scholarly journals GREEN ALGAE Ulva sp. AS RAW MATERIAL FOR BIOGAS PRODUCTION

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Tri Dian Oktiana ◽  
Joko Santoso ◽  
Mujizat Kawaroe

Ulva sp. is a non edible seaweed and posses a high growth rate. Therefore, this species is potential to be developed as a raw material for biogas production. One important factor on the biogas production is to determine organic loading rate (OLR). The aim of this study was to determine the potential of Ulva sp. as a raw material for biogas and to find out the optimum loading rate in the process of biogas production.  Biogas production was carried out in the digester with a capacity of 22 l that was made of fiber and equipped with a manual stirrer and gas flow meter to measure gas production. Parameters analised were pH, COD, TSS, VSS, and gas composition. Organic loading rates used in this study were 0.5, 1, 1.5, and 2 kg COD.m-3.day-1.  The results showed that the optimum loading rate was 1.5 kg COD.m-3.day-1. In the loading rate of 1.5 kg COD.m-3.day-1, we obtained the highest biogas production rate of 12.14 l/day with methane content of 42.96%, average COD removal of 51.97%, and methane production of 0.33 l/g COD.   Keywords: anaerobic, biogas, COD, loading, methane, Ulva sp.

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Tri Dian Oktiana ◽  
Joko Santoso ◽  
Mujizat Kawaroe

<p><em><span style="text-decoration: underline;">Ulva</span></em><em> <span style="text-decoration: underline;">sp</span>. is a non edible seaweed and posses a high growth rate. Therefore, this species is potential to be developed as a raw material for biogas production. One important factor on the biogas production is to determine organic loading rate (OLR). The aim of this study was to determine the potential of <span style="text-decoration: underline;">Ulva</span> <span style="text-decoration: underline;">sp</span>. as a raw material for biogas and to find out the optimum loading rate in the process of biogas production.  Biogas production was carried out in the digester with a capacity of 22 l that was made of fiber and</em> <em>equipped with a manual stirrer and gas flow meter to measure gas production. Parameters analised were pH, COD, TSS, VSS, and gas composition. Organic loading rates used in this study were 0.5, 1, 1.5, and 2 kg COD.m<sup>-3</sup>.day<sup>-1</sup>.  The results showed that the optimum loading rate was 1.5 kg COD.m<sup>-3</sup>.day<sup>-1</sup>. In the loading rate of 1.5 kg COD.m<sup>-3</sup>.day<sup>-1</sup>, we obtained the highest biogas production rate of 12.14 l/day with methane content of 42.96%, average COD removal of 51.97%, and methane production of 0.33 l/g COD.</em></p> <p> </p> <p><strong>Keywords</strong>: anaerobic<em>, </em>biogas, COD, loading, methane, <em>Ulva</em> sp.</p>


Climate ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 142 ◽  
Author(s):  
Carla Asquer ◽  
Emanuela Melis ◽  
Efisio Antonio Scano ◽  
Gianluca Carboni

The present work shows the experimental evidence carried out on a pilot scale and demonstrating the potential of Cannabis sativa L. by-products for biogas production through anaerobic digestion. While the current state-of-the-art tests on anaerobic digestion feasibility are carried out at the laboratory scale, the here described tests were carried out at a pilot-to-large scale. An experimental campaign was carried out on hemp straw residues to assess the effective performance of this feedstock in biogas production by reproducing the real operating conditions of an industrial plant. An organic loading rate was applied according to two different amounts of hemp straw residues (3% wt/wt and 5% wt/wt). Also, specific bioenhancers were used to maximize biogas production. When an enzymatic treatment was not applied, a higher amount of hemp straw residues determined an increase of the median values of the gas production rate of biogas of 92.1%. This reached 116.6% when bioenhancers were applied. The increase of the specific gas production of biogas due to an increment of the organic loading rate (5% wt/wt) was +77.9% without enzymatic treatment and it was +129.8% when enzymes were used. The best management of the biodigester was found in the combination of higher values of hemp straw residues coupled with the enzymatic treatment, reaching 0.248 Nm3·kgvolatile solids−1 of specific biogas production. Comparisons were made between the biogas performance obtained within the present study and those found in the literature review coming from studies on a laboratory scale, as well as those related to the most common energy crops. The hemp straw performance was similar to those provided by previous studies on a laboratory scale. Values reported in the literature for other lignocellulosic crops are close to those of this work. Based on the findings, biogas production can be improved by using bioenhancers. Results suggest an integration of industrial hemp straw residues as complementary biomass for cleaner production and to contribute to the fight against climate change.


