scholarly journals Simultaneous Coproduction of Hydrogen and Ethanol in Anaerobic Packed-Bed Reactors

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Cristiane Marques dos Reis ◽  
Edson Luiz Silva

This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT) (1–8 h). Two reactors filled with expanded clay and fed with glucose (3136–3875 mg L−1) were operated at different total upflow velocities: 0.30 cm s−1(R030) and 0.60 cm s−1(R060). The effluent pH of the reactors was maintained between 4 and 5 by adding NaHCO3and HCl solutions. It was observed a maximum hydrogen production rate of 0.92 L H2 h−1 L−1in R030 at HRT of 1 h. Furthermore, the highest hydrogen yield of 2.39 mol H2 mol−1glucose was obtained in R060. No clear trend was observed by doubling the upflow velocities at this experiment. High ethanol production was also observed, indicating that the ethanol-pathway prevailed throughout the experiment.

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Pietro Carlozzi

The main goal of this study was to increase the hydrogen production rate improving the culture technique and the photobioreactor performances. Experiments were carried out at a constant culture temperature of 30°C and at an average irradiance of 480 W m−2using a cylindrical photobioreactor (4.0 cm, internal diameter). The culture technique, namely, the semicontinuous regime for growingRhodopseudomonas palustris42OL made it possible to achieve a very high daily hydrogen production rate of 594 ± 61 mL (H2) L−1 d−1. This value, never reported for this strain, corresponds to about 25 mL (H2) L−1 h−1, and it was obtained when the hydraulic retention time (HRT) was of 225 hours. Under the same growth conditions, a very high biomass production rate (496 ± 45 mg (dw) L−1 d−1) was also achieved. Higher or lower HRTs caused a reduction in both the hydrogen and the biomass production rates. The malic-acid removal efficiency (MAre) was always higher than 90%. The maximal hydrogen yield was 3.03 mol H2mol MA−1at the HRT of 360 hours. The highest total energy conversion efficiency was achieved at the HRT of 225 hours.


2013 ◽  
Vol 777 ◽  
pp. 173-177
Author(s):  
Xin Yuan Liu ◽  
Ru Ying Li ◽  
Min Ji ◽  
Di Liu ◽  
Yan Ming Cai

As lignocellulosic biomass, the cornstalk should be pretreated before anaerobic fermentation for hydrogen production. In this study, HCl, NaOH and enzyme were employed for cornstalk pretreatment and the products were used for anaerobic biohydrogen production. Hydrogen yield and hydrogen production rate were investigated to optimize cornstalk pretreatment method. In addition, the economic effect and energy consumption were also considered to evaluate the pretreatment methods. The optimum cornstalk pretreatment method was soaking in 2% NaOH at 50°C for 48h with a hydrogen yield of 55.0 ml/g-TS and a hydrogen production rate of 6.5 ml/h/g-VS in anaerobic hydrogen production.


2020 ◽  
Vol 14 (2) ◽  
pp. 303-307
Author(s):  
Zhiping Zhang ◽  
Yameng Li ◽  
Chenyang Wang ◽  
Bing Hu ◽  
Jianjun Hu ◽  
...  

Food waste is rich in starch or cellulose, which can be utilized as carbon source for fermentation. Hence, in this paper, different food wastes (vegetable, rice, corn, potato) were taken as substrate to evaluate their hydrogen yield potential. The characteristics of fermentation broth, cumulative hydrogen yield, and hydrogen production rate were investigated in the photo-fermentation bio-hydrogen production process. Modified Gompertz Model was utilized to deal with experiment data. Results showed that food waste can be effectively utilized by photosynthetic bacteria. Waste rice was determined to have the best hydrogen production capacity with hydrogen yield of 696 mL, and the maximum hydrogen production rate of 17.71 mL/h, the average hydrogen concentration was 55.78%.


2014 ◽  
Vol 884-885 ◽  
pp. 433-436 ◽  
Author(s):  
Bo Wang ◽  
Ya Nan Yin ◽  
Rong Cheng ◽  
Qiong Zhang ◽  
Liang Wang ◽  
...  

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.


2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Jiang-Yu Ye ◽  
Yue Pan ◽  
Yong Wang ◽  
Yi-Chao Wang

Abstract Purpose This study utilized the principle that the bacteriorhodopsin (BR) produced by Halobacterium salinarum could increase the hydrogen production of Rhodobacter sphaeroides. H. salinarum are co-cultured with R. sphaeroides to determine the impact of purple membrane fragments (PM) on R. sphaeroides and improve its hydrogen production capacity. Methods In this study, low-salinity in 14 % NaCl domesticates H salinarum. Then, 0–160 nmol of different concentration gradient groups of bacteriorhodopsin (BR) and R. sphaeroides was co-cultivated, and the hydrogen production and pH are measured; then, R. sphaeroides and immobilized BR of different concentrations are used to produce hydrogen to detect the amount of hydrogen. Two-chamber microbial hydrogen production system with proton exchange membrane-assisted proton flow was established, and the system was operated. As additional electricity added under 0.3 V, the hydrogen production rate increased with voltages in the coupled system. Results H salinarum can still grow well after low salt in 14% NaCl domestication. When the BR concentration is 80 nmol, the highest hydrogen production reached 217 mL per hour. Both immobilized PC (packed cells) and immobilized PM (purple membrane) of H. salinarum could promote hydrogen production of R. sphaeroides to some extent. The highest production of hydrogen was obtained by the coupled system with 40 nmol BR of immobilized PC, which increased from 127 to 232 mL, and the maximum H2 production rate was 18.2 mL−1 h−1 L culture. In the 192 h experiment time, when the potential is 0.3 V, the hydrogen production amount can reach 920 mL, which is 50.3% higher than the control group. Conclusions The stability of the system greatly improved after PC was immobilized, and the time for hydrogen production of R. sphaeroides significantly extended on same condition. As additional electricity added under 0.3 V, the hydrogen production rate increased with voltages in the coupled system. These results are helpful to build a hydrogen production-coupled system by nitrogenase of R. sphaeroides and proton pump of H. salinarum. Graphical abstract


2016 ◽  
Vol 105 ◽  
pp. 137-151 ◽  
Author(s):  
Giuseppe Diglio ◽  
Piero Bareschino ◽  
Erasmo Mancusi ◽  
Francesco Pepe

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