Effect of pH control strategies and substrate concentration on the hydrogen yield from fermentative hydrogen production in large laboratory-scale

2012 ◽  
Vol 65 (2) ◽  
pp. 262-269 ◽  
Author(s):  
I. Mariakakis ◽  
J. Krampe ◽  
H. Steinmetz
Keyword(s):  
Hydrogen Production ◽  
Control Strategies ◽  
Sucrose Concentration ◽  
Ph Control ◽  
Laboratory Scale ◽  
Hydrogen Yield ◽  
Batch Experiments ◽  
Ph Adjustment ◽  
Fermentative Hydrogen Production ◽  
Initial Ph

A series of batch experiments investigating two different pH control strategies, initial pH adjustment and continuous pH control, have been carried out in large laboratory-scale reactors with working volumes of 30 L. In both cases, pH was varied between 5 and 7.5. Sucrose concentrations were also varied starting from 0 up to 30 g/L. Higher hydrogen production yields can be achieved by batch experiments through continuous pH control than by simple initial pH adjustment. In the case of continuous pH control, maximization of hydrogen yield was acquired for slightly acidic pH of 6.5. Continuous pH control in the neutral pH range of 7.0 and in pH lower than 6.5, induced a reduction in the hydrogen production yield. Sucrose can be completely degraded only for a pH higher than 6. Lower pH values seem to inhibit the hydrogen-producing bacteria. Under the conditions of continuous pH adjustment at pH 6.5 and a sucrose concentration of 25 g/L the maximum hydrogen yield of 1.79 mol H2/mol hexose was obtained. These conditions could be applied for the batch start-up of large fermentors.

Effect of Sulfate Concentration on Biohydrogen Production by Enriched Anaerobic Sludge

2014 ◽  
Vol 884-885 ◽  
pp. 433-436 ◽  
Author(s):  
Bo Wang ◽  
Ya Nan Yin ◽  
Rong Cheng ◽  
Qiong Zhang ◽  
Liang Wang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Production Rate ◽  
Experimental Results ◽  
Anaerobic Sludge ◽  
Hydrogen Yield ◽  
Sulfate Concentration ◽  
Hydrogen Production Rate ◽  
Fermentative Hydrogen Production ◽  
Initial Ph ◽  
Fermentative Hydrogen

The effect of SO2-4 concentration ranging from 0 to 10 g/L on fermentative hydrogen production by enriched anaerobic sludge was investigated using glucose as substrate at 35°C and initial pH 7.0. The experimental results showed that the hydrogen yield increased with increasing SO2-4 concentration from 0 to 0.05 g/L. The maximum maximum hydrogen yield of 272.2 mL/g glucose were obtained at the SO2-4 concentration of 0.05 g/L. The average hydrogen production rate increased with increasing SO2-4 concentration from 0 to 0.1 g/L and the maximum average hydrogen production rate of 8.4 mL/h was obtained at the SO2-4 concentration of 0.1 g/L. The Han-Levenspiel model could describe the effect of SO2-4 concentration on average hydrogen production rate successfully.

scholarly journals Anaerobic treatment of glycerol for methane and hydrogen production

2013 ◽  
Vol 14 (2) ◽  
pp. 149-156 ◽  
Keyword(s):  
Hydrogen Production ◽  
Ph Value ◽  
Anaerobic Treatment ◽  
Microbial Culture ◽  
Batch Reactors ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Loading Rates ◽  
Fermentative Hydrogen Production ◽  
Initial Ph

This work focused on glycerol exploitation for biogas and hydrogen production. Anaerobic digestion of pure glycerol was studied in a continuous stirred tank reactor (CSTR), operated under mesophilic conditions (35oC) at various organic loading rates. The overall operation of the reactor showed that it could not withstand organic loading rates above 0.25 g COD L-1 d-1, where the maximum biogas (0.42 ± 0.05 L (g COD)-1) and methane (0.30 ± 0.04 L (g COD)-1) production were achieved. Fermentative hydrogen production was carried out in batch reactors under mesophilic conditions (35oC), using heat-pretreated anaerobic microbial culture as inoculum. The effects of initial concentration of glycerol and initial pH value on hydrogen production were studied. The highest yield obtained was 22.14 ± 0.46 mL H2 (g COD added)-1 for an initial pH of 6.5 and an initial glycerol concentration of 8.3 g COD L-1. The main metabolic product was 1.3 propanediol (PDO), while butyric and acetic acids as well as ethanol, at lower concentrations, were also determined.

