Continuous Biohydrogen Production with CSTR Reactor under High Organic Loading Rate Condition

2013 ◽  
Vol 864-867 ◽  
pp. 225-228
Author(s):  
Zhi Qin ◽  
Qing Qin ◽  
Ying Yang

A continuous stirred-tank reactor (CSTR) was used to produce biohydrogen gas from organic wastewater. The hydrogen producing reactor was operated under high organic loading rate of 21 kgCOD/m3·d, and molasses wastewater was used as substrate. Hydrogen production rate, pH value, sugar utilizing rate and fermentative products in effluent were investigated in continuous fermentation. When Organic Loading Rate was controlled at 21 kgCOD/m3·d, the average concentrations of acetic acid, ethanol, propionic acid, butyric acid and valeric acid in liquid fermentative products were 833, 748, 482, 484 and 256mg/L respectively. There is not any fermentation product playing dominant role absolutely in hydrogen production fermentation. The pH value in effluent was about 4.7~4.9, the average utilizing rate of sugar reached 92.1%, most of the sugar in molasses wastewater was utilized. The biogas production rate in hydrogen producing fermentation was from 21.2 to 27.1L/d, and the average biogas production rate was about 25.1L/d. The hydrogen content was about 37%.

2018 ◽  
Vol 56 (2A) ◽  
pp. 37-42
Author(s):  
Dinh Thi Nga

This research was carried out to evaluate the effect of organic loading rate to the performance of anaerobic co-digestion digester treating organic fraction of food waste (FW) and sludge waste (SW) from wastewater treatment plant. The experiment was conducted in two runs: Run S50, substrate contained 50 % of FW and 50 % of SW in term of volatile solid (VS) concentration; Run S100 (control run) contained 100 % SW in the influent substrate. The experiment was performed in a 3L working volume reactor at ambient temperature with three levels of organic loading rate (OLR) as 2; 4; 6 kgVS/m3/day, the duration of experiment was 18 days for each level of OLR. As results, the average of biogas production rate (BPR) at OLR 2;4;6 kgVS/m3/day,in Run S50 and Run S100 was 390 – 520;  860 – 1220; 1140 - 2440 ml/day and 160 – 300; 560 – 640; 700 - 1400 ml/day, respectively. The maximum methane yield (mlCH4/gVSadded/day) of organic loading rate 2; 4; 6 kgVS/m3/day was 118.96; 326.49; 628.20 for Run S50 and; 58.28; 160.27; 255.54 for Run S100, respectively. In conclusion, Run S50 always produced higher biogas production rate and higher methane yield at all 3 OLR levels. The higer OLR could enhance BPR and methane yield but at OLR 6 kgVS/m3/day made unstable performance and high concentration of COD in the effluent. Therefore, in this experimental conditions it has better operation at OLR under 6 kgVS/m3/day for the stable performance of reactors.


2011 ◽  
Vol 345 ◽  
pp. 326-330
Author(s):  
Zhi Qin ◽  
Nan Qi Ren ◽  
Jian Zheng Li

Hydrogen gas was obtained from organic wastewater by acidogenic fermentation of two-phase anaerobic wastewater treatment process. In this paper, the hydrogen production of mixed acid fermentation was investigated. In mixed acid fermentation, pH value of fermentation was in the range of 4.5~5.0, the COD removal rate was about 20%. The average transferring rate of sugar was about 94.6%. Our results demonstrated that when Organic Loading Rate was 15 kgCOD/m3·d, the specific biogas production rate of mixed acid fermentation was 1834~2392 mmol/(kg∙d), and the average specific biogas production rate was about 2077 mmol/(kg∙d). The specific hydrogen production rate of mixed acid fermentation was about 532~710 mmol/(kg∙d), and the hydrogen content was around 30%. The main liquid products of our experiments in mixed acid fermentation were ethanol, acetic acid and propionic acid.


2011 ◽  
Vol 64 (2) ◽  
pp. 320-325 ◽  
Author(s):  
J. Gustavsson ◽  
B. H. Svensson ◽  
A. Karlsson

The aim of this study was to investigate the effect of trace element supplementation on operation of wheat stillage-fed biogas tank reactors. The stillage used was a residue from bio-ethanol production, containing high levels of sulfate. In biogas production, high sulfate content has been associated with poor process stability in terms of low methane production and accumulation of process intermediates. However, the results of the present study show that this problem can be overcome by trace element supplementations. Four lab-scale wheat stillage-fed biogas tank reactors were operated for 345 days at a hydraulic retention time of 20 days (37 °C). It was concluded that daily supplementation with Co (0.5 mg L−1), Ni (0.2 mg L−1) and Fe (0.5 g L−1) were required for maintaining process stability at the organic loading rate of 4.0 g volatile solids L−1 day−1.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1487
Author(s):  
Vicky De Groof ◽  
Marta Coma ◽  
Tom C. Arnot ◽  
David J. Leak ◽  
Ana B. Lanham

Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to produce biogas, the retention times had to be doubled when fed with the high-COD FW to maintain biogas production. The AD microbiome comprised a diverse mixture of hydrolytic and acidogenic bacteria, and acetoclastic methanogens. The results suggest that manipulation of organic loading rate and food-to-microorganism ratio may be used as an operating strategy to direct an AD microbiome towards AF, and to stimulate chain elongation in FW fermentation, using a simple, un-supplemented stirred tank set-up. This outcome provides the opportunity to repurpose existing AD assets operating on food waste for biogas production, to produce potentially higher value MCCA products, via simple manipulation of the feeding strategy.


2010 ◽  
Vol 113-116 ◽  
pp. 1132-1137 ◽  
Author(s):  
Yong Feng Li ◽  
Yong Ming Hui ◽  
Xin Yao ◽  
Lu Wang ◽  
Qian Wen Song ◽  
...  

In this experiment, brown sugar was chosen as the substrate of continuous operation. A lab-scale expanded granular sludge blanket (EGSB) reactor was employed. Stable ethanol-type fermentation was formed by controlling the organic loading rate (OLR). The results showed a maximum hydrogen production rate of 5.73L / L reactor•d was achieved, under the condition that the hydraulic retention time (HRT) = 2h, OLR = 97.2kg COD/m3 reactor•d. The average hydrogen content in the biogas during the 73-day operation was 41.27%.


2012 ◽  
Vol 37 (22) ◽  
pp. 16925-16934 ◽  
Author(s):  
Géssia Momoe Shida ◽  
Leandro Takano Sader ◽  
Eduardo Lucena Cavalcante de Amorim ◽  
Isabel Kimiko Sakamoto ◽  
Sandra Imaculada Maintinguer ◽  
...  

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