THE ALKALINE NITROBENZENE OXIDATION OF ASPEN WOOD AND LIGNIN MODEL SUBSTANCES

1955 ◽  
Vol 33 (1) ◽  
pp. 24-30 ◽  
Author(s):  
K. R. Kavanagh ◽  
J. M. Pepper
Keyword(s):  
Reaction Time ◽  
Sodium Hydroxide ◽  
Maximum Yield ◽  
Aspen Wood ◽  
Wood Meal ◽  
Nitrobenzene Oxidation ◽  
Subsequent Heating ◽  
Lignin Model ◽  
Model Substances

The yields of vanillin and syringaldehyde obtained by the alkaline nitrobenzene oxidation of aspen wood meal have been determined at various temperatures for various times. The maximum yield of each of these aldehydes, ca. 15 and 36% respectively, was obtained under the same conditions. Similar maximum yields result at 130 ± 5 °C. as at 170 ± 5 °C. if the reaction time is markedly increased. Treatment of the wood meal with sodium hydroxide at 160 °C. for two and one half hours prior to the addition of nitrobenzene and subsequent heating under the same conditions decreases, by over 30%, the yields of aldehydes. Samples of 3,4,5-trimethoxybenzaldehyde, β-D-glucovanillin, and β-D-glucosyringaldehyde were oxidized by alkaline nitrobenzene at 160 °C. for two and one half hours and yields of the corresponding phenolic aldehydes of 10.7, 69.6, and 71.9% respectively were obtained. These results are discussed with respect to the chemistry of aspen lignin.

scholarly journals Central Composite Design and Desirability of RSM for Optimization of Biodiesel Production from Mixture of Animal Waste Fat Oil and used Cooking Oil

2020 ◽  
Vol 9 (4) ◽  
pp. 1565-1571
Keyword(s):  
Reaction Time ◽  
Sodium Hydroxide ◽  
Maximum Yield ◽  
Animal Waste ◽  
Sodium Hydroxide Concentration ◽  
Used Cooking Oil ◽  
Input Parameters ◽  
Desirability Approach ◽  
Central Composite ◽  
Waste Fat

In this work, central composite design(CCD) and desirability approach of Response surface methodology (RSM) has been used for optimization of biodiesel yield produced from mixture of animal waste fat oil and used cooking oil (AWO) in the ratio of 1:1through alkaline transesterification process. In this work, methanol quantity, reaction time and sodium hydroxide concentration are selected as input parameters and yield selected as response. The combined effect of methanol quantity, reaction time and sodium hydroxide concentration were investigated and optimized by using RSM. The second order model is generated to predict yield as a function of methanol quantity, reaction time and sodium hydroxide concentration. A statistical model predicted the maximum yield of 96.9779% at 35ml methanol quantity (% v/v of oil), 75 min. reaction time and 0.6g (% wt./v of oil) of sodium hydroxide. Experimentally, the maximum yield of 97% was obtained at the above optimized input parameters. The variation of 0.02% was observed between experimental and predicted values. In this work, an attempt has also made to use desirability approach of RSM to optimize the input parameters to predict maximum yield. Desirability approach predicts maximum yield (97.075%) at CH3OH (35.832% vol. /vol. of oil), NaOH (0.604 % wt./vol. of oil) and reaction time (79.054min.) was found for the AWO.

Characterization of autohydrolysis aspen (P. tremuloides) lignins. Part 4. Residual autohydrolysis lignin

1979 ◽  
Vol 57 (19) ◽  
pp. 2612-2616 ◽  
Author(s):  
Morris Wayman ◽  
Miranda G. S. Chua
Keyword(s):  
Enzymatic Hydrolysis ◽  
Time Varying ◽  
Residual Lignin ◽  
Aspen Wood ◽  
Milled Wood Lignin ◽  
Wood Meal ◽  
Nitrobenzene Oxidation ◽  
Infrared Studies ◽  
Lignocellulosic Residue

Lignocellulosic residue remaining after autohydrolysis of extractive-free aspen wood meal at 195 °C for periods of time varying from 5 to 120 min followed by extraction with 90% dioxane was subjected to enzymatic hydrolysis to obtain residual lignin. Infrared studies indicated that in the early stages of autohydrolysis residual lignin resembles protolignin, but as autohydrolysis proceeds it changes to resemble more and more the extracted lignin. Residual lignin was found to be higher in carbon but lower in hydrogen and oxygen than aspen milled wood lignin. The methoxyl content was also lower than the reference lignin. From alkaline nitrobenzene oxidation, residual lignin is seen to become more condensed with increasing autohydrolysis time. The insolubility of residual lignin is attributed to the existence of strong bonds between this lignin and carbohydrate.

