Study on Furfural Production from Hemicelluloses

2013 ◽  
Vol 690-693 ◽  
pp. 1382-1385 ◽  
Author(s):  
Bin Shen ◽  
Yan Xue Liu ◽  
Yu Xin Liu ◽  
Jin Hui Peng
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Acid Hydrolysis ◽  
Solid Ratio ◽  
Several Variables ◽  
Higher Temperature ◽  
Temperature Liquid ◽  
Furfural Production

In this paper, furfural was produced from hemicelluloses of bagass by hydrolization reaction with sulfuric acid and acetic acid respectively. The effect of several variables such as temperature , liquid-to-solid ratio ,time and catalyst charge（KCL） on furfural yield was studied. The results showed that the better yield of furfural was obtained in acetic acid hydrolysis system. However, compared to yield of acetic acid hydrolysis system, it need more time and higher temperature at the same liquid-to-solid ratio. At last, when sulfuric acid as catalyst, liquid-to-solid ratio was 1:6 and time was 5h at 150°C, furfural yield can reach 75 %.

Study on Direct Acid Leaching Vanadium without Grinding and Roasting from Clay Vanadium Ore in Hunan

2013 ◽  
Vol 316-317 ◽  
pp. 882-886
Author(s):  
Wei He ◽  
Guo Hua Ye ◽  
Xiong Tong
Keyword(s):  
Sulfuric Acid ◽  
New Technology ◽  
Acid Leaching ◽  
Leaching Rate ◽  
Solid Ratio ◽  
Acid Type ◽  
Temperature Liquid ◽  
The Cost ◽  
Grinding System ◽  
Acid Dosage

Abstract：A new technology of direct acid leaching vanadium without grinding and roasting was put forward, and the effects of leaching factors including dosage of sulfuric acid, type and dosage of assistant leaching agent, leaching time and temperature, liquid-solid ratio on the vanadium leaching rate were systematically investigated. The results show that vanadium leaching rate could be up to 92.58% under the optimal conditions of sulfuric acid dosage of 30%, MnO2 as assistant leaching agent and its dosage of 1.5%, leaching time of 6h, leaching temperature of 90°C, liquid-solid ratio of 1:1, and the leaching performance is perfect. Due to leaving out the high costing grinding system and the complex roasting system, the new technology has advantages in shortening the process, decreasing the cost, avoiding pollution generated by roasting comparing with the traditional technologies, and it can meet the requirement of modern metallurgy very well.

The role of acidity profile in the nanotubular growth of polyaniline

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena Konyushenko ◽  
Miroslava Trchová ◽  
Jaroslav Stejskal ◽  
Irina Sapurina
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Reaction Temperature ◽  
Subsequent Growth ◽  
Subsequent Oxidation ◽  
Ammonium Peroxydisulfate ◽  
Aniline Oligomers ◽  
Positive Effect ◽  
Granular Morphology

AbstractConditions of polyaniline (PANI) nanotubes preparation were analyzed. Aniline was oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. There are two subsequent oxidation steps and the products were collected after each of them. At pH > 3, neutral aniline molecules are oxidized to non-conducting aniline oligomers. These produce templates for the subsequent growth of PANI nanotubes, which takes place preferably at pH 2–3. At pH < 2, granular morphology of the conducting PANI is obtained. High final acidity of the medium should be avoided in the preparation of nanotubes, e.g., by reducing the amount of sulfuric acid which is a by-product. Reduction of the peroxydisulfate-to-aniline mole ratio was tested for this purpose in the present study. Lowering of the reaction temperature from 20°C to −4°C had a positive effect on the formation of nanotubes.

Improved synthesis of anti-sesquinorbornene

1984 ◽  
Vol 62 (9) ◽  
pp. 1840-1844 ◽  
Author(s):  
Karl R. Kopecky ◽  
Alan J. Miller
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Lead Tetraacetate ◽  
Carboxyl Group ◽  
Silver Acetate ◽  
Benzenesulfonyl Chloride ◽  
Methoxide Ion ◽  
Hydrolysis Of ◽  
Monomethyl Ester

Treatment of methyl hydrogen decahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a,8a-dicarboxylate with lead tetraacetate in benzene – acetic acid replaces the carboxyl group by an acetoxy group. Hydrolysis of this product with 25% sulfuric acid at 130 °C forms 8a-hydroxydecahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a-carboxylic acid 10. The reaction between 10 and benzenesulfonyl chloride in pyridine containing triethylamine at 95 °C produces anti-sesquinorbornene 1 in 34% yield. In the absence of triethylamine 1 is converted to the hydrochloride. The iodohydroperoxide of 1 is converted by silver acetate at 0 °C to the diketone in a luminescent reaction. The 1,2-dioxetane could not be isolated. Decahydro-1,4:5,8-exo,exo-dimethanonaphthalene-4a,8a-dicarboxylic anhydride is converted slowly by methoxide ion in methanol at 150 °C to the monomethyl ester which then undergoes demethylation. The isomeric exo,endo anhydride undergoes reaction readily with methoxide ion at 80 °C.