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.


Author(s):  
Javkhlan Ariunbaatar ◽  
Robert Bair ◽  
Onur Ozcan ◽  
Harish Ravishankar ◽  
Giovanni Esposito ◽  
...  

Anaerobic digestion of food waste (FW) is typically limited to large reactors due to high hydraulic retention times (HRTs). Technologies such as anaerobic membrane reactors (AnMBRs) can perform anaerobic digestion at lower HRTs while maintaining high chemical oxygen demand (COD) removal efficiencies. This study evaluated the effect of HRT and organic loading rate (OLR) on the stability and performance of a side-stream AnMBR in treating diluted fresh food waste (FW). The reactor was fed with synthetic FW at an influent concentration of 8.24 (± 0.12) g COD/L. The OLR was increased by reducing the HRT from 20 to 1 d. The AnMBR obtained an overall removal efficiency of &gt;97 and &gt;98% of the influent COD and total suspended solids (TSS), respectively, throughout the course of operation. The biological process was able to convert 76% of the influent COD into biogas with 70% methane content, while the cake layer formed on the membrane gave an additional COD removal of 7%. Total ammoniacal nitrogen (TAN) and total nitrogen (TN) concentrations were found to be higher in the bioreactor than in the influent, and average overall removal efficiencies of 17.3 (± 5) and 61.5 (± 3)% of TAN and TN, respectively, were observed with respect to the bioreactor concentrations after 2 weeks. Total phosphorus (TP) had an average removal efficiency of 40.39 (± 5)% with respect to the influent. Membrane fouling was observed when the HRT was decreased from 7 to 5 d and was alleviated through backwashing. This study suggests that the side-stream AnMBR can be used to successfully reduce the typical HRT of wet anaerobic food waste (solids content 7%) digesters from 20 days to 1 day, while maintaining a high COD removal efficiency and biogas production.


2020 ◽  
Vol 265 ◽  
pp. 121688
Author(s):  
Sayed Mohammad Nasiruddin ◽  
Zifu Li ◽  
Heinz-Peter Mang ◽  
Sayed Mohammad Nazim Uddin ◽  
Xiaoqin Zhou ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Patrice Ramm ◽  
Carsten Jost ◽  
Elisabeth Neitmann ◽  
Ulrich Sohling ◽  
Oliver Menhorn ◽  
...  

The use of recently developed magnetic foam glass particles for immobilization of microbial biomass was tested. The effect of the particles was illustrated at the production of biogas from sugar beet silage as the sole substrate. Lab-scale fermentation experiments were conducted using a mesophilic completely stirred tank reactor and a magnetic separator. Microscopic analysis revealed biofilm coverage of 50–60% on the surface of the particles within 110 days. It was possible to recover 76.3% of the particles from fermentation effluent by means of a separation procedure based on magnetic forces. Comparing a particle charged reactor with a control reactor showed a small performance gain. The methane rate was increased from1.18±0.09to1.25±0.06 L L−1 d−1and the methane yield was increased from0.302±0.029to0.318±0.022 L g−1(volatile solids) at an organic loading rate of3.93±0.22 g L−1 d−1(volatile solids). Maximum methane rates of 1.42 L L−1d−1at an organic loading rate of 4.60 g (volatile solids) L−1 d−1(reactor including magnetic particles) and 1.34 L L−1 d−1at 3.73 g L−1 d−1(control reactor) were achieved. Based on the results, it can be concluded that the use of magnetic particles could be an attractive option for the optimization of biogas production.


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