Characterization of autohydrolysis aspen (P. tremuloides) lignins. Part 2. Alkaline nitrobenzene oxidation studies of extracted autohydrolysis lignin

1979 ◽  
Vol 57 (19) ◽  
pp. 2599-2602 ◽  
Author(s):  
Morris Wayman ◽  
Miranda G. S. Chua
Keyword(s):  
Molecular Weight ◽  
Molar Ratio ◽  
Low Molecular Weight ◽  
Aspen Wood ◽  
Milled Wood Lignin ◽  
Wood Meal ◽  
Nitrobenzene Oxidation ◽  
Carbon Carbon Bonds ◽  
Degree Of Condensation

Alkaline nitrobenzene oxidation of the lignins extracted from extractive-free aspen wood meal after autohydrolysis at 195 °C for periods varying from 5 min to 2 h indicated that these lignins were structurally more condensed in terms of an increase in new carbon–carbon bonds than aspen milled wood lignin. The degree of condensation generally increased with longer autohydrolysis times. It is postulated that condensation involved materials from both the carbohydrate and lignin components of the wood which were generated during the autohydrolysis. The molar ratio of syringaldehyde to vanillin of extracted lignin on oxidation was observed to decrease with increasing autohydrolysis time. It is suggested that syringyl units are preferentially extracted as low molecular weight material.

The Synthesis of Levulinic Acid Synthesis from Glucose Using ZSM-5 Zeolite Catalyst

2013 ◽  
Vol 291-294 ◽  
pp. 782-785 ◽  
Author(s):  
Jun Ping Zhuang ◽  
Chun Sheng Pang ◽  
Ying Liu
Keyword(s):  
Reaction Time ◽  
Levulinic Acid ◽  
Zeolite Catalyst ◽  
Maximum Yield ◽  
Value Added ◽  
Acid Synthesis ◽  
Temperature Reaction ◽  
Experimental Parameters ◽  
Fuels And Chemicals ◽  
Broad Variety

Levulinic acid （LA）is a highly versatile platform chemical that can be converted into a broad variety of value-added fuels and chemicals. LA can be produced from the botanic biomass by hydrolyzing. The aim of the present study is to investigate the conversion of glucose to LA by ZSM-5 zeolite catalyst for LA production and optimized to obtain the maximum yield of LA. The main experimental parameters are the amount of ZSM-5 zeolite added, reaction temperature, reaction time and concentration of glucose. The results showed that the optimization of the conversion of glucose to LA by ZSM-5 zeolite. An optimized LA yield was obtained at 190 °C for 2.5 h with 3 g ZSM-5 zeolite catalys and the highest LA yield was 69. 32%.

Synthetic Technology and Performance of a Novel Fatty Alcohol Polyoxyethylene Carboxylate Surfactants

2011 ◽  
Vol 298 ◽  
pp. 163-168 ◽  
Author(s):  
Yuan Yuan Lei ◽  
Guo Zheng ◽  
Yu Sun ◽  
Yong Zhou
Keyword(s):  
Reaction Time ◽  
Optimum Condition ◽  
Sodium Hydroxide ◽  
Fatty Alcohol ◽  
Succinic Anhydride ◽  
Foam Stability ◽  
Raw Materials ◽  
Molar Ratio ◽  
New Type ◽  
And Performance

In this paper, with fatty alcohol polyoxyethylene (AEO9), succinic anhydride (SA) and sodium hydroxide as raw materials, a new type of fatty alcohol polyoxyethylene carboxylate surfactants (SAE9C-Na) was obtained by esterification and neutralizing effect. The influencing factors were researched and its surface properties were studied. The optimum condition of synthesis was determined: molar ratio of alcohol to acid was 1:1.1, reaction temperature was 85°C, reaction time was 60 min, under this condition, the yield could reach up to 95.8%. The results received from this experiment showed that SAE9C-Na had excellent surface activity and foaming and foam stability, whose emulsification and solubility enhancement were improved greatly.

scholarly journals Simple Protocol for the Knoevenagel Condensation Under Solvent Free Conditions using Tungstophosphoric Acid as Catalyst

2019 ◽  
Vol 31 (10) ◽  
pp. 2181-2184
Author(s):  
Abdulrahman I. Alharthi
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Room Temperature ◽  
Model Compound ◽  
Knoevenagel Condensation ◽  
Maximum Yield ◽  
Tungstophosphoric Acid ◽  
Grinding Method ◽  
Solvent Free Conditions ◽  
Simple Protocol

The effect of calcination on the performance of tungstophosphoric acid for the product of Knoevenagel condensation was investigated. Substituted aldehydes and dimedone has been used in the presence of calcined tungstophosphoric acid as a heterogeneous catalyst using grinding method at room temperature. The results of reactions revealed that calcined tungstophosphoric acid has superior catalytic activity comparing to non-calcined catalyst in terms of yield and reaction time. Maximum yield of model compound was achieved by using 10 mol% of calcined catalyst in a reaction time that does not exceed 10 min, whereas the yield at same amount of non-calcined catalyst was 86 % in a reaction time of 35 min.

