scholarly journals Simultaneous Biohydrogen and Bioethanol Production from Anaerobic Fermentation with Immobilized Sludge

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Wei Han ◽  
Zhanqing Wang ◽  
Hong Chen ◽  
Xin Yao ◽  
Yongfeng Li
Keyword(s):  
Acetic Acid ◽  
Ethanol Production ◽  
Production Rate ◽  
Anaerobic Fermentation ◽  
Hydrogen Yield ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Loading Rates ◽  
Ethanol Production Rate ◽  
Continuous Stirred Tank

The effects of organic loading rates (OLRs) on fermentative productions of hydrogen and ethanol were investigated in a continuous stirred tank reactor (CSTR) with attached sludge using molasses as substrate. The CSTR reactor with attached sludge was operated under different OLRs, ranging from 8 to 24 kg/m3·d. The H2and ethanol production rate essentially increased with increasing OLR. The highest H2production rate (10.74 mmol/hL) and ethanol production rate (11.72 mmol/hL) were obtained both operating at OLR = 24 kg/m3·d. Linear regression results show that ethanol production rate () and H2production rate () were proportionately correlated and can be expressed as (). The best energy generation rate was 19.08 kJ/hL, which occurred at OLR = 24 kg/m3·d. In addition, the hydrogen yield was affected by the presence of ethanol and acetic acid in the liquid phase, and the maximum hydrogen production rate occurred while the ratio of ethanol to acetic acid was close to 1.

Effect of Organic Loading Rate on Fermentative Hydrogen Production in CSTR

2010 ◽  
Vol 156-157 ◽  
pp. 732-736
Author(s):  
Shuang Gao ◽  
Bing Wang ◽  
Lei Lei Zhu ◽  
Wei Han ◽  
Hong Chen ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Hydrogen Production ◽  
Acid Concentration ◽  
Statistical Correlation ◽  
Organic Loading Rate ◽  
Hydrogen Yield ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Biogas Yield ◽  
The Impact

This study investigated the impact of five organic loading rates (OLRs) ranging from 16 kg COD/m3-d to 32 kg COD/m3-d on the performance of a continuous stirred tank reactor (CSTR) for biological hydrogen production, with molasses as substrate. Hydraulic Retention Time (HRT) was kept at 6 hours and the temperature 35°C. Oxidation-reduction potential (ORP) varied from -328 mV to -419 mV. The ethanol-type fermentation has been conducted during the process. A positive statistical correlation was observed between OLR and biogas yield; however, it became negative for the OLR of 32 kg COD/m3-d (Fig1). The system maintained the highest average biogas and hydrogen yield of 14.66 L/d and 5.17 L/d at OLR of 28 kg COD/m3-d. Compared with the first stage (16 kg COD/m3-d), ethanol and butyric concentration of the last stage (32 kg COD/m3-d) increased about 2.01 and 3.79 times, respectively; Acetic acid concentration surged around 200 mg/L; Prop ionic acid concentration dropped slightly; Valeric acid concentration, which took a small portion in the volatile fatty acid (VFA), kept low. When OLR was kept at 28 kg COD/m3-d, the average ethanol to acetic acid ratio is 3.90.Thus proved that the optimal OLR for hydrogen production under experimental condition is 28 kg COD/m3-d.

The Operation Characteristics of Biohydrogen Production in Continuous Stirred Tank Reactor with Molasses

2010 ◽  
Vol 152-153 ◽  
pp. 613-618
Author(s):  
Zhan Shu ◽  
Hong Chen ◽  
Xue Ying Di ◽  
Yong Feng Li
Keyword(s):  
Anaerobic Fermentation ◽  
Biohydrogen Production ◽  
Stirred Tank ◽  
Organic Loading Rate ◽  
Hydrogen Yield ◽  
Continuous Stirred Tank Reactor ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Continuous Stirred Tank ◽  
Operation Characteristics

The feasibility and operation characteristics of anaerobic fermentation biohydrogen production in a continuous stirred tank reactor (CSTR) were investigated for treating molasses wastewater. The research indicates that the reactor has the capacity of continuously producing hydrogen in an initial biomass (as volatile suspension solids) of 17.74 g/L, temperature of (35±1) °C, hydraulic retention time (HRT) of 6 h, and the reactor can start up the ethanol-type fermentation in 12 days and realize stable hydrogen production. Furthermore, the CSTR reactor enjoys a favorable stability even with an organic shock loading. When the organic loading rate (OLR) increased from 8 kg/(m3•d) to 24 kg/(m3•d), the CSTR system reached a new steady state within 9 d. The hydrogen yield and COD removal increased from 3 L and 8% to 12 L and 20% respectively with the hydrogen content of 47 %.

