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.

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.

Hydrolysis of S. platensis Using Sulfuric Acid for Ethanol Production

2022 ◽  
Vol 1048 ◽  
pp. 451-458
Author(s):  
Megawati ◽  
Astrilia Damayanti ◽  
Radenrara Dewi Artanti Putri ◽  
Zuhriyan Ash Shiddieqy Bahlawan ◽  
Astika Arum Dwi Mastuti ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Ethanol Production ◽  
Raw Material ◽  
Effect Of Temperature ◽  
Second Step ◽  
Carbohydrate Composition ◽  
Hydrolysis Time ◽  
Glucose Yield ◽  
Hydrolysis Temperature ◽  
Hydrolysis Of

S. platensis is a microalga that contains carbohydrate composition of 30.21% which makes it potential to be used as raw material for ethanol production. Hydrolysis of S. platensis is the first step for converting its carbohydrates into monosaccharides. The second step is fermentation of monosaccharides into ethanol. This research aims to study the effect of temperature and microalgae concentration on the hydrolysis of S. platensis using sulfuric acid as catalyst. This research was conducted using 300 mL sulfuric acid of 2 mol/L, hydrolysis temperatures of 70, 80 and 90 °C, and microalgae concentrations of 20, 26.7, and 33.3 g/L. The effect of temperature is significant in the hydrolysis of S. platensis using sulfuric acid. At microalgae concentration of 20 g/L and hydrolysis time of 35 minutes, the higher the temperatures (70, 80, and 90 °C), the more the glucose yields would be (8.9, 13.5, and 22.9%). This temperature effect got stronger when the hydrolysis was running for 15 minutes. Every time the hydrolysis temperature increased by 10 °C, the glucose yield increased by 13.0% at microalgae concentration of 33.3 g/L. At temperature of 90 °C and time of 35 minutes, the higher the microalgae concentrations (20, 26.7, and 33.3 g/L), the higher the glucose yields would be (25.5, 27.7, and 28.2%). The highest glucose concentration obtained was 2.82 g/L at microalgae concentration of 33.3 g/L, temperature of 90 °C, and time of 35 minutes.

Process’ Optimization of Nanocrystalline Cellulose and its Properties

2012 ◽  
Vol 200 ◽  
pp. 373-376 ◽  
Author(s):  
Ping Ping Zou ◽  
Ping Zhang ◽  
De Gao ◽  
Qiao Na Xia
Keyword(s):  
Thermal Properties ◽  
Sulfuric Acid ◽  
Microcrystalline Cellulose ◽  
Freeze Drying ◽  
Sulfuric Acid Concentration ◽  
Nanocrystalline Cellulose ◽  
Electronic Microscopy ◽  
Hydrolysis Time ◽  
Reaction Conditions ◽  
Hydrolysis Temperature

This paper concerned nanocrystalline cellulose(NCC)’s isolation from microcrystalline cellulose(MCC) by sulfuric acid hydrolysis, meanwhile centrifuging, ultrasonic treatment and freeze-drying were carried out afterwards. It covered the effect of reaction conditions on the yield of NCC. It indicated that hydrolysis time was the factor that matters most and it was possible to obtain the largest yield with hydrolysis time being 108min, hydrolysis temperature being 43oC and sulfuric acid concentration being 33%. It also investigated the microcosmic morphology of NCC by Transmission Electronic Microscopy(TEM). MCC and NCC’s thermal properties were studied further.