scholarly journals Optimized acid hydrolysis of the polysaccharides from the seaweed Solieria filiformis (Kützing) P.W. Gabrielson for bioethanol production

2017 ◽  
Vol 39 (4) ◽  
pp. 423 ◽  
Author(s):  
George Meredite Cunha de Castro ◽  
Norma Maria Barros Benevides ◽  
Maulori Curié Cabral ◽  
Rafael De Souza Miranda ◽  
Enéas Gomes Filho ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sulfuric Acid ◽  
Acid Hydrolysis ◽  
Kinetic Parameters ◽  
Renewable Resource ◽  
Bioethanol Production ◽  
Seaweed Species ◽  
Mild Conditions ◽  
Hydrolysis Of ◽  
Solieria Filiformis

 The seaweeds are bio-resource rich in sulfated and neutral polysaccharides. The tropical seaweed species used in this study (Solieria filiformis), after dried, shows 65.8% (w/w) carbohydrate, 9.6% (w/w) protein, 1.7% (w/w) lipid, 7.0% (w/w) moisture and 15.9% (w/w) ash. The dried seaweed was easily hydrolyzed under mild conditions (0.5 M sulfuric acid, 20 min.), generating fermentable monosaccharides with a maximum hydrolysis efficiency of 63.21%. Galactose and glucose present in the hydrolyzed were simultaneously fermented by Saccharomyces cerevisiae when the yeast was acclimated to galactose and cultivated in broth containing only galactose. The kinetic parameters of the fermentation of the seaweed hydrolyzed were Y(P⁄S) = 0.48 ± 0.02 g.g−1, PP = 0.27 ± 0.04 g.L−1.h−1, h = 94.1%, representing a 41% increase in bioethanol productivity. Therefore, S. filiformis was a promising renewable resource of polysaccharides easily hydrolyzed, generating a broth rich in fermentable monosaccharides for ethanol production. 

Effect of Oxidant on the Leaching Rate of Indium from Water Quenching Slag

2013 ◽  
Vol 591 ◽  
pp. 122-125
Author(s):  
Li Jiao Yang ◽  
Si Chen ◽  
Yan Zhang ◽  
Nan Chun Chen ◽  
Jun Gao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Potassium Permanganate ◽  
Crystal Violet ◽  
Acid Leaching ◽  
Water Quenching ◽  
Test Results ◽  
Leaching Rate ◽  
Initial Concentration ◽  
Solid Ratio

Extracting indium from water quenching slag, which contains poor indium, by two process of leaching, the effect of different oxidants and dosages on the leaching rate of indium in water quenching slag were studied. The leaching conditions: temperature 80 °C, leaching time 2 h, the liquid to solid ratio of neutral leaching 8︰1, the liquid to solid ratio of acid leaching 2︰1, initial concentration of sulfuric acid 500 g·L-1, adding different oxidants, the concentration was detected by crystal violet spectrophotometry. Test results showed that the leaching rate of indium was significantly improved by adding hydrogen peroxide and potassium permanganate. Compared with the effect of different oxidants, the effect of potassium permanganate was significantly higher than that of hydrogen peroxide on the leaching rate of indium.

scholarly journals Extraction Optimization of Polysaccharides From Corn Silk and Their Antioxidant Activities in vitro and in vivo

2021 ◽  
Vol 12 ◽  
Author(s):  
Liang Zhang ◽  
Yang Yang ◽  
Zhanyong Wang
Keyword(s):  
Antioxidant Activities ◽  
Dry Weight ◽  
Extraction Time ◽  
Solid Ratio ◽  
Corn Silk ◽  
Response Surface Technique ◽  
Experimental Yield ◽  
Temperature Liquid

Response surface technique was employed for improving the extraction of corn silk polysaccharides (CSP). Temperature, liquid-to-solid ratio, and per extraction time were all examined as separate factors. The optimal extraction parameters were determined by fitting experimental data to a second-order polynomial; a liquid-to-solid ratio of 21.5 ml/g, temperature equivalent to 88°C, and extraction time of 1.87 h. The experimental yield of the extracted polysaccharides following the application of these conditions was 4.33 ± 0.08% (dry weight), which fit quite well with the predicted value. CSP’s strong scavenging capabilities against hydroxyls, 1,1-diphenyl-2-picrylhydrazyl radicals, and superoxide anions along with its excellent reducing potential, were demonstrated in an in vitro antioxidant experiment. Meanwhile, in vivo testing revealed that CSP substantially enhanced glutathione peroxidase and superoxide dismutase activities. The Malondialdehyde levels in the liver and serum of aged mice also underwent a decrease. This study found that CSP has a substantial antioxidant potential in vitro and in vivo, suggesting that it might be used as an antioxidant in food and medicine.

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