scholarly journals Influence of the pH control strategy and reactor volume on batch fermentative hydrogen production from the organic fraction of municipal solid waste

2019 ◽  
Vol 37 (5) ◽  
pp. 478-485 ◽  
Author(s):  
Francesco Baldi ◽  
Renato Iannelli ◽  
Isabella Pecorini ◽  
Alessandra Polettini ◽  
Raffaella Pomi ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Control Strategy ◽  
Ph Control ◽  
Organic Fraction ◽  
Experimental Conditions ◽  
Reactor Volume ◽  
Fermentative Hydrogen Production ◽  
Fermentative Hydrogen

Three different experimental sets of runs involving batch fermentation assays were performed to evaluate the influence of the experimental conditions on biological hydrogen production from the source-separated organic fraction of municipal solid waste collected through a door-to-door system. The fermentation process was operated with and without automatic pH control, at a pH of 5.5 and 6.5, food-to-microorganism ratios of 1/3 and 1/1 (wet weight basis) and with different working volumes (0.5 and 3 L). The experimental results showed that the pH control strategy and the reactor volume did not affect the final hydrogen production yield but played an important role in determining the time evolution of the process. Indeed, although the different experimental conditions tested yielded comparable hydrogen productions (with maximum average values ranging from 68.5 to 88.5 NLH2 (kgTVSOF)−1), the automatic pH control strategy improved the process from the kinetic viewpoint resulting in a t95 reduction from an average of 34.9 h without automatic pH control to an average of 19.5 h.

scholarly journals Fermentative hydrogen production in packed-bed and packing-free upflow reactors

2006 ◽  
Vol 54 (9) ◽  
pp. 95-103 ◽  
Author(s):  
C. Li ◽  
T. Zhang ◽  
H.H.P. Fang
Keyword(s):  
Hydrogen Production ◽  
Granular Sludge ◽  
Packed Bed ◽  
Synthetic Wastewater ◽  
Extracellular Polysaccharides ◽  
Hydrogen Yield ◽  
Bacterial Cells ◽  
Fermentative Hydrogen Production ◽  
Packing Rings ◽  
Fermentative Hydrogen

Fermentative hydrogen production from a synthetic wastewater containing 10 g/L of sucrose was studied in two upflow reactors at 26°C for 400 days. One reactor was filled with packing rings (RP) and the other was packing free (RF). The effect of hydraulic retention time (HRT) from 2 h to 24 h was investigated. Results showed that, under steady state, the hydrogen production rate significantly increased from 0.63 L/L/d to 5.35 L/L/d in the RF when HRT decreased from 24 h to 2 h; the corresponding rates were 0.56 L/L/d to 6.17 L/L/d for the RP. In the RF, the hydrogen yield increased from 0.96 mol/mol-sucrose at 24 h of HRT to the maximum of 1.10 mol/mol-sucrose at 8 h of HRT, and then decreased to 0.68 mol/mol-sucrose at 2 h. In the RP, the yield increased from 0.86 mol/mol-sucrose at 24 h of HRT to the maximum of 1.22 mol/mol-sucrose at 14 h of HRT, and then decreased to 0.78 mol/mol-sucrose at 2 h. Overall, the reactor with packing was more effective than the one free of packing. In both reactors, sludge agglutinated into granules. The microbial community of granular sludge in RP was investigated using 16S rDNA based techniques. The distribution of bacterial cells and extracellular polysaccharides in hydrogen-producing granules was investigated by fluorescence-based techniques. Results indicated that most of the N-acetyl-galactosamine/galactose-containing extracellular polysaccharides were distributed on the outer layer of the granules with a filamentous structure.