Response Surface Optimization of Concentrated Sulfuric Acidic Hydrolysis of Poplar Sawdust

2011 ◽  
Vol 236-238 ◽  
pp. 259-263
Author(s):  
Shan Shan Liu ◽  
Gui Gan Fang ◽  
Yong Jun Deng ◽  
Shan Ming Han
Keyword(s):  
Sulfuric Acid ◽  
Sulfuric Acid Concentration ◽  
Xrd Analysis ◽  
Acid Pretreatment ◽  
Hydrolysis Time ◽  
Glucose Content ◽  
Response Surface Optimization ◽  
Sulfuric Acid Pretreatment ◽  
Hydrolysis Temperature ◽  
Poplar Sawdust

The primary goal of this study was optimized condition for hydrolyzed of papermaking waste (poplar sawdust) as a potential bio-ethanol source by sulfuric acid pretreatment. Based on 23 factorial design, fifteen operations were performed by varying on T, t and c (T: hydrolysis temperature, t: hydrolysis time and c: sulfuric acid concentration). The components of the hydrolysate and solid fractions were analyzed by GC, X-RD and SEM, respectively. The results showed that optimal condition was T 44.8°C, t 120min and c 60%, and reducing sugar yield of 43.3% can be obtained. Through GC detection, glucose content of 26.10 g/L and xylose content of 9.00 g/L is available in hydrolyzate for fermentation. The residue crystallinity declined 74.34% from XRD analysis, the fiber structure was destroyed completely by acid hydrolysis from SEM photograph.

scholarly journals Uji Daya Hambat Senyawa Xylitol dari Limbah Tongkol Jagung pada Bakteri Streptococcus Mutans

2017 ◽  
Vol 4 (2) ◽  
pp. 111
Author(s):  
Mahyati Mahyati
Keyword(s):  
Sulfuric Acid ◽  
Streptococcus Mutans ◽  
Acid Concentration ◽  
Extraction Method ◽  
Sulfuric Acid Concentration ◽  
Water Soluble ◽  
Antibacterial Substance ◽  
Hydrolysis Time ◽  
Corn Cobs ◽  
Xylan Content

Corncob contains xylan content of 12.4 - 12.9% which can be converted to xylitol [1]. Xylitol significantly reduces the population of Streptococcus mutans (S. mutans) in saliva compared with fluoride [3]. The effectiveness of xylitol from corn cobs waste is an antibacterial substance of S. mutans in safe and water-soluble mouthwash. The purpose of this research is to produce xylitol from corn cobs waste and to test the xylitol inhibition as anti bacterial in S. mutans bacteria. The xylitol extraction method of corncob using aqueous sulfuric acid is 0.25; 0.5; 0.75 and 1.0%. The extraction time was then varied from 15, 30, 45, 60, 75 and 90 min. The results showed xylitol compound from corn tuna waste was highest at 0.25% sulfuric acid concentration with 30 minutes hydrolysis time of 249.7 ppm and the lowest at 0.75% acid concentration and hydrolysis time of 90 minutes is 5.6 ppm. Xylitol compounds can be obtained from corn cobs waste has the value of inhibitory growth of S. Mutans bacteria in all variations of acid concentration (H2SO4) and hydrolysis time is 100%.

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%.

Study on the Hydrolysis of Corn Stalk and Photosynthetic Bacteria Group Fermentation Hydrogen Production

2011 ◽  
Vol 194-196 ◽  
pp. 2187-2190
Author(s):  
Bao Chen Cui ◽  
Guo Xin Zhang ◽  
Bo Hou ◽  
Jing Yan Zhao ◽  
Rui Li
Keyword(s):  
Sulfuric Acid ◽  
Hydrogen Production ◽  
Acid Concentration ◽  
Photosynthetic Bacteria ◽  
Sulfuric Acid Concentration ◽  
Optimum Process ◽  
Process Conditions ◽  
Hydrogen Yield ◽  
Corn Stalk ◽  
Hydrolysis Temperature

Hydrogen production of photosynthetic bacteria group (PSBG) was studied using corn stalk hydrolyzate as hydrogen production substrate. The effects of sulfuric acid concentration, hydrolysis pH values and hydrolysis temperature on hydrogen production were investigated. The optimum process conditions were as follows: the sulfuric acid concentration was 1%, hydrolysis pH value was 6.0 and the hydrolysis temperature was 110°C , respectively. Three hydrolyzate detoxification methods were compared. The method of calcium hydroxide obtained the optimal detoxification effect and the maximum hydrogen yield was 472 mL H2/ (L-medium).

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

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