Influence of temperature, time, liquid/solid ratio and sulfuric acid concentration on the hydrolysis of palm empty fruit bunches

2013 ◽  
Vol 129 ◽  
pp. 506-511 ◽  
Author(s):  
Ana Ferrer ◽  
Ana Requejo ◽  
Alejandro Rodríguez ◽  
Luis Jiménez
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Influence Of Temperature ◽  
Solid Ratio ◽  
Empty Fruit Bunches ◽  
Hydrolysis Of ◽  
Temperature Time

Study on Leaching Zinc Calcine with High Iron

2013 ◽  
Vol 826 ◽  
pp. 118-121
Author(s):  
Jin Lin Yang ◽  
Hong Mei Zhang ◽  
Xiu Juan Su ◽  
Shao Jian Ma
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Great Influence ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Leaching Rate ◽  
Iron Extraction ◽  
High Iron ◽  
Solid Ratio ◽  
Leaching Efficiency

In recent years, recovering zinc from zinc calcine with high iron has been a matter of discussion. In this paper, sulfuric acid leaching was carried out to assess the effect of several parameters on zinc and iron extraction in zinc calcine with high iron in which the grade of zinc and iron is 53.90% and 19.38%, respectively. Parameters, such as stirring speed, sulfuric acid concentration, liquid to solid ratio and leaching time, were investigated. The results show that leaching time has done nothing to the leaching rate, but has great influence on leaching efficiency. Liquid to solid ratio and sulfuric acid concentration have significant influence on leaching results, and stirring rate has not obvious influence on leaching results. Under the condition of 120g/L sulfuric acid, 6:1 liquid to solid ratio, 55°C leaching temperature and 120min leaching time, the recovery of zinc and iron is 82.24% and 9.64%, respectively. It is obvious that ZnO in zinc calcine is easy to dissolve in acidity solution, which shown in two aspects: high leaching rate and high leaching speed. ZnO can be dissolved entirely in sufficient sulfuric acid in 10min.

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.

Atmospheric Acid Leaching of a Ferruginous Nickel Laterite

2013 ◽  
Vol 634-638 ◽  
pp. 3196-3200
Author(s):  
Kui Liu ◽  
Xue Mei Su
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Atmospheric Pressure ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Nickel Laterite ◽  
Nickel Extraction ◽  
Solid Ratio ◽  
Acid Consumption ◽  
Two Factors

A ferruginous nickel laterite was leached by sulfuric acid at atmospheric pressure. Nickel extraction was largely dependent on sulfuric acid concentration and leaching temperature. Besides these two factors, leaching time and liquid/solid ratio also influenced cobalt extraction significantly. Nickel was easier to be extracted than cobalt. About 95% nickel and cobalt could be extracted when leaching with 5mol/L sulfuric acid for 2h at 100°C, and the acid consumption was 1.417kg H2SO4/kg dry ore.

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

Study on the Extraction of Arsenic in Destruction Residues of Arsenical Chemical Weapons

2014 ◽  
Vol 955-959 ◽  
pp. 2874-2879 ◽  
Author(s):  
Li Juan You ◽  
Ting Zhou ◽  
Xue Feng Wang ◽  
Yong Xu ◽  
Gang Rao ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Extraction Rate ◽  
Chemical Weapons ◽  
Single Factor ◽  
Solid Ratio ◽  
Orthogonal Experiments ◽  
Five Factors ◽  
Extraction Agent

In order to treat these arsenical residues produced when some arsenical chemical weapons were destroyed in Nanjing and recycle the arsenic, sulfuric acid was used as the extraction agent to extract the arsenic contained in the residuals, and single factor experiments and orthogonal experiments were carried out to study the effects of factors including concentration, liquid-to-solid ratio, temperature, shaking speed and time on the extraction effect. The results show that these five factors all have some effect on the arsenic extraction rate with the degree in the following order: Liquid-to-solid ratio> temperature> extraction agent concentration > time > shaking speed; when the sulfuric acid concentration is 1.2 mol/L and the liquid-to-solid ratio is 30, keeping the shaking speed at 200 r/min and extracting the residues at 40 °C for 2h, the arsenic extraction rate of the residues could reach up to 98.95%.

scholarly journals Optimization of hydrolysis conditions for xylans and straw hydrolysates by HPLC analysis

2021 ◽  
Author(s):  
Alexander Beckendorff ◽  
Anne Lamp ◽  
Martin Kaltschmitt
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Hplc Analysis ◽  
Degradation Products ◽  
Sulfuric Acid Concentration ◽  
Corn Cob ◽  
Hydrolysis Time ◽  
Conversion Rates ◽  
Hydrolysis Temperature ◽  
Hydrolysis Of

AbstractOligosaccharide analysis is commonly done by acid hydrolysis and following HPLC analysis. A major problem is the incomplete hydrolysis of oligosaccharides and disaccharides and the increasing formation of volatile furfural from pentose monomers and hydroxymethylfurfural (HMF) from hexose monomers. This paper optimizes the conditions of hydrolysis approaches and proposes a method for oligosaccharide quantification. The optimal condition for hydrolysis of model xylan from corn cob was found to be for 100 °C hydrolysis temperature, 120 min hydrolysis time, and 2 wt% sulfuric acid concentration. Under these conditions, the total free and bound xylose yield was 77.4% and hemicellulose conversion 87.4% respectively; no degradation products were found. The optimal conditions for hydrolysis of model xylan from beech wood were found to be for 120 °C hydrolysis temperature, 120 min hydrolysis time, and 2 wt% sulfuric acid concentration. Under these conditions, the total free and bound xylose yield was 65.1% and hemicellulose conversion 70.5% respectively; no degradation products were found. For pentosan hydrolysate, conditions were further optimized (110 °C, 60 min, 2 wt% H2SO4). Standard addition of xylan from the corn cob for hydrolysation showed similar conversion rates (< 2% deviation); no matrix effects were detected.

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