Comparison of Different Pretreatment Methods to Increase Hydrogen Production from Cornstalk

2013 ◽  
Vol 724-725 ◽  
pp. 216-221 ◽  
Author(s):  
Cristiano Varrone ◽  
Lei Zhao ◽  
Guang Li Cao ◽  
Tao Sheng ◽  
Nan Qi Ren ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Lignocellulosic Biomass ◽  
Room Temperature ◽  
Reducing Sugar ◽  
Chemical Components ◽  
Hydrogen Yield ◽  
Alkali Pretreatment ◽  
Pretreatment Condition ◽  
Fermentative Hydrogen Production ◽  
Fermentative Hydrogen

Lignocellulosic biomass can be an ideal feedstock for fermentative hydrogen production if properly pretreated and hydrolyzed. In this research, to enhance hydrogen production from cornstalk, acid and alkali pretreatments were performed. Alkali pretreatment was conducted at 80°C for 60 min and room temperature for 7 days with the addition of 4% NaOH; acid pretreatments at 190°C, and 120°C for 10 min and 120 min, respectively, with the addition of 1.7% H2SO4. All the chemical components change of the substrates was detected. The highest lignin reduction of 75.6%, compared to untreated samples, was found at 80°C with 4% NaOH dosage. Under this pretreatment condition, highest increase in reducing sugar and hydrogen yield (up to 11.8 g/L and 71.8 ml/g-pretreated cornstalk) was obtained. The present results suggested an efficient pretreatment method to increase hydrogen production from lignocellulosic biomass.

The Separation Identification and Culture Optimization of Hydrogen Production X9 Bacteria

2012 ◽  
Vol 512-515 ◽  
pp. 1446-1449 ◽  
Author(s):  
Hong Xu Bao ◽  
Wei Wei Cai ◽  
Xi Ping Ma ◽  
You Tao Song ◽  
Man Li Shen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
High Efficiency ◽  
Cellulose Degradation ◽  
Orthogonal Experiment ◽  
Hydrogen Yield ◽  
Technological Parameters ◽  
Fermentative Hydrogen Production ◽  
Culture Optimization ◽  
Rdna Sequencing ◽  
Fermentative Hydrogen

A high efficiency simultaneous cellulose degradation and hydrogen production strain X9 was obtained from the screening of the 125 strains of fermentative hydrogen production bacteria which were isolated from a continuous stirred-tank hydrogen production bioreactor (CSTR) with LM-1 and microcrystalline cellulose (MCC) medium and improved Hungered technique in this study. X9 was confirmed a new category by analyzing the results of biochemical and physiological test, shape character, 16S rDNA sequencing and phylogenetic, and then analysis characteristics of growth, culture parameters, the effects of components of medium on growth and ability of hydrogen production, the optimum technological parameters have been determined from orthogonal experiment and single factor test. Finally, X9 achieved maximum specific hydrogen yield of 4.9mmol/g with MCC under the optimal conditions.

Characteristics of Biohydrogen Production by Mixed Culture Using Bagasse as the Substrate

2010 ◽  
Vol 113-116 ◽  
pp. 1749-1754
Author(s):  
An Ying Jiao ◽  
Yong Feng Li ◽  
Bing Liu ◽  
Kun Liu
Keyword(s):  
Gas Chromatography ◽  
Mixed Culture ◽  
Dark Fermentation ◽  
Biohydrogen Production ◽  
Hydrogen Yield ◽  
Batch Experiments ◽  
Ethanol Acetic Acid ◽  
Liquid Products ◽  
Initial Ph ◽  
Favorable Conditions

Batch culture of dark fermentation was carried out to study the feasibility of biohydrogen production using bagasse as the substrate. In dark fermentation, hydrogen was produced by mixed culture using bagasse as the substrate. To establish favorable conditions for maximum hydrogen production, process parameters such as temperature and initial pH of the medium were investigated. Also, the component of biogas and liquid products of effluent by fermentation were analyzed by gas chromatography. The VFAs were mostly ethanol, acetic acid, propionic acid and butyric acid, and no valeric acid was observed. It is demonstrated that the hydrogen yield reached the maximum of 30.5mlH2/g bagasse while the temperature was 35°C in batch experiments under a series of temperature (25, 30, 35, 40°C) conditions. The initial pH ranged from 6.8 to 8.5, and the yield of hydrogen reached the maximum of 32mlH2/g bagasse with the initial pH of 8.5.

