Evaluation of the effect of substrate amount, sulfuric acid concentration and reaction temperature on acidic hydrolysis of cellulose casings applying a central composite design

2012 ◽  
Vol 29 ◽  
pp. S205-S206
Author(s):  
Jesús J. Vidal-Vidal ◽  
Guillermo Arzate-Martínez ◽  
Lizzette Moreno-García ◽  
Oscar M. Portilla-Rivera
Keyword(s):  
Sulfuric Acid ◽  
Central Composite Design ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Sulfuric Acid Concentration ◽  
Acidic Hydrolysis ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of ◽  
Central Composite

The hydrolysis of thioacetic, thiobenzoic, and three substituted thiobenzoic acids in perchloric and sulfuric acids

1978 ◽  
Vol 56 (7) ◽  
pp. 935-940 ◽  
Author(s):  
John T. Edward ◽  
Graeme Welch ◽  
Sin Cheong Wong
Keyword(s):  
Sulfuric Acid ◽  
Activity Coefficients ◽  
Acid Concentration ◽  
Perchloric Acid ◽  
Transition States ◽  
Sulfuric Acid Concentration ◽  
Thiobenzoic Acid ◽  
The Difference ◽  
Different Response ◽  
Hydrolysis Of

The rates of hydrolysis of thioacetic, thiobenzoic, and three substituted thiobenzoic acids increase with concentration of solvent sulfuric or perchloric acid to a maximum in 30–40% acid and then decrease. Yates–McClelland r, Bunnett–Olsen [Formula: see text], and Hammett ρ parameters, and entropies of activation indicate an AAC2 mechanism over this range of acid concentrations. In acid concentrations above 50–60% the rates increase sharply and the same mechanistic criteria now indicate an AAc1 mechanism. The difference between the rate–acidity profile of thiobenzoic acid and that of ethyl thiolbenzoate can be explained by the different response of the activity coefficients of their transition states to increase in sulfuric acid concentration.

Study on Sugar Production Conditions of Dilute Sulfuric Acid Hydrolysis of Corn Straw

2014 ◽  
Vol 1008-1009 ◽  
pp. 97-100
Author(s):  
Qing Sun ◽  
Shu He Huang ◽  
Bo Wang ◽  
Xiao Run Deng ◽  
Jia Sheng Yi ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Sugar Yield ◽  
Corn Straw ◽  
Experimental Conditions ◽  
Dilute Sulfuric Acid ◽  
Hydrolysis Of

In this paper, through the study of reducing sugar conditions of corn straw hydrolysis under acidic condition, looking for the production of experimental conditions relatively reasonable. Mainly by dilute sulfuric acid hydrolysis of corn straw by single factor test, effects of sulfuric acid concentration, temperature, reaction time, particle size, ratio of solid to liquid five factors, effects on sugar yield of corn straw. The dilute sulfuric acid concentration 5%, ratio of solid to liquid was 1:14, when the reaction time is 140 min, particle fineness of 120 mesh, the reaction temperature is 100 °C, corn stalk sugar yield reached a maximum 20.11%.

scholarly journals HIDROLISIS SELULOSA DARI SEKAM PADI (Oryza sativa) MENJADI GLUKOSA DENGAN KATALIS ARANG TERSULFONASI

KOVALEN ◽  
2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Adeks Pramana ◽  
Abdul Rahman Razak ◽  
Prismawiryanti Prismawiryanti
Keyword(s):  
Oryza Sativa ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Rice Husk ◽  
Contact Time ◽  
Sulfuric Acid Concentration ◽  
Cellulose Hydrolysis ◽  
Hydrolysis Reaction ◽  
Rice Husks ◽  
Hydrolysis Of

Cellulose hydrolysis from rice husk (Oryza sativa) into glucose with sulfonated charcoal catalyst was conducted. The aim of this research was to determine sulfuric acid concentration and contact time on the sulfonation process of charcoal which would produce the highest glucose rendement from cellulose hydrolysis of rice husk. Sulfuric acid concentrations in this experiment were 8, 10, and 12 N with variation of contact time of 4, 6, 8, 10 and 12 hours respectively.  Rice husk was delignified with NaOH 10% to produce cellulose which was hydrolyzed by sulfonated charcoal catalyst. Hydrolysis reaction with the ratio cellulose/aquadest 1:25 (w/v) was conducted in autoclave with temperature 130 oC for 3 hours. The result showed that 8 N concentration of sulfuric acid and 12 hours of contact time produced the highest glucose rendement 17,9%. Keywords : rice husks, cellulose, glucose, sulfonated charcoal

scholarly journals Statistical Study for Leaching of Covellite in a Chloride Media

