreated substrates. An inverse relationship between the total methane yield and the lignin content of the substrates was observed. Kinetic analysis of the methane production showed that the process followed a first-order model for all untreated and pretreated lignocelluloses.

Effect of Cellulase and Tannase Enzymes Supplemention on the Productive Performance of Lactating Buffaloes Fed Diets Contain Date Palm Fronds

2016 ◽  
Vol 10 (6) ◽  
pp. 307-312 ◽  
Author(s):  
A. M. Abd El ◽  
M. S.A. Khatt ◽  
H. M. El-Zaia ◽  
O. H. Matloup ◽  
A.A. Hassan ◽  
...  
Keyword(s):  
Date Palm ◽  
Productive Performance ◽  
Lactating Buffaloes ◽  
Palm Fronds

scholarly journals Novel Kinetic Models of Xylan Dissolution and Degradation during Ethanol Based Auto-Catalyzed Organosolv Pretreatment of Bamboo

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1149 ◽  
Author(s):  
Jing Liu ◽  
Zhenggang Gong ◽  
Guangxu Yang ◽  
Lihui Chen ◽  
Liulian Huang ◽  
...  
Keyword(s):  
Kinetic Models ◽  
Degradation Products ◽  
Practical Significance ◽  
Order Kinetic ◽  
Organosolv Pretreatment ◽  
Dependent Parameter ◽  
Pretreatment Temperature ◽  
Pretreatment Conditions ◽  
Main Components ◽  
The Relationship

Due to the invalidity of traditional models, pretreatment conditions dependent parameter of susceptible dissolution degree of xylan (dX) was introduced into the kinetic models. After the introduction of dX, the dissolution of xylan, and the formation of xylo-oligosaccharides and xylose during ethanol based auto-catalyzed organosolv (EACO) pretreatments of bamboo were well predicted by the pseudo first-order kinetic models (R2 > 97%). The parameter of dX was verified to be a variable dependent of EACO pretreatment conditions (such as solvent content in pretreatment liquor and pretreatment temperature). Based on the established kinetic models of xylan dissolution, the dissolution of glucan and the formation of degradation products (furfural and acetic acid) could also be empirically modeled (R2 > 97%). In addition, the relationship between xylan and lignin removal can provide guidance for alleviating the depositions of lignin or pseudo-lignin. The parameter of dX derived novel kinetic models can not only be used to reveal the multi-step reaction mechanisms of xylan, but also control the final removal of main components in bamboo during EACO pretreatments, indicating scientific and practical significance for governing the biorefinery of woody biomass.

scholarly journals Chemical synthesis of all-trans-β-retinoyl phosphate

1976 ◽  
Vol 159 (3) ◽  
pp. 799-801 ◽  
Author(s):  
J P Frot-Coutaz ◽  
L M de Luca
Keyword(s):  
Retinoic Acid ◽  
Chemical Synthesis ◽  
Cellulose Acetate ◽  
Silica Gel ◽  
Absorption Maximum ◽  
Ammonium Acetate ◽  
Deae Cellulose ◽  
Thin Layers ◽  
Molar Ratio ◽  
Chloroform Methanol

all-trans-β-Retinoic acid is phosphorylated to retinoyl phosphate by bis(triethylamine) phosphate with yields of 10-15%. The product is soluble in methanol and is eluted from DEAE-cellulose acetate at a concentration of 0.1M-ammonium acetate in 99% (v/v) methanol. Its phosphate/retinoic acid molar ratio is 1. Retinoyl phosphate has an absorption maximum at 360nm in methanol, whereas retinoic acid has a maximum at 350 nm. The compound is hydrolysed at pH2 and pH13 for 20 min at 37 degrees C, but is relatively stable under the same conditions at pH4, 6, 8 and 10. Retinoyl phosphate (RF 0.1) can be separated from retinyl phosphate (RF 0.2) by chromatography on thin layers of silica gel in chloroform/methanol/water (60:25:4, by vol.).

Effects of feeding ensiled date palm fronds and a by-product concentrate on performance and meat quality of Omani sheep

2007 ◽  
Vol 135 (3-4) ◽  
pp. 210-221 ◽  
Author(s):  
Osman Mahgoub ◽  
Isam T. Kadim ◽  
Musab H. Al-Busaidi ◽  
Kanthi Annamalai ◽  
Naseeb M. Al-Saqri
Keyword(s):  
Meat Quality ◽  
Date Palm ◽  
Palm Fronds

Characterisation of Drawing Papers for Borko Lazeski’s Cartoons (1951–56)

2018 ◽  
Vol 39 (3) ◽  
pp. 157-183
Author(s):  
Maja Kostadinovska
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Nature ◽  
Lignin Content ◽  
Mural Painting ◽  
Micro Raman Spectroscopy ◽  
Different Types ◽  
Informed Treatment ◽  
Acidic Conditions ◽  
Spot Tests ◽  
High Lignin Content

Abstract This paper presents a study of the drawing papers from Borko Lazeski’s cartoons for a mural painting. The collection is comprised of more than 20 single pieces (170×500 cm) executed in charcoal, pencil, pastel, tempera and ink. The cartoons exhibit different types of damages, such as grease stains, moisture stains, cracks, flaking paint, areas of loss caused by insects and mould stains. The study included spot tests, ATR-FTIR and micro-Raman spectroscopy to characterise the artist’s papers. They were found to be a type of paper composed of partly bleached, neutral sulphite semi-chemical (NSSC) wood pulp originating from coniferous trees (softwood) with the occasional use of abaca fibres. The laboratory tests revealed slightly acidic conditions (pH=5.01–6.52), high lignin content (>5 %) and alum-rosin sizing. Infrared spectroscopy confirmed all findings of the spot tests. Micro-Raman spectroscopy showed the presence of gypsum in the papers. The study addresses conservation issues arising from the chemical nature of the paper support and highlights the need for an extended study in order to be able to make informed treatment choices.

PRETREATMENT OF MILLET HUSK USING ALKALINE HYDROGEN PEROXIDE TO ENHANCE ENZYMATIC HYDROLYSIS FOR REDUCING SUGAR PRODUCTION

2021 ◽  
Vol 5 (2) ◽  
pp. 289-294
Author(s):  
Zeenat Ibrahim Saulawa ◽  
Lawal Nura ◽  
Muntari Bala ◽  
Abdullahi A. Iman
Keyword(s):  
Hydrogen Peroxide ◽  
Enzymatic Hydrolysis ◽  
Reducing Sugars ◽  
Reducing Sugar ◽  
Sugar Concentration ◽  
Sugar Production ◽  
Alkaline Hydrogen Peroxide ◽  
Pretreatment Time ◽  
Pretreatment Temperature ◽  
Reducing Sugar Concentration

The effectiveness of alkaline hydrogen peroxide as a suitable choice of pretreatment for the conversion of millet husk to reducing sugars using cellulase enzyme for hydrolysis and subsequent ethanol production was determined. The effects of three variables on reducing sugar production from millet husk were determined using one factor at a time (OFAT) method namely; peroxide concentration, pretreatment time and pretreatment temperature. From the results, it was observed that a significant (P<0.05) amount of reducing sugars were lost during pretreatment of millet husk. The untreated group which was only physically pretreated (milled) however yielded a significantly higher (P<0.05) reducing sugar concentration of 10.67mg/ml after enzymatic hydrolysis while the highest reducing sugar concentration of 4.82mg/ml was obtained using 0.375%v/v peroxide concentration for 60minutes at 250C. Therefore, pretreatment of biomass with alkaline hydrogen peroxide may be more suitable for feedstock with high lignin contents than millet husk.

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