scholarly journals Biohydrogen production from sweet sorghum biomass using mixed acidogenic cultures and pure cultures of Ruminococcus Albus

2013 ◽  
Vol 9 (2) ◽  
pp. 144-151
Keyword(s):  
Hydrogen Production ◽  
Sweet Sorghum ◽  
Liquid Fraction ◽  
Continuous System ◽  
Extraction Process ◽  
Raw Material ◽  
Hydrogen Yield ◽  
Ruminococcus Albus ◽  
Fermentative Hydrogen Production ◽  
Pure Cultures

The present study focuses on the exploitation of sweet sorghum biomass as a source for hydrogen in continuous and batch systems. Sweet sorghum is an annual C4 plant of tropical origin, well-adapted to sub-tropical and temperate regions and highly productive in biomass. Sweet sorghum biomass is rich in readily fermentable sugars and thus it can be considered as an excellent raw material for fermentative hydrogen production. Extraction of free sugars from the sorghum stalks was achieved using water at 30°C. After the extraction process, a liquid fraction (sorghum extract), rich in sucrose, and a solid fraction (sorghum cellulosichemicellulosic residues), containing the cellulose and hemicelluloses, were obtained. Hydrogen production from sorghum extract was investigated using mixed acidogenic microbial cultures, coming from the indigenous sorghum microflora and Ruminococcus albus, an important, fibrolytic bacterium of the rumen. Hydrogen productivity of sorghum residues was assessed as well, using R. albus. The highest hydrogen yield obtained from sorghum extract fermented with mixed microbial cultures in continuous system was 0.86 mol hydrogen per mol of glucose consumed, at a hydraulic retention time of 12 hours. This corresponded to a hydrogen productivity of 10.4 l hydrogen per kg of sorghum biomass and was comparable with those obtained from batch experiments. On the other hand, the hydrogen yield obtained from sorghum extract treated with R. albus was as high as 2.1-2.6 mol hydrogen per mol of glucose consumed. Hydrogen productivity of sorghum residues fermented with R. albus reached 2.6 mol hydrogen per mol of glucose consumed. In total, the productivity of sorghum biomass (that of sorghum extract plus that of sorghum residues) could be 60 l hydrogen per kg of sorghum biomass if R. albus is used.

Hydrogen production from wastewater by acidogenic granular sludge

2003 ◽  
Vol 47 (1) ◽  
pp. 153-158 ◽  
Author(s):  
H. Liu ◽  
H.H.P. Fang
Keyword(s):  
Hydrogen Production ◽  
Carbon Balance ◽  
Volatile Fatty Acids ◽  
Sucrose Concentration ◽  
Maximum Yield ◽  
Granular Sludge ◽  
Hydrogen Yield ◽  
Gas Composition ◽  
Acidogenic Reactor ◽  
Constant Loading Rate

Sludge was granulated in a hydrogen-producing acidogenic reactor when operated at 26°C, pH 5.5 treating a sucrose-rich wastewater. The influence of hydraulic retention time (HRT) and sucrose concentration on hydrogen production by the acidogenic granular sludge was investigated at a constant loading rate of 25 g-sucrose/(láday). Results show that the gas composition was not greatly influenced by HRT or sucrose concentration. The hydrogen accounted for 57% to 68% of the biogas at HRT ranging 4.6-28.6 h and sucrose concentration ranging 4,800-29,800 mg/l. However, the hydrogen yield was more dependent on HRT and sucrose concentration. It ranged from 0.19 to 0.27 l/g-sucrose with the maximum yield occurring at HRT 13.7 h and sucrose concentration 14,300 mg/l in the wastewater. The acidified effluent was composed of volatile fatty acids and alcohols. The predominant products were butyrate (59-68%) and acetate (10-25%), plus smaller amounts of i-butyrate, valerate, i-valerate, caproate, methanol, ethanol, propanol, and butanol. The sludge yield averaged 0.2 g-VSS/g-sucrose. The carbon balance was 98-107% throughout the study.

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