Research on Ethanol Production by Biological Fermentation of Potato Pulp

2013 ◽  
Vol 805-806 ◽  
pp. 281-285
Author(s):  
Zhong Xu
Keyword(s):  
Chemical Composition ◽  
Ethanol Production ◽  
Production Rate ◽  
Liquid Ratio ◽  
Fermentation Time ◽  
Potato Pulp ◽  
Fermentation Temperature ◽  
Ethanol Production Rate ◽  
Solid Liquid

Bioconversion of potato pulp to fuel ethanol, analysing the potato pulp chemical composition and determining the potato pulp in the role of microorganism produce ethanol under the best conditions is the major research. An analysis of the chemical composition of potato pulp showed that : the basic ingredients are Protein (9.72%), Starch (25.52%), Cellulose (17.90%). The effects of ethanol production rate of solid-liquid ratio, fermentation temperature, inoculumconcertration, fermentation time. The results showed that: the best conditions producting ethanol from potato pulp obtained by single factor experiments are: solid-liquid ratio: 1:15, fermentation temperature: 35°C, inoculumconcertration: 3mL, fermentation time: 20h. Under this occasion, the ethanol production rate was 0.183mL·g-1.

Specific Ethanol Production Rate in Ethanologenic Escherichia coli Strain KO11 Is Limited by Pyruvate Decarboxylase

2008 ◽  
Vol 15 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Gerardo Huerta-Beristain ◽  
José Utrilla ◽  
Georgina Hernández-Chávez ◽  
Francisco Bolívar ◽  
Guillermo Gosset ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ethanol Production ◽  
Production Rate ◽  
Pyruvate Decarboxylase ◽  
Ethanol Production Rate

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 Tolerance of plum (Prunus domestica L.) fruits stored in low-oxygen atmosphere

2011 ◽  
Vol 31 (No. 1) ◽  
pp. 1-6
Author(s):  
J. Goliáš ◽  
A. Němcová ◽  
L. Šuderlová
Keyword(s):  
Ethanol Production ◽  
Production Rate ◽  
Storage Period ◽  
Final Concentration ◽  
Ambient Atmosphere ◽  
Prunus Domestica ◽  
Low Oxygen ◽  
Anaerobic Conditions ◽  
Storage Atmosphere ◽  
Ethanol Production Rate

Plum fruits of the cultivars Stanley and Valjevka picked at the beginning of climacteric were stored in different storage atmospheres for 31 days at 3&deg;C. The relations between the O<sub>2</sub> and CO<sub>2</sub> content during this period and after removal from the gas mixture to ethanol, acetaldehyde, non-volatile compounds and some textural values of fruits were investigated. Concentrations of ethanol in the flesh were related to levels of oxygen and CO<sub>2</sub> in ambient atmosphere. In anaerobic conditions (&lt; 0.2% O<sub>2</sub>) ethanol reached 1,109 mg/l for the cultivar Valjevka and 628 mg/l for Stanley. The results of single fruit analysis showed a steeply increasing concave curve of ethanol production in the period of anaerobic conditions, followed by the phase of a drop of the production rate in air stored fruit. The concentration of oxygen at a level of 0.9% (ultra low oxygen &ndash; ULO) does not physiologically harm the tissues of plums by producing mostly negligible content of ethanol and acetaldehyde, but an ethanol increase to half concentration after 31 days was observed to compare with anaerobic conditions in the cultivar Valjevka. From this aspect plums seem to be relatively sensitive to low oxygen. The post-storage period was extended up to 53 to 63 days, respectively. The senescence caused an increase in ethanol production rate that was exponentially increased after 20 days of cold storage atmosphere. The final concentration after 53 days was still higher for cv. Valjevka than for cv. Stanley at the respective content of 828 mg/land 498 mg/l. Skin firmness was differentiated for both cultivars, and softness was higher for the cultivar Valjevka. &nbsp;

scholarly journals Performance of Anaerobic Digestion of Chicken Manure Under Gradually Elevated Organic Loading Rates

2019 ◽  
Vol 16 (12) ◽  
pp. 2239 ◽  
Author(s):  
Fei Wang ◽  
Mengfu Pei ◽  
Ling Qiu ◽  
Yiqing Yao ◽  
Congguang Zhang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Poultry Manure ◽  
Ammonia Nitrogen ◽  
Methane Content ◽  
Chicken Manure ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Biogas Yield ◽  
Loading Rates

Poultry manure is the main source of agricultural and rural non-point source pollution, and its effective disposal through anaerobic digestion (AD) is of great significance; meanwhile, the high nitrogen content of chicken manure makes it a typical feedstock for anaerobic digestion. The performance of chicken-manure-based AD at gradient organic loading rates (OLRs) in a continuous stirred tank reactor (CSTR) was investigated herein. The whole AD process was divided into five stages according to different OLRs, and it lasted for 150 days. The results showed that the biogas yield increased with increasing OLR, which was based on the volatile solids (VS), before reaching up to 11.5 g VS/(L·d), while the methane content was kept relatively stable and maintained at approximately 60%. However, when the VS was further increased to 11.5 g VS/(L·d), the total ammonia nitrogen (TAN), pH, and alkalinity (CaCO3) rose to 2560 mg·L−1, 8.2, and 15,000 mg·L−1, respectively, while the volumetric biogas production rate (VBPR), methane content, and VS removal efficiency decreased to 0.30 L·(L·d)−1, 45%, and 40%, respectively. Therefore, the AD performance immediately deteriorated and ammonia inhibition occurred. Further analysis demonstrated that the microbial biomass yield and concentrations dropped dramatically in this period. These results indicated that the AD stayed steady when the OLR was lower than 11.5 g VS/(L·d); this also provides valuable information for improving the efficiency and stability of AD of a nitrogen-rich substrate.

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