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 477
Author(s):  
Kevin Pérez ◽  
Norman Toro ◽  
Manuel Saldaña ◽  
Eleazar Salinas-Rodríguez ◽  
Pedro Robles ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Statistical Study ◽  
Sulfuric Acid Concentration ◽  
Chloride Concentration ◽  
Quadratic Model ◽  
Copper Extraction ◽  
Optimization Methodology ◽  
Composite Face ◽  
Central Composite

Covellite is a secondary copper sulfide, and it is not abundant. There are few investigations on this mineral in spite of it being formed during the leaching of chalcocite or digenite; the other investigations on covellite are with the use of mineraloids, copper concentrates, and synthetic covellite. The present investigation applied the surface optimization methodology using a central composite face design to evaluate the effect of leaching time, chloride concentration, and sulfuric acid concentration on the level of copper extraction from covellite (84.3% of purity). Copper is dissolved from a sample of pure covellite without the application of temperature or pressure; the importance of its purity is that the behavior of the parameters is analyzed, isolating the impurities that affect leaching. The chloride came from NaCl, and it was effectuated in a size range from –150 to +106 μm. An ANOVA indicated that the leaching time and chloride concentration have the most significant influence, while the copper extraction was independent of sulfuric acid concentration. The experimental data were described by a highly representative quadratic model obtained by linear regression (R2 = 0.99).

Synthesis of Polypropylene Strong Acid Cationic Exchange Fiber

2015 ◽  
Vol 1088 ◽  
pp. 434-438
Author(s):  
Wei Chen
Keyword(s):  
Sulfuric Acid ◽  
Adsorption Capacity ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Sulfuric Acid Concentration ◽  
Strong Acid ◽  
Swelling Agent ◽  
Liquor Ratio ◽  
Cationic Exchange ◽  
Grafting Degree

A novel polypropylene strong acid cationic exchange fiber (SACEF) was prepared by sulphonation reaction of polypropylene graft styrene (PP-g-St) fiber, using 1,2-dichloroethane as swelling agent. Factors effected the adsorption capacity of SACEF synthesized from PP-g-St fiber, such as swelling time, grafting degree of PP-g-St, liquor ratio (mass of fiber vs. volume of the reaction reagent), reaction temperature, and sulfuric acid concentration were investigated. The results showed that the average adsorption capacity of SACEF was 4.42 mmol·g-1.

The kinetics of vanadium extraction from spent hydroprocessing catalyst by leaching with sulfuric acid at atmospheric pressure

2019 ◽  
Vol 116 (2) ◽  
pp. 214
Author(s):  
Hongjun Wang ◽  
Yali Feng ◽  
Haoran Li ◽  
Xiangyi Deng ◽  
Jinxing Kang
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Atmospheric Pressure ◽  
Sulfuric Acid Concentration ◽  
Dissolution Kinetics ◽  
Membrane Diffusion ◽  
Shrinking Core ◽  
Dissolution Ratio ◽  
Kinetics Of

The dissolution kinetics of vanadium from spent hydroprocessing catalyst was investigated by leaching with sulfuric acid at atmospheric pressure. The effects of stirring speed (400–800 rpm), initial sulfuric acid concentration (0.60–1.20 mol/l) and reaction temperature (373–423 K) on the vanadium dissolution were studied. The results showed that the vanadium dissolution ratio was practically independent of stirring speed at the investigated range, while increasing with the increases of sulfuric acid concentration and reaction temperature. The experimental data agreed quite well with the shrinking core model, with solid membrane diffusion as the rate controlling step. The apparent activation energy was calculated as 11.44 kJ/mol, and the reaction order with respect to sulfuric acid concentrations was determined to be 1.51. The kinetics equation of the leaching process was established as: 1 − 2x/3 − (1 − x)2/3 = 0.067[H2SO4]1.51exp[ − 11563/RT ]t.

Kinetics of Sulfuric Acid Leaching of Boron Slurry

2011 ◽  
Vol 366 ◽  
pp. 370-373
Author(s):  
Feng Gao ◽  
Xiang Guang Xu ◽  
Lei Li ◽  
Huai Yu Sun ◽  
Hong Xin Wang
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Product Layer ◽  
Leaching Kinetics ◽  
Diffusion Controlled ◽  
Reaction Activation Energy

The results of a leaching kinetics study of boron slurry with sulfuric acid were presented. Effect of ore particle size, reaction temperature, and acid concentration on magnesium dissolution rate were determined. The results shown that leaching of about 64.61% of magnesium was achieved using (-200+ 250) mesh ore particle size at a reaction temperature of 60°C for reaction time 100 min with 25% sulfuric acid concentration. Leaching kinetics indicated that diffusion through the product layer was the rate controlling process during the reaction. The reaction activation energy was determined to be about 3.35 kcal/mol, which was characteristic for a diffusion– controlled process.

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