Comparison between Conventional and Ultrasonic Preparation of Chitosan from Shrimp Shells Waste

2015 ◽  
Vol 1123 ◽  
pp. 205-208
Author(s):  
Zainal Arifin ◽  
D. Irawan
Keyword(s):  
Reaction Time ◽  
Sodium Hydroxide ◽  
Ultrasonic Irradiation ◽  
Ultrasound Irradiation ◽  
Promising Alternative ◽  
Acidic Solutions ◽  
Degree Of Deacetylation ◽  
Shrimp Shells ◽  
Ultrasonic Preparation ◽  
Enzymatic Methods

Chitosan is a natural biopolymer derived by deacetylation of chitin from the two main sources of crustaceans, shrimp and crabs. Chitosan, which is soluble in acidic solutions, is used in many applications (biomedical/pharmaceutical, water engineering, food, cosmetics). There have been many researchers who have developed a process of deacetylation of chitin from shrimp shells waste by thermochemical or enzymatic methods. However, application of ultrasonic irradiation for chitin deacetylation has received little attention. In this work, the deacetylation of chitin with concentrated sodium hydroxide was performed using ultrasound irradiation (80 W, 42 kHz). The reaction time and degree of deacetylation were compared with conventional process. Results showed that under the same condition, the degree of deacetylation was similar. However, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative method to the conventional method.

Resource recovery of waste incineration fly ash: Synthesis of tobermorite as ion exchanger

1999 ◽  
Vol 14 (11) ◽  
pp. 4437-4442 ◽  
Author(s):  
Zhidong Yao ◽  
Chikashi Tamura ◽  
Motohide Matsuda ◽  
Michihiro Miyake
Keyword(s):  
Fly Ash ◽  
Reaction Time ◽  
Sodium Hydroxide ◽  
Hydrothermal Treatment ◽  
Reaction Temperature ◽  
Sodium Hydroxide Solution ◽  
Waste Incineration ◽  
Naoh Solution ◽  
Temperature Time ◽  
Waste Incineration Fly Ash

Tobermorite was synthesized successfully from waste incineration fly ash by hydrothermal treatment in the presence of sodium hydroxide solution. The tobermorite synthesis was examined as a function of reaction temperature, time, and NaOH concentration. The formation of tobermorite was identified in all of the fly ash treated with NaOH at 180 °C, followed by the minor generations of sodalite and cancrinite phases with increasing NaOH concentration and extending reaction time. The NaOH-treated fly ash revealed the uptake behaviors for Cs+ and NH4+, whereas the fly ash untreated with NaOH solution did not show that. The uptake amounts of resulting products were also determined: 0.40 mmol/g for Cs+ and 0.35 mmol/g for NH4+ in the fly ash treated with 2.0 M NaOH at 180 °C for 20 h.

Synthesis of the Carboxyl and Pyridine Functional Ionic Liquids

2014 ◽  
Vol 513-517 ◽  
pp. 246-250 ◽  
Author(s):  
Ying Xiong ◽  
Min Yang
Keyword(s):  
Ionic Liquids ◽  
Reaction Time ◽  
Anion Exchange ◽  
Room Temperature ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Maximum Yield ◽  
Step Method ◽  
Strong Base ◽  
One Step

The effects of different solvents on synthesis of base functional ionic liquid, butyl pyridinium hydroxide ([bPy]OH), from butyl pyridinium bromine ([bPy]Br) were investigated systematically using KOH/NaOH as the base agent and strong base anion exchange resin. The results showed that the yield of [bPy]OH achieved 35% with the molar ratio of 1:1.1 ([bPy]Br to NaOH) using dichloromethane under room temperature. With isopropanol and 8 h of the reaction time, the yield could reach 88% with byproducts. The yield of 97% without byproduct was achieved by using strong base anion exchange resin in column chromatography static reaction for 0.25 h. The yield of carboxyl and pyridine functional ionic liquids based on neutralization method, exchange method and one-step method were compared and the results showed that the one-step method possessed the maximum yield of 88% with 3 h of the reaction time at room temperature.

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